EPA.454/B-95-
006
              United States
              Environmental Protection
              Agency
Office of Air Quality
Planning and Standards
Research Triangle Part NC 27711
EPA-454/B-95-006
July 1995
             Air
             A USER'S GUIDE FOR T
              CALPUFF DISPERSION MODEL
                          ENVIRONMENTAL
                           PROTECTION
                            AGENCY
                          DALLAS, TEXAS

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                                                                      c
                                                 EPA-454/B-95-006
            A USER'S GUIDE FOR THE CALPUFF
                     DISPERSION MODEL
                U.S.  Environmental Protection Agency
         Emissions, Monitoring and Analysis Division (MD-14)
            Research  Triangle Park, North Carolina 27711
                       National Park Service
                       Air Quality Division
                      Denver, Colorado 80225
,                        TJSDA Forest Service
                       Office of Air Quality
                    Fort Collins,  Colorado 80526
                   U.S. Fish and Wildlife Service
                        Air Quality Branch
                      Denver, Colorado 80225
                            July 1995

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                                 DISCLAIMER

      The information in this document has been reviewed in its entirety by the U.S.
Environmental Protection Agency (EPA), and approved for publication as an EPA document.
Mention of trade names, products, or services does not convey, and should not be interpreted
as conveying official EPA approval, endorsement, or recommendation.
                                EPA-454/B-95-006
                                     11

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                                     PREFACE

       The Interagency Workgroup on Air Quality Modeling (IWAQM) was formed to
provide a focus for development of technically sound, regional air quality models for
regulatory assessments of pollutant source impacts on Federal Class I areas.  Meetings were
held with personnel from interested Federal agencies, viz,  the Environmental Protection
Agency, the U.S. Forest Service, the National Park Service, and the U.S. Fish and Wildlife
Service.  The purpose of these meetings was to review respective regional modeling
programs, to develop an organizational framework, and to formulate reasonable objectives
and plans that could be presented to management for support and commitment. The
members prepared a memorandum of understanding (MOU) that incorporated the goals and
objectives of the workgroup and obtained signatures of management officials in each
participating agency.  Although no States are signatories, their participation in IWAQM
functions is explicitly noted in the MOU.

       This report describes the CALPUFF dispersion model and associated processing
programs. The CALPUFF model described in this report reflects improvements  to the model
including 1)  new modules to treat buoyant rise and dispersion from area sources (such as
forest fires), buoyant line sources, and volume sources, 2) an improved treatment of complex
terrain, 3) additional model switches to facilitate its use in regulatory applications, 4) an
enhanced treatment of wind shear through puff splitting, and 4) an optional PC-based GUI.
CALPUFF has been coupled to the Emissions Production Model (EPM) developed by the
Forest Service through an interface processor. EPM provides time-dependent emissions and
heat  release data for use in modeling controlled burns and wildfires.

       This report is the sixth document published by the IWAQM in an effort to provide the
sponsoring agencies and other interested  parties information on appropriate "off-the-shelf1
methods for  estimating long range transport impacts of air pollutants on Federal Class I areas
and impacts on regional visibility.  The IWAQM members anticipate issuing additional
publications  related to progress toward meeting the IWAQM goals and  objectives, the results
of model evaluation studies, proposed  and final recommendations on modeling  systems for
regulatory applications,  and other topics  related to specific objectives in the MOU.

       The Environmental Protection Agency must conduct a formal and public review
before the Agency can recommend for routine use new algorithms  in regulatory analyses.
These reports are being released to establish a basis for reviews of the capabilities of this
methodology and of the consequences  resulting from  use of this methodology in routine
dispersion modeling of air pollutant impacts. These reports are one part of the overall
information that must be considered before any formal changes can be adopted.
                                         111

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                           ACKNOWLEDGEMENTS
      The members of IWAQM acknowledge the special efforts of Joseph S. Scire,
Elizabeth M. Insley, Robert J. Yamartino and Mark E. Femau of EARTH TECH.  This
report was prepared by EARTH TECH (formerly Sigma Research, Inc.) for W. W.
Engineering and Science under Contract No. 53-56A6-3-00838 to the U. S. Department of
Agriculture (USDA) Forest Service, with Richard W. Fisher as the Work Assignment
Manager. This work was accomplished in partial fulfillment of Interagency Agreement
DW12544201 between the USDA and EPA, with John S. Irwin as the Project Officer.
                                      IV

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                                   Table of Contents
1. INTRODUCTION	  1-1

       1.1    Background		  1-1
       12    Overview of Modeling System  	  1-2
       13    Major Model Algorithms and Options	  1-9
       1.4    Summary of Data and Computer Requirements	  1-13

2. TECHNICAL DISCUSSION	2-1

       2.1    Solution of the Puff Equations	2-1
             2.1.1  Integrated Puff Sampling Function Formulation	2-4
             2.1.2  Slug Formulation and Sampling Functions  	2-8
             2.13  Sampling Function Testing	  2-16

       2.2    Dispersion Coefficients  	  2-22
             22.1  Atmospheric Turbulence Components 	  2-25
             222  Plume Buoyancy Components	  2-38
             2.23  Initial Plume Size	  2-38
             22.4  Vertical Wind Shear	  2-39

       2.3    Building Downwash  	  2-39
             2.3.1  Huber-Snyder Downwash Procedure	  2-41
             2.3.2  Schulman-Scire Downwash Procedure	  2-42

       2.4    Plume Rise	  2-43
             2.4.1   Basic Plume Rise Equations	  2-43
             2.4.2   Stack-tip Downwash	  2-44
             2.43   Partial Plume Penetration	  2-45
             2.4.4   Building Downwash  	  2-46
             2.4.5   Vertical Wind Shear	  2-48
             2.4.6   Area Source Plume Rise	  2-50

       2.5    Overwater and Coastal Dispersion	  2-55
I:\calpufl\jul95\tocwph

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                             Table of Contents (Continued)


       2.6    Complex Terrain  	  2-59
             2.6.1   Complex Terrain Algorithm for Sub-Grid Scale
                    Features (CTSG)	  2-59
                    2.6.1.1  Modeling Regions	  2-60
                    2.6.1.2  Description of Terrain Features	  2-65
                    2.6.13  Upper Layer	  2-70
                    2.6.1.4  Lower Layer	  2-76
                    2.6.1.5  Operational Characteristics	  2-78
             2.6.2   "Simple Terrain Adjustments  	  2-80
                    2.6.2.1  ISC Terrain Treatment	  2-88
                    2.62.2  Simple Terrain Adjustments in Existing Complex
                           Terrain Plume Models  	  2-88
                    2.62.3  Alternate Approach to Terrain Adjustment
                           in a Puff Model	  2-92

       2.7    Dry Deposition  	  2-101
             2.7.1   Vertical Structure and Mass Depletion	  2-106
             2.7.2   Resistance Deposition Model for Gases	  2-110
             2.7.3   Resistances for Paniculate Matter 	  2-114

       2.8    Chemical Transformation	  2-116
             2.8.1   Description of the MESOPUFF H Chemical Mechanism	  2-117

       2.9    Wet Removal	  2-123

       2.10   Odor Modeling	  2-127

3.  CALPUFF MODEL STRUCTURE  	 3-1

       3.1    Memory Management 	 3-1
       3.2    Structure of the CALPUFF Modules	 3-1
I:\calpufl\jul95\tocwph

                                         vi

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                            Table of Contents (Concluded)
4. USER'S INSTRUCTIONS	4-1

      4.1    OPTfflLL 	4-1
             4.1.1  CTSG Terrain Information	4-1
             4.1.2  Example OPTfflLL Application	  4-4

      4.2    CALPUFF Model Input Files 	  4-12
             42.1  User Control File (CALPUFF.INP)	  4-13
             4.2.2  Meteorological Data Files	  4-64
                   42.2.1 CALMET.DAT 	  4-64
                   4.2.2.2 ISCMET.DAT 	  4-76
                   4.2.2.3 PLMMET.DAT .'.	  4-81
             4.2.3  Point Source Emissions File With Arbitrarily Varying
                   Emissions (PTEMARB.DAT)	  4-86
             42.4  Buoyant Area Source Emissions File with Arbitrarily
                   Varying Emissions (BAEMARB.DAT)	  4-95
             4.2.5   Volume Source Emissions File (VOLEM.DAT) with Arbitrarily
                   Varying Emissions  	  4-104
             4.2.6  User-Specified Deposition Velocity Data File (VD.DAT)	  4-111
             4.2.7  Hourly Ozone Data File (OZONE.DAT)	  4-113
             4.2.8  User-Specified Chemical Transformation Rate
                   Data File (CHEM.DAT)  	  4-120
             4.2.9  Site-Specific Turbulence Data (SIGMA.DAT)	  4-122
             4.2.10  CTDMPLUS Terrain Feature Description - for
                   CTSG (TERRAIN)  	  4-128

      4.3    CALPUFF Output Files	  4-130
             4.3.1  Concentration File (CONCDAT)  	  4-130
             4.3.2  Dry Flux File (DFLX.DAT)	  4-137
             433  Wet Flux File (WFLX.DAT)  	  4-144

      4.4    CALPOST Postprocessing Program	  4-152

5.    REFERENCES	  5-1
I:\calpufl\jul95\toc. wph                            Vli

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                                  1. INTRODUCTION

1.1    Background

       As part of a study to design and develop a generalized non-steady-state air quality
modeling system for regulatory use, Sigma Research Corporation developed the CALPUFF
dispersion model and related models and programs, including the CALMET meteorological
model The original development of CALPUFF and CALMET was sponsored by the California
Air Resources Board (GARB). Systems Application, Inc. (SAI) served as a subcontractor to
Sigma Research with the responsibility for developing the wind field modeling component of the
modeling system.

       The original design specifications for the modeling system included: (1) the capability to
treat time-varying point and area sources, (2) suitability for modeling domains from tens of
meters to hundreds of kilometers from a source, (3) predictions for averaging times ranging
from one-hour to one year, (4) applicability to inert pollutants and those subject to linear
removal and chemical conversion mechanisms, and, (5) applicability for rough or complex
terrain situations.

       The modeling system (Scire et al, 1990a, 1990b) developed to meet these objectives
consisted of three components: (1) a meteorological modeling package with both diagnostic and
prognostic wind field generators, (2) a Gaussian puff dispersion model with chemical removal,
wet and dry deposition, complex terrain algorithms, building downwash, plume fumigation, and
other effects, and (3) postprocessing programs for the output fields of meteorological data,
concentrations and deposition fluxes.

       In July, 1987, CARB initiated a second project with Sigma Research to upgrade and
modernize the Urban Airshed Model (UAM) to include state-of-the-science improvements in
many of the key technical algorithms including the numerical advection and diffusion schemes,
dry deposition, chemical mechanisms, and chemical integration solver.  The new photochemical
model, called CALGRID, was integrated into the  CALMET/CALPUFF modeling framework to
create a complete modeling system for both reactive and non-reactive pollutants.  The
CALPUFF and CALGRID models were designed to be compatible with the common
meteorological model, CALMET, and share a postprocessor for the time-averaging and display
of the modeling results.

       The Interagency Workgroup on Air Quality Modeling (IWAQM) has reviewed various
modeling approaches suitable for estimating pollutant concentrations at Class I areas, including

i\ca^)ufl\jul95\sectl.wph                            1-1

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the individual and cumulative impacts of proposed and existing sources on Air Quality Related
Values (AQRVs), Prevention of Significant Deterioration (PSD) increments, and National
Ambient Air Quality Standards (NAAQS). IWAQM consists of representatives from the U.S.
Environmental Protection Agency (EPA),  U.S. Forest Service, National Park Service, and U.S.
Fish and Wildlife Service. IWAQM released a Phase I report (EPA, 1993) which recommended
using the MESOPUFF H dispersion model and MESOPAC n meteorological model for
simulating regional air quality and visibility impacts. These recommendations were considered
interim until more refined (Phase n) techniques could be identified and evaluated. As part of
the Phase n work, IWAQM has reviewed  and  intercompared diagnostic wind field models,
tested the use of coarse gridded winds fields from the Penn State/NCAR Mesoscale Model with
four dimensional data assimilation (MM4-FDDA) as input into the diagnostic models, and
evaluated the MESOPUFF n and CALPUFF modeling systems using tracer data collected
during Cross-Appalachian Tracer Experiment (CAPTEX). The CAPTEX evaluation results
(EPA,  1995) indicated that by using the CALMET/CALPUFF models with MM4-FDDA data,
performance could be improved over that  obtained with the interim Phase I modeling approach.

       The CALMET and  CALPUFF models have been enhanced as part of work for IWAQM,
U.S. EPA, the U.S. Forest Service, the Environmental Protection Authority of Victoria
(Australia), and private industry in the U.S. and Australia. The improvements to CALMET
included modifications to make it more  suitable for regional applications such as the use of a
spatially variable initial guess field, an option for using hourly MM4-FDDA gridded fields as a
supplement to observational data, the ability to compute Lambert conformal map factors, a
modified mixing height scheme, an option to use similarity theory to extrapolate vertically
surface wind observations, an enhanced  algorithm to compute the three-dimensional
temperature field over water bodies, and an optional PC-based Graphical User Interface to
facilitate model setup and execution and to provide access to on-line Help files. Improvements
to CALPUFF include new modules to treat buoyant rise and dispersion from area sources (such
as forest fires), buoyant line sources, volume sources, an improved treatment of complex terrain,
additional model switches to facilitate its use in regulatory applications, enhanced treatment of
wind shear through puff splitting, and an optional PC-based GUI. CALPUFF  has been coupled
to the Emissions Production Model (EPM) developed by the Forest Service through an interface
processor. EPM provides time-dependent emissions and heat release data for use in modeling
controlled burns and wildfires.

1.2    Overview of the Modeling System

       The overall modeling system configuration is presented in Figure 1-1. The
meteorological modeling with the CALMET model is detailed in Figure  1-2. Note that the

i:\caipufl\jul95\tectl.wph                           1-2

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preprocessors for the raw meteorological data are written to accommodate the U.S. National
Climatic Data Center (NCDC) file formats. Figure 1-3 is the schematic of the CALPUFF
dispersion model indicating the model input and output files. The postprocessing approach for
the meteorological and dispersion modeling results is shown in Figure 1-4.  The major
components of the modeling system and interfaces to external programs are summarized below.

METSCAN is a meteorological preprocessor which performs quality assurance checks on the
       hourly surface meteorological data in the NCDC CD-144 format which is used as input
       to the SMERGE program.

READ56 and READ62 are meteorological preprocessors which extract and process upper air
       wind and temperature data from standard data formats used by NCDC.  READ56 and
       READ62 process TD-5600 and TD-6201 formatted data, respectively.

SMERGE is a meteorological preprocessor which processes hourly surface observations from a
       number of stations in NCDC CD-144 format and reformats the data into a single file
       with the data sorted by time rather than station.

EXTRACT is a meteorological preprocessor which extracts precipitation data for stations and a
       time period of interest from a fixed length, formatted precipitation data file in NCDC
       TD-3240 format.

PMERGE is a meteorological preprocessor responsible for reformatting the precipitation data
       files created by the PXTRACT program.  PMERGE resolves "accumulation periods" into
       hourly values and flags suspicious or missing data.  The output file can be formatted or
       binary, which can be directly input into the CALMET model, containing the precipitation
       data sorted by hour rather than station.

CSUMM (a version of the Colorado State University Mesoscale Model) is a primitive equation
       wind field model which simulates mesoscale airflow resulting from differential surface
       heating and terrain effects.  The diagnostic wind field model within CALMET contains
       options that allow wind fields produced by CSUMM to be combined with observational
       data as part of the CALMET objective analysis procedure.

MM4-FDDA (Penn State/NCAR Mesoscale Model) is a prognostic wind field model with four
       dimensional data assimilation.  CALMET has been modified to incorporate
       MM4-FDDA winds into its Diagnostic Wind Model (DWM).
i;\calpufl\jul95\ieetl.wph                            1-3

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CALMET is a meteorological model which includes a diagnostic wind field generator containing
       objective analysis and parameterized treatments of slope flows, kinematic terrain effects,
       terrain blocking effects, and a divergence minimization procedure, and a
       micrometeorological model for overland and overwater boundary layers.

CALPUFF is a non-steady-state Lagrangian Gaussian puff model containing modules for
       complex terrain effects, overwater transport, coastal interaction effects, building
       downwash, wet and dry removal, and simple chemical transformation.

CALGRID is an Eulerian photochemical transport and dispersion model which includes modules
       for horizontal and vertical advection/diffusion, dry deposition, and a detailed
       photochemical mechanism.

OPTHILL is a processor program which uses topographical data (such as terrain maps) to
       develop hill shape factors that are used in the subgrid scale complex terrain (CTSG)
       module in CALPUFF.

PRTMET is a postprocessing program which displays user-selected portions of the
       meteorological data base produced by the CALMET meteorological model

CALPOST is a postprocessing program with options for the computation of time-averaged
       concentrations and deposition fluxes predicted by the CALPUFF and CALGRID
       models. CALPOST will also compute visibility impacts in accordance with IWAQM
       recommendations.

       This report describes the CALPUFF model and its related processors OPTHILL and
CALPOST. Section 2 contains a description of the technical formulation of CALPUFF.' The
structure of the CALPUFF code is discussed in Section 3. The inputs and outputs of the
CALPUFF model and the preprocessing and postprocessing programs are described in
Section 4.

       A series of companion reports describe other components of the modeling system.  The
technical formulation and user instructions for the revised CALMET model are contained in
Scire et al. (1995). The prognostic wind field model, CSUMM, is described in a report by
Kessler (1989). A stand-alone version of the Diagnostic Wind Model (DWM) used as the wind
field module in CALMET is discussed by Douglas and Kessler (1988).  Finally, the CALGRID
model  is documented in a paper by Yamartino et al. (1992) and reports by Yamartino et al.
(1989)  and Scire et al. (1989).

i:\calpufl\jul95\iectl.wph                            1-8

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 13     Major Model Algorithms and Options

        CALPUFF is a multi-layer, multi-species non-steady-state puff dispersion model which
 can simulate the effects of time- and space-varying meteorological conditions on pollutant
 transport, transformation, and removal  CALPUFF can use the three dimensional
 meteorological fields developed by the CALMET model, or simple, single station winds in a
^format consistent with the meteorological files used to drive the ISC2 (EPA, 1992) or
 AUSPLUME (Lorimer, 1976) steady-state Gaussian models. However, single-station ISC2 or
, AUSPLUME winds should be used with caution, because they do not allow CALPUFF to take
 advantage of its capabilities to treat spatially-variable meteorological fields.

        CALMET includes a diagnostic wind field generator, and overland and overwater
 boundary layer modules. CALMET has the ability to combine the  wind fields generated by the
 CSUMM prognostic wind field model or the MM4-FDDA model with observational data
 through an objective analysis procedure.

        CALPUFF contains algorithms for near-source effects such as building downwash,
 transitional plume rise, partial plume penetration, subgrid scale terrain interactions as well as
 longer range effects such as pollutant removal (wet scavenging and  dry deposition), chemical
 transformation, vertical wind shear, overwater transport and coastal interaction effects. It can
 accommodate arbitrarily-varying point source and gridded area source emissions. Most of the
 algorithms contain options to treat the physical processes at different levels of detail depending
 on the model application.

        The major features and options of the CALPUFF model are summarized in Table 1-1.
 Some of the technical algorithms are briefly described below.

        Dry Deposition:  A full resistance model is provided in CALPUFF for the computation
        of dry deposition rates of gases and participate matter as a function of geophysical
        parameters, meteorological conditions, and pollutant species.  Options are provided to
        allow user-specified, diurnally varying deposition velocities to be used for one or more
        pollutants instead of the resistance model (e.g., for sensitivity testing) or to by-pass the
        dry deposition model completely.

        Wet Deposition:  An empirical scavenging coefficient approach is used in CALPUFF to
        compute the depletion and wet deposition fluxes due to precipitation scavenging.  The
        scavenging coefficients are specified as a function of the pollutant and precipitation  type
        (i.e., frozen vs. liquid precipitation).

 fc\ca]pufl\jul95\secU.wph                            1-9

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                                            Table 1-1
                            Major Features of the CALPUFF Model
               Source types
               • Point sources (constant or variable emissions)
               • Line sources (constant emissions)
               • Volume sources (constant or variable emissions)
               • Area sources (constant or variable emissions)

               Non-steady-state emissions and meteorological conditions
               • Gridded 3-D fields of meteorological variables (winds, temperature)
               • Spatially-variable fields of mixing height, friction velocity, convective velocity scale, Monin-
                 Obukhov length, precipitation rate
               • Vertically and horizontally-varying turbulence and dispersion rates
               • Time-dependent source and emissions data

               Efficient sampling functions
               • Integrated puff formulation
               • Elongated puff (slug) formulation

               Dispersion coefficient (or oj options
               • Direct measurements of ov and ow
               • Estimated values of ov and ow based on similarity theory
               • Pasquill-Gifford (PG) dispersion coefficients (rural areas)
               • McElroy-Pooler (MP)  dispersion coefficients (urban areas)

               Vertical wind shear
               • Puff splitting
               • Differential advection and dispersion

               Plume rise
               • Partial penetration
               • Buoyant and momentum rise
               • Stack tip effects
               • Vertical wind shear
               • Building downwash effects

               Building downwash
               • Huber-Snyder method
               • Schulman-Scire method
(Continued)
i:\calpufl\jul9S\iectl.wph                               1-10

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                                      Table 1-1 (Concluded)
                             Major Features of the CALPUFF Model
               Subgrid scale complex terrain
               • Dividing streamline, H^:
                       -  Above H0, puff flows over the hiD and experiences altered diffusion rates
                       -  Below H* puff deflects around the hiD, splits, and wraps around the hill

               Interface to the Emissions Production Model (EPM)
               • lime-varying heat flux and emissions from controlled burns and wildfires

               Dry Deposition
               • Gases and partici'late matter
               • Three options:
                       -  FuD treatment  of space and time variations of deposition with a resistance model
                       -  User-specified  diurnal cycles for each pollutant   •
                       -  No dry deposition

               Overwater and coastal interaction effects
               • Overwater boundary layer parameters
               • Abrupt change in meteorological conditions, plume dispersion at coastal boundary
               • Plume fumigation

               Chemical transformation options
               • Pseudo-first-order chemical mechanism for SOj, SO~4, NO* HNO3, and
                 (MESOPUFF H method)
               • User-specified diurnal cycles of transformation rates
               • No chemical conversion

               Wet Removal
               • Scavenging coefficient approach
               • Removal rate a function of precipitation intensity
                 and precipitation type

               Graphical User Interface
               • Click-and-point model setup and data input
               • Enhanced error checking of model inputs
               • On-line  Help files
fc\calpiifl\juBS\iectl.wph                               1-11

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      Chemical Transformation: CALPUFF includes options for parameterizing chemical
      transformation effects using the five species scheme (SO* SO~4, NOr HNO,, and NO;)
      employed in the MESOPUFF n model or a set of user-specified, diurnally-varying
      transformation rates.

      Subgrid Scale Complex Terrain:  The complex terrain module in CALPUFF is based on
      the approach used in the Complex Terrain Dispersion Model (CTDMPLUS) (Perry et
      aL, 1989). Plume impingement on subgrid scale hOls is evaluated using a dividing
      streamline (ILJ to determine which pollutant material is deflected around the sides of a
      hill (below H*) and which material is adverted over the hill (above ILJ. Individual puffs
      are split into up to three sections for these calculations.

      Puff Sampling Functions:  A set of accurate and computationally efficient puff sampling
      routines are included in  CALPUFF which solve many of the computational difficulties
      with applying a puff model to near-field releases. For near-field applications during
      rapidly-varying meteorological conditions, an elongated puff (slug) sampling function is
      used. An integrated puff approached is used during less demanding conditions. Both
      techniques reproduce continuous plume results exactly under the appropriate steady state
      conditions.

      Wind Shear Effects:  CALPUFF contains an optional puff splitting algorithm that allows
      vertical wind shear effects across individual puffs to be simulated. Differential rates of
      dispersion and transport occur on the puffs generated from the original puff, which
      under some conditions, can substantially increase the  effective rate of horizontal growth
      of the plume.

      Building Downwash: The Huber-Snyder and Schulman-Scire downwash models are both
      incorporated into CALPUFF. An option is provided  to use either model for all stacks,
      or make the choice on a stack-by-stack and wind sector-by-wind sector basis.  Both
      algorithms have been implemented in such a way as to allow the use of wind direction
      specific building dimensions.

      Overwater and Coastal Interaction Effects: Because  the CALMET  meteorological
      model contains both overwater and overland boundary layer algorithms, the effects of
      water bodies on plume transport, dispersion, and deposition can be simulated with
      CALPUFF. The puff formulation of CALPUFF is designed to handle spatial changes in
fc\
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       meteorological and dispersion conditions, including the abrupt changes which occur at
       the coastline of a major body of water.

       Dispersion Coefficients: Several options are provided in CALPUFF for the computation
       of dispersion coefficients, including the use of turbulence measurements (ov and ov ), the
       use of similarity theory to estimate ov and ov from modeled surface heat and momentum
       fluxes, or the use of Pasqufll-Gifford (PG) or McElroy-Pooler (MP) dispersion
       coefficients, or dispersion equations based on the Complex Terrain Dispersion Model
       (CDTM). Options are provided to apply an averaging time correction or surface
       roughness length adjustments to the PG coefficients.

1.4    Summary of Data and Computer Requirements

                                  Data Requirements

       The input data sets used by CALPUFF are summarized in Table 1-2 (also see the modeling
system flow diagram, Figure 1-1). CALPUFF reads user inputs from a "control file" with a default
name of CALPUFF.INP.  This file contains the user's selections for the various model options,
technical input variables, output options, and other user-controllable options.

       A  meteorological  data  file  (CALMET.DAT)  contains  hourly gridded  fields  of
micrometeorological parameters and three-dimensional  wind and  temperature fields.  The
meteorological data file also contains geophysical data such as terrain heights and land use which
are required by both the meteorological model (e.g., for terrain adjustment of the wind fields) and
by the CALPUFF model. The contents of the CALMET.DAT input file and the other input data
bases are summarized in Table 1-3. Options also exist for using single-station meteorological data
in ISC2 or AUSPLUME data format. Note: CALPUFF requires the addition of three header
records at the beginning of the ISC2 or AUSPLUME meteorological data (see Section 4.2.2).

       Four files are provided for the input of emissions data. The control file, CALPUFF.INP
includes point, line, volume and area source data for sources with constant emission parameters.
Arbitrarily-varying point source data is read from a file with a default name of PTEMARB.DAT.
Gridded, time-varying volume source emissions are obtained from the file VOLEM.DAT. Time-
varying area source data is read from a file called BAEMARB.DAT.

       Hourly observations  of  ozone data are used  in  the  calculation  of  SO2  and  NO,
transformation rates if the MESOPUFF n chemical transformation scheme is selected. The hourly
ozone data for one or more ozone stations are read from a data file called OZONE.DAT.

i-\calpufl\ju»5\«ectl.wph                           1-13

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                                          Table 1-2
                              Summary of CALPUFF Input Files
 Default
 Hie Name
Contents
Unit*     Type
Number
 PUFFILES.DAT
 CALPUFFJNP

 CALMET.DAT
    or
 ISCMETDAT
    or
 PLMMETDAT
 PTEMARB.DAT


 BAEMARB.DAT



 VOLEM.DAT


 VD.DAT

 OZONE.DAT


 CHEM.DAT

 SIGMA.DAT

 HILL.DAT
FQe containing the filename and path for each of the      IO14      Formatted
input and output (I/O) files used in the current run.  If
an I/O filename is not specified in the PUFFILES DAT
file, the model uses the default filenames shown in this
table

Control file inputs                                   IO5       Formatted

Geophysical and hourly meteorological  data, created by    IO7       Unformatted
the CALMET meteorological model


Single-station ASCII meteorological data in slightly        IO7       Formatted
modified ISC2-format
Single-station ASCII meteorological data in slightly        IO7       Formatted
modified AUSPLUME format

Source and emissions data for point sources with          IO16      Unformatted
arbitrarily-varying emission parameters (optional)

Emissions data for area sources with time-varying         IO17      Unformatted
emission parameters. Can be derived from EPM model
files (optional)

Emissions data for volume sources with time-varying       IO18      Formatted
emission parameters (optional)

User-specified deposition velocities (optional)             IO20      Formatted

Hourly ozone measurements at one or more ozone        IO22      Formatted
stations (optional)

User-specified chemical transformation rates (optional)    IO24      Formatted

Hourly turbulence measurements (
-------
                                           Table 1-3
                          Summary of Input Data Used by CALPUFF
Geophysical Data (CALMETJ)AT)

        Gridded fields of:
               • surface roughness lengths
               • land use categories
               • terrain elevations
               • leaf area indices

Meteorological Data (CALMETJ)AT)

        Gridded fields oft
               • u, v, w wind components (3-D)
               • air temperature (3-D)
               • surface friction velocity (u.)
               • convective velocity scale (w.)
               • miring height (Zj)
               • Monin-Obukhov length (L)
               • PGT stability class
               • Precipitation rate

        Hourly values of the following parameters at surface met stations:
               • air density (pj
               • air temperature
               • short-wave solar radiation
               • relative humidity
               • precipitation type

Emissions Data (CALPUFF.INP, PTEMARB.DAT, BAEMARB.DAT, VOLEM.DAT)

        Point source emissions:
               • Source and emissions data for point sources with constant emission parameters
                 (CALPUFF.INP)
               • Source and emissions data for point sources with arbitrarily-varying emission parameters
                 (PTEMARB.DAT)

        Area  source emissions
               • Emissions and  initial  size, height, and location for area sources with constant emission
                 parameters (CALPUFF.INP)
               • Gridded emissions data for buoyant area sources with time-varying emission parameters
                 (BAEMARBDAT)
(Continued)
fc\calpufl\jul95\«ectl.wph                             1-15

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                                    Table 1-3 (Concluded)
                          Summary of Input Data Used by CALPUFF


       Volume source emissions

       • Emissions, height, size, and location of volume sources with constant emission parameters
         (CALPUFFJNP)
       • Emissions data for volume sources with tune-varying emission parameters (VOLEM .DAT)

       Line source emissions

       • Source and emissions data, height, length, location, spacing, and orientation of line sources with
         constant emission parameters (CALPUFFJNP)

Deposition Velocity Data (VDJ)AT)

       • Deposition velocity for each user-specified species for each hour of a diurnal cycle

Ozone Monitoring Data (OZONE.DAT)

       • Hourly ozone measurements at one or more monitoring stations

Chemical Transformation Data (CHEM.DAT)

       • Species-dependent chemical transformation rates for each hour of a diurnal cycle

Turbulence Observational Data (SIGMA.DAT)

       • Hourly measurements of turbulence (ow ow) at an onsite meteorological tower

Hill Data (HILL.DAT)

       • Hill shape and height parameters for use in the subgrid-scale complex terrain  module
         (CTSG)
i:\calpufl\jul95\iectl.wph                              1-16

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       Two additional input files, VD.DAT and CHEMJ3AT, contain diurnal cycles of user-
specified deposition velocities and chemical transformation rates, respectively.  These files are
necessary only if the user wishes to substitute the values normally computed internally by the
deposition and chemical models with sets of time-varying but spatially-uniform externally specified
values.

       Another optional input file, SIGMA.DAT, contains hourly observations of ov and a*. These
parameters can be used to compute the plume dispersion coefficients o, and oz.

       The structure, format and contents of each CALPUFF input data set are described  in
Section 4.2. The CALPUFF output files are summarized in Table 1-4. The list file contains a copy
of the inputs used in the run, optional output fields of gridded and discrete receptor concentrations,
wet deposition fluxes, and dry deposition fluxes and other run data. The CONC.DAT, WFLX.DAT,
and DFLX.DAT files contain the output concentrations, wet and dry fluxes, respectively, in an
unformatted form suitable for further processing by the postprocessing program, CALPOST. The
VISB.DAT file contains relative humidity information which is required by CALPOST in order to
perform certain visibility-relative computations.
                                Computer Requirements

       The memory management scheme used in CALPUFF is designed to allow the maximum
array dimensions in the model to be easily adjusted to match the requirements of a particular
application. An external parameter file contains the maximum array size for all of the major arrays.
A re-sizing of the program can be accomplished by modifying the appropriate variable or variables
in the parameter file and re-compiling the program.  All appropriate arrays in the model will be
automatically re-sized by the updated parameter values. For example, the  maximum number of
horizontal grid cells allowed in the model, MXNX and MXNY, are two of the variables which can
be adjusted within the parameter file. However, no change to the parameter file is necessary if a
particular application requires a smaller array size than  the maximum values specified in the
parameter file.

       The memory required by CALPUFF will be a strong function of the specified maximum
array dimensions in the  parameter file.    However, as  an example,  CALPUFF required
approximately 300 K bytes of memory for a test run with a 10 x 10 horizontal grid, with 5 vertical
layers, and a maximum number of puffs of 100.  This type of configuration may be suitable for

L\caJpufl\jul95\secU.wpti                            \.\*l

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                                           Table 1-4
                             Summary of CALPUFF Output Files
 Default
 File Name
Contents
Unit*     Type
Number
 CALPUFFJLST

 CONCDAT



 DFLXDAT



 WFLJCDAT



 VISBDAT


 DEBUGDAT
List file produced by CALPUFF

One-hour averaged concentrations (g/m1) at the
gridded and discrete receptors for species selected by
the user in the control file (optional)

One-hour averaged dry deposition fluxes (g/m2/s) at
the gridded and discrete receptors for species selected
.by the user in the control file (optional)

One-hour averaged wet deposition fluxes (g/m2/s) at
the gridded and discrete receptors for species selected
by the user in the control file (optional)

Relative humidity data required for visibility-related
postprocessing (optional)

Tables of detailed puff/slug data useful for debugging
(optional)
IO6       Formatted

IO8       Unformatted



IO9       Unformatted



IO10      Unformatted



IO11      Unformatted


IO30      Formatted
        Variable shown is the parameter controlling the FORTRAN unit number associated with the file.
        Usually, the value assigned to the parameter is consistent with the name (i.e., IO8 = 8).
        However, the value can be easily changed in the parameter file to accommodate reserved unit
        numbers on a particular system.
fc\calpuff\jul95\«ecU.wph
                          1-18

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 evaluating the near-field impact of a small number of point sources. For studies involving long-
 range transport, memory requirements will typically be at least 8 megabytes, with more required for
 simulations involving large numbers of sources.

       The run time of CALPUFF will vary considerably depending on the model application.
 Variations of factors of 10-20 are likely depending of the size of the domain, the number of sources,
 selection of technical options, and meteorological variables such as the mean wind speed. Because
 each puff is treated independently, any factor which influences the number and residence time of
 puffs on the computational grid will affect the run time of the model
                                   Program Execution

       CALPUFF (Version 3.0 and above) can be executed with the following DOS command line:

                                  CALPUF3  filename

where it is assumed that the executable file is called CALPUF3.EXE and the "filename" is the name
of the file (up to 70 characters in length) containing the input and output (I/O) files to be used in
the run.  The default I/O file name is PUFFILES.DAT. In the I/O file the user can change the
name of any of the input and output files from their default names, and change the directory from
which the files will be accessed by specifying the file's full pathname (see Section 42).
fc \c»lpufl\juJ95\Kctl.wph                           1-19

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                             2. TECHNICAL DISCUSSION
2.1    Solution of the Puff Equations

       Puff models represent a continuous plume as a number of discrete packets of pollutant
material  Most puff models (e.&, Ludwig et aL, 1977; van Egmond and Kesseboom, 1983;
Peterson,  1986) evaluate the contribution of a puff to the concentration at a receptor by a
"snapshot" approach.  Each puff is "frozen" at particular time intervals (sampling steps). The
concentration due to the "frozen" puff at that time is computed (or sampled).  The puff is then
allowed to move, evolving in size, strength, etc, untfl the next sampling step.  The total
concentration at a receptor is the sum of the contributions of all nearby puffs averaged for all
sampling steps within the basic time step.  Depending on the model and the application, the
sampling step and the time step may both  be one hour, indicating only one "snapshot" of the
puff is taken each hour.

       A traditional drawback of the puff  approach has been the need for the release of many
puffs to adequately represent a continuous plume dose to a source.  Ludwig et aL (1977) have
shown that if the distance between puffs exceeds a maximum of about 2 OT inaccurate results
may be obtained (see Figure 2-1). Better results are obtained if the puff separation is reduced
to no  more than one or  If the puffs do not overlap sufficiently, the concentrations at receptors
located in the gap between puffs at the time of the "snapshot" are underestimated, while those at
the puff centers are overestimated.

       Ludwig et al. (1977) recommend spacing puffs uniformly in space rather than in time
with a puff merging/purging scheme to reduce the total number of puffs.  Zannetti (1981)
suggests tracking fewer puffs than necessary for adequate sampling, but then saturating the area
near a receptor with artificially generated puffs to provide the required puff overlap (see
Figure 2-2). Although both schemes act to reduce the number of puffs carried by the model, the
snapshot sampling method still requires that an uneconomically large number of puffs be
generated near the source. For example, at a receptor 100 meters from a source, and assuming
PGT dispersion rates, puffs at a density corresponding to a release rate of over 1300 puffs/hour
are required to meet the 2 oy criterion for F stability, 3 m/s wind conditions. During high wind
speed, neutral conditions (10 m/s, D stability), nearly 2200 puffs/hour are needed. The more
stringent one oy criterion would double the number of puffs required.

       Two alternatives to the conventional snapshot sampling function are discussed below.
The first is based on the integrated sampling function in the MESOPUFF n model (Scire et aL,

i:\oUpun\jul95\»ect2.wph                           2-1

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                         I     I      I
I      I
                       PUFF SEPARATION -  O5oy.  1.00
                              PUFF SEPARATION  •  20
                               PUFF SEPARATION - 40
                         0.2         0.4         0.6         OS         1.0
                    FRACTION OF DISTANCE BETWEEN PUFF CENTERS
Figure 2-1.    Normalized concentration between two puffs in a string of puffs of equal size and
             spacing.  [From Ludwig et aL (1977)].
u\c»lpomjuJ95\iea2.wph
                                        2-2

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Figure 2-2.    Dlustration of the puff generation scheme of Zannetti (1981). The adverted puffs
              (A - A', B - B') in the vicinity of Receptor 1 are not sufficient to resolve the plume.
              The mass from the original puffs is redistributed into n, x n, new puffs (asterisks) for
              sampling purposes. [From Zannetti (1981)].
i:\ca4Mfl\jal93\>cct2.wpli
2-3

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1984a,b), with modifications for near-field applications.  Hie second scheme uses a non-circular
puff (slug) elongated in the direction of the wind to eliminate the need for frequent releases of
puffs. The performances of the original and modified integrated sampling functions and the slug
model are evaluated for unsteady and steady-state conditions.  The sampling scheme used in
CALPUFF is a hybrid circular puff/elongated slug method taking advantage of the strengths of
each algorithm.

2.1.1 Integrated Puff Sampling Function Formulation

       The basic equation for the contribution of a puff at a receptor is:
                  8="              "+2nA2/2o'                             (2"2)
where, C     is the ground-level concentration (g/m3),
       Q     is the pollutant mass (g) in the puff,
       ox     is the standard deviation (m) of the Gaussian distribution in the along-wind
                     direction,
       oy     is the standard deviation (m) of the Gaussian distribution in the cross-wind
                     direction,
       oz     is the standard deviation (m) of the Gaussian distribution in the vertical
                     direction,
       da     is the distance (m) from the puff center to the receptor in the along-wind
                     direction,
       dc     is the distance (m) from the puff center to the receptor in the cross-wind
                     direction,
       g      is the vertical term (m) of the Gaussian equation,
       H     is the effective height (m) above the ground of the puff center, and,
       h      is the mixed-layer height (m).

       The summation in the vertical term, g, accounts for multiple reflections off the mixing lid
and the ground. It reduces to the uniformly mixed limit of 1/h for oz > 1.6 h. In general, puffs
within the convective boundary layer meet this criterion within a few hours after release.
i:\aUpufl\jul95\iect2.wph                             2-4

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       For a horizontally symmetric puff, with oz = of Eqn. (2-1) reduces to:

                                    g(s) ezp[-*V)/(20>))]                             (2-3)
where, R is the distance (m) from the center of the puff to the receptor, and,
       s is the distance (m) traveled by the puff.

       The distance dependence of the variables in Eqn. (2-3) is indicated (e.&, C(s), Oy(s),
etc.). Integrating Eqn. (2-3) over the distance of puff travel, ds, during the sampling step, dt,
yields the time averaged concentration, C.
                                                                                       (2-4)
where s0 is the value of s at the beginning of the sampling step.
       If it is assumed that the most significant s dependencies during the sampling step are in
the R(s) and Q(s) terms, an analytical solution to this integral can be obtained.  Figure 2-3
illustrates the movement of a puff from coordinates (x^yj to (x^Vj). Assuming the trajectory
segment is a  straight line, and transforming s to a dimensionless trajectory variable, p, the radial
distance to the receptor at (XpVr) is:
                        [ft -xr+p 
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Figure 2-3.    Illustration of the puff movement during the sampling step and  the associated
               changes in the puff-receptor distance.
t\c«lpyfl\jul95\«eett.wph
2-6

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                                                                                     (2-7)
       The solution of the integrals in Eqn. (2-7) is expressed in terms of error functions and
exponentials:
                      2nol
                                                                                     (2-8)
                                                                                     (2-9)
                          2a
                                    exp
                                                                                    (2-10)
                                 (dr2 + dy*)lo*y                                     (2-H)

                                                     ;                               (2-12)

                                                                                    (2-13)
       The horizontal dispersion coefficient, or and the vertical term, g, are evaluated and held
constant throughout the trajectory segment.  In MESOPUFFII, oy and g are computed at the
mid-point of the trajectory segment (p = 0.5).  At mesoscale distances, the fractional change in
the puff size during the sampling step is usually small, and the use of the mid-point values of oy
and g is adequate. This assumption reduces the number of times that the dispersion coefficients
and vertical reflection terms need be computed to one per sampling step (independent of the
number of receptors).  This optimization for mesoscale distances, however, may not be
appropriate in the near-field, where the  fractional puff growth rate can be rapid and plume
height may vary.  For this reason, the integrated sampling function has been also tested with
receptor-specific values of oy and g, evaluated at the point of closest approach of the puff to
t\calpufl\jul95\sect2.wph
2-7

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each receptor.  The results of the test runs of both puff models as well as the slug model
described in the next subsection are discussed below.
2.12   Slug Formulation and Sampling Functions

       In the slug model, the "puffs" consist of Gaussian packets of pollutant material stretched
in the along-wind direction. A slug can be visualized as a group of overlapping circular puffs
having very small puff separation distances. In fact, the slug represents the continuous emission
of puffs, each containing the infinitesimal mass q dt  The length of the main body of the slug is
u At,, where u is the wind speed, and Ate is the time of emission of the pollutant. The
concentration due to the presence of a slug can be described as:
                                 Fq
                                   «'o.
  2o,'
                                         (2-14)

                                                                                      (2-15)
where, u      is the vector mean wind speed (m/s),
       u'     is the scalar wind speed (defined as u' = (u2 + o^ )1/2 with ov = wind speed
                     variance),
       q      is the source emission rate (g/s),
       F      is a "causality" function, and
       g      is the vertical coupling factor of Eqn. 2-2.

       The quantities dc and d. are cross-slug (i.e., perpendicular to the slug axis) and along-slug
distances, respectively, to the receptor. In particular, d^ is the distance from slug end 2 (with
d.2 > 0 in the direction of end 1), whereas the distance from slug end 1 is defined as -d^ • d^ -
ty with t,y being the length of the slug projection in the x-y plane. The subscripts 1 and 2 on
the dispersion coefficients refer to values at the oldest and youngest ends of the slug,
respectively. The absence of a numerical subscript indicates a value defined at the receptor.

       This "slug" formulation retains many of the important properties of the circular puff
model, while significantly reducing puff overlap problems associated with snapshot sampling of
circular puffs. The concentration distribution within the body of the slug, away from the slug
endpoints, approaches that of the Gaussian plume result under the appropriate steady-state
conditions.  The concentrations near the endpoints of the slug (both inside and outside of the
i;\calpufl\jul95\iec«2.wph
2-8

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body of the slug) fall off in such a way that if adjacent slugs are present, the plume predictions
will be reproduced when the contributions of those slugs are included (again, during steady-state
conditions).  Eqn. (2-14) can be explicitly shown to conserve mass. As with circular puffs, each
slug is free to evolve independently in response to the local effects of dispersion, chemical
transformation, removal, etc. However, unlike puffs, we constrain the end points of adjacent
slugs to remain connected. This ensures continuity of a simulated plume without the gaps
associated with puff or segmented plume models.

       The "causality" function, F, accounts for edge effects near the endpoints of the slug.  For
long emission times such that u Ate > op and points well inside the body of the slug, evaluation
of the error functions in Eqn. (2-15) produces F = 0.5(1 - (•!)) = 1 (Le., no edge effects). For
receptors well outside the slug, F becomes zero, indicating that the pollutant material has not
yet reached the receptor or has already passed it by.  Near the endpoints, the causality factor
produces a leading/trailing Gaussian tail on the distribution.

       The factor (u/u') allows low wind speed and calm conditions to be properly treated. As
u approaches zero, the exponential crosswind term becomes unity and F approaches -erf{dJ[(J2
Oy]}.  Under these conditions, the radial concentration dependence of the distribution is
determined by the causality factor.  For u greater than a few meters per second,  (u/u') is very
close to one, so that this ratio becomes unimportant.  The factors (u/u') and F make the slug
model more "puff-like" than segmented plume models (e.g., Hales et aL, 1977; Benkley and Bass,
1979). Unlike the slug model, segmented plume models generally do not properly treat low
wind speed conditions or segment edge effects.

       Eqn. (2-14) represents a "snapshot" description of the elongated puff at time t.
Figure 2-4 displays the concentration isopleths of two such slug snapshots.  As with the
"snapshot" puff equation, Eqn. (2-14) must be integrated during the sampling step to produce a
time-averaged concentration. In the case where the emission rate and meteorological conditions
do not vary during the sampling step, a generalized analytical solution to the integral can be
obtained for "emitting" slugs (Le., the endpoint of the "youngest" end of the slug is at the
source):
                        C = —— g exp
                                  °y
                                                 «2
(2-16)
t\calpuff\jul9S\iect2.wph                             2-9

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        IIII   I
             I   r   i  i   i   i   i   I   i   i   r
      i   r  i   i
          i   i
     i   i   i
i   i   i   i    i   i   i    i
                                                       i    i
i   i   i
i   i
Figure 2-4.    Isopleths of two slug "snapshots." The slug snapshot at left represents the slug at the
              beginning of a time step whereas the snapshot at right shows the instantaneous
              distribution at the end of the time step.  During the time step, the slug experienced
              advection (to the right), diffusion, and some aiong-slug stretching due to wind shear.
i:\ca^iafl\jul9!S\Mct2.wpb
                          2-10

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               F - 4 trf «>,\  + \
                                2
                              + —
                                2
where                               5. - -s—	'                                  (2-18)
                                            V2°,

represents the situation at the end of the time step At,.
represents the situation at the beginning of the time step,
                                       ~-                                         (2-20)
represents the steady state conditions at the source, and where At, is the duration of the
sampling step.

*      For Eqn. (2-16) to apply, the sampling interval must correspond to the emission interval,
its is normally the case for fresh emissions. The value of o^ used is the initial lateral spread (if
any) of the emissions at the source.  For older slugs, the endpoint of the slug is no longer fixed
at the source and the long axis of the slug is not likely to be along the adverting wind direction.
An analytical integration of Eqn. (2-14) is not possible for these slugs unless restrictive
conditions are imposed on the form of the puff growth equations. Because of the importance of
generality in the puff growth equations, the time-averaged concentrations of older/ slugs are
determined  by numerical integration of Eqn. (2-14). As discussed in the next subsection, this
integration can be accomplished at reasonable computation cost. Figure 2-5 shows the result of
such integral averaging for the situation where the Figure 2-4 "snapshots" depict the start and
end slug states of the averaging period.

       The  above development also ignores the effect of loss or production mechanisms;
however, this can be handled in much the same "linearized" manner that MESOPUFF n
invokes.  This is accomplished by allowing the effective emission rate, q, to vary linearly over
time as:

t\calpufl\jul95\«ect2.wph                            2-11

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 I   I
                               i   r
                                             i   i   i   r
J	I
I    I   I   I
I    I   i   I   i   I   I
                                                       111
  Figure 2-5.     Receptor-time averaged concentrations resulting from the transport and evolution
                 of the slug depicted in Figure 2-4 from its initial (left "snapshot") to final (right
                 "snapshot") state. The tick marks on the border suggest the 2-d mesh of receptors
                 considered.
  i\ca]pufl\ju»5\j«s2.wpb
                                               2-12

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where, ^      is the effective emission rate for the slug at the beginning of the time step
                      (n.tx, % = q for fresh emissions),
        (k      is the effective emission rate including loss or production which occurs during the
                      time step, and,
        At.      is the duration of the time step.
       The variable € is also the function
                                                                                       (2,22)
of the dimensionless time variable t/At,, where 0 s t/At, i 1, such that
and the causality function becomes
                                                                                       (2-24)
Thus, the time averaging process yields
where F0 is just F from Eqn. (2-17) and
                                                                                       (2"26)
with
Substituting in Eqn. (2-24) then yields
L\calpufl\juJ95\iect2.wph
                                            2-13

-------
where  fdx e/f(x) = x «/(x) + -i- exp(-x2)                                          (2-28)
                               V*

has already been used to obtain Eqn. (2-17) and where

             (dx x erf(x) = ±x*erf (x) + 1 JL expf-x2) - 7 erf(x)                    (2-29)
is a special case of the more general expression developed by Geller and Ng (1971) in terms of
the generalized hypergeometric function 2F2.

       Generalizing the problem of dealing with older slugs is trivial if one deals with a
numerical integration (Le., time average) of Eqn. (2-14). The time dependent expression q(t)
given by Eqn. (2-21), simply replaces q and the numerical integration proceeds.

       This numerical integration process has itself received special attention because it greatly
influences the computing time needs of the slug model. First, all receptors lying outside of the
slug's ± 3oy envelope during the entire averaging time interval are eliminated from
consideration. Second, for those receptors remaining, integration time limits are computed such
that sampling is not performed when the receptor is outside of the ± 3oy envelope. As the
endpoints of the slug are advected separately such that the slug may "tumble", the algebra for
finding the appropriate time limits involves the roots of cubic equations, but is otherwise
straightforward and is not discussed further.

       Invocation of the "frozen o" methodology (Le., oy and oz are fixed at receptor specific
values throughout the averaging time period) creates another class of situations which can be
integrated analytically; however, the most general case involves indefinite integrals of the form

                          fdt exp(-pV)«/(« + fe),                                  (2-30)
which defy solution except in a few simple cases (e.g., a = 0 and b =  p).  In fact, integrability
has proven not to be the sole criteria in these slug sampling problems. For example, the
preceding work on linear time variation of loss (or production) mechanisms can also be
evaluated for the more realistic exponential process; however, the analytic forms are found to be

L\calpufl\jul95\i«ct2,wph                            2-14

-------
very volatile on a computer because subtraction of large numbers to obtain small numbers is
required.

       One tractable case involves the quite physical scenario of a slug passing rapidly over a
receptor and with slug endpoints sufficiently far away that the along-slug causality factor, F(t), is
time independent  In this case the causality factor also becomes fixed and can be taken outside
the integral and approximated as
which is just the average of values at the beginning and end of the time step.  This
approximation is, however, made only if Fb and Fe are within a specified fractional tolerance of
each other. A similar procedure enables one to move the vertical coupling factor, g, outside the
integral and replace it with the mean value g~. The tolerance factor for both causality and
vertical coupling coefficient variation is currently set at a conservative 0.02 (Le., 2%).  Finally
the variability of the lateral coupling term,
                                                ,                                     (2-32)
where  t,(/) =     -  -
               fay    »'

and dc(t) is the time dependent crosswind distance, is checked and the integrals

                                 Al*
                                          f,)" Y(t)                                    (2-33)
                                  0   '

evaluated for m = 0 and 1.

       These integrals can be solved to yield


                     'o - ^KK) '  ^Ml/fr. - TU)                              (2-34)

and


                                     --'tf                            (2-35)
fc\calpuff\jii»5\iece.wph                             2-15

-------
so that the final time-averaged concentrations can be written as

                                                                                     (2-36)
as an alternative to numerical integration for the older slugs.

       Computations are also performed for the vertically integrated counterparts to
Eqns. (2-25 and 2-36) as these are required for evaluation of wet removal and wet fluxes at a
ground level receptor; however, Gaussian normalization dictates that this is accomplished simply
by replacing g with 1.0 in Eqn. (2-25) or J with 1.0 in Eqn. (2-36).

2.1.3   Sampling Function Testing

       The slug model and two versions of the integrated (circular) puff model have been
subjected to several sensitivity tests in order to:

              evaluate the performance of each formulation in reproducing the known steady-
              state plume solution under the appropriate emission and meteorological
              conditions;

              demonstrate and intercompare the models' capabilities under non-steady
              conditions;

              assess the cost-effectiveness of the  different algorithms;

              demonstrate the consistency of the circular puff/elongated slug models and the
              feasibility of the proposed hybrid approach.

       Tables 2-1  (a,b) and 2-2 (a,b) present the plume, puff, and slug results for two sets of
steady-state emission  and meteorological conditions.  Plume centerline values are presented at
receptors from 100 m to 10 km from the source. A constant emission rate of 1 g/s from a 10 m
high source is assumed.  The first set of results assume neutral (D class) stability conditions with
10 m/s winds.  Stable (F class) conditions with 3 m/s winds are applied in the second set  of
runs. Puff model #1  employs the integrated puff sampling function with trajectory mid-point
values of oy and g.  The puff release rate and sampling rate were varied from 100/hr to 500/hr
for the puff model #1 simulations. Puff model #2 uses the same integrated sampling function
as #1, except receptor-specific values of oy and g are used instead of trajectory mid-point values.


L\ca]pufi\jul9S\iect2.wph                            2-16

-------
                                        Table 2-1 (a)
           Comparison of Plume, Puff, and Slug Models for Steady-State Conditions

                (Wind Speed:  10 m/s, Stability Class: D, Stack Height:  10m,
Distance
(m)
100
200
300
400
500
600
700
800
900
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Compaq-286
CPU time (s)
Plume Model
(g/m5)
8273x10^
1204 xlO4
8270x10*
5.711 x Iff5
4.145 x Iff5
3.144 x 10s
2.469x10*
L995 x Iff5
1.648 x Iff5
1387 xl(Ts
4.863xlff*
1616 x Iff6
1.702 x 10*
1219 x 10*
9284 x Iff7
7374 x Iff7
6.040 x lO"7
5.066 x Iff7
4329 x Iff7
1.0
^ .._.•— a^.**) m~mmmm~
100pufls/hr
lOOsamp./hr
1266 xlO4
1266x10"*
1288 x Iff1
3.164 x Iff*
3.693 x Iff5
3.733 x Iff5
3.189 x Iff5
L559xlff5
1.658 x Iff5
1.654 x Iff5
4.871 x Iff*
2.613 x Iff*
1.704 x Iff*
1219 x Iff6
9280 x Iff7
7372 x Iff7
6.029 x Iff7
5.060 x Iff7
4326 x Iff7
249.4
"*»*^r»» ••«^»^« m. A
Puff Model #1
300pufis/hr
300 samp./hr
L749 x Iff4
1295 x Iff4
8341 x Iff3
5.183 x Iff5
3.976 x Iff5
3212 x Iff5
2329 x Iff5
2.002 x Iff5
1.644 x Iff5
1394 x Iff5
4.853 x Iff*
2.614 x Iff*
1.699 x Iff*
1217 x Iff*
9270 x Iff7
7364 x Iff7
6.023 x Iff7
5.055 x Iff7
4324 x Iff7
20543
i "/
500puffs/hr
500 samp./hr
9.618 x Iff5
1306 xlO4
7529 x Iff5
5.682 x Iff5
4 .176 x Iff5
3.145 x Iff5
2.467 x Iff5
1.995 x Iff5
1.648 x Iff5
1393 x Iff5
4.856 x Iff6
2,612 x Iff*
1.698 x Iff*
1217 x 10*
9268 x Iff7
7359 x Iff7
6.022 x Iff7
5.053 x Iff7
4321 x Iff7
5592.4
t\aUpufl\juI95\iect2.wph
2-17

-------
                                        Table 2-1 (b)
           Comparison of Plume, Puff, and Slug Models for Steady-State Conditions

                (Wind Speed: 10 m/s, Stability Class: D, Stack Height: 10m,
S-IAl UTTTTT? IfStTXTTT T7P
Distance
(m)
100
200
300
400
500
600
700
800
900
1000
2000
3000
4000
5000
6000
7000
8000
9000
0000
Compaq-286
CPU time (s)
Plume Model
(g/m3)
8373 xlff5
1204 xlff4
8270x10^
5.711 x Iff5
4.145 x ID"5
3.144 x Iff5
2.469 xlff5
L995X105
L648XHT5
1387 xKT5
4.863 x Iff6
2.616 x 10*
1.702x10*
1219 x 10*
9284 x Iff7
7374 x Iff7
6.040 x Iff7
5.066 x Iff7
4329 x Iff7
1.0
Integrated Puff „. . . . ..
Modd- Slug Model-
fe/".") ^
8273 x Iff5
L204XKT4
8270x10^
5.711 x Iff5
4.145 x Iff3
3.144 x Iff5
2.469 x Iff5
L995 x Iff5
1.648 x 103
1387 x Iff5
4.863 x Iff6
2.616 x Iff*
1.702 x Iff*
1219 x Iff*
9284 x Iff7
7374 x Iff7
6.040 x 10'7
5.066 x Iff7
4329 x Iff7
1.8
8273 x Iff5
1204 x Iff*
8270 x Iff5
5.711 x Iff5
4.145 x Iff5
3.144 x Iff5
2.469 x Iff5
L995X105
1.648 x Iff5
1387 x Iff5
4.863 x Iff*
2.616 x Iff*
1.702 x Iff6
1219 x Iff*
9284 x 10'7
7374 x Iff7
6.040 x 10'7
5.066 x 10'7
4329 x Iff7
12-5.7
               * Same as plume model to four places of accuracy.
i:\calpufl\jul95\secl2.wph
2-18

-------
                                        Table 2-2 (a)
           Comparison of Hume, Puff, and Slug Models for Steady-State Conditions

                 (Wind Speed: 5 m/s, Stability Class:  F, Stack Height: 10m,
Distance
(m)
100
200
300
400
500
600
TOO
800
900
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Compaq-286
CPU time (s)
Phune
Model
(gM3)
6.495 x Iff7
L017 x 10"
2.075 x 10"
2255x10"
1076x10"
L816 x 10"
1367x10"
1357 x 10"
1.184x10"
1.042 x 10"
4.154 x 10s
2397 x Iff5
1.644 x ID"5
1224 xlO"5
9.612 x lO"6
7.830x10*
6396 x Iff6
5.669 x Iff4
4.950 x Iff*
1.1
— o — -o 	 1 	
lOOpuffs/hr
100 samp./hr
1379 x Iff7
L823xlO"
L869X10"
2.171 x 10"
2234x10"
1.733x10"
1.736x10"
1337x10"
1.197x10"
1.062 x 10"
4.135 x Iff3
2,401 x Iff3
1.644 x Iff3
1224 x Iff*
9.609 x 10*
7.832 x Iff*
6.584 x 10*
5.661 x 10*
4.945 x Iff*
309.8
Puff Model #1-
300puffs/hr
300 samp./hr
1379 x Iff7
L159xlO"
2X133x10"
2313x10"
2.027x10"
LSlSxlO"
1375x10"
1351 x 10"
1.185 x 10"
L041 x 10"
4.153 x Iff3
2398 x Iff5
1.641 x Iff3
1223 x Iff5
9.592 x Iff*
7.822x10*
6.581 x Iff*
5.659 x Iff*
4.939 x 10*
2566.7
i -/
500pufls/hr
500 samp./hr
5^14 x Iff3
LOlSxlO"
2.046x10"
2242x10"
2.078x10"
1^13 x 10"
1366x10"
1355 x 10"
1.183 x 10"
1.040 x 10"
4.154 x Iff3
2394 x Iff3
1.641 x Iff5
1222 x Iff5
9394 x Iff6
7.818 x Iff6
6380 x 10*
5.658 x 10*
4.940 x Iff6
70493
t\calpufl\jul95\iect2.wph
2-19

-------
                                        Table 2-2 (b)
           Comparison of Hume, Puff, and Slug Models for Steady-State Conditions

                 (Wind Speed: 5 m/s, Stability Class:  F, Stack Height:  10m,
<-• » ¥ m rtrr? »»/-»T-V¥ n T?O
Distance
(m)
100
200
300
400
500
600
700
800
900
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Compaq-286
CPU time (s)
Plume Model
fe/m3)
6.495 x Iff7
1.017 x Iff4
1075 x 10"
2255x10"
2.076 x Iff4
L816 x Iff4
L567 x Iff4
1357x10"
L184xlO"
1.042 x 10"
4.154 x 10*
2397 x Iff6
1.644 x Iff*
1224x10*
9.612 x 10*
7.830x10*
6.596 x 10*
5.669 x 10*
4.950 x 10*
1.1
Puff Model* Integrated
(g/m3) Slug Model*
(g/m3)
6.495 x Iff7
1.017x10"
2.075 x 10"
2255x10"
2476x10"
1-816 x 10"
L567X104
1357x10"
1.184x10"
1.042 x 10"
4.154 x 10*
2397x10*
1.644x10*
1224x10*
9.613 x Iff8
7.830x10*
6.596x10*
5.669 x 10*
4.950 x 10*
1.5
6.495 x Iff7
L017 x 10"
2:075 x 10"
2255x10"
2X176x10"
L816 x 10"
L567xlO"
1357x10"
L184xlO"
L042 x 10"
4.154 x 10*
2397x10*
1.644x10*
1224x10*
9.613 x Iff*
7.830x10*
6.596 x 10*
5.669 x 10*
4.950 x 10*
13-5.7
               * Same as plume model to four places of accuracy.
i:\caIpufl\jul9S\iectZwph
2-20

-------
The puff release rate and sampling rate in the puff model #2 runs were both 1/hr.
Operationally, the slug model would employ the efficient time-integrated relationship
(Eqn. 2-16) for the slug originating at the source; however, these concentrations will always be
slightly less than the plume concentrations, but do approach them asymptotically as At, - «.
Instead, the slug model was evaluated by considering the slugs as being "old", and both the
numerical integration technique of Eqn. (2-14) and the approximate, factored form  of
Eqn. (2-36) were considered Both of these "old" slug methods gave predictions identical to the
plume model for the four significant digits displayed. (It should be noted that numerical
integration was not necessary in this special case of steady-state conditions, but was performed
anyway to demonstrate the more general technique and allow its evaluation in terms of its
consistency with the  plume solution and its cost effectiveness.)

       The results indicate that a large number of puffs/samples are necessary to adequately
reproduce the plume solution at near-field receptors when the puff model #1 assumptions are
employed.  The  errors are associated with the use of the trajectory iriid-point values of oy and g.
This model is optimized for source-receptor distances on scales from tens to hundreds of
kilometers, and is not cost effective for application dose to the source. Puff model  #2, using
receptor-specific dispersion coefficients and the integrated sampling function, reproduces the
plume solution exactly with a computational cost less than 1% of that required for puff model
#1.  In fact, its CPU requirements are competitive with those needed to solve the steady-state
plume equation. The CPU costs of the slug model are comparable  to the plume model when
the analytic form is used, but is somewhat more costly than puff model #2 when the 40
iteration, numerical solver is selected. Additional test runs of the puff and slug models under a
range of different meteorological conditions produced similar results.

       The slug and puff (#2) models were also used to simulate a case of non-steady
emissions.  An emission rate  of 1 g/s for a duration of one hour was modeled.  Although a one-
hour release was used in this demonstration run, either model is capable of handling arbitrary
variations in emission rates, including those on time scales of less than one hour.  B stability,  1
m/s winds were  the assumed meteorological conditions.  The results are presented in
Figures 2-6 and 2-7 along with the steady-state plume solution. The puff and slug model results
intercompare well  (within a few percent, except at the tails of the distribution with very low
concentration values).  The puff/slug predictions approach the steady-state results when the
center of the pollutant cloud passes the receptor, but  dearly show the causality and  edge effects
of the approaching/passing distribution. The puff model lumps the pollutant mass into n
packets (puffs), each with 1/n of the total emission (n = 100 in this test). The mass actually
release from time t = 0 to t = dt/n is packaged into  the puff released at t =  0. The puff
lumping effect tends  to result in a slightly premature  arrival/departure of the pollutant, which is

t\ealpufl\iuBS\ied2.»ph                            2-21

-------
not seen in the case of steady emissions.  In the non-steady runs, because the correct puff
causality is obtained by increasing the puff release rate, the slug model is more computationally
efficient.
       In order to provide a cost-effective sampling scheme for a range of meteorological,
emission, and source-receptor configurations, a hybrid circular puff/elongated slug scheme is
proposed. The model will store information on the trailing endpoint of the emission doud
(required for the slug model) in addition to the data describing the leading edge (used in both
the puff and slug models), at least initially, when the ratio oy/(u dt,) is small  In the far-field,
the initial elongation of the slug becomes unimportant, and puff sampling is nearly always the
most efficient.  For near-field receptors, however, if the emission rate changes rapidly, or a large
wind direction change results in advection of a slug segment at a large angle to its long axis, the
slug model is more cost effective. Therefore, internal checks will be performed to select the
most appropriate sampling scheme. Although an all-slug or all-puff model could be engineered
to produce appropriate results under all conditions, this hybrid approach, which takes advantage
of the strengths of each algorithm, can produce the same results at lower computational cost.

2.2    Dispersion Coefficients

       A key modeling consideration is the specification of the horizontal and vertical Gaussian
dispersion coefficients, oy and oz. The dispersion coefficients n time steps from the source each
consist of a number of different components:
                         .
where £B.i is defined implicitly by the relation
relation Oy,2(50)  = v^2, and
                                                   0J,                              (2-37)

                                                   = oyj,.j and £0 is defined implicitly by the
                                                                                     (2-38)
where o^t^)
where, oy B,o^n
                axf.l defines
       °yt»°zb
                                implicitly and a^(^0) = v^,2 defines £0 implicitly, and
                     are the total horizontal and vertical dispersion coefficients at the end of n
                            time steps,
                     are the functional forms of the components (m) of oy and oz due to
                            atmospheric turbulence,
                     are tne components (m) of oy and oz due to plume buoyancy,
                     are tne 1™^ values (m) of oy and oz due to the nature of the source
                     (e.g.,   area source) or the rapid initial dilution associated with building
                            downwash of point sources,
i:\calpufl\jul9S\iect2.wph
                                           2-22

-------
 -3.0
                          Non-Steady Emission (1—Hr  Release)
      2.0
          3.0
LOG (Distance)   (m)
4.0
Figure 2-6.    Concentration predictions of puff model  #2 for non-steady emission conditions.
              Emission rate: 1 g/s, Emission duration: 1 hour, Wind speed: 1 m/s, Stability class:
              B, Stack height:  10 m, Mixing height: unlimited.
iA
-------
    -3.0
                             Non-Steady  Emission  (1—Hr Release)
o>
o

o
o
o
o
                                                                Steady-State Plume
    -7.0  -
                                                   3.0

                                        LOG (Distance)   (m)
    Figure 2-7.    Concentration predictions of the slug model for non-steady emission conditions.

                  Emission rate:  1 g/s, Emission duration: 1 hour, Wind speed: 1 m/s, Stability class:

                  B, Stack height: 10 m, Mixing height: unlimited.
    i:\calpalt\jii«S\iect2.wpb
                                               2-24

-------
       Oy,           is the component of the horizontal dispersion coefficient (m) due to
                           vertical wind shear effects,
       £„.!           is the pseudo-value based on the previous time step's total sigma,
       *€            is the incremental transport distance or time variable, and,
       €0            is the initial pseudo-value of this variable and is defined implicitly and
                           separately for y and z.

       Thus, quadratic addition of initial dispersion components is assumed, but subsequent
growth of the puff or slug is accomplished using the pseudo-distance or pseudo-transport time
approach. This pseudo-variable approach is necessary if current puff growth is to be dependent
only on the current size of the puff and not on how it reached that size.

22.1   Atmospheric Turbulence Components

       The basic strategy in the design of the dispersion module is to allow the use of the most
refined data available in the calculation of o^ and OA while providing for backup algorithms not
requiring specialized data for situations in which these data are not available. Three levels of
input data will be allowed:

       (1)     Direct measurements of turbulence, ov and ow (Option 1)

       (2)     Micrometeorological scaling parameters u., w., L, and h, from CALMET or other
              meteorological model yielding internally computed estimates of the crosswind and
              vertical components of turbulence based on similarity theory, (Option 2), or

       (3)     Pasquill-Gifford-Turner (PGT) class and user choice of either ISC or
              AUSPLUME dispersion coefficients (Option 3) or the MESOPUFF n
              implementation of PGT rural dispersion coefficients (Option 4).

       The general forms of a^ and OA (Hanna et aL, 1977) for Options (1) and (2) are:

                                                                                  (2-39)

                                                                                  (2-40)


where, ov     is the standard deviation (m/s) of the horizontal crosswind component of the
                    wind,
       ow     is the standard deviation (m/s) of the vertical component of the wind,

L-\calpuff\jii»5\ieet2.«ph                           2-25

-------
              is the travel time (s) of the plume to the receptor, and,
              are the horizontal and vertical Lagrangian time scales (s).

       Equations (2-39) and (2-40) can be expressed in terms of the horizontal and vertical
components (iy and ij of the turbulence intensity using the following relationships.
                               iy = oju -  a,                                       (2-41)

                               it *oju-  o                                        (2-42)
where, u      is the wind speed (m/s),
       ot     is the standard deviation (m/s) of the horizontal wind angle, and,
       Of     is the standard deviation (m/s) of the vertical wind angle.

       The most desirable approach is to relate the dispersion coefficients directly to the
measured turbulence velocity variances (ov and ow) or intensity components (iy and ij.
However, it is important that the quality of the observational data be considered in the selection
of the method for computing the dispersion coefficients.  For example, inaccurate observations
of ip which is difficult to measure, may lead to less accurate modeling results that predictions
based on more routine data. It is recommended that the default selection be Option 2, which
uses similarity theory and micrometeorological variables derived from routinely available
meteorological observations and surface characteristics.  Many laboratory experiments, field
studies, and numerical simulations (e.g., Deardorff and Willis, 1975; Caughey, 1981; Lamb, 1981)
have shown the importance and utility of convective scaling in the convective boundary layer.
Convective scaling has been successfully applied to data collected at a wide  variety of sites,
including oceans, rural land surfaces (e.g., Hicks, 1985) and urban areas (Ching et al., 1983).
Similarly,  in the stable boundary layer, local scaling has been shown to apply (e.g., Hunt, 1982;
Nieuwstadt, 1984). The micrometeorological model, (see Section 4) explicitly relates the
aerodynamic and thermal characteristics of the surface to the sensible heat  flux and momentum
transfer rates that are used in the computation of the dispersion coefficients.

       Weil (1985) and Briggs (1985) provide reviews on the use of similarity theory in diffusion
models. In the convective boundary layer, Weil describes the turbulence characteristics in three
layers:

       (1)    Surface layer - z z 0.1 h;            ov ~ constant with height,
                                                 ow increases with height
fc\calpu(r\jul95\ied2.wph                            2-26

-------
        (2)     Mixed layer - O.lh < z < 0.8h;       ov - constant with height,
                                                  ow ~ constant with height

        (3)     Entrainment layer - z > 0.8h;        ov decreases with height,
                                                  ov decreases with height

        In the surface layer, Panofsky et aL (1977) propose the following relations.

                          a, « u. [4 + 0.6(-A/tfT                                  (2-43)

                                                                                      (2-44)
where, u.      is the surface friction velocity (m/s), and
       L      is the Monin-Obukhov length (m).

       Hicks (1985) suggests the following for the mixed layer (0.1 to 0.8 h).

                           o, = (3.6 u\ + 035  w^f2                                   (2-45)


                           ow = (1.2 ul + 0.35  vtf*                                   (2-46)

       In the neutral boundary layer, Arya (1984) reports monotonically decreasing values of ov
and ow throughout the mixed layer.  Using Blackadar and Tennekes (1968) relationship for the
neutral boundary layer height, Arya's results can  be expressed as:

                            ov = 1.8 exp (-0.9 z/h)                                    (2-47)

                            ow = 1.3 exp (-0.9 zlh)                                    (2-48)

       In the stable boundary layer, Nieuwstadt (1984) finds that ov and ow bear constant ratios
with the local friction velocity.

                                 «v/«.«  = C,                                         (2-49)

                                 <>„/«.«  - Cw                                         (2-50)

where, u., is the local friction velocity (m/s), and,
       Q and Cw are constants.
fc\calpufl\juB5\iect2.wph                             2-27

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       Hanna et aL (1986) suggest that Q - 1.6.  C. has a value - U (Nieuwstadt, 1984). The
local friction velocity, u.r can be expressed (Nieuwstadt, 1984) as:
                             «., - «. (1  - tUP*                                     <2'51)

       The modeling requires a formulation that yields the proper values and vertical variations
for ov and ow in the convective, neutral, and stable limits, and one that provides a mechanism
for interpolating the results for intermediate conditions without physically unrealistic
discontinuities.  The following equations for the neutral-convective boundary layer are based on
the data discussed above and satisfy these  conditions.  The formulation for the entrainment
layer is based on data reported by Caughey (1981).

Surface Laver:        z s 0.1 h              (L * 0)

                           oy = [4 ul al + 0.35 wl\*                                  (2-52)


                      0W = [1.6 ul al  «• 2.9 «! (-zl If*}*                              (2-53)

                             an  -  exp[-0.9(z/A)]                                     (2-54)


Mixed-Layer:        z = 0.1-0.8 h          (L z 0)

                           ov = [4 u\ a\ * 0.35 w*]"2                                  (2-55)


                         cw  = [1.15 ul al * 0.35  wl]*                                 (2-56)
Entrainment Layer:  z > 0.8 h            (L s 0)

                          ov = [4 ul al + 0.35 w*]"2                                  (2-57)

       for z = 0.8 to 1.0 h

                       *w = [1.15 ul al * arf OJ5 v^                               (2-58)
                          ael = [1/2 + (A - z)/(o.4A)j                                  (2-59)

       for z = 1.0 to 1.2 h


fc\c«]pufl\jul95\«ect2.wph                             2-28

-------
                            [1.15 ul a\ + aa 035 w.f2                               (2-60)
                         aa - [1/3  + (llh - z)/(L2A)]                                 (2-61)

       In the neutral-stable boundary layer, the following equations can be used to interpolate
vertical profiles of ov and ow as a function of stability. As with the neutral-convective equations,
they provide the proper values in the appropriate stability limits.
              o, - «.[(1.6 C. (z/I)  + 1.8 *„)/(!  + i/I)]   (L > 0)                      (2-62)

               o   - 13 11. [(C, &L) «• a.)/(l *  zIL)]    (L > 0)                        (2-63)
                w
                          C. = (1  - z/A)*4    (L > 0)                                  (2-64)

       It is assumed that the similarity-based values of a^ ow from which oy oz are derived, are
representative of one-hour average values.  In order to provide for non-zero plume growth rates
above the mixing height and to prevent numerical problems associated with near-zero plume
dimensions, minimum ov and ow values are applied Hanna et aL (1986) suggest an appropriate
minimum one-hour average ov value is - 0.5 m/s. This is significantly higher than ov expected
based on PGT E and F stability curves. Appropriate default minimum values for ov and ow can
be input by the user.

       Equation (2-52) to (2-61) have been tested with the original data providing the basis for
the Panofsky et al. (1977) and Hicks (1985) formulations.  The results (summarized in
Table 2-3) indicate that the modified equations compare well with the original equations and the
observational data.  The modified equations have the advantage of allowing a smooth and
continuous transition to the neutral stability results of Arya (1984).

       Irwin  (1983) has evaluated several schemes for determining the fy and 4 functions. It
was concluded that a parameterization suggested by Draxler (1976) performed best overall.

                          /, = [!+ 0.9 (f/lOOO)"2]'1                                   (2-65)


                      /, - [l + 0.9 (r/SOO)172]"1   L < 0                               (2-66)


                     ft =  [1 + 0.945 (f/100)-106]'1    L > 0                              (2-67)


i:\calpafl\jul95\iect2.wph                            2-29

-------
                                             Table 2-3
                        Comparison of Panofsky et aL (1977)/Hidcs (1985)
                          Oy, ow Formulations with Eqns. (2-52) to (2-61)
Panofsky et aL data
Observed ovvs.
Panofsky
Observed OTVS.
Eqns. (2-52) to (2-61)
Panofsky ovvs.
Eqns. (2-52) to (2-61)
Average
Corr. Coet
Average Bias
Average Abs. Error
RMSE
(L14, L20)
£1
.07
.10
.13
(L14,121)
M
.07
.09
.12
(L20.L21)
391
.00
J02
JB2
Hicks 1985 data
Observed o, vs.
Hicks
Observed or vs.
Eqns. (2-52) to (2-61)
Hicks OY vs.
Eqns. (2-52) to (2-61)
Average
Corr. Coef.
Average Bias
Average Abs. Error
RMSE
(L17, 1.12)
.79
-.05
 20
 27
(1.17, 1.06)
.77
-.11
 23
 30
(1.12,1.06)
.998
 .06
 .06
 .08
Hicks 1985 data
Observed ow vs.
Hicks
Observed ov vs.
Eqns. (2-52) to (2-61)
Hicks ow vs.
Eqns. (2-52) to (2-61)
Average
Coir. Coef.
Average Bias
Average Abs. Error
RMSE
(.98, 1.01)
 .91
 .03
 .12
 .15
(.98, .98)
 .91
 .00
 .11
 .14
(1.01, .98)
 .998
-.03
 .03
 .04
i:\ca]pufl\jul95\«ect2.wph
                         2-30

-------
       At longer transport distances, an option is provided to switch to the Heffter (1965)
equations (Le., a^ - t, OA - tl/2). The transition from distance-dependent to time-dependent
(i.e., Heffter) dispersion coefficients occurs in CALPUFF when the lateral dimensions of the
plume reach a critical size, defined by the variable SYTDEP in Input Group 12 of the control
file. The default value of SYTDEP is 550 m.  Assuming PG dispersion rates under neutral
conditions, a plume's oy will reach 550 m after approximately 10 km of travel distance.

       The user may also wish to have puff growth determined on the basis of gridded input
fields of PGT class. The approach is particularly useful if one is trying to compare the modeling
results with steady-state regulatory model predictions or attempting to achieve compatibility with
regulatory requirements.  The user may select either AUSPLUME (Lorimer, 1986) or ISC2
model (U.S. EPA, 1992) dispersion methodology (Option 3) or the MESOPUFF H (Scire et al.,
1984b) implementation of the PGT dispersion curves (Option 4).

       Option 3 also requires the specification of gridded land use type, which in turn
determines whether the ISC "rural" or "urban" dispersion curves are  used. The "rural" dispersion
equations and parameters are presented in Tables 2-4 and 2-5 for oy and at respectively and are
based on parameterizations of the PGT curves. The "urban" dispersion equations and
parameter values are based on Briggs' (as reported in Gifford,  1976) parameterizations of the
St. Louis dispersion data  analyzed by McElroy and Poole (1968) and are presented in Tables 2-6
and 2-7 for oy and oz respectively.

       If the MESOPUFF H form  of the PGT stability-dependent dispersion curves is selected
(Option 4), the puff growth functions are of the form:

                                 o=axb>                                        (2-68)
                                 a. =a_xb>                                         (2-69)
                                  I    Z
where a^ by, a^ bz are the stability dependent coefficients presented in Table 2-8.

       The regulatory modeling guidance from the US EPA indicates that the PG dispersion
curves, as defined above, are suitable for predicting one-hour average concentrations.  The EPA
of Victoria (Australia) bases the PG dispersion curves on a 3-minute averaging time and a
surface roughness length (z0) of 0.03 m. CALPUFF has the option to scale the PG dispersion
coefficients for different averaging times or surface roughness lengths.  The averaging time
adjustment applies only to oy and is of the form:
i:\calpufl\jiil9S\tedZwph                           2-31

-------
                                           Table 2-4
                        Parameters Used to Calculate Pasquill-Gifford oy

-------
                                             Table 2-5
                         Parameters Used to Calculate Pasquill-Gifford oz*

Pasqnffl
Stability Class
A**








B**


C**
D





E








F










x(km)
< .10
0.10 - 0.15
0.16 - 020
021 - 025
026-030
031 - 0.40
0.41 - 0.50
051 - 3.11
> 3.11
< 20
021 - 0.40
>0.40
All
< 30
031 -LOO
1.01 - 3.00
3.01 - 10100
10.01 - 30.00
> 30.00
< .10
0.10 - 030
031 - 1.00
1.01 - 2.00
2.01 - 4.00
4.01 - 10.00
10.01 - 20.00
20.01 - 40.00
> 40.00
< 20
021 - 0.70
0.70 - 1.00
1.01 - 2.00
2.01 - 3.00
3.01 - 7.00
7.01 - 15.00
15.01 - 30.00
30.01 - 60.00
> 60.00
oy (meters)
c
121800
15&080
170220
179520
217.410
258.890
346.750
453.850
•»
90.673
98.483
.109300
61.141
34.459
32.093
32.093
33504
36.650
44.053
24.260
23331
21.628
21.628
22534
24.703
26.970
35.420
47.618
15209
14.457
13.953
13.953
14.823
16.187
17.836
22,651
27.074
34219
-ax-
el
0.94470
L05420
1,09320
1.12620
126440
1.40940
1.72830
2.11660
**
0.93198
0.98332
1.09710
0.91465
0.86974
0.81066
0.64403
0.60486
056589
051179
0.83660
0.81956
0.75660
0.63077
057154
050527
0.46713
037615
0.29592
0.81558
0.78407
0.68465
0.63227
054503
0.46490
0.41507
032681
027436
021716
            * Source: U.S. EPA (1992)
            ** If the calculated value of ot exceeds 5000 m, o, is set equal to 5000 m
fc\calpufl\jnl95\ied2.wph
2-33

-------
                                             Table 2-6
                      Briggs Formulas Used to Calculate McElroy-Pooler
             PasquOl Stability Category
                     qy (meters)*
                        A

                        B

                        C

                        D

                        E

                        F
 * Source:  U.S. EPA (1992)
 ** where x is in meters
               032 x (LO + 0.0004 x)'1/2

               032 x (LO + 0.0004 x)-1'2

               022 x (LO + 0.0004 x)'1/2

               0.16 x (LO + 0.0004 x)-l/2

               0.11 x (LO + 0.0004 x)'1/2

               0.11 x (LO + 0.0004 x)'1/2
t\calpuff\jul95\»eca.wph
2-34

-------
                                              Table 2-7
                       Briggs Formulas Used to Calculate McElroy-Pooler
                      PasquDl Stability Category	c, (meters)**

                                 A                       0.24 x (LO + OJOOI x)*1/2

                                 B                       024 x (1.0 + 0.001 x)+1/2

                                 C                       020 x

                                 D                       0.14 x (1.0 + 0.0003 x)'I/2

                                 E                       OJOS x (LO + 0.0015 x)'1/2

                                 F                       0.08 x (LO + 0.0015 x)'1/2
             * Source: U^. EPA (1992)
             ** where x is in meters
t\calpuffl\jul95\Kct2.wph                               2-35

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                                          Table 2-8
                     MESOPUFF n Growth Rate Coefficients a,, b,, a^ bz*
Stability Class
A
B
C
D
E
F
^
036
025
0.19
0.13
0.096
0.063
b.
0.9
0.9
0.9
0.9
0.9
0.9
a,
0.00023
0.058
0.11
057
0.85
0.77
b,
2.10
1.09
0.91
058
0.47
0.42
                     •Source: Scirc ct al. (1984b)
fc\calpiifi\jul9S\«ed2.wph                             2-36

-------
where T^ is the averaging time (minutes) assumed for the standard PG curves (e.g., 60
              minutes by U.S. EPA, 3 minutes in Australia).
       TM is the averaging time (minutes) of the concentrations predicted by CALPUFF
              (t^ * 60 minutes).
       °y (*bne)> °y ("*•«) are the values of oy assumed for averaging times of t^ and T^
              minutes, respectively.

       The values of T^ is defined as 60 minutes in CALPUFF. The TM variable is specified
by the user in Input Group 1 of the control file (see the variable AVET). The value of T^
should not exceed 60 minutes, because multi-hour average concentrations are computed
explicitly by time-averaging hourly values in CALPUFF.

       The roughness length adjustment to the PG oz  curves is based on Smith (1972), as
implemented in the AUSPLUME model (Lorimer, 1986). This adjustment is most appropriate
for near-surface releases and is not recommended for tall stack emissions (e.g., sources above
100 m). The adjusted value of oz is
where

                               i' = a - (1.585 (1000)»z0OJ301}                       (2-74a)
                               a
                                p = 0.0777  * 0.0215 In(z0)                         (2-74c)
and    z0 is the surface roughness length (m),
       x is the downwind distance (m),
       0; is the roughness adjusted value of or and
       a, b are the PG dispersion curve parameters (see Table 2-5).
fc\calpufl\ju»S\iect2.wph                           2-37

-------
For 0y, the roughness length adjustments is:
                                                                                  (2-75)
where the reference roughness length (Zo^) is 0.03 meters, and the prime indicates the
roughness length adjusted value of or

       It is recommended that the surface correction be limited to surface roughness lengths no
greater than one meter. The time average and surface roughness adjustments can be applied to
either the ISO or MESOPUFF n PG rural dispersion curves. Adjustments are not made to
the McElroy-Pooler urban curves or the similarity-based dispersion curves, which have the
effects of roughness implicitly included.

2.2.2   Plume Buoyancy Components

       The effect of plume buoyancy on the dispersion coefficients are parameterized in terms
of the plume rise (Pasquill, 1976; Irwin, 1979).

                               00  = AH/ 3.5                                       (2-76)

                               a*  = AH/ 3.5                                       (2-77)

where AH is the plume rise (m).

2.2.3   Initial Plume Size

       The initial size of puffs emitted by volume sources is determined by user-specified initial
dispersion coefficients,  oyo and OM.  The volume source option allows the emissions from a
number of smaller sources in a given area (e.g., a grid cell) to be combined into a single source.
The volume source emissions are immediately spread over a volume described by oyo and am.
The subsequent growth of the volume source puff is computed in the same manner as the point
source puffs, using a virtual source to match the initial values  of oy and oz.

       Point source emissions subject to building downwash effects experience a rapid initial
growth due to the high building-induced turbulence intensity in the lee of the building.  A
building downwash model (described in Section 2.3) is used to internally compute initial plume
dimensions for downwashed  point source emissions as a function of building dimensions, stack
height, momentum flux, and  meteorological conditions.


i:\c.lpufl\jul95\ieca.wph                            2-38

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22A   Vertical Wind Shear

       Vertical wind shear can sometimes be an important factor affecting plume transport and
dispersion. The change of wind speed and wind direction with height causes a differential
advection of pollutant material emitted at different heights.  Even for material emitted at a
given height, when plumes become large enough, across-plume shear may transport the upper
portion of a plume in a different direction than the lower portion.  When vertical mixing brings
the entire plume to the ground, the effective horizontal dispersion of the plume may be
significantly enhanced as a result of the differential transport.  CALPUFF explicitly models wind
shear effects on different puffs by allowing each puff to be independently adverted by its local
wind speed and direction, and independently mixed vertically to the ground.  For example,  puffs
emitted from two sources co-located in the horizontal, but with different release heights will be
transported in CALPUFF in different directions and at different speeds if the wind fields
indicate such a shear exists.  Shear across a single puff is handled in CALPUFF by allowing the
puff to split into two pieces when across-puff shear becomes important  Each portion of the
puff is then independently transported and dispersed. A single puff may be split multiple times
if it remains in the modeling domain long enough. Because across-puff wind shear effects are
not likely to be important in all applications, and because puff splitting increases computational
requirements, the puff splitting feature  is an option that can be turned off. It is controlled  by
the MSPLTT variable in Input Group 2 of the control file.

2.3    Building Downwash

       The dispersion and buoyant rise of plumes released from short stacks can be significantly
modified by the presence of buildings or other obstacles to the flow.  Hosker (1984) provides a
description of the flow patterns in three regions near buildings. Figure 2-8 shows (1) a
displacement zone upwind of the buildings, where the flow is influenced by the high pressure
along the upwind building face, (2) a cavity zone characterized by recirculating flow, high
turbulence intensity, and low mean wind speed, and (3) a turbulent wake region where the  flow
characteristics and turbulence intensity  gradually approach the ambient values.

       The parameterization of building downwash in CALPUFF is appropriate for use in  the
turbulent wake region and is based on the procedures used in the ISC2 model ISC2 contains
two building downwash algorithms:

              Huber-Snyder model (Huber and Snyder, 1976; Huber, 1977). In ISC2, this
              model is applied when the source height is greater than the building height (Hj,)
              plus one-half of the lesser of the building height or projected width (LJ. It
              applies either a full building wake effect or none at all, depending on the
              effective height of the emitted plume.

fc\caJpufl\jul95\iect2.wph                           2-39

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     INCIDENT WIND
     PROFILE
-SEPARATED ZONES
 ON ROOF AND SIDES
                                   •REATTACHMENT LINES
                                   ON ROOF AND SIDES
                                                        LATERAL EDGE AND
                                                        ELEVATED VORTEX PAIR
                                                               MEAN CAVITY
                                                               REATTACHMENT LINE
       HORSESHOE VORTEX
       SYSTEM AND MEAN
       SEPARATION LINES
                                               TURBULENT
                                               WAKE
Figure 2-8.    Flow near a sharp-edged building in a deep boundary layer. [From Hosker, (1984)]

                                         2-40
u\olpufl\jul9S\
-------
              Schulman-Scire model (Scire and Schulman, 1980; Schulman and Hanna, 1986).
              This model applies a linear decay factor to the building-induced enhancement of
              the dispersion coefficients and accounts for the effect of downwash on plume rise.
              It is used in ISC2 for stacks lower in height than H^ + 0 .5 L,,.

       The main difference in the treatment of downwash between ISC2 and CALPUFF is that
the height threshold determining which model is used is an input variable.  This option allows
the user to apply one of the models for all stacks, which has the desirable effect of eliminating
the discontinuity of the ISC2 approach at stack heights of EL, + 0.5 L,,.  Thus, in CALPUFF, the
Huber-Snyder technique is used for stacks greater than Hj, + TM L^ where TM has a default
value of 0.5. A negative value of TM indicates the Huber-Snyder method is used for all stacks,
and a value of 1.5 results in the Schulman-Scire method being always used.  If XR, is set equal to
0.5 (its default value), the CALPUFF treatment will be equivalent to than in ISC2.
       Both downwash methods use wind direction-specific building dimensions (i.e., EL,,
L,,).  CALPUFF, like the short-term version of ISC2, uses 36 wind direction-specific values of
the building dimensions, corresponding to wind vectors from 10° to 360° in increments of 10°.
The EPA Building Profile Input Program (BPIP) (EPA, 1993) can be used to develop the wind
direction-specific building dimensions for CALPUFF and determine Good Engineering Practice
(GEP) stack height associated with one or more buildings.

2.3.1   Huber-Snyder Downwash Procedure
       If the stack height exceeds IL, + T^L^, the Huber-Snyder algorithm is applied. The first
step is to compute the effective plume height, He, due to momentum rise at a downwind
distance  of two building heights.  If He exceeds FL, + 1.5 Lj, (where H* and Lj, are the wind
direction specific values), building downwash effects are assumed to be negligible. Otherwise,
building-induced enhancement of the plume dispersion coefficients is evaluated. For stack
heights, H,, less than 1.2Hb, both oy and oz are enhanced.  Only oz is enhanced for stack heights
above 1.2 Hb (but below Hb +  1.5 L,,).

       A building is defined as a squat building if the projected building width, H*, exceeds the
building height (i.e., tL, * FL, ). A tall building is defined as one for which H, <  H,,.  Because
both the  controlling building height and projected width can vary with wind direction, the
classification of a building as squat or tall can also vary by direction. For a squat building, the
enhanced oz is:

                       o't = 0.7 Hb  + 0.067 (x  - 3Hb)                               (2-78)

where x is the downwind distance (in meters).

i:\calpufl\jul95\iecl2.wph                           2-41

-------
For a tall building,

              o't = 0.7 Hw + 0.067 (x - 3HW)   3HW < x < 10HW                      (2-79)
       If the ratio HJH* is less than or equal to 12, the horizontal dispersion coefficient, ar is
enhanced. For a squat building with a projected width to height ratio (H^/H,,) less than 5, the
equation for oy is:
              o'y = 035 Hw + 0.067 (x - 3Hk)    3J5T, < x < 10H>                       (2-80)

For buildings with (H*/!^) greater than 5, two options are provided for or

              o'y = 035 Ht + 0.067 (x - 3H>)    3JJ, < x < 10#t                       (2-81)

or,

              o'y = i:75 Hj + 0.067 (x - 3ffA)    3fft < x < lOHb                       (2-82)

       Eqn. (2-81) results in higher centerline concentrations than Eqn. (2-82), and is
considered as an upper bound estimate of the impacts of the source. The ISC2 manual suggests
that Eqn. (2-82) is most appropriate if the source is located within 25 H,, of the end of the
building. Eqn. (2-81) is a better estimate if the source is located near the center of the building.
However, in practice, the more conservative Eqn. (2-81) is usually used for regulatory
applications regardless of the position of the stack.

       For a tall building, the equation for  oy is:

              o'y = 0.35 Hw + 0.067 (x - 3HW)    3Hw
-------
This dilution reduces the rate of rise of the plume and results in lower plume heights. As
discussed in Section 2.4.4, the initially high dilution rate is modeled by applying an initial
"dilution radius" to the plume.  The inclusion of downwash effects in the plume rise equations is
a key part of the Schulman-Scire downwash method.

       The second component of the model is the linear decay function which is applied to the
enhancement of or The vertical dispersion coefficient is determined as:

                                 o'l-Aa't                        .                 (2-84)

where o'z is determined from Eqns. (2-78) and (2-79), and,
                                                      H
                                                       t
                                L) + 1      Hi
-------
       u      is the stack height wind speed (m/s),
       x      is the downwind distance (m),
       Pi     is the neutral entrainment parameter (~ 0.6),
       Pj     is the jet entrainment coefficient (Pj « 1/3 + u./w), and,
       w      is the stack gas exit speed (m/s).

       The distance to final plume rise, x^ is:
                           !3.5jc*                   F > 0
                           ^                    F                                 (2-87)
                           4D (w «• 3a,)2/(«,w)      F « 0
                              14                                                     (2.88>
                             34

where D is the stack diameter (m).

       During stable conditions, the final plume rise, z* is determined by:

                                                                                    (2-*9)
where, p      is the stable entrainment parameter (~  0.6),
       S      is a stability parameter [(g/TJ(d8/dz),
       g      is the acceleration due to gravity (m/s2),
       Ta     is the ambient temperature (deg. K), and,
       d6/dz  is the potential temperature lapse rate (deg. K/m).

       Transitional plume rise during stable conditions is computed by Eqn. (2-86) up to the
point at which ZD  = zrf. For low wind speed and calm conditions, the following equation (Briggs,
1975) is used to compute the plume centerline rise:

                               z  = 4 FV4/53/8                                       (2-90)
2.4.2   Stack-tip Downwash

       If the ratio of the stack gas exit speed to the ambient wind speed is less than 1.5, the
plume may be drawn into the lee of the stack. Briggs (1973) suggests modifying the stack height
to adjust for this stack-tip effect:
t\olpufi\jul9S\Kd2.wph                            2-44

-------
                  »'-!*•*
                   •   i*.
«, -  1.5)      w/u, < 1.5
             W/K, i 1.5
where hj is the adjusted stack top height
2.43  Partial Plume Penetration

       Plumes from tall stacks may frequently interact with the capping inversion at the top of
the mixed layer. A fraction of the plume mass may penetrate the inversion, and therefore be
unavailable for immediate mixing to the ground.  Manins (1979) developed a procedure for
estimating partial plume penetration into an elevated inversion using water tank experimental
data. This scheme is adopted for use in CALPUFF.          -• - «—

^      A penetration parameter, P, is defined as:

                                      P	—                              (2-92a)
                                           u bt A/I;

where u   is the stack height wind speed,
       Fb  is the initial buoyancy of the stack emissions,
           is the height of the inversion (h) above the stack top (h,), (i.e., Ahj - h-hj
          is the strength of the inversion (b; = gATj/TJ,
         fj is the temperature jump across the inversion,
       Ta  is the ambient air temperature, and
       g   is the acceleration due to gravity.

       The fraction, f, of the plume remaining below the inversion is:

                               1                  (P < 0.08)

                              — - P  + 0.08     (0.08 

0.3) Thus, no penetration is predicted for P < 0.08, and nearly full penetration is suggested for P = 03 and above. Manins (1979) compared this scheme with the partial penetration fc\c»lpufl\juB5\ied2.wph 2-45


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       Thus, no penetration is predicted for P < 0.08, and nearly full penetration is suggested
for P = 03 and above. Manins (1979) compared this scheme with the partial penetration
methods of Briggs (1969) and Briggs (1975) using water tank data.  He found that the Briggs
(1969) model underestimates the amount of penetration into the inversion layer, while the
Briggs (1975) method tends to overestimate it Field data collected at the Gladstone power
station in Queensland, Australia, also supported these conclusions (Manins, 1984).

       Knowing f from Eqn. (2-92b), the effective final height of the plume trapped below the
inversion can be estimated as the minimum of (Ah, AhJ where Ah is evaluated at x « x, and Aht
is defined below.

                                                   A                             (2-93a)
Note that Ah, Aht, and Ah, are all measured above the stack top height.

       The effective height of the portion of the plume above the inversion base is (Hanna and
Chang, 1991):
                                                                                 (2-93b)
where Eqns. (2-93a) and (2-93b) apply only for plumes which partially penetrate the inversion.

2.4.4   Building Downwash

       Wind tunnel observations of plume dispersion and plume rise indicate that plume rise
can be significantly reduced by building downwash. Huber and Snyder (1982) found that. during
downwash conditions, plume rise was reduced by one-third below the value obtained in the
absence of the building. In an analysis of plume rise observations, Rittmann (1982) found lower
plume rise than predicted by the 2/3 law (a form of Eqn. 2-86) for smaller sources which are
most likely to be affected by downwash. Several studies (e.g., Bowers and Anderson, 1981; Scire
and Schulman,  1981; Thuillier, 1982) with the original version of the ISC building downwash
algorithm, which did not account for the effects of building downwash on plume rise, showed
that neglecting  building downwash effects on  plume rise can significantly underestimated peak
concentrations  during downwash conditions.

       The increased mechanical turbulence  in the building wake which leads to enhanced
plume dispersion, causes a rapid dilution of the plume. This dilution reduces the rate of rise of
the plume and leads to lower plume heights.  One method of treating the initially high dilution
rate is to assume an initial "dilution radius" for the plume (Scire and Schulman,  1980). This

i:\calpufl\jul95\KXlZwph                            2-46

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rate is to assume an- initial "dilution radius" for the plume (Sore and Schulman, 1980). This
technique is incorporated in the Buoyant Line and Point Source (BLP) model (Schulman and
Scire, 1980) and a modified version of the ISC model It has been shown (Schulman and  -
Hanna, 1986), to produce more realistic estimates of ground-level concentrations during building
downwash conditions.

       The plume rise of a downwashed plume with o^ s om during neutral-unstable conditions
is given by:

         *} + (3V,/ Pi * 3g + SFx'/fcPA3)]                (2-94)

where RD is the dilution radius [R, « (2)1/2oIJ and a^ OM are the horizontal and vertical
dispersion coefficients, respectively, at a downwind distance of 3H,, (see Section 23). The factor
of (2)1/2 in the R,, equation converts the Gaussian dispersion coefficient into an effective top-hat
distribution for the plume rise calculations.

       Final stable plume rise is:

                                                                                  (2-95)
Transitional plume rise during stable conditions is computed with Eqn. (2-94) until the final
plume height predicted by Eqn. (2-95) is obtained.

       When horizontal mixing of the plume in the building wake causes o^ > a^, it is
necessary to account for the elongated shape of the plume.  The plume can be represented as a
finite line source. The plume rise for a line source of length Le during neutral-unstable
conditions is:
                                                                                  (2-96)
                             /(PX) * 3F,*/(2PX3)]

and, for final stable plume rise:

                             3/^,/p, - 6*/./*p   * 3/£/P?k, =
                                                                                  (2-97)
       The effective line length, 1^, is (2rc)1/2 (o^ - o^,) if o^ > om. Otherwise, 1^ = 0, and
Eqns. (2-96) and (2-97) reduce to Eqns. (2-94) and (2-95).
fc\calpufl\jul95\iecl2.wph                           2-47

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       As described in Section 23, the enhanced dispersion coefficients, aK and o^ vary with
stack height, momentum rise, and building dimensions. The variation of RO with for several
stack heights is illustrated in Figure 2-9.  As an and o^ approach zero (Le., building downwash
effects become negligible), Eqns (2-94) to (2-97) approach the unmodified Briggs equations.
The effect of RO and L, is always to lower the plume height, thereby tending to increase the
predicted maximum ground-level concentration.

2,4 5   Vertical Wind Shear

       The variation of wind speed up to stack height is usuaDy accounted for in plume rise
algorithms by the use of the stack height wind speed in the plume rise equations. Most
formulations assume that the wind speed is constant above the stack top. This assumption is
reasonable for mid-sized and tall stacks.  However, the variation of wind speed above the stack
top can have a significant effect on reducing the plume rise of buoyant releases from short
stacks imbedded in the surface (shear) layer of the atmosphere (Scire and Schulman, 1980).
Assuming the vertical wind speed profile above the stack can be approximated as
u(z) -  uf(z/h,)p, where u, is the wind speed at the stack top, h,, and u(z) is  the wind speed at
height  z, the plume rise from a short stack can be represented during neutral and unstable
conditions as:
                                                                                   (2-98)
                                 e  - 3  + 3p                                        (2-99)
where p is the wind speed power law exponent.

       During stable conditions, the final plume height is:
                                                                                  (2-100)
       The wind shear exponent can be estimated from the atmospheric stability class or
computed from the vertical wind data generated from the wind field model. It should be noted
that Eqns. (2-98) and (2-100) both reduce to the Briggs buoyant plume rise equations when
there is no wind shear above the stack top (i.e., p = 0).
fc\alpufl\jiil93\iect2.wph                            2-48

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                     RO»HB
       suck = HB
                                                  T
                                                 R0 =
Stack = 2HB
Stack = 3HB
Figure 2-9.    Illustration of the initial dilution radius, R,,, as a function of stack height for a squat

              building (from Schulman and Scire (1981)). Momentum plume rise is neglected in

              the figure.
                                          2-49

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       The assumption of u(z) - u, (z/h,y is most valid for short stacks where the shear effect
is expected to be the greatest However, it breaks down for taller stacks. Therefore, Eqns.
(2-98) and (2-100) are used to provide an upper limit of the plume height for short stacks, Le.,
that the actual plume height be taken as the minimum of the predictions of the shear,
downwash, and no-shear predictions, as appropriate.
2.4.6   Area Source Plume Rise

       The treatment of plume rise from large buoyant area sources requires special
considerations that include effects of vertical wind shear, large initial plume size, and potentially
large density differences between the plume and ambient air.

       The area source plume rise model in CALPUFF is formulated to calculate the rise of
buoyant plumes resulting from forest fires, the burning of leaking oil, and other type of buoyant
area sources. The model is designed to be general, with applicability to the following conditions:

       (a)    all types of ambient temperature stratifications;
       (b)    all types of wind stratifications;
       (c)    any size of finite emission source;
       (d)    includes the effects of plume radiative heat loss; and
       (e)    is free of the limitations of the Boussinesq approximation.

       All these factors may be important in large forest fire plumes. Due to the complex
mountainous terrain in many forested areas and the strong influence it has on meteorological
conditions, complex temperature and wind patterns may exist. The ambient temperature
stratification is usually more complicated than linear stratification which is  normally assumed in
most plume rise models. Wind shear is important because the forest fire plume starts at ground
where there is a zone of large velocity gradients in the vertical. Therefore, it is necessary to
allow for arbitrary profiles of winds and temperatures to be  accounted for in the plume rise,
including potential stability and wind reversals in the vertical The initial fire size may be large,
of the order of ten or more kilometers in radius. Since the  plume temperature near the burning
source is much higher than the ambient air temperature, up to  1600 °K, radiative heat loss will
reduce the heat flux which is carried by the plume along its  trajectory. This reduction of heat
flux also reduces the buoyancy flux and thus  eventually reduces the final plume rise. Also, since
the initial temperature of the plume is high,  and the initial density difference between the plume
and ambient air is large, the application of Boussinesq approximation becomes questionable.
t\calpufl\jul95\«ect2.wph                            2-50

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         The source parameters of a forest fire are usually not constant The life cycle of a
 forest fire includes an initial developing stage with large increases in heat generation and
 pollutant emission rates, followed by a stage of decreasing values. The magnitude of the
 variation in heat generation and emission rates may be two orders of magnitude over the course
 of burn.  The resulting time dependency to the plume rise can be calculated assuming that the
 plume motion is quasi-steady so that the input of source condition is time-dependent but the
 time-derivatives in the governing equations are neglected  This assumption is reasonable
-because the time scale for plume rise is much shorter than that of the fire life-span.

        The derivation of the governing equations are similar to the one given by Wefl (1988)
 except that the Boussinesq approximation has not been applied.  The Boussinesq approximation
 simplifies the plume rise equations by assuming that the plume density is dose enough to the
 ambient density that density variations, other than in the buoyancy term, can be neglected.  The
 plume cross section is assumed to be circular with radius r.  (Although the plume cross section,
 as it rises, appears to be dominated by a pair of counter-rotating line vortices, its effect on the
 plume rise trajectory can still be well quantified by integral models (Zhang, 1993)).  All the
 physical quantities are assumed to be uniform within this cross section.  The mass conservation
 law can be expressed in terms of entrainment hypothesis, which accounts for the entrainment of
 the ambient air flowing both parallel and cross the plume centerline (Hoult and Weil, 1972),

                                              | + 2rp"pjtf.«n4>|                 (2-101)

*where a = 0.11 and p = 0.6 are the entrainment parameters corresponding to the differences of
 velocity components between the wind and the plume in directions parallel and normal to the
 plume centerline, respectively (Weil, 1988); U, (z) is the ambient horizontal wind speed, which
 can be an arbitrary function of height; and
                               Vx = V«2 + w2                                      (2-102)

 is the velocity of the plume cross section along its centerline, with two components u and w in
 the horizontal and vertical directions, p and pa are the plume density and air density,
 respectively, s is the length of the plume centerline measured from the emission source, and 4> is
 the centerline inclination. See Figure 2-10 for a schematic view of the plume rise and various
 variables.

       The momentum equation in the wind direction is

                     -j- (ptf. r2 (« - U$ - -r2 p w £$!                           (2-103)
t\«Jpufl\ju»5\$e£l2.wph                            2-51

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                 z,  w
                  Wind
                             Ua(Z)
                              Pa(2)
                             Ta(Z)
                                         PI
a/Tie
                   Rame
                                                (rrouna
Figure 2-10.   Schemadc and nomenclature for plume in a crosswind.

                                 2-52

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where the right hand side is related with the wind shear.  The momentum equation in the
vertical direction is a balance among inertia! acceleration, entrained momentum, and buoyancy:
                        •j- (P U* ** ») - 8** (P. - P)                              (2-104)

where g is the gravitational acceleration. The energy equation can be written as




where

                              di\t    dTm    ^
                               dz     dz    cf

is the vertical lapse rate of the ambient potential temperature. The constant on the right hand
side is

                           -£- = 9.76 x 10-J°K/m                                  (2-106)

where Cp is the specific heat of the ambient air.

       The last term in Eqn. (2-105) corresponds to the radiative heat loss from the plume to
the ambient air.  This term is expected to be important only initially when the plume
temperature is high. Q is the heat loss per unit volume of the plume.  This last term can be
estimated by
               ^r2 = - 2*€or(r» - T*a)lcf = -Rfr(l* - lj)                      (2-107)
               Cf

where a and e are the Stefan-Boltzmann constant and the emissivity respectively, and

 "  -      a-is a variable which characterizing the radiation properties. If we choose,
                          c, = 103 J/kg*,o = 5.67 x
                           '
and let e = 0.8, then Rp = 9.1 x 10'" kg/m2K3s.  The energy equation finally becomes
fc\c»lpu«f\juH5\ieea.wph                           2-53

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It is expected that the radiative heat loss is large for high T and small r.

       In deriving equations (2-103) and (2-105), it is assumed that the ambient wind is
                                                        dU  dT
horizontal and the vertical gradients of ambient properties —-i, —- do not vary significantly
                                                        dz    az
across the plume cross section.

       To close the equation set, two geometric relations are needed:

                                                                                    (2-109)
                                                                                    (2-110)
       These equations can be solved subject to the following initial conditions and ambient
meteorological conditions.  Initial conditions are specified at the source location s = 0, where
x = 0. The following information is needed as input:  plume density, p0; vertical velocity, w0;
plume radius, r0; and temperature, T0.  The ambient conditions are specified in terms of
horizontal wind profile, U,(z), and air temperature profile, T,(z).  (In the case of a forest fire
plume, the source parameters are to be provided by EPM and the meteorological conditions by
the CALMET model.)

       Most meteorological observations give the atmospheric stratification in the form of
temperature distribution versus pressure. To obtain relations of air density versus height, and
plume density versus height, it is assumed that the atmospheric pressure distribution can be
approximated as that of an adiabatic atmosphere.
where T*, is the ground level air temperature. Based on (2-111), if the air temperature and
plume temperature are T, and T respectively at height z, the corresponding densities can be
obtained as
t\olpuB\Jul95\«6d2.*ph                            2-54

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                           p. -     and p =                                      (2-112)

where R is the gas constant of the ambient air and the plume.

       The equations described above are solved numerically using a second order, marching in
s, Heun's predictor-corrector scheme.

                            £ •**

                            y -y' +/(s",y") AJ

                          ,-* - y" +    Jft-.y-) + /(f*.y*)] A*
2.5    Overwater and Coastal Dispersion

       There are important differences in the structures of the marine and continental boundary
layers which can have significant effects on plume dispersion in the overwater and coastal
environments. These differences arise for three basic reasons (LeMone, 1978):

              Water has a high heat capacity and is partially transparent to solar radiation,
              resulting in a relatively small diurnal temperature range (~ 0.5 deg. C).

              The sea surface is generally more uniform and less aerodynamically rough than
              typical land surfaces.

              There is a constant source of moisture in the marine boundary layer.

       As a result of these differences, the sensible heat flux over the open water is typically
more than an order of magnitude less than over land. The absence of a strong sensible heat flux
to drive the marine  mixed-layer  and  the small surface roughness result in relatively low mixing
heights that offer the potential for significant  plume trapping effects. LeMone (1978) indicates
that the typical marine mixing depth is only about 500 m. Data from three offshore and coastal
experiments reported by Hanna  et al. (1985) (two of which were conducted in California) show
many hours with mixing heights  less  than 100 m.
t\oUpufl\jul9S\sed2.wph                           2-55

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       Another result is that the diurnal and annual variations of stability over water are
completely unrelated to the typical overland behavior. For example, North Sea observations of
water and air temperatures reported by Nieuwstadt (1977) (Figure 2-11) show that temperature
inversions typically persist most of the day in June, while unstable conditions occur all day in
January. During other times of the year, the overwater diurnal stability cycle is out of phase
with the overland cycle (Le., stable over water during the day and unstable at night).

       The techniques used in the CALMET meteorological model for determining overwater
mixing height, stability, and turbulence levels based  on the air-sea temperature difference, wind
speed, and the specific humidity have been discussed in Scire et aL (1995). These methods are
applied by CALMET to the portions of the modeling domain over water. At the land-sea
interface, rapid changes in the dispersion characteristics may occur which can significantly affect
the ground-level concentrations from coastal sources.  The puff model formulation is well-suited
to accommodate these  spatial changes in the coastal transition zone.

       A typical situation during stable onshore flow conditions is shown in Figure 2-12. A
narrow plume imbedded in the stable layer above the shallow mixed-layer is intercepted by a
growing Thermal Internal Boundary Layer (TTBL).  The growth of the TLBL is caused by the
sensible heat flux associated with solar heating of the land surface.  The convective overland
conditions can rapidly bring the elevated pollutant to the ground, causing locally high ground-
level concentrations. Many coastal fumigation models assume immediate mixing of the pollutant
intercepted by the TffiL to the ground (e.g., Lyons and Cole, 1973, Misra, 1980). Deardorff and
Willis (1982), based on laboratory experiments, suggest the importance of turbulent fluctuations
in the TTBL height and indicate the plume does not become well-mixed immediately.  In the
Offshore and Coastal Dispersion (OCD) model, Hanna et aL (1985) use the minimum
concentration predicted by a virtual source technique or that predicted by the Deardorff and
Willis model to describe shoreline fumigation.

       In CALPUFF, the land-sea interface is resolved on the scale of the computational grid.
The CALPUFF model provides the turbulence and  dispersion characteristic of the overwater as
well as the overland boundary  layers.  The transition from marine to continental dispersion rates
is assumed to occur at  the coastal boundary determined from the gridded land use data.  Once a
puff within a marine layer encounters  the overland mixed layer height, the puff growth is
changed from that appropriate for the marine layer to that appropriate for the overland
boundary  layer.
t\ca|pufl\juB5\iecC.wph                            2-56

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  Tm»C
"20 T
, 0
                                                     oir temperature
                                                     water temperature
         Jan   Febr    Mar    Apr    May    June   July    Aug   Sept    Oct.    Nov    Dec.
Figure 2-11.   Daily average  air and water temperatures  measured  in  the North  Sea (from
              Nieuwstadt (1977)).
                                           2-57

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                                                                                   T18L
Figure 2-12.   Schematic illustration of a typical coastal fumigation condition (from Hanna et aL,
              (1985)).
                                           2-58

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2.6    Complex Terrain

       The effect of terrain on ground-level concentrations is simulated in CALPUFF in three
ways:

              1.     Adjustment of the wind field to large-scale terrain features;

              2.     Explicit simulation of puff-terrain interaction for distinct features too
                    small to influence the large-scale wind field;

              3.     "Simplified" treatment for puff-terrain interaction with both large and
                    small-scale features.

This allows CALPUFF to respond to the presence of terrain on two scales.  Options are
available in CALMET for invoking either a diagnostic or prognostic wind field model to
simulate the response of the large-scale flow to the presence of terrain. The effect of terrain
that extends over a scale large enough to be resolved by the grid used in CALMET will be
manifest in the boundary conditions for the flow field. A puff embedded in this flow will either
rise with the flow along the surface of the terrain, or it will be steered by the flow along the
terrain, depending on the degree of stratification.  Smaller-scale terrain features encountered by
a puff in this flow can then be simulated explicitly by a separate subroutine, CTSG (COMPLEX
TERRAIN ALGORITHM  FOR SUB-G.RID SCALE FEATURES), that embodies the methods
used in the Complex Terrain Dispersion Model (CTDM). Concentration estimates on any
terrain features not treated by CTSG (this is an option in CALPUFF) include simpler
adjustments to the effective height of the puff above the ground that are consistent with the
procedures used in ISC. As an alternative option, we have also included a more elaborate
terrain adjustment which does draw on CTDM concepts, without requiring the terrain
description procedures of CTSG. Section 2.6.1 provides a complete description of the CTSG
module, and Section 2.6.2 describes the  alternative "simple" terrain adjustment procedures.

2.6.1   COMPLEX IERRAIN ALGORITHM FOR SUB-GRID SCALE FEATURES (CTSG)

       CTSG accepts the flow field produced by the flow model  (both the wind and temperature
structure) in the vicinity of  a terrain feature as the incident flow toward that feature. It then
proceeds to simulate changes in the flow and in the rate of dispersion that are induced by that
terrain feature. At the core of CTSG is  the modeling approach adopted in CTDM, the complex
terrain model developed in  EPA's Complex Terrain Model Development program. Our goal in
                                         2-59

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designing CTSG is to produce a puff algorithm that contains those elements of the CTDM
approach that have the greatest impact on ground-level concentrations.

       Figure 2-13 illustrates the intended role of CTSG in the CALPUFF system.  In the
upper panel of the figure, a cross-section of steep terrain rising with distance inland from a
coast is depicted. The vertical dashed lines  show the boundaries of a grid used by the wind-field
model The idealized terrain consists of a nearly uniform slope over much of the grid-square,
plus a secondary feature right at the coast At night, one might imagine a puff of material
traveling down this slope in a drainage flow toward the secondary  feature. The interaction of
the puff with this secondary feature would be simulated by CTSG.

       In the lower panel, the puff is shown as it is "seen" in the modeling system. The wind
model provides the transport speed and direction for the puff, and concentrations are computed
at receptors beneath  the puff as if the terrain were flat  However, the secondary feature is now
represented as an obstacle to the flow, and CTSG produces concentrations at receptors on this
feature using methods developed for CTDM.

2.6.1.1  Modeling Regions

       A central feature of CTDM adopted for use in CTSG is the dividing-streamline concept
The flow is taken to be composed of two layers. In the upper layer, the approach flow has
sufficient energy to transport a fluid parcel up and over the hill against a stable potential density
gradient. In the lower layer, the flow is constrained to travel around the hill  This concept was
suggested by theoretical arguments of Drazin (1961) and Sheppard (1956) and was demonstrated
through laboratory experiments by Riley et al (1976), Brighton (1978), Hunt and Snyder (1980),
Snyder (1980), and Snyder and Hunt (1984).

       Hd, the dividing-streamline height  (m), is obtained from profiles of wind speed (m/s) and
temperature (as the Brunt-Vaisala frequency, N (1/s)).  H,, is computed for  each hill by locating
the lowest height at which the kinetic energy of the approach flow just balances the potential
energy attained in elevating a fluid parcel from this height to the top of the hill.  The statement
that defines this balance is:
                                   a
                        .5  u2(H4) = / N\z)  [H - z]dz                               (2-113)


where u(Hd) is the wind speed at z = H,,, H is the elevation of the top of the hill, and N(z) is
the Brunt-Vaisala frequency at height z.  In  practice, the value of Hd is obtained by rewriting the

t\calpuffl\jul95\»ec«26.wph                           2-60

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                 Grid
                 Boundary
Puff
                                                     Puff
                                                                           Grid-Plane
                                                                           Elevation
                                 CTSG Terrain
                                    Feature
Figure 2-13.  Depiction of the intended use of CTSG. The lower panel illustrates the portion of
             the terrain present in the upper panel that can be simulated by CTSG,  and it
             illustrates the relationship between the gridded terrain, the modeled winds, and the
             CTSG terrain feature.
                                         2-61

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integral on the right-hand side (RHS) of Eqn. (2-113) as a sum over layers of constant N. For
layer n,

                          Vi
          KHS.  = UB.* +  / *J (ff - z) 4 = Wf (ff -
where z,^ denotes the mean height of the layer, 0.5 (z,+1 + zj. The layer that contains Hd is
found by comparing the LHS of Eqn. (2-113) at each measurement height n with the
corresponding RHSB, starting with the layer that contains the top of the hill If LHS, exceeds
RHSn, then H,, must lie below z,, and so the process is repeated until the lowest layer is found
in which the LHS becomes less than the RHS (in the layer above, the LHS is greater than the
RHS). This then identifies the layer that contains H,,.

       Hd is then computed within this layer by assuming that the wind speed follows a linear
profile.  Denote this as layer j, where the elevations at the top and bottom of the layer are zn+1
and Zj, respectively.  Denote u(z) in the layer as

       u(z) - Oj + bjZ

then Eqn. (2-113) becomes

         \ (aj + bj *t  -*?(*-  vz&i +  *-]) fc*i - *<) + «*/.i                 (

where the last term, RHSj+1, denotes the value of the RHS from Zj+1 to the top of the hill. Eqn.
(2-115) is quadratic in Hd, and is readily solved  for H,, .

       Once Hd is computed for a hill, the stratification length scale for the flow above Hd is
computed as u^N,,, where um and Nm are average values between Hd and the first model-layer
above the top of the hill.  This length scale characterizes the degree of stratification of the flow
above Hd.  Note that Nn is computed from the temperature difference across the layer.

       Puff material above  H,,, the dividing-streamline height, experiences an altered rate of
diffusion in the deformed flow field over the hill. It is this change in the  effective dispersion
that leads to increased ground-level concentrations (GLC's) observed over hills when H,, is zero.
When Hd is not zero, only that portion of the puff that lies above H,j as the puff encounters the
hill travels over the hill. The puff is modeled as if it were sheared off at  Hd so that material
nearer the center of the puff may reach the  surface without further dilution. The theory of
fc\ralpu«\ju»5\ied26.wph                          2-62

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diffusion of narrow plumes embedded in a deforming flow field (Hunt and Mulhearn 1973)
provides the basis for estimating GLC values in the upper layer (subroutine UPPER).

       Puff material below H* is deflected around the hill, being embedded in a horizontal two-
dimensional flow.  The stagnation streamline in this flow forms the boundary of the hill and
therefore separates portions of the puff which travel around one  side or the other. The center
of the puff is able to impinge on the hillside only if the puff is centered on the stagnation
streamline, and lies below H*. Concentration estimates from subroutine LOWER are based on
the analysis of Hunt et aL (1979) which indicates that the GLC near the impingement point is
essentially that obtained by sampling the puff (in the absence of the hill) along the stagnation
streamline at the elevation of the receptor.  As the puff encounters the hill, the lateral
distribution of material in the puff is separated along the stagnation streamline, and each
segment is allowed to travel around the hfll with complete reflection at the plane z-0 as  well as
y=Yd (stagnation streamline), Le., the hillside. Figure 2-14 illustrates how the puff material is
treated in CTSG.  For the sake of illustration, the outline of a continuous series of puffs  is
portrayed as a plume and the height of the center of the plume exceeds Hd.

       Three  regions are identified in the figure.  Boundaries between these three regions are
defined differently in the upper and lower layers, as discussed later. For illustration, we will
consider the boundaries identical, as drawn in Figure 2-14.  The distinction between the upper
flow and the lower flow as described above is strictly applied in region 2.  Prior to this, in
region 1, the portion of the puff above  H,, has not reached the hill (at z = HJ and so the
vertical structure remains continuous. Concentrations are estimated as if receptors in this region
were positioned  on poles. Receptors below Hd in region 1 are placed on poles to simulate an
impingement calculation. The pole height is equal to the height of the receptor above the base
of the hill, and the lateral position of the pole is shifted to the location of the stagnation
streamline. In essence, the flow below  Hd in region 1 is turned much as it is in region 2,  but no
reflection from the side of the hill is included. Receptors may also be located above Hd in
region 1. Figure 2-15 depicts a situation in which departures in shape between the actual terrain
feature and the simplified hill used in CTSG cause ground-level receptors to be placed above Hd
in region 1. In this case receptor 2 is also modeled as a receptor-on-a-pole, but the height of
this pole is set to Hj, and its lateral position is the same as that of the receptor.  This approach
assumes that flow above Hd is deflected in the vertical,  but not in the lateral direction.  No
alterations are made to the dispersion rates.  Differences in the way receptors in region 1 are
treated can be summarized as follows:  the flow above H,, is considered to be terrain-following
in the vertical, with no horizontal deflection, and the flow below Hd is considered to be terrain-
following in the horizontal, with no vertical deflection.  Note that the stagnation streamline
defines the boundary that shifts the flow left or right in the horizontal Using Hd in this way

i:\calpufl\jul9S\Mct26.wpb                           2-63

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       REGION  1
 REGION 2
(REGION 3)
                        REGION  2
       REGION
   Contour  of
Figure 2-14.  Illustration of modeling regions and partitioning of the flow above and below the
             dividing-streamline height Hd.
t\cmlpiia\jul95\iect26.wph
2-64

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enforces a dear and sometimes abrupt distinction in the way concentrations may be obtained at
nearby receptors.  This can lead to discontinuities in concentrations determined at receptors that
straddle Hd just upwind of the hill, when the puff is located "far" from the stagnation streamline
of the flow below H* yet travels toward the hfll in the layer above H,,.  Subroutine PUFFC
performs these calculations in region 1. Details of the model for regions 2 and 3 are provided
in the following subsections.

       The CISC algorithm may be invoked whenever concentration estimates are needed at
receptors that are located on terrain elements that are not reserved by the grid in the flow-field
model It specifies the relationship between a single puff and all receptors on a single terrain
feature for the current averaging/transport time-period. Consequently, CTSG is called for each
puff/terrain-element pair during each time-step.  Some reduction in execution time is be gained
by screening out puff/terrain-elemeht pairs for combinations of puff size and position, relative
to those of the terrain feature, that exhibit minimal terrain influence.  These combinations are
then modeled as if the terrain were absent.

       When the "slug" representations of the doud is employed (Le., at times small enough that
the turbulent spread at the end-points of the slug are less than the length of the slug), the
puff/terrain formulation  cannot be applied directly. Instead, the slug is partitioned into an
equivalent  series of overlapping puffs and each of these is modeled separately for the time-step.

2.6.1.2 Description of Terrain Features

       CTSG uses simple analytical obstacle shapes to represent sub-grid scale terrain features.
Below Hd,  CTSG uses an elliptical cylinder to represent the hill. The axes and orientation of
this ellipse represent the overall scale and orientation of the terrain.feature at  the minimum of
the elevation of the puff, or Hd.  Above Hd, CTSG uses a Gaussian shape to represent the hill.
The height of the Gaussian hill is equal to the difference in height from the peak of the hill to
Hd. The horizontal length scales and orientation of the hill are chosen so that  the lateral extent
of the Gaussian hill at one half its height is representative of the scale of the terrain feature half
way between Hd and the  top of the hill. When the major axis of the hill lies along the x-axis of
the coordinate system, these shapes are defined by

                          ellipse:    1
IJ * (£]                                (2-116a)
i:\calpufi\jul9S\ied26.wph                           2-65

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                             Actual Receptor Heights
                                                               	H
                                                                   Actual Hill-Shape
                                   Modeled Hill-Shape
                            Modeled Receptor Heights
              Region 1
Region 2

Figure 2-15.  Treatment  of height of  receptors located upwind  of the impingement point
             (Region 1).
i:\
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                   Gaussian:    h = H
                                                                                   (2-116b)

where (a,b) are the semi-axis lengths of the horizontal cross-section of the elliptical cylinder
below H* and (L*Ly) are the Gaussian length scales along the two axes of the hill above H^.
For each puff, hill, and value of H* the model selects a particular elliptic cylinder and Gaussian-
shaped hflL

        To do this, the user must describe each terrain feature as an inverse polynomial hill
(Figure 2-16).  For each axis, the shape that must be fit to the height-profile of the terrain
feature has the functional form:
                       ht « relief
                                   1 - (|*| /axmaxf90
                                       (|jc|
(2-117a)
where "ht" is the elevation of a point on the hill above the grid-plane, "|x|" is the unsigned
distance from the center of the hfll to the inverse polynomial profile at the elevation "ht",
"axmax" is the value of "|x|" at which "ht" equals zero (the base of the hill), "relief is the height
of the hill above the grid-plane, "scale" is the length scale of the polynomial function which is
half the span of the function at one half the peak of the function, and "expo" is the power
(exponent) of the function.

       Given this description of the hfll,  CTSG solves for V at specific elevations "ht" along
each axis of the hill to obtain the semi-axes for the elliptic cylinder and the Gaussian hill:
             axis (ht) = scale
                                                          ' 1 /expo
                                      1 -ht/ relief
                              /tf/relief + (scale /
(2-117b)
Below Hd, the height used to obtain the axes of the elliptic cylinder is the minimum of Hd and
the puff height.  Above Hd, the length scales are obtained halfway between H<, and the top of
the hill, and the corresponding length scales for the Gaussian hill are formed by multiplying
these scales by 120. The factor 1.20 is obtained by demanding that the Gaussian hill and the
polynomial hill function have the same span at an elevation halfway between H,, and the top of
the hill (Figure 2-17).

       Alternatively, the user may elect to use a terrain feature description file that is identical
to the one used in CTDMPLUS. The file, named "TERRAIN" (as in CTDMPLUS), provides
i:\calpiifl\)ul9S\iect26.wph                           2-67

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      Height-Profile  of
      Terrain Feature
                    Grid-Plane '
                    Elevation
Height-Profile
Of Inverse-Polynomial
 	   	  	   	   Base Of Inverse-Polynomial-  ——  	  —— 	
Figure 2-16.  Profile of a terrain feature along one of its two axes. A best-fit inverse polynomial

           function describes this profile to CTSG.


                                   2-68

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                          CROSS-SECTION ALONG ONE  AXIS
         Gaussian  Shape Matches
         At These  Points
                                           i— Puff Height
                                                    Axis
                                               (2D  Cylinder)
Figure 2-17.  Use of hill profile function within CTSG. The model extracts the length scales for
            a Gaussian profile above Hd, and an elliptical cylinder below H,,.
i:\calpaa\jul95\tea2&wpti
2-69

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the model with a series of parameters that define ellipses and polynomial hill profiles which
have been fit to the terrain feature at a series of Hj's.  With this option, CALPUFF uses the
interpolation functions of CTDMPLUS to obtain the ellipse and Gaussian hill information
appropriate to a specific value of H*. An example of the format of this file can be found in
Section 42. Anyone wishing to use this option should be famfliar with the contents of the
CTDMPLUS users guide (Perry et aL, 1989).

2.6.13 Upper Layer

       An  estimate of the concentration (g/m,)  at a receptor at the surface of a hfll in region 2,
due to a plume whose initial position is (Zp,yp), is given by
                                                                                  (2-118)
where tR is the travel-time (s) from the source to the receptor, t0 is the travel-time along the
plume centerline from the source to the upwind base of the hill (if FL, is non-zero, t0 is the time
to the point where the flow first encounters the hill at an elevation equal to the lesser of z,, and
ILJ, yR is the cross-wind location (m) of the receptor, q is the mass flux (g/s), Fz and Fy are the
vertical and horizontal distribution functions, u is the mean wind speed (m/s) at the elevation of
the center of the plume, and OK and o^ are the effective dispersion parameters (m) given by

                 «L -  i * l'~lTf   -J, - o,.«- [
-------
                 exp(-.5 [z, - atf /«!) «#:(v[*, - z,]/pr, o. oj)                  (2-122)
                 exp(-.5 fc, * *J/oJ) e*(oz*[ir, * z,]/prz o. oj)
Fy contains information on the deflection in the trajectory over the hill as well as information on
changes in the diffusivity. Hie effective lateral position of the receptor relative to the centerline
of the plume is altered by the deformation in streamlines over the hill, and the effective rate of
growth  of the plume is altered as well Hence, an effective receptor location (y^) and an
effective lateral plume size (or) are used to compute the horizontal distribution function.  Fz
also contains the change in diffusivity in the effective vertical plume size, ow , and it includes
complete reflection from the surface of the hill (marked by H^) for only that material which lay
above H,, at t = t0. "Cutting" the puff at z = Hd and allowing reflection from this surface gives
rise to the combination of exponential and error function products in Eqn. (2-122). A full
discussion of the development of these equations is contained in Strimaitis et aL (1988).

       These expressions do not include the effect of an elevated inversion on the vertical
distribution of the puff. When a mixing lid is present, the Fz function contains many  more terms
to simulate multiple reflections.  The derivation of Fz with a mixing lid is an extension to the
formulation found in CTDMPLUS, because the lid is not treated for the stable boundary layer,
and it is explicitly included in the PDF representation of dispersion in the mixed layer. It is
required in the puff implementation because puffs with a Gaussian distribution of mass in the
vertical can be released below either a mechanical or convective  mixing lid, a may remain
Gaussian in the vertical (not well-mixed) during subsequent sampling steps.

       For a mixing lid of height zu the vertical  distribution function in a puff just upwind of
the hill  is given by

     Fm -  exp (-.5 [z, - zf /<£) + exp (-J [z, + zf /«£)

        +  £ {exp (-J pfc£ - z, - zf / «i) + erp (-.5 [2izL - z, * zf / «»)}            (2.123)

                                            exp (-3 [2iz£ Zf * af /4
Over the hill, the vertical distribution function (evaluated for a receptor at the surface of the
hill— Ha) due to a point source located at a height V just upwind of the hfll is given by
i\ca]pufl\jul9S\tect26.wph                           2-71

-------
                      ezp (-.5 p (ZL - Hj) - (z - £T^]2/oJ./r-z2)                    (2-124)
                                                             •»
Therefore, the total influence of the vertical distribution of puff material just upwind of the hill
on the concentration at a receptor on the surface of the hill is obtained by integrating the
product of these two distributions from z = Hj to z « z^. The resulting F, is given by

               Ft - JJ£ £ 4jff(fy££) + £ £ AJB(EJtE^\                      (2-125)

where
and
where
                         (2 J)
                    2 |/ -  1] [Zi - JTj                                              (2-126)
      ,£.) = exp(-.5[£ - £. + F^/oJ) (erf(K[o^zL - H4]-Dl)} + «/(r DJ)}

                                                 - H,]-D2J\ + erf(K D2)}

                                                 - Jfj * A9)] - «^T D3)}

                                                              - erf(f D4)}
                        itt =  oj. [B.  - Fj/lJ  - «4 £                               (2-128)

                        D3 «
i:\c»)pufl\ju!95\iect26.wph                           2-72

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       Each term in the sum in Eqn. (2-125) is a product of the exponential function and error
functions as in Eqn. (2-122), representing the multiple reflections at H,, and 2^.  Clearly, not all
of the terms in the sum are needed. Hie inner sum over index j represents reflections between
Hj and ZL once the puff moves over the hfll, whereas the outer sum over index i represents
reflections between 0 and ZL before the puff reaches the hflL Hie algorithm that evaluates these
sums continues to include greater values of the index until the fractional change in Fz is reduced
to less than 1%. The distribution of material in the vertical becomes well-mixed when oz
reaches 1.6 z^. At this point, Fz in Eqn. (2-125) reduces to
       These equations take on a more familiar form when H,, is zero and when ZL is infinite.
In that limit Dl « D4, D2 « D3, and inspection of the exponential factors reveals that the
indices (ij) must be equal to obtain non-zero terms. Further inspection of the error functions
shows that the only non-zero term is that for i = j = 1, so that

                    Ft(H4  = 0,zL = ~) = 2 expf-^yoj2)                           (2-130)

which is the form commonly used for fiat terrain.

       Evaluation of the Fz  and Fy distribution functions requires the use of a flow model that
provides streamlines for stratified flow over a hill. The effective lateral receptor location, y^,
and the effective puff dimensions, on and o^ depend on the properties of the flow.  These
properties are provided by the flow algorithm contained in CTDM.  This algorithm incorporates
an approximate solution to the linearized equation of motion for steady-state Boussinesq flow
over a Gaussian-shaped hill. It is formulated as a "backwards-looking" solution in which the
deflection of a streamline that passes through a given point over a hill Js provided. Hence, the
algorithm answers the question:  "Where did the streamline that passes through the point (x,y,z)
come from?" rather than the question:  "Where does the streamline that passes through the
point (x,y,z) in the flow upwind of a hill go as the flow  is deflected by the presence of the hill?"
As such, the relationship between the lateral position of the center of the puff in the absence of
terrain-deflections (yp), and the "original" lateral position (y^) of the streamline that passes
through the receptor is directly obtained from the flow algorithm because the receptor position
on the hill (XR^R^R) is  known.  The description of the algorithm is contained in the
CTDMPLUS user's guide (Perry et al. 1989), as modified by Strimaitis and Yamartino (1992).

       Evaluation of ou and o^  is more complicated.  As indicated in Eqn. (2-119), these
effective puff dimensions require the quantities oz./Tz and  Oy/Ty, which depend on the rate of
puff growth in the absence of the hill and on the amount of distortion to the flow induced by the


i\ealpiifl\jul95\«ect26.wph                          2-73

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hflL  These are estimated on the basis of the theory for a narrow plume embedded in a flow
with arisymmetric strain developed by Hunt and Mulhearn (1973).  Their results show that the
spread of material in a straining flow is approximately equal to
                                                                                  (2-131)
                               4
where K, and Ky are the diffusMties, Sz and Sy are functions of the strain in the flow, and o^
and 0,4 describe the size of a deformed plume. Because we assume that the strain is negligible
away from the hill, Eqn. (2-131) can be rewritten as
4*/
     '.
                                 oj, *
                                                    A
                                                                                  (2-132)
The expressions in brackets are equivalent to the quantities o2w and o^ defined by
Eqn. (2-119), so that
                           ofo -
                                                                                  (2-133)
       The strain functions are given by

                 Sz(t)  = exp( - Hi®)     Sy(t) = exp(l - 71(0)
                                                (2-134)
where Th and Tl are deformation factors. Th is the ratio of streamline spacing in the vertical in
the deformed flow to that in the undistorted flow.  Tl is the corresponding ratio for streamline
spacing in the lateral direction (normal to the flow).  The inverse of the product of these two
factors at any point in the flow equals the speed up factor, Tu. These factors are computed
k\calpufl\jul9S\Kd26.wph
         2-74

-------
 from the flow model contained in CTDM. The integrals in Eqn. (2-133) are evaluated
 numerically along the trajectory of the center of the puff.  Vertical and lateral diffusivities
 (m2/s) in the absence of the terrain are found from the dispersion coefficients as

                                2JD® - <*y)/<*                                       (2-135)
where o denotes either a, or or The effect of the terrain on the diffusivity is assumed to be
restricted to the change in the vertical turbulence over the hflL  We write the dispersion
-coefficient as the product of the turbulence and a function of time (in the absence of terrain).
Over the hill, the vertical turbulence velocity is assumed to increase with wind speed as in the
"inner layer" theory, and the lateral turbulence velocity is assumed constant as in the "rapid
distortion" theory (e.g., see Britter et aL (1981) for a discussion of these theories). These
assumptions tend  to accentuate the effect of the hill in the diffusion calculation.  Substituting
Eqns. (2-134) and (2-135) and augmenting the the vertical turbulence intensity by the speed-up
factor Tu, the integrands of Eqn. (2-133) become
                          2Kf = eg>2(l  - Th) Til2  -^
                                                                                     (2-136)
                                 «p2(l  - It)   A
       Due to the computations required to obtain Th, Tl, and Tu, these factors are evaluated
at no more than 25 points along the streamline that passes through the center of the puff.
Linear interpolation between these points is then used in the numerical integration required to
evaluate Eqn. (2-133) for each receptor. The range of points is centered at the midpoint of the
intersections of the puff trajectory (without deflection) and the ellipse that marks the boundary
of the portion of the hill below H* and cover a distance equal to one and one-half times the
distance between points of intersection of the line y = 0 (the centerplane of the flow over the
hill) and the ellipse. If the undeflected trajectory of the puff does not intersect the ellipse, then
the distortion factors are  set to unity and the hill has no effect on oz and ar  Note that the hill
also has no effect on oz or oy when the growth rate of the puff is virtually zero. This is not to
say that the hill has no  effect on concentrations, however, because the flow distortion over the
hill results in y^ * yR, and the dividing-streamline height still allows puff material at z = Hd to
contact the surface of the hill.
fc\calpufl\jul95\Ket26.wph                            2-75

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2.6.1.4 Lower Layer
       The equation for estimating the concentration (g/m3) at a receptor at the surface of a
hfll in region 2, due to a plume whose initial position is (z,,yr), is given by
                                                                                    (2-137)
where Yd is the cross-wind location (m) of the lateral dividing-streamline which coincides with
the side of the hfll, ZR is the elevation of the receptor on the surface of the hill, Fx and Fy are
the vertical and horizontal distribution functions, u is the mean wind speed (m/s) at the
elevation of the center of the plume, and oz and oy are the dispersion parameters (m) at tR.
Note that unlike Eqn. (2-118) for the upper layer,  changes to the rate of diffusion that are
induced by the hfll in the lower layer are considered small

       In the case of a puff, the sampling function allows us to rewrite the concentration
estimate for a receptor on the surface (Eqn. (2-137)) as
          GLC
                         4 x  it
                                erf
(2-138)
The distribution functions are given by
.5 eao>-^[z, - ztf / o   [erf([bl - b2

.5 exp(-5[zf + zj / oj) [afljbl - b2
                                                      erf([bl + b2

                                                               b2
(2-139)
where
                                             bl
                                                                                    (2-140)
The notation is the same as that in section 2.6.13. The only new quantity introduced in these
equations is Y^, the lateral position of the stagnation streamline upwind of any flow distortion.
As in CTDM, it is found by solving for the two-dimensional streamline pattern about an ellipse.
L-\calpufl\jul9S\iec»26.wph
                                    2-76

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       Fy contains information about the amount of material on each side of the hill and about
how the puff is sampled in the lateral direction.  The lateral offset is the distance from the
centerline to Y^ reflecting the notion that att receptors lie along the side of a hill, coincident
with the lateral dividing-streamline position. Furthermore, material may be split on either side,
and complete reflection of material is allowed along this surface, giving rise  to the form of the
product of the exponential and error functions in Eqn. (2-139).  Note that the sign of the error
function (taking the sign of its argument into account) is positive when both the receptor and
the trajectory of the center of the puff lie on the same side of Y^  If all of the material were to
reside on one side of Yd at t^ then Fy would equal either 2 or 0, depending on whether the
receptor were on the same side or on the other side of Yd as the puff.

       Fz contains information about the amount of material below H,, at t^ and about how this
material is sampled in the vertical The form is a product  of an exponential function and error
functions in which the sampling height ZR is most evident in the exponential  function, and the
effects of splitting the plume at Hd are contained in the error functions.  A full discussion of the
development of these equations is contained in Strimaitis et aL (1988).
 ^.
       These expressions do not include the effect of an elevated inversion on the vertical
distribution of the puff.  When a mixing lid is present, the Fz function contains many more terms
to simulate multiple reflections and the result is similar to  that discussed in 2.6.13:
                                                                                   (2-141)
where
                             E; = 20 -1^ + *,
                             E7 = VJ - \)LL - z,
                              '            *   *                                    (2-142)
                             £ - 20 - Ifc + *>
                             Ej = 2(1 - Ifc -z,
and
i:\caIpufl\jiil9S\Mct26.wph                           2-77

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  B(E,E.) - «p-.5[E. - Efl<${etf?[bl  - b2 - b3]) + etfRbl  + U

                                                               - b2
where

                      T-	     bl
                           1* "« "» <>,.                                             (2.144)

                      62 = E o£,            63 « E^ o'
                                                       .
The form of the "B-function" is identical to Fz (Eqn. (2-139)) for the case of no limit to vertical
mixing. Differences arise in the use of (E£0) rather than (ZR^,), so that the presence of the
mixing lid is manifest in Eqn. (2-142).

       The outer sum over the index i accounts for reflections between the mixing lid and the
surface before the puff reaches the hill The inner sum over the index j accounts for reflections
that may occur as material diffuses above Hj when the puff passes the hilL The  inner
summation will generally produce non-zero terms only for j  = 1, unless a mixing height only
slightly greater than Hd is found. This circumstance may not occur at all, given the definition of
H,, and ZL. In evaluating the sums, terms are included for greater values of each index until the
fractional change in Fz is reduced to less than 1%. The distribution of material in the vertical
becomes well-mixed when oz reaches 1.6 ZL- At this point, Fz in Eqn. (2-138) reduces to
                                                                                    (2-145)
2.6.1.5 Operational Characteristics
       The best way to illustrate the behavior of CTSG is to present concentrations obtained for
a specific application, and to compare these with what would have been obtained if the terrain
feature had been ignored.  We take this approach in this section by simulating ground-level
concentration patterns at receptors on a hill for the situation in which a single puff moves across
the hill along a curved trajectory.

       The hill chosen for this exercise is twice as long as it is wide, with its major dimension
oriented north-south. The relief height of the hill is set to 100 m, and its dimensions at its base
i\c«lpufl\ju!9S\«ect26.wph                            2-78

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are 2264 m by 1132 m.  The polynomial function describing its shape is characterized by the
following parameters:

       relief (m)            100
       expo (1,2)            2, 2
       scale (U) (m)       800,400
       axmax (U) (m)      1132,566
       xc,yc(m)            0,0
       thetah (deg)          0
       zgrid (m)            25

Note that (xc,yc) are the coordinates of the center of the hill, thetah is the angle (CW) from
north to the major axis of the hill, and zgrid is the elevation of the grid-plane above sea level.

       The incident flow for this hill consists of a height-profile in which wind speeds are
constant at 1.5 m/s, and the temperature gradient is constant with a Brunt-Vaisala frequency of
0.0167 s"1.  For the 100 m tall hill, this profile produces a dividing-streamline height of 10.18 m.
The mixing height is set at 2000 m.

-•     For this demonstration, the following formulas were used to specify the dispersion
parameters:
                                    •• .945(r/100)-**)

where o^ = 5 m and L = 0.1; and
where Oj = 50 m and i = 0.25.
These equations result in a puff size that produces significant concentrations on the ground in
the absence of the hill, since the puff height is set at 45 m (MSL), or 20 m above the local grid
elevation. Hence, the center of the puff is approximately 10 m above Hd for this demonstration.
fc\calpufl\jul95\iee»26.wph                           2-79

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       The puff initially lies to the southwest of the hflL Its movement is tracked in timesteps
of 5 minutes, so that it takes several timesteps to move across the hflL The wind direction shifts
by 10 degrees each time-step, from an initial direction of 270 degrees.  The puff contains 600 g
of material

       The 1-hour average "foot-print" of concentrations produced by the movement of this puff
is shown in Figure 2-18. The left panel illustrates simulated concentrations in the absence of the
hill, and the right panel illustrates concentrations simulated by CTSG when terrain is present
The base of the hill function is outlined as an ellipse in each of these panels.  Major features of
CTSG are immediately apparent in these concentration patterns. Peak concentrations over the
crest of the hill are larger by almost a factor of two, and puff material below H,, travels around
the hill on either side. Note that some detail in the contours arises from discrete receptor
locations. Even though 325 receptors were used (one at each intersection of the 100 m tic-
marks), there is not enough coverage to produce smooth contours everywhere.

       The "foot-prints" of the puff during each of the time-steps in which the puff was over the
hill are shown in Figures 2-19 (a-f) corresponding to time-steps 3 through 8. These figures
illustrate how CTSG partitions the puff during each step according to the relative position of the
center of the puff, the dividing streamline height (HJ, and the position of the stagnation
streamline. It is important to note that this partition does not increase the number of puffs in
the model. Although the distribution becomes fragmented in the mathematics,  all information
remains referenced to a circular puff of a prescribed size.  When a variable such as the flow
direction changes between steps as it does in this example, the concentrations are obtained as if
the current properties of the flow existed for all time, and the puff is partitioned according to
those properties.  Hence, the stagnation streamline in this demonstration differs from one step
to another, and so the separation distance between the trajectory of the center of the puff and
the stagnation streamline also differs from one step to another.

2.6.2   "Simple" Terrain Adjustments

       Terrain adjustments other than those provided by the wind field model and the CTSG
subroutine are needed in CALPUFF.  Because CALPUFF is designed to emulate ISC in the
limit of steady winds and a constant emission rate, it must also contain the terrain treatment
used in ISC.  This is described in Section 2.6.2.1.  Furthermore, general applications typically
involve terrain variations on many spatial scales which are impractical to address with CTSG.
The wind field transports a puff along the  surface of the terrain, but never causes its height
above the surface to change.  Hence, puffs in the flow may be channeled or deflected by the
terrain, but they do not "impinge" or otherwise strongly interact with the  terrain without a

i:\caIpun\jul9SVecl26.wph                           2-80

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   1-HOUR  AVERAGE  (g/m  3)  -  FLAT
    -800  -400   -200    0    200    400    600
  1200
  1000
  800
  600
  400
  200
 -200
 -400
 -600
 -800
-tooo
-1200
        i	i

 1200
 1000
800
                                            600
400
200
           1-HOUR  AVERAGE  (g/m 3) -  CTSG
             -600   -400   -200    0    200   400   600
1200
1000
                                                      BOO
                                                      600
 400
 200
1200
                                          1000
                                          800
                                                    600
-200      -200
-400      -400
                                           -600      -600
                                           -800      -800
                                           -1000    -1000
    -600   -400  -200    0     200    400   600
                                           -1200    -1200
                                                   -600
                                                                                               -800
                                                                                               -1000
            -600  -400  -200    0    200    400   600
                                                                                               -1200
     Figure 2-18.   Concentrations (g/m3) produced by CTSG (both with and without the hfll), averaged
                   over a period of one hour. The single puff that was simulated traveled over the hfll
                   in approximately 25 minutes during the hour.
                   (Contour interval = 2 g/m3; grid units = m).
     i:\aUpafl\ja05\ieel26.wpb
    2-81

-------
 1200
 1000
  BOO
  600
  400
  200
                 PUFF  STEP  3
    -600   -400  -200     0     200    400    600
                    PUFF  STEP 3
 -200
 -400
 -6OO
 -eoo
-1000
-1200

                                               1200      1200
                                               1000       1000
                                               800
                                               600
                                               400
                                               200
       -600   -400   -200    0    200    400     600
      800
      600
                                                         400
     200
                                               -200      -200
                                               -400      -400
                                               -600      -«00
                                               -aoo      -800
                                               -1000    -1000
    -600   -400   -200     0     200    400    600  '
                                               -1200    -1200
                                                  1200
                                                                                                      1000
                                                                                                      800
                                                                                                      600
                                                                                                      400
                                                                                                      200
                                                                                                      -200
                                                                                                      -400
                                                                                                      -600
                                                                                                      -eoo
                                                                                                      -1000
       -600   -400   -200    0    200    400    600
                                                                                                      -1200
     Figure 2-19a.  Concentrations (g/m3) produced by CTSG (both with and without the hill) during
                     5-minute time-step number 3.
                     (Contour interval = 20 g/m3; grid units = m).
      i:\ealpaa\JanS\i«l26.«pb
2-82

-------
                  PUFF STEP  4
-1200
     -600  -400   -200    0    200    400   600
 -200
 -400
 -600
 -600
-1000
                                              -BOO
                                                        1200
                                                        1000
                                                         800
                                                         600
                                                         400
                                                         200
                      PUFF  STEP 4
                -400   -200    0    200    400    (00
                                              -200      -200
                                              -400       -400
                                              -600       -600
                                                        -800
                                              -1000     -1000
                                                                                                    1200
                                                                                                    1000
                                                   800
                                                   600
    -600   -400   -200    0     200    400    600
                                              -1200     -1200
                                                                                                    -600
                                                                                                    -800
                                                   -1000
         -600   -400   -200     0     200    400    600
                                                                                                    -1200
    Figure 2-19b.  Concentrations (g/m3) produced by CTSG (both with and without the hill) during
                   5-minute time-step number 4.
                   (Contour interval = 20 g/m3; grid units = m).
    t\caipuff\JQl95\iea26.wph
2-83

-------
                 PUFF  STEP  5
   -600   -400   -200
t200
                               200   400    600
 1000
  000
  600
  400
  200
 -200
 -400
 -600
 -BOO
-1000
-1200
                 \
                          30-
                             i	t

                                 L
                                              1200
                                             BOO
                                              600
                                              400
                                             200
                                                                      PUFF  STEP  5
  -600   -400  -200
1200
                                                                                     200    400    600
                                             1000      1000
                                                        800
                                                        600
                                                        400
                                                        200
                                                        •400
                                              -200
                                              -400
                                              -600
                                              -800     -500
                                              -1000     -1000
    -600   -400   -200    0     200    400    600
                                             -1200    _,200
                                                                         f /  A

                                                                                30-
                                                                                       i
                                                                                       I

                                                                                     LL
                                                                                                    1200
                                                                                                    1000
                                                                                                   800
                                                                                                    600
                                                                                                    400
                                                                                                    200
                                                                                                    -200
                                                                                                    -400
                                                                                                    -600
                                                                                                   -aoo
                                                                                                   -1000
                                                          -600   -400   -200    0     200    400    600
                                                                                                    -1200
    Figure 2-19c.  Concentrations (g/m3) produced by CTSG (both with and without the hill) during

                   5-minute time-step number 5.

                   (Contour interval = 20 g/m3; grid units = m).
    i:\calpafl\jiil»3\Mct2&«ph
                                                 2-84

-------
  1200
 1000
  800
  800
                PUFF STEP   6
    -600   -400   -200    0    200   400    600
 -aoo
-1000
tooo
800
600
1200       1200
                        PUFF  STEP  6
            -800  -400   -200   0     200    400   600
                                                       1000
                                                       aoo
                                                       «oo
                                                       400
                                                       200
                                                                                                  1200
                                                                                                  1000
                                                      -200*
                                                      -400
                                                      -600
                                                      -800
                                                     -1000
-1200
   -600   -400  -200    0     200    400    600
                                             -1200    .,200
                                                    -200
                                                    -400
                                                                                                 -600
                                                                                                 -aoo
                                                                                                 -1000
                                                         -600   -400  -200    0    200    400    600
                                                    -1200
   Figure 2-19d.  Concentrations (g/m3) produced by CTSG (both with and without the hffl) during
                 5-minute time-step number 6.
                 (Contour interval  = 20 g/m3; grid units = m).
                                               2-85

-------
                 PUFF  STEP  7
 1200
 1000
  800
  800
  400
  200
    -600   -400  -200    0     200   400    600
 -200
 -400
 -600
 -BOO
-1000
-1200
1200      1200
1000      1000
800
600
400
200
                         PUFF  STEP  7
             -600  -400   -200    0    200    400   600
                                                         800
                                                         600
400
200
                                              -200      -200
                                              -400      -400
                                              -600      -600
                                              -800      -800
                                              -1000    -1000
    -600    -400   -200    0     200    400    600
                                              -1200    -1200
                                            1200
                                                                                                     1000
                                                       800
                                                                                                     600
                                                                                                     400
                                                                                                     200
                                                       -200
                                                       -400
                                                                                                     -600
                                                                                                     -800
                                                                                                     -1000
             -600   -400   -200    0    200    400    600
                                                                                                     -1200
    Figure 2-19e.  Concentrations (g/m3) produced by CTSG (both with and without the hill) during
                   5-minute time-step number 7.
                   (Contour interval = 20 g/m3; grid units = m).
    t\c»4poa\Jul93\«ea26.wph
   2-86

-------
  1200
  1000
   BOO
   600
  400
  200
                  PUFF STEP  8
     -600   -400   -200    0     200    400    600
 -200
 -400
 -600
 -800
-1000
-1200
          I      I       I      I
 1200      '200
 1000      1000
                                               000
 600
                                               400
200
                          PUFF STEP  8
             -600   -400   -200    0     200    400    600
                                                         BOO
                                                         600
                                                         400
           200
-200      -200
-400      -400
-600      -600
-800      -BOO
-1000    -1000
    -600   -400   -200    0     200    400    600
                                              -1200    -1200
                                                                        \
                                                                                                 »  -
                                                                                                 \
                                                                                                     1200
                                                                                                     1000
                                                                                                     600
                                                                                                     600
                                                                                                     400
                                                                                                     200
                                                                                                     -200
                                                                                                     -400
                                                                                                     -600
                                                                                                     -800
                                                                                                     -1000
                                                           -600   -400   -200    0     200    400    600
                                                                                                     -1200
     Figure 2-19f.  Concentrations (g/m3) produced by CTSG (both with and without the hill) during
                   5-minute time-step number 8.
                   (Contour interval  =  20 g/m3; grid units = m).
     L-\olpaa\JiinS\iect2i.vpb
    2-87

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simple terrain treatment.

       A simple terrain adjustment such as the plume path correction factor (e.g., the half-
height adjustment found in plume models such as COMPLEX I) could be used for such general
terrain, but this technique has several drawbacks. A new treatment has been developed that
avoids such drawbacks.  It is derived from concepts that lie behind the bask CTSG treatment,
but employs sufficient simplifications that it is readily applied to any array of terrain. We
review simple terrain adjustments that are used in other models, and identify drawbacks that are
particularly troubling in the context of a puff model, in Section 2.622; and we develop the
rationale for a new "simple" treatment that is based on the same theory used in CTSG in
Section 2.6.23.

2.6.2.1 ISC Terrain Treatment

       ISC is not intended for use in situations in which receptors are placed on terrain that
exceeds the height of the "stack". Any receptors that are found above this height are lowered to
a height that is 0.005 m below the height of the stack. This is done hourly for each source in
the simulation, and is therefore source-specific. The mixing height is not adjusted for the
presence of any terrain feature, and the result of any downwash calculations does not modify the
stack height used to determine the height of the receptor. Once the receptor height is
determined, the vertical distribution factor contains the difference in elevation between the
centerline of the plume and the receptor. In effect, the centerline of the plume is lowered by an
amount equal to the modified elevation of the receptor above the base of the stack.

       This treatment has been implemented in CALPUFF, but the dependence of the effective
puff height above a receptor on the elevation at which puffs are initially released (prior to any
buoyant rise) can lead to troubling inconsistencies.  If two sources with different stack heights
are being modeled, consider a situation in which plume rise differs for the two in such a way
that the puffs reach identical elevations. Why should the difference in elevation between the
puff and a receptor depend upon the stack heights?  We believe that they should be treated
alike in this  regard, so we have sought alternate formulations.

2.6.2.2 Simple Terrain Adjustments in Existing Complex Terrain Plume  Models

COMPLEX I/n

       COMPLEX I is a screening model for use in complex terrain.  It differs from
COMPLEX n only in its use of 22.5° sector-averaging rather than the traditional Gaussian

i:\calpufl\jul9S\tect26.wph                           2-88

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lateral distribution function. Within the context of puff-modeling, we are only interested in the
treatment of the vertical distribution, which is the same in both variants, so we shall refer to the
models as one - named COMPLEX.  COMPLEX employs the partial height correction method
to simulate the effect of terrain. The height of the plume at a receptor depends on the height
of the plume over level terrain (which is taken to be the height of the plume above the elevation
at the base of the stack from which the plume was released), the receptor height (above the
base of the stack), and the plume path coefficient (which depends on the stability class).  Values
for the plume path coefficient are typically C«0.0 for stable (classes E and F), and C=OJ for
the rest (classes A, B, C, and D). The "half-height" correction model is equivalent to C=0.5.

       Let H. be the elevation of the base of the stack above sea level, and  H, be the elevation
of the receptor above sea level  Furthermore, let AH, be the height of the plume at the source,
and AH, be the height of the plume at the receptor. If the elevation of the receptor exceeds the
elevation of the centerline of the plume at the source,

              AH, = AH. * C                                                      (2-146)

If the elevation of the receptor lies below the centerline of the plume at the source,

              AH, = AH. - (Hr-Hi)*(l - C)             „                            (2-147)
C
In either case, AH, is not allowed to be less than some minimum value, which is typically set at
10 m. Note that H^H, is assumed in the above equation, so that the terrain-following plume
result is obtained (C - 1) if the terrain on which the receptor sits lies below the elevation of the
base of the stack. The mixing height is not altered unless C = 0.0, in which  case the mixing
height is reset to 5000 m to simulate unlimited mixing.

       When C = 0.0, the full difference between the plume height and the receptor height is
obtained, subject to the specified minimum.  This gives the appearance of keeping the plume
level, and is therefore known as the level-plume treatment. It also results in sending the plume
over all terrain greater than  plume height, which is not consistent with the behavior of plumes in
stably-stratified flows. Therefore, the "400 m correction" factor originally used in the Valley
model is applied.  This factor varies linearly from  1.0 at the plume centerline height to 0.0 at
400 m above the plume centerline height.

       Application of the partial height correction to receptors that lie below the height of  the
plume centerline is illustrated in Figure 2-20 which depicts the situation for C = 0.5.  Panel A
shows the relationship between the initial plume height and five receptors located on a single

fc\calpgfl\juBS\i«126.wph                           2-89

-------
 hflL  Panel B shows how the model treats receptors 1 and 5 which are located at the base of the
 hfll, panel C shows how the model treats receptors 2 and 4 which are located halfway up the hill,
 and panel D shows how the model treats receptor 3 which is located at the top of the hill The
 central feature seen in the figure is that a different plume height is used for each receptor
 elevation, and concentrations are estimated as if the terrain were flat for each plume.  That is,
 the entire "history" of reflection of plume material from both the ground and the mixing lid (if
 present) differs for receptors located at different heights. The partial height correction
 treatment is not a unified, local adjustment, as is sometimes assumed.

        In addition to the treatment of reflection, the basic notion of "plume height over level
 terrain* poses a real problem for modeling puffs.  When sources are distributed throughout a
 modeling region of complex terrain, the elevation at the base of each stack can vary
 considerably.  Suppose puffs from two stacks reach the same height  above ground after buoyant
 rise,  and suppose that they both are of identical size when they reach a receptor or high terrain.
"Should both puffs contribute equally to the concentration at that receptor? Eqn. (2-147)
 indicates that the terrain adjustment for each puff could be different, as H,, the height of the
 receptor above the base of the stack, depends on the elevation of the terrain at the location of
 the stack. Qualitatively, we see that the receptor would appear "higher" to one source location
 than the other, and so some difference in the effect of terrain on each puff might appear
 reasonable.  But if we take the height-adjustment seriously, these two puffs should not be
 treated differently at the receptor, since they  coincide (after terrain  adjustment) at some points
 upwind of the terrain.

        All puffs might be treated similarly at receptors on elevated  terrain if H, were defined
 relative to a base-plane elevation, rather than stack-base elevation.  This would require terrain
 adjustments at the sources as well as at receptors.  In effect, streamlines would be defined on
 the basis of the height-correction rules and plumes or puffs would follow streamlines.  But there
 are two problems with this approach:  (1) a base-plane elevation will not be obvious in many
 applications; and (2) terrain adjustments to streamlines of the type listed in Eqn. (2-146)  reduce
 to a  single height, which would lead to some plumes following a streamline that remains a fixed
 height above the surface as it travels across higher elevations.  The latter situation would
 produce a "flat terrain" calculation for all receptors located at such higher  elevations.

 RTDM

        RTDM adds several features to the partial height correction treatment described above,
 including a reflection coefficient, the concept of the critical dividing-streamline height, and
 alterations to the mixing height. The reflection coefficient seeks to  present a more unified

 fc\aJpufl\juB5\tect26.wph                            2-90

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                                                                                      (a)
                                                                                      (c)
                                                                                      (d)
Figure 2-20.   Partial height correction method used in COMPLEX for non-stable periods in which
              receptors lie below the centerline of the plume. (C =  0.5)
i:\calp«fl\Jul9S\iMt2i.«pfc
2-91

-------
treatment of receptors located on the same feature by adding the restriction that peak
crosswind-integrated concentrations not increase with distance from the source.  Such an
increase can be produced in a model if the effective plume height is reduced rapidly in going
from one receptor to the next (from receptor 2 to 3 in Figure 2-20, for example) because of the
change in the history of the reflection from the lower boundary.

       The critical dividing-streamline (ILJ is used to separate the flow into two layers when it
is stably-stratified. Plumes below H,, are modeled with a plume path coefficient C = 0.0, while
those above are modeled with C = 0.5. Equations similar to those in COMPLEX for the
adjusted plume height are revised by subtracting H,, from the plume and receptor elevations.
If the elevation of the receptor exceeds the elevation of the centerline of the plume, the
effective plume height (AH,.) becomes:
          *
              AH, = (AH. - Ha + H.) * C                                          (2-148)

If the elevation of the receptor lies below the centerline of the plume,

              AH, = (AH. - H, + H.) - (H, - H,) * (1  - C)                           (2-149)

Furthermore, C = 0.0 if the receptor lies below Hd. There is no minimum limit to the size of
AHr so that the plume becomes a ground-level release for receptors located at or above the
elevation of the plume. The mixing height above the ground (AHm) is adjusted in exactly the
same way, so that AH, and AH, in the equations above  are replaced by AH,,, and
       This use of Hd results in the use of the level plume treatment only when Hd is non-zero.
Otherwise, a value of C = 0.5 is used. Furthermore, plumes above H,, treat Hd as the lower
surface for reflection when receptors lie at the same elevation as Hd, and the partial height
correction for higher receptors is based on heights above Hd, so that the adjustments are
effectively more severe than the standard half-height (C = 0.5) correction.

       Because of its reliance on the base of each stack (independently) to define the terrain
adjustment, the same problems noted for COMPLEX also plague the use of the RTDM
procedures in the context of a puff model.

2.6.2.3 Alternate Approach to Terrain Adjustment in a Puff Model

       The method of adjusting properties of a puff to simulate the effects of dispersion over
terrain should include the following attributes:

i:\calpufl\juJ95\iect26.wph                            2-92

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       (1)    Adjustment should be analytic functions of readily-available physical properties of
              the flow, dispersion, and terrain.

       (2)    Problems associated with "reflections" should be minimized.

       (3)    Adjustments should be based on local properties of the terrain, so that heights
              relative to particular "stack-base" elevations or "base-plume" elevations are not
              required.

       (4)    Adjustments should be related to concepts used in the CTSG (CTDM) routine.

       (5)    Puffs from different sources that happen to  coincide at some point should be
              treated alike as they interact with subsequent terrain features.

       In the method outlined below, the properties of a puff are adjusted on the basis of the
local strain to the flow imparted by the underlying terrain,  using a simplification of the theory
on which CTDM is based.  The local strain is estimated from the slope of the underlying terrain.
Terrain slopes are obtained from a gridded  field of terrain elevations, and apply to the segment
of the trajectory over which a puff travels during one time-step.

       For very stable conditions (Froude number less than 1), we assume that the wind field
model will force much of the flow to be parallel to contours of terrain-height,  so that puffs will
directly encounter relatively minor terrain.  For such minor terrain, the strain-induced
adjustments described above will also apply.  But in addition, we allow the lateral distribution of
the puff to remain level by placing receptors on "poles" whose heights are relative to the
elevation of the terrain beneath the center of the puff. This allows the "edges" of a puff to
brush against the side-walls of a valley or channel, producing "impingement" concentrations. An
explicit calculation and use of the dividing-streamline height (Hd) is not included in this
approach.

       Figure 2-21 depicts this treatment. The puff is travelling into the plane of the figure, and
its size is denoted by the extent of the dotted lines (equal to or oz). The elevation of the
terrain under the puff is denoted by the horizontal dashed  line, and the actual terrain is  denoted
in the cross-section by the solid lines. Three receptors are  marked. Receptors 1 and 3 lie above
the terrain elevation at the puff location, while receptor 2 lies below it. When the Froude
number is small, receptors 1 and 3 are placed on "poles", so that they intercept concentrations
within the puff.  When the Froude number is large, receptors 1 and 3 are placed at the elevation
of terrain beneath the center of the puff.  Because receptor 2 lies below this terrain elevation, it

i:\calpufl\juI95\tect26.wph                           2-93

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is always moved up to the dashed line in the figure. Receptor heights that are modeled along
the dashed line produce familiar "flat terrain" results.

       In the absence of a dividing-streamline, the LIFT component of CTDMPLUS essentially
computes an effective oy and oz from which terrain-altered concentrations are obtained using
the "standard" Gaussian plume equation. The effective oy and oz are given in the notation of
CTSG by Eqn. (2-132).  For the "simplified" approach described below, we will focus solely on
changes induced on the vertical spread of the puff. Following the implementation for oz in
CTSG, we define a strain factor Tz - r\/Zf where TJ is the spacing between streamlines in the
strained flow, and z, is the spacing between the same streamlines in the unstrained flow over
"flat" terrain. The notion of an effective size of the doud is introduced to allow concentrations
to be calculated in the flat-terrain frame of reference. It is assumed that the primary effect of
strain in the flow is to alter the rate of exchange of material across streamlines in the flow.
Hence, the ratio of oji\ in the straining flow can be larger than the corresponding ratio  o^/Zj.
Therefore, the effective size of the doud in the flat-terrain frame of reference (o^) is defined
by:

                                      =  -3-                                         (2-150)
or
                                                                                    (2-151)
This allows o  to be calculated as
            u
                                                      dt'                           (2-152)
The integral is evaluated over the life of a cloud, thereby incorporating the history of all of the
strain experienced by the cloud.

       The strain function Sz depends on the local value of the strain factor, Tz:

                               St(t) = *<' ' T'W>                                      (2-153)

For weak strain, we can approximate the strain function as


t\olpafl\jiins\iect26.wph                           2-94

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           Terrain
Figure 2-21.   Depiction of treatment of puff interaction with a "side-wail" for strongly stratified
               (stable) conditions.  The flow is into the page.
c\ca*Mfl\ju!95\McS26.wpfe
2-95

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                                                                                   (2-154)
so that the product Sz(t) T, is unit/. Although the strain likely to be encountered will not be
entirely weak, we adopt the equivalence stated in Eqn. (2-154) as an approximation to simplify
the leading factor in Eqn. (2-152).
       With this assumption,
                               / 2JT(t')
                                                                                   (2-155)
which can be expressed for an incremental timestep At as

     At) =
                                     2K(t + t'\ S(l - r* * •*» dt'
                                                                                   (2-156)
Over a short timestep in a puff model, Eqn. (2-156) can be approximated by replacing
2K (t + t') with its mean value during the timestep:
                                           At

Furthermore, we assume that the strain factor Tz varies linearly over the timestep, so that
                          T(t
                                             at
and Eqn. (2-156) becomes
(t + At)

                                                     " "^  / dt'
                                                                                   (2-158)
                                                                                   (2-159)
Evaluating the integral in Eqn. (2-159),
              (t + At) =
                                2£(t,At)
                                                      2dTJdt
                                                                   (2-160)
we have the new expression for the growth in OK during one timestep. In the limit that the
strain factor is constant over the timestep, Eqn. (2-160) reduces to
L-\olpuff\juJ95\i«cl26.wph
                                           2-96

-------
                                Af) <£(0 + e2*1 ' "*%# * Af) - ofr               (M«l)
       Implementation of Eqn. (2-160) requires a model for the strain Tx(t) in the flow field  In
CTSG, we have a description of the length scales and position of a terrain feature, and a flow
model within CTSG provides information about the strain in the flow over the feature.  Here,
we use a surrogate to obtain the strain-we infer the scale of a two-dimensional terrain feature
(tying across the flow) from the slope of the underlying surface along the flow
(Figure 2-22). The slope  | a | of the terrain is identified with a surrogate hill of height h^ and
half-length L, so that


                                  '• I  'IE                                        (2"162)

The flow model used in CTSG provides the following equation for the. deflection of a streamline
(6) over a two-dimensional ridge in stratified flow:
                    6(x,ti) - MX) «-*'* (cos In -  i sin li\\                          (2-163)

where the hill height function has the form

The stratification factor is I - N/u, x is directed downwind, with origin at the center of the
"hill", and i\ is the height of the streamline above the surface at the position x.

       Because we wish to associate a strain with the local slope along the puff trajectory and
not a complete hill feature, we must assign representative values of Tz and dTj/dt from
somewhere over our surrogate hill The location chosen to evaluate Tz and dTj/dt is the point
at which dT^dx is an extreme value.  The strain factor is defined by the local streamline height
divided by the streamline height far upwind (Figure 2-23):
                     T(r\ -       -  _   _                            o !«-,
                     •«ZW --  -  TTT - — - — - -                            ( 2-165)
                                               -
The position x/L at which dTj/dx reaches an extreme value is approximately:


i:\caJpufl\jul95\icct26.wph                           2-97

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                  Puff
Terrain
Segment
                                                                  Slope (a)
                                    Surrogate Hill
Figure 2-22.   Identification of a surrogate 2-D hill of the same overall slope («) as the terrain
               directly beneath the puff.
c\alpufl\iii«S\ieci26.«ph
                                             2-98

-------
                                  t|. + 6 - h
Figure 2-23.   Depiction of streamline height (r\), streamline deflection (5), and strain factor (TJ
              nomenclature.
                                            2-99

-------
                                                         cos
                               •  i     V
                              ™ -V]
                                          (2-166)
                                                        sin
                                                    .cos III  -
for the upwind "face", and:
1 + IM (i _ e-"/*) 1 -
3
! , f «in In [
icos in - *'/LJ
sin In ]
(cob In - e^J
                                                                                     (2-167)
for the downwind "face". The "face" is determined by the sign of the slope.  For example, if a is
less than zero, then we assume that the puff is travelling down the lee-side of the terrain, and
(x/L)d is selected.
       The strain factor at (x/L) is given by

          In  -    sin
                                                                                     (2-168)
and the change in Tz with distance at (x/L) is

                  "2  |g|   '
                n (i
[-2(xll)
   (2(xlL) cos In + (l  -
                                                                           in In)]    C2'169)
We assign dTj/dt by using the puff speed and dTj/dx.
       The streamline height n> and its ratio to the horizontal length scale of the surrogate hill
L remain to be assigned.  We set n equal to the centroid height of the puff, because the strain
over the scale of the puff will determine its modified growth. As for L, its minimum value is of
the same order as the size of one grid cell used to define the terrain. For large features, L can
be several kilometers. Therefore, we shall fix the ratio n/L = 0.1.  While this cannot be
representative of all puff heights and terrain features, it fixes our focus on the lower part of the
flow over terrain in which the strain is most pronounced.
t\calpuff\jul9S\iect26.wph
2-100

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       In summary, this simplified implementation of the principles embodied in CTSG involve
the following steps:

       1)     The slope | o | of the terrain beneath the puff, taken along the transport
              direction, provides the single piece of information used to estimate the influence
              of the terrain on the growth of the puff on the vertical during one timestep.

       2)     A surrogate, two-dimensional hfll of the same overall slope is used to represent
              the scale of the terrain.

       3)     The strain factor Tz is found from the streamline deflection equation used in
              CTSG, for the surrogate hill

       4)     Both Tz and its derivative dTj/dt are evaluated at the location on the surrogate
              hill at which dTJdt is an extreme value (upwind face of hill if the terrain slope is
              positive, downwind face if slope is negative).

       5)     The strain factor is assumed to be a linear function over the timestep, and ott is
              computed from Tp dTj/dt, and the ambient rate of growth (the diffusiviry).

       This formulation  conforms to all five attributes stated at the beginning of this subsection.
However, several assignments have been made without the benefit of an evaluation study.
Because of this, this terrain adjustment procedure should be used with caution at this time.

2.7    Dry Deposition

       Many complex processes are involved in the transfer and deposition of pollutants at the
surface.  Sehmel (1980) compiled a list (Table 2-9) of some of the most important factors that
are known to influence dry deposition rates. The variables listed include the properties of the
depositing material (e.g., particle size, shape, and density; gas diffusiviry, solubility, and
reactivity), the characteristics of the surface (e.g., surface roughness, vegetation type, amount,
and physiological state), and atmospheric variables (e.g., stability, turbulence intensity).  Hicks
(1982) noted the important differences controlling the deposition of large particles (e.g.,
gravitational settling, inertia! impaction) and those controlling gases (e.g.,  turbulence, molecular
diffusion).  Deposition of small particles is complicated by the fact that they may be influenced
by the processes affecting both gases and large particles.

       A commonly used measure of deposition is the deposition velocity, vd, defined as:

t\c«lpufl\ju»5\iec«26.*ph                           2-101

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                                            Table 2-9
                            Factors Influencing Dry Deposition Rates
Micrometeorological Variables
Aerodynamk roughness
- Mass transfer
(a) Particles
(b) Gases
-Heat
- Momentum
Atmospheric stability
Diffusion, effect of:
-Canopy
- Diurnal variation
-Fetch
Flow separation:
-Above canopy
- Below canopy
Friction velocity
Inversion layer
Pollutant concentration
Relative humidity
Seasonal variation
Solar radiation
Surface heating
Temperature
Terrain
- Uniform
- Nonuniform
Turbulence
Wind velocity
Zero-plane displacements
- Mass transfer
(a) Particles
(b) Gases
-Heat
- Momentum








From: Sebmel (1980)
Depositing Material
P.tfrU.

Agglomeration
Diameter
Density
Diffusion
- Brownian
- Eddy equal to
(a) Particle
(b) Momentum
(c)Heat
- Effect of canopy on
Diffusiopboresis
Electrostatic effects
-Attraction
- Repulsion
Gravitational settling
Hygroscopiciry
Impaction
Interception
Momentum
Physical properties
Resuspension
Shape
Size
Solubility
Thermophoresis


Gases

Chemical activity
Diffusion:
- Brownian
-Eddy
Partial pressure in
equilibrium with
surface
Solubility



Surface Variables
Ar/yMnmivlarinn

- Exudates
- Trichomes
- Pubescence
-Wax
Biotic surfaces
Canopy growth:
- Dormant
. PrpanHinp
I Cf
Senescent
Canopy structure:
- Area! density
-Bark
-Bole
- Leaves
- Porosity
- Reproductive
structure
-Soils
-Stem
-Type
Electrostatic
properties
Leaf-vegetation:
- Boundary layer
- Change at high
winds
-Flutter
- Stomatal
resistance
Non-biotic surfaces
pH effects on:
- Reaction
- Solubility
Pollutant
penetration and
distribution in
canopy
Prior deposition
loading
Water

t\calpufl\jul95\8ect26.wph
2-102

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                                                                                     (2-170)

where, vd      is the deposition velocity (m/s),
       F      is the pollutant deposition flux (g/m2/s), and,
       X.      is the pollutant concentration (g/m3).

       Due to the number and variability of the factors influencing dry deposition rates,
reported deposition velocities exhibit considerable variability. For example, SO2 deposition
velocity measurements summarized by Sehmel (1980) range over two orders of magnitude
(Figure 2-24).  Particle deposition velocities (Slinn et aL,  1978) show an even greater variability
(Figure 2-25).  Although it is not practical to include in the deposition model the effects of all of
the variables listed in Table 2-9, it is possible, based on the atmospheric, surface, and pollutant
properties to parameterize many of the most important effects.  The CALPUFF deposition
module provides three options reflecting different levels of detail in the treatment of dry
deposition.
 .,•
 f     •       Full treatment of spatially and temporally varying gas/particle deposition rates
               predicted by a resistance  deposition model

               User-specified 24-hour cycles of deposition velocities for each pollutant.  This
               option allows a "typical" time dependence of deposition to be incorporated, but
 T             does not include any spatial dependencies.
 Uc
               No dry deposition. A  switch is incorporated into the model to by-pass all the dry
               deposition calculations. This option will provide for faster model execution for
               screening runs or pollutants not experiencing significant  deposition.

       The user specifies a flag in the control file for each pollutant which determines if dry
deposition is treated and the specific  method used to compute the deposition velocities (see
Input Group 2, Section 4.2.1).

       If the resistance deposition model is used,  the user must input values for several
parameters describing the characteristics of the pollutant  (e.g., solubility, reactivity, diffusivity for
gases, the size distribution for particles)  (see Input Group 7 and 8) which are used in the
computation of the resistances.  In addition, several reference parameters and a flag indicating
the state of unirrigated vegetation (i.e., stressed, unstressed, or inactive) are required (see Input
Group 9).
fc\calpufl\jul9S\«ect26.wph                           2-103

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         Mb -ST. LOUIS -Iff!
         ttl- ST. LOUIS -OT)
         SBd- HEDGE
         61 9 -WATER. LAPSE AIM.
         56e - fcQ  MAX RATE
         JBc • GRASS. 0 STABIUTY
         S4 - ALFALFA
         61 b- CRASS. NEUTRALATM.
         »a - CEMENT. MAX RATE
         61 a -GRASS. LAPSE ATM.
         49 - GRASS
         61 h - WATER. NEUTRAL ATM.
         SI - GRASS
         J5b- CEMENT. MAX RATE
         52l - FOREST           -
         52 d - GRASS. MEDIUM
         55 e - STUCCO. MAX RATE
         58 1 - GRASS. 0 STABIUTY
         »d- CEMENT. MAX RATE
         61 d- SNOW. LAPSE ATM.
         59 - GRASS
         57 - GREAT BRITAIN
         52 1 • SOU. CALCAREOUS
         58 b- WATER. I STABILITY
         56 •- SOIL ADOBE CLAY-MAX
         55 1- STUCCO. MAX RATE
         58 b - WATER. B STABILITY
         55 e- STUCCO. MAX RATE
         60* - WHEAT
         58f - GRASS. 0 STABIUTY
         5Ba- GRASS.  B STABILITY
         5SI- SOIL ADOBE CLAY-MAX
         55              1               10
            DEPOSITION VELOCITY,  en/ste
Figure 2-24.  Summary of observed SO2 deposition velocities (from Sehmel (1980)).

L-\aJpafl\Ju«S\ieci2&wpb                               2-104

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                    	11
                   a	44
                b-o
                   x        -40   —0,05
                    *S£HMEL AND SUITER (1974)

                  **MOLl£R AND SHUMANN (197Q)
                                10 '               1

                                 PARTICLE DIAMETER,
Figure 2-25.   Observed deposition velocities as a function of particle size for 1.5 g/cm density

              particles. Measured by Sehmel and Suiter (1974) and Moller and Schumann (1970).

              Figure from Slinn et aL (1978).
c\aipaa\jii0S\ie(S26.wph
2-105

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       If any pollutant is flagged as using "user-specified" deposition velocities, the user must
prepare a data file with a 24-hour diurnal cycle of deposition velocities for each flagged species
(see Section
2.7.1   Vertical Structure and Mass Depletion

       The CALPUFF dry deposition model is based on an approach which expresses the
deposition velocity as the inverse of a sum of "resistances" plus, for particles, gravitational
settling terms.  The resistances represent the opposition to transport of the pollutant through
the atmosphere to the surface. Slinn et al. (1978) describe a multilayer resistance model for dry
deposition.  As illustrated in Figure 2-26, the atmosphere can be divided into four layers for
purposes of computing dry deposition rates. For gases, an additional (vegetation) layer is
included.

       (A) Layer Aloft.  The top layer is the region above the current mixing height. It
       contains pollutant material either injected directly from tall stacks, or dispersed upward
       during previous turbulent activity.  Due to the low rate of turbulent mixing in this layer,
       its pollutant is essentially cutoff from the surface. Therefore, this material is not subject
       to dry deposition until it becomes entrained into the mixed-layer.

       (B) Mixed-Layer. The top of the mixed-layer defines the depth of the turbulent
       boundary layer. Layer B extends down to a reference height within the atmospheric
       surface layer.  Pollutant mixing is dominated by turbulent processes. During convective
       conditions, pollutants in this layer quickly become uniformly mixed in the vertical. The
       resistance to pollutant transfer during these conditions is very small compared to the
       resistances in layers C, D, and E.  However, during stable conditions, the mixed-layer
       resistance may be substantial (Wesely and Hicks, 1977).  The treatment of the mixed-
       layer resistance is based on the overall boundary layer diffusivity parameterized in terms
       of micrometeorological scaling variables.

       (C) Surface Layer.  The surface layer is a shallow layer (~10 m) next to the ground that
       rapidly adjusts to changes in surface conditions. Because vertical fluxes are nearly
       constant,  this layer  is also called the constant-flux layer. The atmospheric resistance, r,,
       is used to parameterize the rate of pollutant transfer in Layer C.

       (D) Deposition Layer. Over very smooth surfaces, a thin non-turbulent layer (the
       deposition layer) develops just above the surface. For typically rough surfaces, this layer
       is constantly changing and is likely to be intermittently turbulent. For this reason, Hicks

i:\calpuH\jul9S\iect26.wph                          2-106

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LAYER
                                                   RESISTANCE
TYPICAL    HEIGHT
DEPTH (M)     (M)
(A)  LAYER  ALOFT
                                                             *1
(B)  ATMOSPHERIC BOUNDARY LAYER
      (MIXED-LAYER)
                                                                   U2-103
                                         'S
(C)  SURFACE LAYER
   -  (CONSTANT-FLUX LAYER)
(D)  DEPOSITION LAYER
      (QUASI-LAMINAR LAYER)
                                                                     V/U*
(E)  VEGETATION LAYER
  .1


  .2
Material  in  the  top layer is not available  for deposition at the
surface until  entrained into the mixed-layer.
     Overall mixed-layer resistance included in Eqn. (2.7-5)
  Figure 2-26.   Multilayer structure used in the dry deposition resistance model (adapted from Slinn
               et aL, 1978).
                                         2-107

-------
       (1982) calls this layer the "quasi-laminar" layer. The primary transfer mechanisms across
       the laminar deposition layer are molecular diffusion for gases, and Brownian diffusion
       and inertia! impaction for particles. However, surface roughness elements (e.g., leaf
       hairs) can sometimes penetrate the deposition layer, providing an alternate route for the
       pollutant transfer (Hicks, 1982). Under conditions of low atmospheric resistance, the
       deposition layer resistance, r* can be the dominant resistance controlling the rate of
       deposition for particles and some soluble, high molecular weight gases.

       (E) Vegetation Layer. Vegetation is a major sink for many soluble or reactive gaseous
       pollutants. After passing through the stomata, soluble pollutants dissolve in the moist
       mesophyll cells in the interior of the leaves.  Reactive pollutants may also interact with
       the exterior (cuticle) of the leaves. Due to the response of the stomata to external
       factors such as moisture  stress, temperature, and solar radiation, the resistance in the
       vegetation layer (Le.,  the canopy resistance, re) can show significant diurnal and seasonal
       variability. An alternate pathway that is potentially important in sparsely vegetated areas
       or overwater is deposition directly to the ground/water surface. Although not involving
       vegetation, it is convenient to include the ground/water surface resistance as a
       component of rc because, like the vegetation resistances, it is  a resistance in a layer
       below the laminar deposition layer.

       In the CALPUFF model, the fraction of the pollutant mass above and below the current
mixed layer is tracked.  At any point in  time, only pollutant material below the mixing height
can be deposited at the surface.  However, each time step as the mixing height changes,
pollutant mass is transferred  between Layers A and B. Typically, in  the morning, as the
boundary layer grows in response to solar heating of the land surface, material in the top layer
is entrained into the mixed-layer and becomes available for dry deposition at the surface. In the
evening, convective activity ceases, and material above the shallow nocturnal boundary layer
height is isolated until the next diurnal cycle.

       Once puffs have become uniformly mixed through the boundary layer, a surface
depletion method (Scire et aL, 1984b) can be used to account for the mixed-layer (Layer B)
resistance. The pollutant flux, F, at the reference height within the surface layer can be written
as:

                       '  -  Du (X. ~ %.)/(*  - z.)  = v,x,                              (2-171)

where, xm    ktne pollutant concentration (g/m3) within the mixed-layer,
       Xs     is the pollutant concentration (g/m3) at the top of the surface layer,
       h      is the mixed-layer height (m),

fc\emlpufl\jul9S\ied26.wph

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       z,     is the surface layer height (m), and,
       Dbl    is an overall boundary layer eddy diffusivity (m2/s).

       The boundary layer eddy difnisivities during stable conditions (Brost and Wyngaard,
1978) can be expressed as:
                                 Du •= kp.h                                        (2-172)

and during neutral or unstable conditions as:
                        DM  -  Maximum ft^A , kpji]                               (2-173)

where k} and k2 are constants with default values of 0.01 and 0.1, respectively.
       The term vdx$ can be written as v^x^, where vd is an effective deposition velocity taking
into account boundary layer mass transfer. From Eqn. (2-171), v^ is;,.

                         vj = DuvJ[Du + v# - Z,)]                                (2-174)
       When turbulent mixing within Layer B is rapid compared to the rate of deposition at the
surface, the atmosphere quickly replaces material that is deposited.  During these conditions,
0bl is large, and v'a ~ vd. However, under other conditions the rate of deposition can
sometimes be limited by the rate of pollutant transfer through Layer B to the vicinity of the
surface.  During stable conditions, Dbl may be small compared to vd(h-z,), and vd may be
substantially smaller than vd.  In the near-field of a source, before the plume has spread through
the boundary layer, it is assumed that vd ~ vd. This allows the near-field vertical Gaussian
distribution to be maintained.

       The resistances in the layers below the reference height in the surface constant-flux layer
determine vd. The parameterization of these resistances is discussed separately for gases and
particles in Sections 2.7.2 and 2.7.3, respectively. Once vd is determined, vd' is computed from
Eqn. (2-174).  Each time step, the mass of the pollutant in the puff is adjusted to account for the
dry removal:
                
-------
       S.S+AS are the positions of the puff at the beginning and end of the time step, and,
       g(s)   is the vertical term of the Gaussian puff equation. For a puff uniformly mixed in
                     the vertical, g(s) « 1/h.

       If user-specified deposition velocities are used for any of the pollutants, the effective
deposition velocity, vd', is set equal to the user specified value read from the VD.DAT file.

2.72   Resistance Deposition Model For Gases

       At the reference height, z,, the deposition velocity for gases is expressed (Wesely and
Hicks, 1977; Hicks, 1982) as the inverse of a sum of three resistances.
                                                                                   (2-176)
where, r,      is the atmospheric resistance (s/m) through the surface layer,
       rd      is the deposition layer resistance (s/m), and,
       rc      is the canopy (vegetation layer) resistance (s/m).
                                  Atmospheric Resistance

       The atmospheric resistance is obtained by integration of the micrometeorological flux-
gradient relationships (Wesely and Hicks, 1977):
where, z,     is the reference height (m),
       z0     is the surface roughness length (m),
       k      is the von Karman constant (~ 0.4),
       u.     is the friction velocity (m/s),
       4>H    is a stability correction term, and,
       L     is the Monin-Obukhov length (m).

       The stability correction term accounts for the effects of buoyancy on the eddy diffusivity
of the pollutant. It is assumed that the pollutant transfer is similar to that for heat (Wesely and
Hicks, 1977).  A gridded field of surface roughness lengths is passed to the model in the output
file of the meteorological model, CALMET. In CALMET, the surface roughness length is
either estimated from the predominant land use of each grid cell, or, if available, based on
i:\calpufl\jul9S\ieci26.wph                           2-110

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actual values entered by the user.  Over water, due to the effect of the wind on wave height, the
surface roughness length varies as a function of wind speed, and is computed internally within
CALPUFF using the parameterization of Hosker (1974).

                             % - 2.0 x 10-* «"                                    (2-178)

where u is the wind speed (m/s) at 10 m.
                                Deposition Layer Resistai

       Due to the importance of molecular diffusion to the transport through the laminar
deposition layer, the deposition layer resistance for gaseous pollutants is parameterized in terms
of the Schmidt number:

                                                                                   (2-179)
where, Sc     is the Schmidt number (u/D),
       u      is the kinematic viscosity of air (0.15 x 10~* m2/s),
       D     is the molecular diffusivity of the pollutant (m2/s), and,
       d1( d2  are empirical parameters.

       Experimental studies summarized by Hicks (1982) suggest a range of values for the
empirical variables of 1.6 to 16.7 for dt/k and 0.4 to 0.8 for d2. Intermediate values of d, = 2
(or d,/k of 5), and d2 = 2/3 are recommended based on Shepherd (1974), Slinn et al. (1978),
and Hicks (1982).
                                    Canopy Resistance

       The canopy resistance is the resistance for gases in the vegetation layer.  There are three
main pathways for uptake/reaction of the pollutant within the vegetation or surface:

       (1)    Transfer through the stomatal pore and dissolution or reaction in the mesophyll
              cells.
       (2)    Reaction with or transfer through the leaf cuticle.
       (3)    Transfer into the ground/water surface.

       In the resistance model, these pathways are treated as three resistances in parallel.


i\calpufl\ju»5\«ecl26.wph                          2-111

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                       r,  = [IAII rf + LAI I r^ + 1 / rj'1                              (2-180)

where, r,      is the internal foliage resistance (s/m) (Pathway 1),
       r^    is the cuticle resistance (s/m), (Pathway 2),
       rg      is the ground or water surface resistance (s/m), (Pathway 3), and,
       LAI   is the leaf area index (ratio of leaf surface area divided by ground surface area).
                     The LAI is specified in the model as a function of land use type.

       The first pathway is usually the most important for uptake of soluble pollutants in
vegetated areas. The internal foliage resistance consists of two components:
r
                                 f = r, + rm                                        (2-181)
where, r,      is the resistance (s/m) to transport through the stomatal pore, and,
       rm     is the resistance (s/m) to dissolution or reaction of the pollutant in the mesophyll
                     (spongy parenchyma) cells.

       Stomatal action imposes a strong diurnal cycle on the stomatal resistance, and, due to its
important role in determining deposition rates for gaseous soluble pollutants such as SO2, on the
deposition velocity, as well.  Stomatal opening/dosing is a response to the plant's competing
needs for uptake of CO2 and prevention of water loss from the leaves. The stomatal resistance
can be written (O'Dell et aL, 1977) as:

                                r, =/»/(W>)                                        (2-182)

where, p      is a stomatal constant (- 23 x 10"8 m2),
       b      is the width of the stomatal opening (m), and,
       D     is the molecular diffusivity of the pollutant (m2/s).

       The width of the stomatal opening is a function of the radiation intensity, moisture
availability, and temperature.  The variation  of b during periods when vegetation is active can be
represented (Pleim et aL,  1984) as:

                                             ^                                   (2-183)
where, b^   is the maximum width (m) of the stomatal opening
              (~ 2.5 x ID"6 m) (Padro et aL, 1991),
       b,,^   is the minimum width (m) of the stomatal opening (~ 0.1 x 10"6 m),
       S      is the solar radiation (W/m2) received at the ground, and,

i:\calpufl\jul95\MCt26.wph                          2- 1 12

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       Sggg   is the solar radiation (W/m2) at which full opening of the stomata occur.

       However, during periods of moisture stress, the need to prevent moisture loss becomes
critical, and the stomata dose. It can be assumed that b - b^ for unirrigated vegetation under
moisture stress conditions. When vegetation is inactive (e.g^ during the seasonal dry periods in
much of California), the internal foliage resistance becomes very large, essentially cutting off
Pathway 1.  In CALGRID, the state of the unirrigated vegetation is specified as one of these
states (A) active and unstressed, (B) active and stressed, or (C) inactive.

       The effect of temperature on stomatal activity has been reviewed by Pleim et aL (1984).
The most significant effects are due to temperature extremes.  During cold periods
(T < 10° C), metabolic activity slows, and b is set equal to b.,,.. During hot weather conditions
(T > ~ 35° C), the stomata are fully open (b  = b^ to allow evaporative cooling of the plant
(assuming the vegetation is in state A - active and unstressed).  These temperature effects
provide additional bounds on the value of r, given by Eqn. (2-182).

                                   Mesophyll Resistance

       The mesophyll resistance depends on the solubility and reactivity of the pollutant It is
an input parameter supplied to the deposition model for each gaseous species.  O'Dell et aL
(1977) estimate the mesophyll resistance for several pollutants.  For soluble pollutants such as
HF, SOj, C12 and NH3, rm ~ 0.0.  The mesophyll resistance can be large for less soluble
pollutants such as NO2 (-500 s/cm) and NO (9400 s/cm). For other pollutants, rm can be
estimated based on the solubility and reactivity characteristics of the pollutant.
                                     Cuticle Resistance

       The second pathway for deposition of gases in the vegetation layer is via the leaf cuticle.
This includes potential direct passage through the cuticle or reaction of the pollutant on the
cuticle surface. Hicks (1982) notes that measurements of SO2 deposition to wheat (Fowler and
Unsworth, 1979) show significant cuticle deposition. However, Hosker and Lindberg (1982)
suggest that passage of gases through the cuticle is negligible. Therefore, the cuticle deposition
is likely to be controlled by the pollutant reactivity.  Pleim et aL (1984) parameterize r^ as a
function of the pollutant reactivity of the depositing gas relative to the reference values for SO2.
                                                                                    (2-184)

where, A            is the reactivity parameter for the depositing gas,
i\c»lpufl\jul95\tecl26.wph                           2-113

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                     is the reference reactivity of SO2 (~ 8.0), and,
       rcu(reO       i* the empirically determined reference cuticle resistance (s/m) of SO2.

       Padro et aL (1991) suggest r^ref) is about 30 s/cm.  Reactivity values for other
pollutants are estimated at 8.0 (NO2), 15.0 (O3), 18.0 (HNO,), and 4.0 (PAN).
                                 Ground/Water Resistance

       The third pathway through the Vegetation layer" involves deposition directly to the
ground or water surface. In moderately or heavily vegetated areas, the internal foliage and
cuticle resistances usually control the total canopy resistance. However, in sparsely vegetated
areas, deposition directly to the surface may be an important pathway. Over water, deposition
of soluble pollutants can be quite rapid.

       The ground resistance, rp over land surfaces can be expressed (Pleim et aL, 1984)
relative to  a reference value for SO2:
                                                                                    (2-185)

where, rg(ref) is the reference ground resistance of SO2 (~ 10 s/cm) (Padro et aL, 1991).

       Slinn et aL (1978) parameterize the liquid phase resistance of the depositing pollutant as
a function of its solubility and reactivity characteristics.  Their results can be expressed as:

                              rf = H/(ec. <*j u,)                                     (2-186)


where, H     is the Henry's law constant, which is the  ratio of gas to liquid phase concentration
                     of the pollutant, (H ~ 4 x 10'2 (SO2), 4 x 10'7 (H2O2), 8 x 10"8 (HNO3),
                     2 x 10° (O3), 3 .5 x 10° (N02), 1 x  10 *2 (PAN), and 4 x 10"6 (HCHO)),
       a.     is a solubility enhancement factor due to the aqueous phase dissociation of the
                     pollutant (a. ~ 103 for SO2, ~ 1 for CO2), and
       d3     is a constant (~ 4.8 x 10"*).

2.7.3   Resistances for Particulate Matter

       Because particulate matter does not interact with vegetation in the same way as gaseous
pollutants, particle deposition velocities are commonly expressed only in terms of r,, rd and a
gravitational settling term.  The atmospheric resistance, r,, for a particle is the same as for a gas

t\calpufl\jul9S\«ect26.wph                           2-114

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 (Eqn. 2-177). The resistance in the vegetation layer (rj is not a factor because once penetrating
 the deposition layer, particles are usually assumed to stick to the surface (e.g., Voldner et aL,
 1986). Therefore, their behavior is similar to highly soluble/reactive gases with rc ~ 0. Based
 on an assumption of steady-state conditions, the deposition velocity for particles can be
 expressed (Slinn and Slinn, 1980; Pleim et aL, 1984) as:

                          v * (r« * T4 * Wf)"1 * v*                                 (2-187)

 where v( is the gravitational settling speed (m/s) of the particle.

       In CALPUFF, the puff centerline height at each receptor is adjusted to account for the
 cumulative effects of gravitational settling.  The puff centerline height is assumed to decrease by
 an amount given by:
where, Ah    is the change in puff height (m) due to settling effects,
       v(     is the gravitational settling velocity (m/s), and
       tfet    is the total travel time (s) from the source to the receptor.

       There are three major mechanisms for transport of particles across the deposition layer.
Small particles ( < 0.1 urn diameter) are transported through the laminar deposition layer
primarily by Brownian diffusion.  This process becomes less efficient as the particle diameter
increases.  Particles in the 2-20 urn diameter range tend to penetrate the deposition layer by
inertia! impaction.  The stopping time, t, defined as the settling velocity divided by the
acceleration due to gravity, is a measure of tendency of a particle to impact  Inertial impaction
is most effective in the 2-20 um diameter range.  Larger particles are dominated by gravitational
settling effects.  The effect of the terms involving vg in Eqn. (2-187) always is to increase the
deposition velocity. Particles in the range of 0.1-2 um diameter range, such as sulfate, have very
small settling velocities and are not efficiently transported across the deposition layer by either
the Brownian diffusion or the inertia! impaction mechanism. As a result, these particles have
the lowest deposition velocities.

       The deposition layer resistance can be parameterized (e.g., Pleim et aL, 1984) in terms of
the Schmidt number (Sc = o/D, where u is the viscosity of air, and, for particles, D is the
Brownian diffusivity of the pollutant in air) and the Stokes number (St = (vg/g)(u.2/«), where vg
is the gravitational settling velocity and g is the acceleration due to gravity).

                           r, = (Sc-w + 10-3/*)-V                                  (2'188)
i:\calpuff\jul9S\ted26.wph                           2-115

-------
       The diffusivity of a partide in air, D, is a function of the partide size.  Smaller particles
tend to be more efficiently transported by Brownian motion, and therefore have higher
diffusivities. The Stokes number is a measure of the likelihood of impaction of the particle. It
increases with increasing particle size.

       The gravitational settling velocity is a function of the particle size, shape, and density.
For spheres, the settling velocity is given by the Stokes equation:

                        v*  * [Wf «fo - p,)c]/(18 »)                              <2-189>
where, dp     is the particle diameter (m)
       pp     is the particle density (g/m3),
       pt     is the air density (g/m3), and,
       C      is the Cunningham correction for small particles.

This correction given by:
                   C = 1 *  2 X/d    * fljexpo/X                            (2-190)
where, X      is the mean free path of air molecules (6.53 x 10"* cm), and
       a.l,a2,&3 are constants (1.257, 0.40, 0.55, respectively).

       Because of the sensitivity of the deposition velocity to particle size, the effective
deposition velocity is computed for a number of individual size categories, and then weighted by
the actual size distribution.  The particle size distribution is specified in terms of the geometric
mass mean diameter and geometric standard deviation of the distribution. For sulfate, the
geometric mass mean diameter is approximately 0.5 um with a geometric standard deviation of
approximately 2 \im.

2.8    Chemical Transformation

       One of the design criteria of the CALPUFF model required the capability of modeling
linear chemical transformation effects in a manner consistent with the puff formulation of the
model.  The CALPUFF chemical module contains three options for dealing with chemical
processes:

       •      A pseudo-first-order chemical reaction mechanism for the conversion of SO2 to
              SO;  and NO, (NO + NO2) to NOj. This mechanism is based on the chemical
              transformation scheme used in the MESOPUFF n model (Scire et al., 1984b)
L\c«lpufl\jul9S\sect26.wph                          2-116

-------
              and incorporates the most significant dependencies of spatially and temporally
              varying environmental conditions on the transformation rates.

       •      User-specified 24-hour cycles of transformation rates. This option allows
              simulation of the diurnal, time-dependent behavior of the transformation rates.
              However, the transformation rates with this option are spatially uniform.

       •      No chemical transformation. An option is provided to completely by-pass the
              chemical transformation calculations. This will reduce computer requirements for
              situations or pollutants for which chemical transformation effects are not
              significant.

       The user selects one of the above options by specifying a mechanism flag in the
CALPUFF control flag (see Section 4.2.1). The MESOPUFF n mechanism (Option 1) uses
ozone concentrations (along with radiation intensity) as surrogates for the OH concentration
during the day when gas phase free radical chemistry is active.  With Option 1, hourly
observations of ozone concentrations  at one or more monitoring stations can be read from a
data file (OZONE.DAT) to provide the necessary estimates of ozone concentrations (see
Section 4.2.6).
-*"                                                   -j
       If "user-specified" transformation rates are used (Option 2), the user must prepare a data
file (CHEM.DAT) with a 24-hour diurnal cycle of typical transformation rates for each species
(see Section 4.2.7).

2.8.1   Description of the MESOPUFF II Chemical Mechanism

       The chemical processes included in the MESOPUFF n mechanism (Option 1) are the
conversion of sulfur dioxide to sulfate and the conversion of nitrogen oxides to nitrate aerosol
Figures 2-26 and 2-27 illustrate the chemical pathways for SO2 and NOX oxidation and aerosol
formation. Oxidation may occur by gas and aqueous phase reactions. The gas phase reactions
for both SO, and NO, involve free radical photochemistry and, therefore, are coupled to the
oxidation of reactive organic gases (ROG). Homogeneous gas phase reaction is the dominant
SO2 oxidation pathway during clear, dry conditions (Calvert et aL, 1978). Ozone and hydrogen
peroxide are believed to be the principal oxidants for aqueous-phase oxidation of SO2.

       The oxidation of NOX is dependent on gas phase ROG/NO^/Oj photochemistry. It is
generally more rapid than SO2 oxidation. As shown in Figure 2-27, NOt can be oxidized to
nitric acid (HNO3) and organic nitrates (RNO3) such as peroxyacetylnitrate (PAN).  Nitric acid

i:\cdpiifl\juSS\*cU<>.wph                           2-117

-------
                        Sunlight
Water  Vapor
                   Aerosol with
                    Metal Ions
                    and Carbon
                                                        «,.
                                                    Evaporation
Figure 2-26.   SO2 oxidation pathways (from Scire et aL, (1984b)).


                                     2-118
I Cloud Wacer
' r


. . . .

? 	
i

-------
                            Photo-
                         chemical
                         Reactions
                         Aqueous
                        Reactions
Figure 2-27.   NO, oxidation pathways (from Scire et aL, (1984b)).


                                       2-119

-------
combines with ammonia gas to form solid or aqueous ammonium nitrate (NI^NC^). Unlike
sulfate formation, the nitrate process is reversible. Equilibrium is established between nitric
acid, ammonia, and ammonium nitrate:

                       NH^NO,  - HN03(g)  + NHj(g)                              (2-191)

       The equilibrium constant for this reaction (K = [NHJfHNOJ/fNIi.NOJ) is a nonlinear
function of temperature and relative humidity as shown in Figure 2-28 (Stetson and Seinfeld,
1982).  The equilibrium constant can vary several orders of magnitude over a typical diurnal
cycle. Given fixed amounts of total nitrate, ammonia, and water vapor, higher NH^NC^
concentrations are expected at night due to lower nighttime temperatures and higher relative
humidities. Thus, the nitrate aerosol cannot be considered a stable product like sulfate. Also,
unlike sulfate, the ambient concentration  of nitrate is limited by the availability of ammonia
which is preferentially scavenged by sulfate (Stelson et aL, 1983).

       The transformation pathways for the five active pollutants (SO* SO;, NO,, HNO3, and
NOj) included in the MESOPUFF n scheme are shown in Figure 2-29.  Transformation rate
expressions were developed by statistically analyzing hourly transformation rates produced by a
photochemical model  The photochemical model employed the RHC/NOj/SO, chemical
mechanism of Atkinson et aL (1982).  Plume 80,/NO, dispersing into background  air containing
ozone and reactive hydrocarbons was simulated over a wide range of conditions representing
different solar radiation intensities, temperatures, dispersion conditions, background ozone and
RHC concentrations, plume NOX concentrations and emission times.  The following
transformation rate expressions, representing curve fits to the daytime hourly conversion rates
predicted by the photochemical model were determined:
                           36 K^pjf71 S'1* + *K-4)                             (2-192)

                            1206 O   S~IM [NO,"0-33                              (2-193)
                      *,  = 1261 [OJ1-45 rlj4 [NO,]-012                             (2-194)

where, kt     is the SO2 to SO4 transformation rate (percent/hour),
       k2     is the NO, to HNO3 + RNO3 transformation rate (percent/hour),
       k3     is the NO, to HNO3 (only) transformation rate (percent/hour),
       R     is the total solar radiation intensity (kw/m2),
       S      is a stability index ranging from 2 to 6 (PGT class A and B=2, C=3, D=4, E=5,
                    F=6),

i:\oUpufl\jul95\KCt26.wph                          2-120

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                                                                2S3
                     40     50     60     70    80     90     WO
                               RELATIVE HUMIDITY .  %
                                                               0.08
Figure 2-28.   NH4NO3 dissociation constant as a function of temperature and relative humidity
              (from Stelson and Seinfeld, (1982)).

                                          2-121

-------
     POLLUTANT 1
POLLUTANT 2
       (so;)
     POLLUTANTS
        (NOJ
 ALL PRODUCTS
                                                         POLLUTANT 4
                                                             (HN03)
     POLLUTANT 4
        (HN03)
                                   NH3
 POLLUTANTS
    (N03)
Figure 2-29.  Schematic representation of chemical pathways in the five-pollutant system assumed with the
           MESOPUFF n chemical mechanism.
                                      2-122

-------
       RH   is the relative humidity (percent),
       [OJ   is the background ozone concentration (ppm),
       [NOJ  is the plume NO, concentration (ppm), and,
              is the aqueous phase SO2 oxidation term (percent/hour).
       The aqueous phase component of the SO2 conversion rate was parameterized as:

                                   3 x W* Rff4                   .                (2-195)
       Equations (2.192) to (2.194) apply only during daytime periods when gas phase free
radical chemistry is active.  The use of the ozone concentration and the radiation intensity as
surrogates for the OH concentration, as in the above equations, is appropriate only during the
day. At night, SO2 and NOX oxidation rates resulting from heterogeneous reactions, are
generally much lower than typical daytime rates (Wilson, 1981; Forrest et aL, 1981). Nighttime
oxidation rates of 02% and 2.0% for SO2 and NO,, respectively, are used as default values in
the model

       Two options are provided for the specification of ozone concentrations: (1) hourly
ozone data from a network of stations (OZONE.DAT, see Section 42.6), or, (2) a single, user-
specified background ozone value may be used. The background ammonia concentration
required for the HNO3/NH4NO3 equilibrium  calculation can be user-specified or a default value
will be assumed.

       The parameterized NO, oxidation rate depends on the NO, concentration.  In situations
where puffs overlap, it is necessary to estimate the total  NO, concentration at a particular point
to properly determine k2 and k3.  Similarly, the nitrate equilibrium relationship requires
knowledge of the total (local average) SO^ NO,, and total nitrate (HNO3 -I- NO,)
concentrations. Because of the preferential scavenging of ammonia by sulfate, the available
ammonia is computed as total ammonia minus sulfate. The local average concentrations within
a puff are estimated as  the sum of contributions from  the puffs own pollutants plus those of
nearby puffs. Local average concentrations are separately computed for puffs within and above
the mixed-layer.

2.9    Wet Removal

       Many studies have shown that during  rain events, wet scavenging of soluble or reactive
pollutants can be of the order of tens of percent per hour (Barrie, 1981; Slinn et al., 1978;

fc\calpufl\iu»5\iecQ6.wph                           2-123

-------
Levine and Schwartz, 1982; Scire and Venkatram, 1985).  Gaseous pollutants are scavenged by
dissolution into cloud droplets and precipitation. For SO* aqueous-phase oxidation can be an
important removal pathway. Paniculate pollutants are removed by both ih-cloud scavenging
(rainout) and below-cloud scavenging (washout). Over source-receptor distances of tens to
hundreds of kilometers, wet scavenging can deplete a substantial fraction of the pollutant
material from the puff.

       A simple approach that has been shown (e.g., Maul, 1980) to yield realistic long-term
estimates of wet removal is the empirically-based scavenging coefficient method.  The depletion
of a pollutant is represented as:
                                   X, «P[- AAr]                                    (2-196)

where, x      is the concentration (g/m3) at time t and t + At, and,
       A      is the scavenging ratio.

       The scavenging ratio can be expressed as:

                                A  =  X (RIRj                                        (2-197)

where, X      is the scavenging coefficient (s"1),
       R      is the precipitation rate  (mm/hr), and,
       R!     is a reference precipitation rate of 1 mm/hr.

       The scavenging coefficient depends on the characteristics of the pollutant (e.g., solubility
and reactivity) as well as the nature of  the precipitation. Table 2-10 contains the default values
of the scavenging coefficient for SO* SOJ, NOr HNO3, and NO,.  A precipitation code
determined from the hourly surface meteorological observations of precipitation type (CD 144
data) is used to determine if the value  of X for liquid or frozen precipitation is most
appropriate.  The reported precipitation code is related to precipitation type as shown in
Table 2-11.  The liquid precipitation  values of X are used for precipitation codes  1-18. The
frozen precipitation values are used for precipitation codes 19-45.

       The user can override the default values of the scavenging coefficient by entering new
values in the CALPUFF control file  (see Section 4.2.1). An option is provided in the model to
completely by-pass the wet removal calculation for pollutants or time periods for which it is not
of importance.
i:\calpufl\jul95\tec426.wph                           2-124

-------
                                           Table 2-10
                       Default Values of the Scavenging Coefficient, ^(s
                             Pollutant      Liquid         Frozen
                                        Precipitation    Precipitation
                                SO2        3 x 10s        0.0
                               so;        11 ur*        3 x iff1
                                NO,        0.0            03
                               HNO3       6 x Iff5        0.0
                                           1 x Iff4        3 x Iff5
t\c«lpufl\jul95\fcct26.wph                            2-125

-------
                                             Table 2-11
          Conversion of Reported Precipitation Type/Intensity To Precipitation Codes
       Precipitation
         Code

       Liquid Precipitation
              1
              2
              3
              4
              5
              6
              7
              8
              9
             10
             11
             12
             13
             14
             15
             16
             17
             18

       Frown Precipitation
             19
             20
             21
             22
             23
             24
             25
             26
             27
             28
             29
             30
             31
             32
             33
             34
             35
             36
             37
             38
             39
             40
             41
              42
              43
              44
              45
Rain
Rain
Rain
Rain Showers
Rain Showers
Rain Showers
Freezing Rain
Freezing Rain
Freezing Rain
Not Used
Not Used
Not Used
Drizzle
Drizzle
Drizzle
Freezing Drizzle
Freezing Drizzle
Freezing Drizzle
Snow
Snow
Snow
Snow Pellets
Snow Pellets
Snow Pellets
Not Used
Ice Crystals
Not Used
Snow Showers
Snow Showers
Snow Showers
Not Used
Not Used
Not Used
Snow Grains
Snow Grains
Snow Grains
Ice Pellets
Ice Pellets
Ice Pellets
Not Used
Han
Not Used
Not Used
Small Han
Not Used
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
 Light
 Moderate
 Heavy
 Light
 Moderate
 Heavy
 Light
 Moderate
 Heavy
 Intensity not currently reported for ice crystals, hail and small hail.
t\calpuff\jul95\iec426.wph
       2-126

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 2.10    Odor Modeling

        CALPUFF uses a simple averaging-time scaling factor to estimate short-term peak
 concentration for assessing the perception of odor. Such adjustments to the mean concentration
 are necessary because the averaging time associated with the dispersion curves are 3 to
 60 minutes, while odors are perceived on time scales of a few seconds.

        The scaling factor (Turner, 1970) for averaging time in AUSPLUME is:
where (t) is the averaging time (min.) of interest, and (t0) is the averaging time consistent with
the dispersion rates used to obtain the mean concentration (assumed to be 60 minutes in
CALPUFF). The concentration averaging time is specified by the variable AVET in Input
Group 1 of the control file.
fc\«alpufl\iu»5\«ect26.wph                          2-127

-------

-------
                          3.  CALPUFF MODEL STRUCTURE

3.1    Memory Management

       A flexible memory management system is used in CALPUFF which facilitates the user's
ability to alter the dimension of the major arrays within the code. Arrays dealing with the
number of horizontal or vertical grid cells, meteorological stations, chemical species, puffs,
sources, and several other internal variables are dimensioned throughout the code with
parameter statements. The declaration of the values of the parameters are stored in a file
called "PARAMS.PUF."  This file is automatically inserted into any CALPUFF subroutine or
function requiring one of its parameters via FORTRAN "include" statements. Thus, a global
redimensioning of all of the model arrays dealing with the number of vertical layers, for
example, can be accomplished simply by modifying the PARAMS.PUF file and recompiling the
program.

       The parameter file contains variables which set the array dimensions or the maximum
allowed number of vertical layers, or horizontal grid cells, etc. The actual value of the variables
for a particular run is set within the user input file (Le., the control file), and can be less than
the maximum value set in the parameter file.

       A sample parameter file is shown in Table 3-1.  In addition to the parameters specifying
the maximum array dimensions of the major model arrays, the parameter file also contains
variables determining the Fortran I/O unit numbers associated with each input and output file.
For example, the input control file (IO5) and output list file (IO6) are normally associated with
unit numbers 5 and 6.  However, if these units are reserved on a particular computer  system,
these files can be redirected to other non-reserved units by setting IO5 and IO6 equal to 1 and
2, for example, as in the sample PARAMS.PUF file.

3.2    Structure of the CALPUFF Modules

       Execution of the CALPUFF model is divided into three major phases: setup,
computational, and termination (see Figure 3-1). In the setup phase of the model execution, a
variety of initialization and one-time I/O and computational operations are performed, including
the following:

          Processing of the command line argument.

          Opening of input and output files.

i:\ailpuff\jul95\iecO.wpli                            3-1

-------
                                                 Table 3-1
                                   Sample CALPUFF Parameter File
c	-	-	
c — PARAMETER statements                                     CALPUFF
c	.	...—.—.	.	.—,—
c — Specify Model version
      char«cter*8 aver, •level, •model
      parameter(mver-'3.0' ,ailevel«'950715' >
      parameter(mmodel«'CALPUFF')
c
c --- Specify parameters
      parameter(mxpuff*5000,mxspec*5)
      parameter(mxnx*90,mxny*90.mxnzBl2)
      paraMeter(mxnxg^,mxnvg*90,mxrecc2000)
      parameter(mxss*150,mxus*20,mxps*60)
      paraaeter(mxpt1*20,mxpt2*20,mxarea*20,n(vert*5)
      parameter(mxlines«10,mxvol-20)
      parameter(mxpdep=2,mxint*9)
      parameter(mxoz*20)
      paramter(mxhill*5,Mxtptse25,«xrect*180,mxcntr*21)
      parameter(mxsg*30,mxvar»60,mxcol«132)
      parameter
-------
                                                 Table 3-1
                            Sample CALPUFF Parameter File (Continued)
c         MXPT1 - Maximum number of point sources with constant
c                 -Mission parameters
c         NXPT2 • Maximum mater of point sources with time-varying
c                 Mission parameters
c        NXAREA • Maximum number of polygon arcs sources with constant
c                 emission parameters (i.e.. non-gridded area sources)
c        NXVERT - Maximum nuaber of vertices in polygon area source
c        NXLIMES- Naxiaui nuaber of line sources with constant
c                 Mission parameters
c         NXVOL - Naximum nuaber of voluae sources
c        NXRISE - Naxiaui nuaber of points in computed pluM rise
c                 tabulation for buoyant area and line sources
c        NXPOEP - Maximum nuaber of particle species dry deposited
c         KXINT - Naxiaui nuaber of particle size intervals used
c                 in defining •ass-weighted deposition velocities
c          MXOZ - Naximum number of ozone data stations (for use in the
c                 chemistry module)
c        NXHILL - Maximum number of subgrid-scale (CTSG) terrain
c                 features
c        NXTPTS - Maximum number of points used to obtain flow
c                 factors along the trajectory of a puff over the hill
c        MXRECT - Maximum number of complex terrain {CTSG) receptors
c        NXCNTR - Maximum number of hill height contours (CTDM ellipses)
c         NXLEV - Naximum number of vertical levels of met.  data
c                 allowed in the CTSG module (set to NXNZ in the
c                 current implementation of CALPUFF)
c
c --- CONTROL FILE READER definitions:
CT          MXSG - Maximum number of input groups in control  file'
c         NXVAR - Naximum number of variables in each input  group
c         NXCOL - Maximum length (bytes) of a control file input record
c~
c --- FORTRAN I/O unit numbers:
c           105 - Control file (CALPUFF.IMP)    • input  - formatted
c           106 - List file (CALPUFF.LST)       - output - formatted
c
c           107 - Meteorological data file      - input  - unformatted,
c                 (CALMET.DAT), or                        formatted,
c                 ISCMET.DAT,  or                           formatted
C                 PLMMET.DAT
c
c           108 - Concentration output file     - output - unformatted
c                 (CONC.OAT)
c           109 - Dry flux output file          - output - unformatted
c                 (DFLX.DAT)
c          1010 - Uet flux output file          - output - unformatted
c                 (UFLX.DAT)
c          1011 - Visibility output file        - output • unformatted
c                 (VISB.DAT)
c          1014 • I/O file name file            - input  - formatted
c                 (PUFFILES.DAT)
c-          1016 - Pt. source emissions file     - input  - unformatted
c                 (PTEMARB.DAT) with arbitrarily
c                 varying point source Missions
c          1017 - Buoyant area sources file     - input  • formatted
c                 (BAEMARB.DAT) with arbitrarily-
c                 varying location & emissions
c          1018 - Gridded volume source         - input  - unformatted
c                 emissions file (VOLEM.DAT)
c          1020 - User-specified deposition     - input  - formatted
c                 velocities (VD.DAT)
i:\calpufl\jul95\sect3.wph                                  3.3

-------
                                               Table 3-1
                          Sample CALPUFF Parameter File (Concluded)
c          1022 -  Hourly ozone Monitoring data  - input  - formatted
C                 (020NE.DAT)
c          1024 •  User-specified chemical      - input  - formatted
c                 transformation rates
C                 (CHEM.DAT)
c          1026 -  Hourly turbulence neasurenents- input  - formatted
c                 sigma v, sigma M
c                 (SIGNA.DAT)
c          1028 -  CTSG hill specifications from - input  - formatted
c                 CTDH terrain processor
c                 (HILL.OAT)
c          1030 -  Tracking puff/slug data      - output - formatted
c                 (DEBUG.OAT)
c        IOMESG -  Fortran unit number for screen- output - formatted
c                 output (NOTE: This unit is HOT
c                 opened -- it must be a
c                 preconnected unit to the screen.
c                 Screen output can be suppressed by
c                 the variable "INESG- in the control
c                 file)
i:\calpuff\jul9S\iecawph                                 3-4

-------
              Start
              SETUP -  Setup phase - Initialization and program setup operations.
              COM?  -  Computational phase - basic time loop with time-dependent I/O and all
                        scientific modules.
              FIN  •    Termination phase - program termination functions.
              STOP
Figure 3-1.  Flow diagram showing the calling sequence of major routines in the CALPUFF MAIN
            program.


t\calpufl\jul95\KCt3.wph                              3-5

-------
          Reading and processing the control file inputs which includes model option flags and
          run control variables.

          Reading and processing the time-invariant data records of the model's input data
          bases (Le., meteorological data file, optional emissions files, ozone data files, and
          user-specified deposition velocities and transformation rate files).

          Performing consistency checks of the input data base information versus the control
          file inputs.

          Performing initialization and setup operations for the chemistry, dry deposition,
          dispersion coefficient, and sampling modules.

          Writing the header records to the model's output concentration and dry/wet
          deposition files.

    The computational phase of the model includes the basic time loop within which the hourly
concentrations and deposition fluxes are computed and, if appropriate, time averaged. The
functions performed in the computation phase include the following:

          Retrieving and processing time-averaging data  from the meteorological, emissions,
          and ozone data files.

          Emitting,  transporting, and removals puffs from the computation grid.

          Evaluating the effects of dispersion, chemical transformation, wet removal, dry
          deposition, and subgrid  scale complex terrain.

          Sampling the puffs to determine concentrations and deposition fluxes at gridded and
          discrete receptors.

          Time-averaging and storing concentrations and deposition flux results to the
          appropriate output files.

    The final phase of the model execution deals with run termination functions. The
termination phase includes the closing of any active data files, computation of model run time,
and printing of summary or normal termination messages.

i:\calpufl\jul95\sect3.wpb                            3-6

-------
     A flow diagram for the setup module is provided in Figure 3-2.  The flow diagram contains
 the name of each subroutine or function called by the setup module along with a brief
 description of the routine's purpose. A flow diagram for the main computational routine,
 subroutine COMP, is shown in Figure 3-3.  As illustrated in the figure, COMP contains the basic
 time loop and calls to all of the technical modules.

     At the beginning of the hour loop, the  data files containing meteorological fields, time-
-varying emissions, and ozone observations are read. Then, a loop over puffs is entered which
•computes plume rise, determines puff-independent complex terrain parameters, and determines
 advective winds for the hour.  Plume dispersion, advection, chemical transformation, wet
 deposition,  dry deposition, terrain effects, and puff/slug sampling are performed within the
 innermost loop over sampling steps.
i:\calpufl\jul95\iect3.wph                            3.7

-------
       Enter SETUP
       DATETM
   Get date and time from the system dock.
       COMLINE   -  Get the I/O file name from the command fine
       READFN    -  Get the control file name and the list file name from the I/O file
       OPENFL    -  Open control file (input) and list file (output).
       READCF    -  Read the control file inputs.
       WRF1LES
   Write the file names used in this run to the list file
       SETCOM


       OPENOT


       RDHDEM2  -


       RDHDEM3  -


       RDHDEM4  -


       CHEMI


       EMQA


       RDTIEM2   -


       RDTIEM3   -



       (Coatinued)
   Set miscellaneous common block parameters (grid parameters, etc.)
   Open all other input and output files.
   Read header records for the PTEMARB.DAT emission file (arbitrarily-
   varying point source emissions).

   Read header records for the BAEMARB DAT emission file (arbitrarily-
   varying buoyant area source emissions).

   Read header records for the VOLEMDAT emissions file (gridded volume source
   emissions).

   Perform setup operations for the chemistry module.
   Perform QA checks on emission header record data, set up cross-referencing
   arrays.

   Read the time-invariant data from the PTEMARB.DAT file (arbitrarily-
   varying point source emissions).

   Read the time-invariant data from the BAEMARB DAT file (arbitrarily-
   varying area source emissions).
Figure 3-2.
Flow diagram showing the calling sequence of major routines in subroutine
SETUP (Setup Phase).
  i:\calpufl\jul95\iect3.wph
                            3-8

-------
       MET!       -  Read the header records for the meteorological data file
       MET2          MET1 for CALMET.DAT, MET2 for ISCMET.DAT, MET3 for PLMMETDAT).
       MET3
         •
         •                                                         f
       ELEVI      -  Interpolate the elevations from the meteorological grid to the gridded
                      receptor points
         •

       RDHDTVW  •  Read the header record from the turbulence data file (SIGMAJ5AT)
         *

       SIGSET     -  Perform setup operations for the dispersion coefficient module.
         *
         •
       SLUGI      -  Perform setup operations for the slug sampling function.

         •
       DRYI       -  Perform setup operations for the dry deposition module.

         •
       CTINTT     -   Perform setup computations for the subgrid-scale complex terrain module (CTSG)


       WROUT1    -  Write the header records to the CONCDAT (concentrations), DFLX.DAT
                      (dry deposition flux), and WFLXJDAT (wet deposition flux) output files.


       Return to MAIN PROGRAM
Figure 3-2.         Flow diagram showing the calling sequence of major routines in subroutine
                   SETUP (Setup Phase).  (Concluded).
  i\
-------
       Enter COMP
         •


       JULDAY    -   Compute the Julian day from the Gregorian date.


      -  Begin Hour Loop
               RDMET,   - Read an hour of meteorological data (RDMET for CALMET.DAT data,
               RDISC,       RDISC for ISCMETDAT data, RDPLM for PLMMETDAT data).
               RDPLM
                 •
               RDTVW   - Read turbulence data from SIGMAJ>AT file (if using turbulence os).
               RDOZ     - Read hourly ozone data from the OZONEJ3AT file (if using
                            MESOPUFF H chemistry).

               INTTR2D   - Initialize concentrations and deposition flux arrays at the beginning of
                            each averaging period.

               GETPRF,   - Compute ratio of wind speed to Brunt-Vaisala frequency and the
               HDUN       dividing streamline height for the CTSG module.
               INTTPUF   - Perform all initialization operations for new puffs. Read time-varying
                            emissions data (from PTEMARBDAT, BAEMARBDAT, VOLEM.DAT).

               Begin Loop Over Puffs


                       ZFTND        - Find the vertical layer containing the puff.
                       POWLAW      - Compute stack height wind speed using power law (only if using
                                          ISC2/AUSPLUME meteorological data).
                        Determine the winds for advection.

                        Determine puff codes.
                        *
                        Determine the sampling parameters for this puff.
                        *


                      (Continued)
Figure 3-3.  Flow diagram showing the calling sequence of major routines in Subroutine COMP
            (Computational Phase).


  i:\calpufl\jul9S\iect3.wph                            3-10

-------
                       Begin Loop Over Sampling Steps
                                •
                                •

                               ADVWND  - Compute plume-averaged advective winds from gridded
                                •           meteorological fields.
                                •

                               POWLAW  • Extrapolate surface winds to compute advective winds
                                            (only if using ISC2/AUSPLUME meteorological data).
                                *

                               SIGWV    - Determine plume turbulence values.
                                •
                                *

                               EXMET    - Transfer this hour's surface meteorological variables.
                                •


                               PTLAPS    - Compute local Brunt-Vaisala'frequency.
                               GETOZ    - Determine the appropriate ozone concentration to use in
                                           the chemistry eqns. for the puff.

                               VMASS    - Set vertical distribution of pollutant mass for this
                                            time step.

                               SETPUF   - Set the remaining parameters for puffs.
                               SETSLG    - Set the remaining parameters for slugs.
                               CHEM     - Determine the chemical transformation rates for this puff
                                            (compute internally or extract from user-specified array
                                            of values).

                               WET       - Compute the wet scavenging coefficients for this puff.
                              DRY
                          (Continued)
- Determine the deposition velocity for the puff (compute
 internally using the resistance model or extract from user-
 specified array of values).
Figure 3-3. Flow diagram showing the calling sequence of major routines in Subroutine
           COMP (Computational Phase).
  L-\calpuff\juI95\iect3.wph
      3-11

-------
                             If puff is treated as circular puff,
                                      •
                                    CALCPF - Compute the concentrations and deposition fluxes
                                                at each non-CTSG receptor using the integrated puff
                                                model
                                      •
                             End circular puff section.
                             If puff is treated as an elongated slug,
                                    CALCSL  - Compute the concentrations and deposition fluxes
                                               at each non-CTSG receptor using the slug model
                                      •
                              End elongated slug section.
                                    SLG2PUF
                                    CTSG

                       End Sampling Loop
  - If using slugs, generate circular puffs to represent
   the slug for the CTSG module.

  - Compute concentrations at the CTSG receptors.
                       TRACK  - Write puff data to the DEBUGJDAT file (if requested).
                 End Puff Loop
               OUTPUT  - Output time-averaged concentrations and deposition fluxes to disk files
                          list file.

               INCR     - Increment the hour and Julian day.
               GRDAY   - Convert the updated Julian day to a Gregorian date.
'—   End Hour Loop
      Return to MAIN PROGRAM


  Figure 3-3. Flow diagram showing the calling sequence of major routines in Subroutine
             COMP (Computational Phase). (Concluded).
  i:\calpufl\jul95\wct3.wph
3-12

-------
                              4. USER'S INSTRUCTIONS

4.1    OPTfflLL

       When the subgrid scale complex terrain (CTSG) option of the CALPUFF model is
invoked, two groups of additional data must be prepared by the user and entered into the
CALPUFF control file:  non-gridded receptor information and sub-grid scale terrain
information. The purpose of the optimizer program OPTHILL is to provide the user with the
means for calculating the set of terrain data that best characterizes each feature.

4.1.1   CTSG Terrain Information

       CTSG requires information on the location, orientation, size, and shape of each terrain
feature being modeled (see Section 422). The variables that contain this information are:

       xc,yc         coordinates (km)  of the center of the hill
       thetah        orientation (deg)  of major axis of hill (clockwise from north)
       zgrid         height (m) of "grid-plane" of grid above mean sea level
       relief        height (m) of crest of hfll above the "grid-plane" elevation
       expo (1)      hill-shape  exponent for major axis
       expo (2)      hill-shape  exponent for minor axis
       scale(l)      horizontal length scale (m) along major axis
       scale(2)      horizontal length scale (m) along minor axis
       axmax(l)     maximum  allowed axis length (m) for major axis
       axmax(2)     maximum  allowed axis length (m) for minor axis

       The profile of the terrain along each axis of the feature is prescribed by the following
equation:
                              1  -
                                  (xlscalef*0
                                              * relief                               (4-1)
where ht is the height of the profile above the base of the feature, at a distance x from the peak
(Figure 4-1).

       The terrain profile-optimizing program (OPTHILL) computes the hill shape exponent
(EXPO)  and horizontal terrain length scale (SCALE) parameters from a user-entered terrain
profile along each of two axes. This terrain profile defines the height of the surface of the hill
at a number of distances from the center of the hill, along each axis.  The OPTHILL program

fc\calpun\jul95\«ect4.wph                           4-1

-------
 Height-Profile  of
 Terrain Feature.
                                          Inverse-Polynomial
               	   Base  Of Inverse-Polynomial-  —  -
Figure 4-1.   Profile of a terrain feature along one of its two axes. A best-fit inverse polynomial

            function describes this profile to CTSG.
i;\eaipufl\ju»5\«e
-------
performs computations for one axis (Le., major or minor axis) of the terrain feature at a time.
Therefore, two runs of OPTHTT.L are necessary for each subgrid scale terrain feature.

       The following procedure is recommended to determine the terrain inputs for the
CALPUFF CTSG algorithm from a topographic map.

a.     Identify the sub-grid terrain features to be modeled.

       Such features will generally be small enough that they could be contained within one
       grid-square. This does not mean that they cannot straddle two or more squares. The
       features should be prominent, and possibly lie near source regions so that the additional
       computations required by CTSG are warranted in resolving important pollutant impact
       areas.

b.     Decide on the orientation of the feature.

       The orientation of the feature is generally evident if the feature is longer in one
       direction than another.  If there is no dominant direction to the feature, model it as a
       symmetric feature, and choose an orientation of north.

c.     Obtain height-profiles along each axis of the feature.

       Choose an  approximate center for the feature and draw axes through it (one axis should
       lie along the direction of orientation).  Along each axis, measure the distance between
       approximate intersections of the axis with marked contours.  The distances so measured
       should extend from the contour furthest to the south to the same contour furthest to the
       north (for a north-south axis).  Divide each of these distances by two, and tabulate the
       results.

d.     Identify the maximum elevation of the feature.

       Take the peak elevation directly from the map.

e.     Identify the elevation at the base of the feature.

       Generally, the base of the feature will be that point at which the feature becomes
       indistinguishable from terrain variations around it.
i:\calpufl\jul95\»ec«4.wph                            4-3

-------
f.      Convert all elevations that were tabulated to heights above the base of the feature.

g.      Use optimizer program (OPTHILL) to obtain shape parameters.

       The "relief parameter is just the peak elevation less the base elevation. The "axmax"
       value for each axis should be representative of the maximum extent of the feature along
       each axis at the elevation of the base of the feature. With these two variables fixed for
       each axis, the height-profile data from step c. can be put through OPTHILL to obtain
       "expo" and "scale" for each axis.

       OPTHILL requires a single input file (OPTHHJLINP) which contains the user's inputs
describing the terrain profile, each height, and maximum axis length. The computed volumes of
EXPO and SCALE for one axis of the hill are listed in the output list file (OPTHBLL.LST).
Table 4-1 summarizes the OPTHILL input and output file contents.  The format and contents of
the OPTHILL control file are variables explained in Table 4-2.

4.1.2   Example OPTHILL Application

       The OPTHILL program is an optimization that takes a value of "relief and "axmax," and
a sequence of pairs of (x,ht) values along an axis, and returns  a value of "expo" and "scale" that
prescribes the profile function that best matches the (x,ht) pairs.  Its use is illustrated by the
following example.

       Figure 4-2 shows the terrain surrounding the site of EPA's "Full-Scale Plume Study"
(FSPS) that was performed in the Truckee River Valley near  Reno, NV (Strimaitis et al., 1985),
as part of the Complex Terrain Model Development Program. Nocturnal flow in this valley is
frequently channeled by the high terrain to the north and south of the Tracy power plant.
Elevations typical of nocturnal plume heights (4600-4800 ft. MSL) are emphasized on the figure.
Given the predominant flow to the east during stable conditions, there is potential for plume
impact on the feature just northeast  of the plant. This feature, marked by axes in Figure 4-2,
was named "Beacon Hill" during the study.

       Following the procedures outlined above, axes were drawn over the feature and distances
between fixed contour elevations were tabulated. After  subtracting the elevation above sea level
of the base of the feature (the floor  of the river valley),  these data were entered into two files.
Figure 4-3 displays the contents of both files. The files (names axisl.inp and  axis2.inp) contain
"relief and the value for  "axmax" for each axis of the hill, followed by five pairs of (x,ht) values.
The first record of each file is reserved for comments to identify the data.  Values for "relief

i:\calpufl\jul95\sect4.wph                            4-4

-------
                                          Table 4-1
                               OPTHILL Input and Output Files
  Unit	File Name     Type	Format	Description	
    5    OPTHDLLJNP    input         formatted        Control file containing user inputs
    6    OPTHILL1ST    output        formatted        List file (line printer output file
i:\calpiifl\jul95\««*4.wph

-------
                                          Table 4-2
                        OPTHILL Control File Inputs (OPTfflLLJNP)
  Record
Variable
  No.
Variable
 Name
Columns
•type of
Format
Description
     1

     2
   1       TTTLE(15)

   1       RELIEF


   1       AXMAX
            1-60         15A4      60 character title

            *           real       Height (m) of the crest of the hill
                                  above the grid elevation

            *           real       Maximum allowed axis length (m)
                                  for the axis (major or minor) being
                                  evaluated

            *           -          This record is skipped by the
                                  program. May contain optional text
                                  data (see example)
     5


     5
   1       DIST


   2       HOT
                        real       Distance-height pairs describing the
                                  profile of the terrain.  Units: m

                        real       Distance-height pairs describing the
                                  profile of the terrain.
                                  Units:  m
 * Entered in FORTRAN free format.
i:\adpufl\jul93\Kct4.wph
                                 4-6

-------
                                                                                  160-ffl Tower
                                                                                  1O-m Tower
                                                                                  Camera
                                                                             CP   Command Canter
Figure 4-2.    Map  of terrain surrounding the site of the FSPS, illustrating the selection and
               characterization of a terrain feature for CTSG modeling.
i:\olpafl\juHS\iecM.wpli
4-7

-------
Optimal SCALE aod EXPO felon - Axk #1 of cnaple problem
300.- Height (m) of hffl cnat above -zero-pUBe1 •fevrtta (RELIEF)
2000.- Madam allowed Ia0h (m) for Ok todi (AXMAX)
	DttaBCc-M«^|>«inde*at>tafUn profile-
S6U39.- DhL(m) tan en*, lemrin fet (•) above Taojt-e' dev.
826,    178.     (RcpatodfaraekdW.-hd^t|Mir)
1062,   ISO.
1193,   117.
1308,   56.
                (a) OFTHILLINP for Axis #1 of the hflL
       Optimal SCALE *od EXPO bcton - Ajk #2 of maple problem
       300.                        -Hd^tf(m) of kffl cmt above "zero-pbaie' ekv^ion (RELIEF)
       1500.                       -Mntaram«IIovedlen^h(
                                 -DfaUace-beJtUpiin describing Un profile
       302,   239.                 - Diit(m) from oat, lemin bt (m) above •zen>^laiie> dev.
       SSL,   178.                  (Repealed (or each disL-beight pair)
       70S,   ISO.
       970,   117.
       1311,  56.
                (b) OFIHILL.INP for Axis #2 of the hffl.
Figure 4-3. Sample OFTHILL input files for (a) Axis #1 and (b) Axis #2 of the hill is in the
             example.

i:\calpuff\juI9S\fect4.wph                                 4-8

-------
and "axmax" are free-format, and should be entered anywhere in the open space provided on the
next two lines.  Pairs of (x,ht) should be entered right after the next comment record.

       OPTHILL must be invoked separately for each of the two axes of the hill. This is
accomplished by renaming one input file (e.g^ axisl jnp) to the OPTHILL input control file
name (OPTHTLLJNP), executing the program,  renaming the output file (OPTHILL.LST) to a
new name (e.g., axisl Jst), and then repeating these steps for the second axis of the hill The
output files produced by OPTHILL for the current example are presented in Figure 4-4 and 4-5.
The output file lists the final values of the profile parameters, and it also lists the profile data
provided by the user along with the corresponding data computed from the profile parameters.

       With these results, hill information that is independent of the choice of coordinate
system and the modeling grid for the wind model can be specified:

       xc,yc (m)                  (depends on choice of coordinates)
       thetah (deg)               69°
       zgrid (m)                  (depends on grid for wind model)
       relief (m)                  300.
       expo (1)                  1.91
       expo (2)                  1.24
       scale (1) (m)               1523.
       scale (2) (m)               2896.
       axmax (1) (m)             2000.
       axmax (2) (m)             1500.

Note that scale(2) is almost twice scale(l), even though  axis 1 corresponds to the longer axis of
the hill. This can occur because the "scale" parameter is a property of the entire inverse-
polynomial function (Equation 4-1), rather than just the portion of the function that is fit to the
profile of the terrain. In Figure 4-1, the shape of the terrain might best conform to the upper
10% of the polynomial function, in which case the "scale" parameter would exceed "axmax."  In
this example application of the OPTHILL program, we see that axmax(2) is substantially less
than axmax(l), whereas scale(2) exceeds scale(l), indicating that a comparatively smaller portion
of the polynomial function represents the terrain profile along the minor axis.
i:\calpufl\jul95\sect4.wph                           4_9

-------
••* Optimal SCALE and EXPO facton - AIM #1 of enable problem •*•

        EVOLTIMEUMTT -    M. SECONDS    SKIP - 10

NUMBER OF PARAMETERS FOR THIS STUDY: 4

PARAMETER             START VALUE STEP CONTROLLOWER UMTTUPPER UMTT
1 RELIEF   O3000E+03     O.OOOOE+00     &3000E+03     03000E+03
2AXMAX   (L2000E+M     O.OOOOE+00     O2000E+04     (UOOOE+04
3 EXPO     OJOOOE+Ol     OJOOOE^-01     0.1000E+00     &1000E+02
4 SCALE    OJOOOE+M     aiOOQE+04     «L200dE-f02     (UOOOE+06
CALCULATIONS STARTED
RETURN VALUE: 2        NORMAL RETURN           FUNCTION VALUE: 0.50303

PARAMETER VALUES:
           RELIEF -   300.00000
           AXMAX -   2000.00000
           EXPO   -     1.90651
           SCALE  -   1522.94500
DfcUnce    Height     Fitted Value

 564.0     239.0      237.4
 826.0     178.0      186.4
 1062.0     150.0      139.9
 1193.0     117.0      115.5
 1508.0      56.0      63.0
Figure 4-4. Content of output file produced by OPTHUJL in processing axis #1 of sample hill.

i:\calpufl\jul95\sect4.wph                                 4-10

-------
 *" Optimal SCALE and EXPO bcton-Axfc #2 of example problem •••

         EVOL TIME LIMIT -    «. SECONDS    SKIP - 10

 NUMBER OF PARAMETERS FOR THIS STUDY: 4

 PARAMETER             START VALUE STEP OONTROLLOWER UMf ItlPPER UMIT
 1 RELIEF   O3000E+03    O.OOOOE+00     OJOOOE+03     OJOOOE+03
 2AXMAX   0.1500E+04    O.OOOOE+00     (U500E+04     0.1500E+04
 3 EXPO     02000E+01    (UOOOE+01     OJOOOE+00     OJOOOE+02
 4 SCALE    0.1500E+04    0.7500E+03     0.1300E+02     OJ500E+06
CALCUL/.TIONS STARTED
RETURN VALUE: 2        NORMAL RETURN            FUNCHON VALUE: 2.17504

PARAMETER VALUES:
           RELIEF  -   300.00000
           AXMAX  -  1300.00000
           EXPO    -    L23912
           SCALE   -  2895.90200
Distance    Height     Fitted Value

 302.0     239.0      244.4
 SS1.0     178.0      189.1
 708.0     150.0      154.7
 970.0     117.0       99.5
 1311.0      56.0       33.0
Figure 4-5. Content of output file produced by OFIHLLL in processing axis #2 of sample hill

i:\calpufl\jul9S\seci4.wph                                 4.11

-------
       CALPUFF Model Input Files

       The CALPUFF model obtains the necessary information concerning sources, receptors,
meteorological data, geophysical data, and model control parameters from a series of input files.
These files are listed in Table 1-2. The model creates several output files, which are listed in
Table 1-4. In this section, detailed information on the structure and content of each of the input
and output files is provided.

       Tables 1-2 and 1-4 show the Fortran unit numbers associated with each file. As
indicated in Section 3.1, these unit numbers are specified in the parameter file (PARAMS.PUF).
They can be easily modified to accommodate system-dependent restrictions on allowable unit
numbers.  Any changes to variables in the parameter file are automatically modified throughout
the CALPUFF Fortran code.  The code must be re-compiled for changes in the parameter file
-to take effect, since .the parameter values are set at the program compilation stage rather than
at program execution.

       The name and full path of each CALPUFF file (except one) is assigned in an I/O file.
The exception, the I/O filename itself, is assigned on the command line.  For example, on a
DOS system,

             CALPUF3 d:\CALPUFF\PUFFTLES.DAT

will execute the CALPUFF code (CALPUF3.EXE), and read the input and output filenames for
the current run from the file PUFFILES.DAT in the directory d:\CALPUFF.  If the I/O
filename is not specified on the command line, the default I/O filename (i.e.,  PUFFILES.DAT
in the current working directory) will be used. The I/O path and filename can be up to 70
characters long.

       The utility routine that delivers a command line argument is system dependent. The
function that provides the system clock time and system CPU time are also system or compiler-
specific. All system-dependent or compiler-specific routines in CALPUFF are isolated into a
file called DATETMjKX, where  the file extension ( JDOC) indicates the system for which the code
is designed. For example, DATETM.HP contains code for Hewlett-Packard Unix systems,
DATETM.SUN is for Sun Unix systems, DATETM.LAH is for Lahey-compiled PC-applications,
and DATETM.MS is for Microsoft-compiled PC applications.  By appending the correct system-
dependent DATETM file onto the main CALPUFF code, the code should run without any
modifications.

i:\calpufl\jul9S\secl4.wph                          4-12

-------
        A sample I/O file is shown in Table 4-3.  Each CALPUFF input and output file has a
 default name and path (Le., the current working directory).  If the filename is not specified in
 the I/O file, the default name will be assumed. Each filename must be less than or equal to 70
 characters long.

        The I/O file is read by the CALPUFF control file reader module.  Therefore, the same
 syntax rules that apply to the control file (explained in Section 4.2.1) also apply to the I/O file.
 Basically, all text except that between the delimiters (Le.,! characters) is treated as user
 comments, and is ignored by the input module. Between the delimiters, the character filename
 variables (e.g., PUFTNP, METDAT, PUFLST, etc.) must be entered as shown in the sample file.
 The control file reader is case insensitive. The filename is placed between the equals sign and
 the right delimiter character (!). Files that are not used or are not to be changed from their
 default names can be omitted from the I/O file.  For example, by replacing the delimiter
 characters ("!"s) with "*"s, the line becomes a comment, and will not be interpreted by the
 program as data:

-            ! PUFINP - calpuffinp !    - this line sets the control file  name

              * PUFINP = calpuff.old *   - this line is a comment that does nothing

~            * PUFLST =         *      this line is OK (interpreted as a comment)

 -            ! PUFLST =         !      - this is not OK (delimiters present, so file must be
                                          specified)

        Blanks within the delimiters are ignored, and all delimiters must appear in pairs.  If the
 optional CALPUFF GUI is being used, the I/O file will automatically be correctly formatted
 and written to disk for used by CALPUFF.


 42.1    User Control File (CALPUFF.INP)

        The selection and control of CALPUFF options are determined by user-specified inputs
 contained in a file called the control file. This file, CALPUFF.INP, contains all the information
 necessary to define a model run (e.g., starting date, run length, grid specifications, technical
 options, output options,  etc.).
 i:\calpuff\jul95\«ecU.wph                           4-13

-------
                                               Table 4-3
                           Sample CALPUFF I/O File (PUFFILES.DAT)
                             CALPUFF file
COMKXI input and output file*

Default Name  Type         File Na*e

CALPUFF.IMP   input   I PUFINP -d:\calpuff\testcase\CALPUFF.INP    I
CALMET.DAT    input   I NETOAT -d:\calplrff\testcase\CALHET.DAT     I
    or
ISCMET.DAT    input   I iscdat «test.«*t      I
    or
PLMMET.DAT    inpCit   I plKlat -austest.wet   I

CALPUFF.1ST   output   ! PUFLST «CALPUFF2.LST
CONC.DAT      output   ! CONOAT -CONC2.DAT
DFLX.DAT      output   I DFDAT  -OFLX2.DAT
WFLX.DAT      output   I UFDAT  -WFLX2.DAT
VISB.DAT      output   I VISOAT -VISB2.DAT

Emission files

PTEMARB.DAT   input   I ptdat  -ptemrb.dat   I
VOLEN.OAT     input   ! voldat «vole».dat     I
BAENARB.DAT   input   I ardat  -baewdat.dat   I

Other Files

OZONE.OAT     input     OZDAT  -OZONE.DAT
SIGMA.DAT     input     sigdat *sigm.dat
VD.OAT        input     vddat  »vd.dat
CHEM.DAT      input     cheffldat-chem.dat
HILL.DAT      input     hildat «hiU.dat
DEBUG.LST     output     debug  -debug.1st

All filenames will be converted to lower case  if  LCFILES = T
Otherwise, if LCFILES = F,  file names will be  converted to UPPER CASE
         T = lower case       ! LCFILES = T !
         F = UPPER CASE
1ENO!

NOTE: (1) file/path names can be up to 70 characters  in length
i:\calpufl\jul95\ted.J.wph
4-14

-------
        CALPUFF has a PC-based, Windows-compatible Graphical User Interface (GUI) that
 can be used to prepare the CALPUFF control file (CALPUFF.INP), execute the model, or
 conduct file management functions.  The user interface contains an extensive help system that
 makes much of the information in this manual available to the user on-line.

       The source data and receptor information required for a CALPUFF run can be entered
through the edit screens or read from external ASCH files (spreadsheet-compatible). Each
 source type (points, areas, volumes, and lines) contains an external ASCH file format description
 and sample file in the help system.

       Although the model can be set up and run entirely within the user interface system, the
 interface is designed to always create an ASCH CALPUFF JNP file.  This allows runs to be set
 up on PC-based systems and the control file transferred to workstation or mainframe computer
 for computational intensive applications. The ASCII CALPUFF.INP file should be directly
 transportable to virtually any non-PC system. Also, the model can be setup and run entirely on
•a non-PC system by using a conventional editor directly on the CALPUFF JNP file, which itself
 contains extensive self-documenting statements.

       The control file is organized into 17 major Input Groups and a variable number of
 subgroups within several of the major Input Groups. The "first three lines of the input file
 consist of a run title. As shown in Table 4-4, the major Input Groups are defined along
 functional lines (e.g., technical options, output options, subgrid scale, complex terrain inputs,
 etc.).  Each subgroup contains a set of data such as source variables, subgrid scale hill
 descriptions, or discrete receptor information. The number of subgroups varies with the number
 of sources, hills, etc., in the model run.

       A sample control file is shown in Table 4-5. The control file is read by a set of Fortran
 text processing routines contained within CALPUFF which allow the  user considerable flexibility
 in designing and customizing the input file. An unlimited amount  of optional descriptive text
 can be inserted within the control file to make it self-documenting. For example, the definition,
 allowed values, units, and default value of each input variable can be included within the control
 file.

       The control file processor searches for pairs of special delimiter characters (!).  All text
 outside the delimiters is assumed to be user comment information and is echoed back but
 otherwise ignored by the input module. Only data within the delimiter characters is processed.
 The input data consists of a leading delimiter followed by the variable name, equals sign, input

 c\ajpufl\ju83\McM.wph                           4-15

-------
value or values, and a terminating delimiter (e.g., !XX = 115 !). The variable name can be
lower or upper case, or a mixture of both (Le., XX, xx, Xx are all equivalent). The variable type
can be real, integer, logical, or character and it can be an array or a scalar. The use of
repetition factors for arrays is allowed (e.g.,! XARRAY « 3 * 1.5 ! instead of! XARRAY =
1.5,1,5,13 !). pifferent values must be separated by commas.  Spaces within the delimiter pair
are ignored Exponential notation (E format) for real numbers is allowed However, the
optional plus sign should be omitted (e.g., enter + 15E+10 as 15E10). The data may be
extended over more than one line (except for character variables, which must be entirely on one
line). The line being continued must end with a comma. Each leading delimiter must be paired
with a terminating delimiter. All text between the delimiters is assumed to be data, so no user
comment information is allowed to appear within the delimiters. The inclusion in the control
file of any variable that is being assigned its default value is optional The control file reader
expects that logical variables will be assigned using only a one character representation (i.e., 'T
or*F).

       The major Input Groups must appear in order, Le., Input Group 1 followed by Input
Group 2, etc. However, the variables within an Input Group may appear in any order. The
variable names in each Input Group are independent, so that the same name can be repeated in
different Input Groups (e.g., as shown in the sample control file, species names (SO2, SO4) are
use in several Input Groups). Each Input Group and subgroup must end with an Input Group
terminator consisting of the word END between two delimiters (Le., !END!). Every major Input
Group, even blank Input Groups (Le., one in which no variables are included) must end with an
Input Group terminator in order to signal the end of that Input Group and the beginning of
another.

       The control file module has a list of variable names and array dimensions for each Input
Group. Checks are performed to ensure that the proper variable names are used in each Input
Group, and that no array dimensions are exceeded.  Error messages result if an unrecognized
variable name is encountered or too many values are entered for a variable.
i:\calpufl\jul95Vect4.wpb                           4-16

-------
                                            Table 4-4
                           Input Groups in the CALPUFF Control File
       Input
       Group       Description

         *         Run title
                       First three lines of control file (up to 80 characters/line)

         1         General run control parameters
                       Starting date and hour, run length, time step.
                       Number of species.

         2         Technical options
                       Control variables determining methods for treating chemistry, wet deposition, dry
                       deposition, dispersion, plume rise, complex terrain, and near-field puff sampling
                       methods

         3         Species list
                       Species names, flags for determining which species are modeled, advected, emitted,
                       and dry deposited

         4         Grid control parameters
                       Specification of meteorological, computational, and sampling grids, number of cells,
                       vertical layers, and reference coordinates.

         5         Output options
                       Printer control variables, disk output control variables

         6a,b,c     Subgrid scale complex terrain (CTSG) inputs
                       Information describing subgrid scale hill location, shape and height. Complex terrain
                       receptor locations and elevations.

         7         Dry deposition parameters - Gases
                       Pollutant diffusivity, dissociation constant, reactivity, mesophyll resistance, Henry's law
                       coefficient

         8         Dry deposition parameters - Particles
                       Geometric mass mean diameter, geometric standard deviation
i:\calpufl\juJ95\sec44.wph                              4-17

-------
                                      Table 4-4 (Concluded)
                          Input Groups in the CALPUFF Control File
      Input
      Group       Description

         9        Miscellaneous dry deposition parameters
                       Reference cuticle and ground resistances, reference pollutant reactivity, vegetation
                       state

         10        Wet deposition parameters
                       Scavenging coefficients for each pollutant and precipitation type (liquid and frozen
                       precipitation)

         11        Chemistry parameters
                       Control  variables  for input of ozone data, background ozone and  ammonia
                       concentrations, nighttime transformation rates

         12        Miscellaneous dispersion parameters and computational parameters
                       Vertical  dispersion  constants, dispersion rate above the boundary layer, crossover
                       distance  to time-dependent dispersion coefficients, land use associated with urban
                       dispersion

      13a,b,c       Point source  parameters
                       Point source data including source location, stack parameters and emissions, and
                       building  dimensions

      14a,b        Area source parameters
                       Area source data including source location, effective height, elevation, initial sigmas
                       and emission rates

      15a,b        Line source parameters
                       Buoyant  line source data including source location, tine length, buoyancy parameters,
                       release height, and emission rates

      16a,b        Volume source parameters
                       Volume  source data including source location, effective height, initial size data

      17a,b        Non-gridded  (discrete) receptor information
                       Receptor coordinates and ground elevation
i:\calpufl\jul95\tect4.wpb                               4-18

-------
                                               Table 4-5

                          Sample CALPUFF Control Ffle (CALPUFFJNP)
                                         Input Groups 1 and 2

CALPUFF tnt run — 3 hour simulation
10 x 10 Meteorological grid
1 point source end CTSG hill set up to compare with  INPUFF 3 test
	 Run title (3 lines) 	
                    CALPUFF MODEL CONTROL FILE
 INPUT GROUP: 1 --  General run control parameters
     Starting date:   Year (IBYR) -- No default
                    Month (IBMO) •• No default
                      Day (IBOY) -- No default
                     Hour (IBHR) — No default

     Length of run (hours) (IRLG) — No default

     Number of chemical species (NSPEC)
                                    Default:  5
     Nuaber of chemical species
     to be emitted  (NSE)
Default:  3
                 I  IBYR*  94  I
                 I  IBMO*  11  I
                 I  IBDY*  1  I
                 I  IBKR*  10  I

                 I-IRLG*  2  I


                 I  NSPEC*  2  !
     Flag to stop run after
     SETUP phase (ITEST)             Default: 2
     (Used to allow checking
     of the model  inputs, files, etc.)
           ITEST * 1 • STOPS program after SETUP phase
           ITEST * 2 - Continues with execution of progr
                      after SETUP
I  NSE*  1   I


I  ITEST* 2 I
     Meteorological Data Format (METFM)
                                    Default:  1
                I METFM
          2  I
           METFM =  1 - CALMET binary file (CALMET.DAT)
           METFM *  2 - ISC ASCII file (ISCMET.DAT)
           METFM *  3 - AUSPLUME ASCII file (PLMMET.DAT)
     Averaging  Time  (minutes) (AVET)
                                    Default: 60.0
     PC sigma-y is adjusted by the equation
     (AVET/60.0)**0.2
                I AVET * 60.0 I
I END!
INPUT GROUP: 2  -- Technical options
     Vertical distribution used in the
     near field  (MGAUSS)
        0 * uniform
        1 - Gaussian
      Default: 1
    ! MGAUSS *  1  I
i:\alpiifl\jul9S\iecM.wph
              4-19

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFFJNP)
                                            Input Group 2
Terrain adjustawnt Method
(MCTADJ)
   0 * no adjustMent
   1 • ISC- type of terrain adjustment
   2 - staple,  CALPUFF-type of terrain
       adjustMent "
Subgrid-scale coaplex terrain
flag (NCTSG)                         Default: 0
   0 • not Modeled
   1 « modeled

Near-field puffs Modeled as
elongated 0 (MSLUG)                   Default: 1
   0 * no
   1 « yes (slug Model used)

Transitional plume rise Modeled ?
(MTRANS)                             Default: 1
   0 * no  (i.e., final rise only)
   1 • yes (i.e., transitional rise coaputed)

Stack tip downwash?  (MTIP)            Default: 1
   0 - no  (i.e., no stack tip downwash)
   1 « yes (i.e., use stack tip downwash)

Effects on pluae rise of vertical wind shear
above stack top Modeled 7 (MSHEAR)    Default: 0
   0 * no  (i.e., shear not Modeled)
   1 • yes (i.e., shear Modeled)

Puff splitting allowed ? (HSPLIT)     Default: 0
   0 = no (i.e., puffs not split)
   1 • yes (i.e., puffs are split)

Chemical Mechanism flag (MCHEN)       Default: 1
   0 « chemical transformation not
       Modeled
   1 = transformation rates computed
       internally (MESOPUFF II scheme)
   2 = user-specified transformation
       rates used

Wet removal modeled  ? (MWET)          Default: i
   0 = no
   1 K yes

Dry deposition modeled ? (MDRY)       Default: 1
   0 = no
   1 * yes
   (dry deposition method specified
    for each species in Input Group 3)
                                         Default: 1     I  MCTADJ «  0
                                                          NCTSG  *  0   I
                                                          MSLUG -   1   I
                                                        I  MTRANS •  0   I
                                                          MTIP > 0  !
                                                        !  MSHEAR «   0   I
                                                        !  MSPLIT * 0  I
                                                        I  MCHEM «  0  I
                                                       !  MUET =  0  !
                                                       I  MDRY =  0  I
fc\calpufl\jul9S\«ect4.wph
                                             4-20

-------
                                         Table 4-5 (Continued)
                          Sample CALPUFF Control File (CALPUFF.INP)
                                             Input Group 2
     Method used to compute dispersion
     coefficients (MDISP)                  Default: 4   I NDISP «  3  !

        1 • dispersion coefficients computed fro* values of
            Sigma v, si DM u read fros) SIGMA.OAT  file
        2 « dispersion coefficients sigma v, sigM u computed
            internally from micrometeorological variables (u*, w*, L, etc.)
        3 « PG dispersion coefficients for RURAL  areas (computed using
            the ISCSI multi-segment approximation) and MP coefficients in
            urban areas
        4 « sane as 3 except PG coefficients computed using
            the MESOPUFF II eqns.
        5 • CTDM signs used for stable and neutral conditions.
            For unstable conditions, sigmas are computed as in
            MDISP « 1,  described above.  NDISP «  5 assumes that
            sigma v, sigma w are read fro* a SIGMA.DAT file

     PG slgma-y, z adj. for roughness?       Default: 0    I NROUGH *  1   I
     (MROUGH)
        0 * no
        1 * yes

     Partial plume penetration of            Default: 0    ! MPARTL «  1   I
     elevated  inversion?
     (MPARTL)
        0 e no
        1 = yes

     Test options specified to see if
     they conform to regulatory
     values? (MREG)                      Default: 0   I MREG =  0  I

        0 s NO checks are made
        1 = Technical  options must conform to USEPA values for
            short-range modeling ( e.g. ISC-type  applications)
        2 = Technical  options must conform to USEPA values for
            long-range modeling (e.g. visibility-type applications)
        3 * Environmental Protection Authority of Victoria (EPAV)
            default values
(END!
i\calpufl\jul9S\«ect4.wph                                4-21

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFFJNP)
                                        Input Groups 3 and 4
INPUT GROUP: 3 — Species list
The following species are Modeled:
I CSPEC • S02
I CSPEC « SO4
     I END I
     IENOI
SPECIES
 NAME
I S02
i S04

I END!
   MODELED
(0*NO,  1-YES)
      1  .
      1  .
                   Dry
   EMITTED       DEPOSITED
(0-NO,  1-YES)  (0-ttO,
               1-COMPUTED-GAS
               2-COMPUTED-PARTICLE
               MJSER-SPECIFIED)
     1  .            1             I
     0  .            2     .        I
INPUT GROUP: 4  — Grid control parameters
METEOROLOGICAL grid:
            No. X grid cells (NX)
            No. V grid cells (NY)
         No. vertical layers (NZ)

           Grid spacing (DGRIDKM)
               Cell face heights
                   (ZFACE(nz*1»
            Reference Coordinates
           of  SOUTHWEST corner of
                 grid P01NT(1. 1):

            X  coordinate (XORIGKH)
            Y  coordinate (YORIGKM)
                 UTM  zone (1UTMZN)

   Reference coordinates of CENTER
        of the domain
            Latitude   (deg.) (XLAT)
           Longitude  (deg.) (XLONG)
             Time zone       (XTZ)
       (PST=8, MSTs?a  CST*6, EST=5)
                          No default
                          No default
                          No default

                          No default
                          Units:  km
                          No defaults
                          Units: m
                          No default
                          No default
                          Units: km

                          :Jo default
                          No default
                          No default
                          No default
                        I  NX *  10  I
                        I  NY «  10  !
                        I  NZ -  2   1

                        I  DGRIDKM «= 4.0 !
                                                    I  ZFACE - 0.0, 200.0, 1000.0 I
                        I  XORIGKM =  -4.0 I
                        I  YORIGKM -  -4.0 I
                        ! IUTMZN -   19  I
                       I XLAT  = 42.0  I
                       I XLONG = 75.0  !
                       < XTZ   * 5.0   !
i:\calpufl\juI9S\MCt4.wpL
                                      4-22

-------
                                         Table 4-5 (Continued)
                          Sample CALPUFF Control File (CALPUFFJNP)
                                             Input Group 4
Computational grid:

     Th« computational grid 1«  identical to or • subset of the NET. grid.
     The lower left (LI) corner of the computational grid 1* it grid point
     (IKONP, JBCQMP) of the MET. grid.  The upper right (UR)  corner of the
     computational grid is at grid point (lECONP, JECOMP) of the NET. grid.
     The grid specify of the computational grid is the same M the NET. grid.
        X index of LI corner (IICOMP)      No default
                  (1 <> I8CONP <- NX)

        Y index of LL corner (JBCONP)      No default
                  (1 <- JBCONP <* NY)
               I  IWONP -  1
               I  JBCONP «  1  !
        X index of UR corner  (IECONP)      No default
                  (1  o IECONP <- NX)

        Y index of UR corner  (JECOMP)      No default
                  (1  <- JECONP <» NY)
               I  IECONP -  10  I


               I  JECONP «  10  I
SAMPLING GRID (GRIOOED  RECEPTORS):

     The lower left  (LL) corner of the sampling grid is at grid point
     (IBSAMP, JBSANP) of the NET. grid.  The upper right  (UR) corner of the
     sampling grid is at grid point (IESANP, JESAHP) of the NET. grid.
     The sampling grid  must be identical to or a subset of the computational
     grid.  It may be a nested grid inside the computational grid.
 ,.   The grid spacing of the sampling grid is OGRIOKN/NESHDN.  The number of sampling
 ,.   grid points is  HXSAM * NYSAN. where:
                                      NXSAN « NESKDN*(IESAMP-IBSANP)+1
                                      NYSAN « NESHDN*(JESANP-JBSANP)t-1
        Logical  flag indicating if gridded
        receptors are used  (LSAMP)         Default:  T
        (T=yes,  F=no)

        X index  of LL corner (IBSAMP)      No default
         (IBCONP <= IBSAMP  <= IECOMP)

        Y index  of LL corner (JBSAMP)      No default
         (JBCONP <= JBSAMP  <= JECOMP)
               I  LSAMP = T I



               1  IBSAMP =  1  I



               I  JBSAMP =  1  !
        X index of UR corner (IESAMP)
         (IBCOMP <=  IESAMP <= IECOMP)

        Y index of UR corner (JESAMP)
         (JBCOMP <=  JESAMP <= JECOMP)

       Nesting factor of the sampling
        grid (MESHDN)
        (MESHON is an integer >» 1)
No default     I  IESAMP =  10  I
No default     I JESAMP *  10  !
No default      I MESHON «  1  I
•END!
i:\caipufl\jul95\McM.wph
        4-23

-------
                                            Table 4-5 (Continued)
                             Sample CALPUFF Control File (CALPUFF.INP)
                                                Input Group 5
INPUT GROUP: 5 - Output Options
     FILE
                        DEFAULT VALUE
                   VALUE THIS RUN
   Concentrations (ICON)              1
   Dry Fluxes (IDRY)                  1
   Uet Fluxes (IWET)                  1
   Relative Huaidity (MS)           1
    (relative timidity file is
     required for visibility
     analysis)
                                                 I    ICON  >  1  I
                                                 !    IDRY  «  0  I
                                                 I    IWET  *  0  I
                                                 I    IVIS  *  0  I
    0 * Do not create file, 1 « create file
    LINE PRINTER OUTPUT OPTIONS:

       Print concentrations (ICPRT)
       Print dry fluxes (IDPRT)
       Print wet fluxes (IUPRT)
       (0 « Do not print, 1 « Print)

       Concentration print interval
       (ICFRQ) in hours
       Dry flux print interval
       (IDFRQ) in hours
       Wet flux print interval
       (IWFRO) in hours

       Messages tracking progress of
       run written to the screen ?
       (INESG) — 0=no, 1«yes
                              Default: 0
                              Default: 0
                              Default: 0
                              Default: 1

                              Default: 1

                              Default: 1

                              Default: 1
                    I ICPRT *  1   I
                    ! IDPRT *  0   I
                    I IUPRT *  0   I
                    I  ICFRQ *  1   I

                    I  IDFRQ *  1   I

                    I  IWFRQ *  1   1

                    I  INESG *  1   I
     SPECIES LIST  FOR OUTPUT OPTIONS

             	 CONCENTRATIONS
( SOZ
! S04
SPECIES
 NAME          PRINTED ?       SAVED ON DISK ?
                                          	 DRY FLUXES 	

                                           PRINTED ?      SAVED ON DISK ?
                                               	  WET  FLUXES 	

                                                PRINTED  ?     SAVED ON DISK ?
            1  .
            1  ,
1 .
1 ,
0 ,
o .
0 ,
o .
o ,
o ,
0 .  !
0 ,  I
     OPTIONS FOR PRINTING "DEBUG" QUANTITIES  (much output)



                                              Default: F
Logical  for debug output
(LDEBUG)
       Number of puffs to track
       (NPFDEB)                               Default: 1
       Time step to start debug output
       (NN1)

       Time step to end debug output
       (NN2)
                                       Default: 1


                                       default: 10
                        1  LDEBUG = F !


                        i  NPFDEB =  1   I


                        t  NN1 =  1  !


                        I  NN2 *  10  I
!END!
    i:\calpufl\jul9S\secl4.wph
                                               4-24

-------
                                           Table 4-5 (Continued)
                             Sample CALPUFF Control File (CALPUFF JNP)
                                               Input Group 6
INPUT GROUP: 6a, 6b, ft 6c '• Subgrid seat* complex terrain Inputs
Subgroup (6a)

       Nuaber of terrain features (MHIU)

       Number of special complex terrain
       receptors  (NCTREC)

       Terrain data for CTSG hills input in
       CTDN format ? (NMILL)
       1 * Hill data created by CTDM
          processors ft read from HILL.DAT
          file
       2 = Hill data created by OPTHILL  t
          input below in Subgroup <6b)
       Factor to convert horizontal diverts ions  Default:  1.0
       to Meters (HHILL « 1)
       Default: 0


       Default: 0


       No Default
I  NHILL >  1  I


I  NCTREC «  9  I


I  NHILL *  2  I
       Factor to convert vertical di
       to Meters (HHILL * 1)
ions   Default: 1.0
IXHILL2N * 1.0 I


IZHILL2M - 1.0 I
I END I
Subgroup (6b>
     HILL  information
HILL
NO.
1 ! HILL =
IENDI
Subgroup (6c)
XC
(km)
0.0,
YC
(km)
0.0.
COMPLEX TERRAIN RECEPTOR
CTREC
CTREC
CTREC
CTREC
CTREC
CTREC
XRCT
(km)
-0.2,
-0.2,
-0.2,
-0.2,
-0.2,
-0.2,
YRCT
(km)
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
TNETAH ZGRID
(deg.) (m)
0.0, 25.0,
1 **
INFORMATION
2RCT
(•)
95.0,
°3.5.
89.3,
82.9,
75.0.
66.4,
RELIEF
(m>
100.0,
XHH
1.0
1.0
1.0
1.0
1.0
1.0
EXPO 1 EXPO 2 SCALE 1 SCALE 2 AMAX1 AMAX2
(m) (m) (m) (m) (m) (m)
2.0, 2.0, 800.0, 400.0, 1132.0, 566.0 1
IENDI
IENDI
(END!
(END)
IENDI
IENDI
    t\calpufl\jul95\«ect4.wph
                 4-25

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control Ffle (CALPUFF JNP)
                                            Input Group 6
I CTREC «     -0.2,      -0.6,      57.8,         1.0       I  IENDI
! CTREC -     -0.2,      -0.7.      49.4,         1.0       I  IENDI
I CTREC »     -0.2,      -0.8,      41.7,         1.0       I  IENOI
     Description of Complex Terrain Variable*:
          XC, YC  - Coordinates of center of hill
          THETAH  * Orientation of wjor axis of hill (clockwise from
                   North)
          ZGR1D   - Height of the  0 of the grid above nean sea
                   level
          RELIEF  > Height of the crest of the hill above the grid elevation
          EXPO 1  • Hill-shape exponent for the major axis
          EXPO 2  * Hill-shape exponent for the major axis
          SCALE 1 > Horizontal length scale along the Major axis
          SCALE 2 * Horizontal length scale along the Minor axis
          AMAX    * Naxiaun allowed axis length for the wjor axis
          BMAX    * Maxi*un allowed axis length for the major axis

          XRCT, YRCT * Coordinates of the complex terrain receptors
          ZRCT    * Height of the ground (HSL) at the coaplex terrain
                   Receptor
          XHH     « Hill number associated with each complex terrain receptor
                   (NOTE: MUST BE ENTERED AS A REAL NUMBER)

    *
     NOTE: DATA for each hill and CTSG receptor are treated as a separate
           input subgroup and therefore must end with an  input group terminator.
i:\calpufl\jul95\sect4.wph                                4-26

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFF.INP)
                                       Input Groups 7, 8, and 9
INPUT GROUP:  7 -- Charted parameter* for dry deposition of gases


SPECIES    OIFFUSIVITY      ALPHA STAR      REACTIVITY   NESOPHYU RESISTANCE    HENRY'S LAW COEFFICIENT
 NAME                                                  (t/ai)               (diwensionless)


I S02         - 0.1509,         1000.0,         8.0,               0.0,                    0.0           !

(END!





INPUT GROUP:  8 — Size parameters  for dry deposition  of particles


SPECIES      GEOMETRIC MASS MEAN       GEOMETRIC STANDARD
 NAME            DIAMETER                  DEVIATION
                 (•icrons)                 (aicrons)

! S04     -         0.48                        2.0       I

(END!





INPUT GROUP:  9 •- Miscellaneous  dry deposition parameters
     Reference cuticle resistance   (RCUTR)  (s/cn)
     Reference ground resistance    (RGR)    (s/cn)
     Reference pollutant reactivity (REACTR)
  !  RCUTR = 30.0 !
  I    RGR = 10.0 !
  I REACTR = 8.0 I
     Vegetation state in unirrigated areas (IVEG)     I
        IVEG=1 for active and unstressed vegetation
        IVEG=2 for active and stressed vegetation
        IVEG=3 for inactive vegetation
      IVEG
              1   I
!ENO!
i:\caJpufl\juJ95\iecU.wph
4-27

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFFJNP)
                                       Input Groups 10 and 11
INPUT GROUP: 10 •- Wet Deposition Parameters
     Pollutant
!  S02
I  S04

I END!
Scavenging Coefficient --  Unit*: (tec)

Liquid Precip.       Frozen Precip.
                                                       -1
                       3.0E-05,
                      10.0E-05.
                          0.0
                       3.0E-5
INPUT  GROUP: 11 -- Chemistry Parameters
     Ozone data input option (MOZ)     Default:  1
     (Used only if NCHEN * 1)
        0 * use a constant background ozone value
        1 * read hourly ozone concentrations from
           the OZONE.DAT data file

     Background ozone concentration
     (BCK03)  in ppb                   Default:  80.
     (Used only if MCHEH = 1 and
      MOZ = 0 or (MOZ « 1 and all hourly
      03 data missing)

     Background ammonia concentration
     (BCKNH3) in ppb                  Default:  10.

     Nighttime S02 loss rate (RNITE1)
     in percent/hour                  Default:  0.2

     Nighttime NOx loss rate (RNITE2)
     in percent/hour                  Default:  2.0

     Nighttime HN03 formation rate (RNITE3)
     in percent/hour                  D«5auU  2.0

(END!
                                         MOZ *  0  I
                                       I  BOC03 = 80 !





                                       I  BCKNH3 = 10 I


                                       !  RNITE1 = .2 !


                                       I  RNITE2 = 2. I


                                       !  RNITE3 * 2. I
i:\alpiiff\jul9S\sect4.wph
                              4-28

-------
                                         Table 4-5 (Continued)
                          Sample CALPUFF Control File (CALPUFF.INP)
                                            Input Group 12
INPUT GROUP: .12 -- Misc. Dispersion and Computational  Parameters
     Horizontal six* of puff (m> beyond Mhich
     tine-dependent dispersion equations (Heffter)
     •re used to determine sigma-y and
     sigma-z (SYTOEP)

     Switch for using  Heffter equation for
     sigM-z as above.  <0«0o NOT use Heffter
     1-Use Heffter for  sigM-z)
     (NHFTSZ)

     Stability class used to determine plume
     growth rates for puffs above the boundary
     layer (JSUP)

     Vertical dispersion constant for stable
     conditions (kl  in  Eqn. 2-173}  (CONK1)

     Vertical dispersion constant for neutral/
     unstable conditions 
-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control Ffle (CALPUFFJNP)
                                           Input Group 12
    Minimal signa-y for a new puff/slug
    (STM1N)

    Miniau* signa-z for a new puff/slug
    (SZMIN)
    Minimi turbulence signa-v
    (SVNIN)
     MiniMLM turbulence sigma-z
     (SZMIN)
    Minimum wind speed allowed for
    non-calm conditions.  Wind speeds
    less than USCALM will be considered
    as "call/1 by the nodel.   Also used
    as the Minimi speed returned when
    using power-law extrapolation
    toward the surface
    (USCALM)

    Maxiaura nixing height
    (XMAXZI)
     Minimum nixing height
     (XMINZI)

     Default wind speed profile power-law
     exponents for stabilities 1-6
             Default:  0.01    I SYMIN • 0.01
             Units: n
             Default: 0.01
             Units: n
             Default: 0.50
             Units: n/s
  SZMIN • 0.01
  SVMIN « 0.50 I
             Default: 0.016  ! SVMIN * 0.016 I
             Units: n/s
            Default: 1.0
            Units: n/s
            Default: 3000.
            Units: n

            Default:  20.
            Units: n
I  USCALM  « 1.0 I
  XMAXZI * 3000.
  XMINZI  = 20.    I
     (PLXO(6))
      Default ISC values used if ALL are ZERO
      ISC RURAL : .07. .07.  .10. .15. .35. .55
      ISC URBAN : ,15, .15.  .20, .25, .30. .30

Stability Class :  A     B     C     D    E     f

        I PLXO » 0.07, 0.07,  0.1. 0.15, 0.35, 0.55 !
     Default  potential temperature gradient
     for stable classes E, F
     
-------
                                        Table 4-5 (Continued)
                          Sample CALPUFF Control File (CALPUFFJNP)
                                            Input Group 13
 INPUT GROUPS: 13a.  13b, 13c — Point source parameters
Subgroup (13a)


     Number of point sources with
     constant mission psrsiwters   (NPT1)  No default  I   NPT1 -  1  I

     Nuaber of point sources with
     variable emission parameters   (NPT2)  No default  1   NPT2 -  0  I

     Clf NPT2 > 0,  the variable point
     source emissions are read from
     the file: PTEMARB.DAT)

IENDI
Subgroup (13b)
                                                                      a
          POINT  SOURCE DATA FOR SOURCES WITH CONSTANT EMISSION PARAMETERS

Sourci
iNo.

1
(END!

e X UTM
Coordinate
(kn)
1 X * 0.1,


Y UTM
Coordinate
(km)
-3.0.


Stack
Height
(•)
40.,


Base
Elevation
(•)
25.,


Stack
Diameter
(*)
2.2,


•"• Exit
Velocity
(•/s)
10..

b
Exit Bldg.
Teap. Oownwash
(deg. K)
450.. 1.,

c
Emission
Rates
(g/s)
1.7. 0.0 1

    a
     Data for each source receptor are  treated as a separate
     input subgroup and therefore Bust  end with an input  group terminator.

    b
     0. - No building dounuash modeled,  1. * downuash modeled

    c
      Emission rates must be entered  for every pollutant  ("NSPEC" values).
      Enter emission rate of zero for secondary pollutants.
Subgroup (13c)


           BUILDING DIMENSION DATA FOR SOURCES SUBJECT  TO DOUNUASH

Source
 No.       Effective building width and height (in meters) every 10 degrees

  1        !  UIDTH  • 9 * 12.5.  9 * 0.0, 9 * 12.5, 9 *  0.0                 !
  1        !  HEIGHT = 9 * 45.0,  9 * 0.0, 9 * 45.0, 9 *  0.0                 !
!END!




fc\aUpufl\jul95\iect4.wpb                                  4-31

-------
                                        Table 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFFJNP)
                                           Input Group 14
INPUT CROUPS:  14a, 14b I 14e — Area source parameters
Subgroup (Ua)


     Number of polygon area sources with
     constant emission parameters (HARD     No default   I  NAR1 *  2

(END)


Subgroup (14b)
          AREA SOURCE DATA FOR SOURCES WITH CONSTANT EMISSION PARAMETERS

                                                     b
Source          Effect.    Base     Initial    Emission
 No.            Height   Elevation  Signs z     Rates
                  (m)              (•)      (g/s/^2)
  1      I X  =     1.0,      0.0,      2.5.       0.85, 0.0 !  (END!
  2      I X  =     1.5,      0.0,      3.0.       1.15, 0.0 I  (END!
    a
     Data for each source are treated as a separate input subgroup
     and therefore aust end with an input group terminator.
    b
      Emission rates must be entered for every pollutant ("NSPEC" values).
      Enter  emission rate of zero for secondary pollutants.
Subgroup (He)
           COORDINATES (UTM-km)  FOR EACH VERTEX(4)  OF  EACH POLYGON

Source                                                            a
 No.       Ordered  list of X followed by list of Y, grouped by source
  11     X = 0.500, 0.510, 0.510, 0.500  !
  11     Y * 1.600. 1.600. 1.610, 1.610  i
IENO!
  2   !     X = 0.750, 0.760, 0.760, 0.750  I
  2   !     Y = 1.800. 1.800, 1.810, 1.810  !
I END!
    a
     Data for each source are treated as a separate input  subgroup
     and therefore must end with an  input group terminator.
L\caipufl\juKS\sect4.wph                                4-32

-------
                                           Table 4-5 (Continued)
                             Sample CALPUFF Control FUe (CALPUFF.INP)
                                               Input Group 2
     Method used to compute dispersion
     coefficients (NDISP)                 Default: 4   ! MDISP =  3  !

        1 = dispersion coefficients computed from values of
            sigma v, sigma w read from SIGNA.DAT file
        2 = dispersion coefficients sigma v,  sigma w computed
            internally from micrometeorological variables (u*, w*, I, etc.)
        3 = PG dispersion coefficients for RURAL areas (computed using
            the ISCST multi-segment approximation) and HP coefficients in
            urban areas
        4 = same as 3 except PG  coefficients  computed us4ng
            the MESOPUFF II eqns.
        5 = CTDM sigross used for stable and neutral conditions.
            For unstable conditions, sigmas are computed as in
            NDISP = 1, described above.  MDISP * 5 assumes that
            sigma v, sigma w are read  from a  SIGMA.DAT file

     PG sigma-y, z adj. for roughness?       Default: 0    ! MROUGH =  1  !
     (MROUGH)
        0 = no
        1 = yes

     Partial plume penetration of             Default: 0    ! MPARTL -  1  !
     elevated inversion?
     (MPARTL)
        0 = no
        1 = yes

     Test options specified to see if
     they conform to regulatory
     values? (MREG)                      Default: 0   !  MREG =  0  !

        0 = NO checks are made
        1 = Technical options must conform to USEPA values for
            short-range modeling ( e.g. ISC-type applications)
        2 = Technical options must conform to USEPA values for
            long-range modeling  (e.g.  visibility-type applications)
        3 = Environmental  Protection Authority of Victoria (EPAV)
            default values
!END!
i:\colpuff\jul95\iect4.wph                                  4-33

-------
                                        TaWe 4-5 (Continued)
                         Sample CALPUFF Control File (CALPUFF.INP)
                                            Input Group 16
INPUT GROUPS:  16a i  16b •- Volume source parameters
Subgroup (16a)
     Number of volume sources with
     constant emission parameters (NVL1)     No default  I   NVL1 «  1   I

     Gridded volume source data
     used ? (GR1DVL)                        No default  I   GRIDVL *  0 I
        0 » no
        1 « yes (gridded volume source
            eiiissions read fro* the file:
            VOLEM.DAT)

     The following parameters apply to the data in the
     gridded volume source emissions file (VOLEM.DAT)

       -  Effective height of emissions
          (VEFFHT) in meters                No default  I  VEFFHT * 10  I

       -  Initial sigma y (VSIGYI) in
          taeters                           No default  I  VSIGYI - 3000 !

       -  Initial sigma z (VSIGZI) in
          meters                           No default  1  VSIGZI = 10  !

!END!
Subgroup (16b)

                                                                      a
         VOLUME SOURCE DATA FOR SOURCES WITH CONSTANT EMISSION PARAMETERS

                                                                            b
       X UTM      Y UTM      Effect.    Base     Initial    Initial    Emission
    Coordinate  Coordinate   Height   Elevation  Sigma y    Sigma z     Rates
       (km)       (km)         (m)       (m)        (m)       (m)      (g/s)


! X =  -5.6,       -1,2,       10.,      0.0,      6.2,       6.2,       2.2, 0.0, !  IEND!
    a
     Data for each source are treated as a separate input subgroup
     and therefore must end with an input group terminator.
    b
      Emission rates  must be entered for every pollutant ("MSPEC" values).
      Enter emission  rate of zero for secondary pollutants.
i:\calpufi\jul95\sect4.wph                                4-34

-------
                                       Table 4-5 (Concluded)
                         Sample CALPUFF Control FUe (CALPUFFJNP)
                                          Input Group 17
 INPUT GROUPS:  17* ft 17b — Non-gridded (discrete) receptor inforMtion
Subgroup (17a)


     Nuaber of non-gridded receptors  (HREC)  No default  I   NREC *  3

IEMOI
Subgroup (17b)
                                           a
          NON-GRIOOED (DISCRETE) RECEPTOR DATA
                X UTM     Y UTN      Ground
Receptor     Coordinate  Coordinate   Elevation
  No.                 (ta>         (•)
  1    I  X >    1.0,         1.0,        12.5  I  IENDI
  2    I  X »    2.5,         4.2,        28.1  I  IENDI
  3    I  X *    2.89,        3.2,        39.6  I  I END I
    a
     Data for each receptor are treated as a separate input subgroup
     and therefore must end with an  input group terminator.
i:\calpufl\jul9S\iect4.wpb                               4-35

-------
                                        Table 4-6
                      CALPUFF Control File Inputs - Input Group 1
                             General Run Control Parameters
Variable
IBYR
ffiMO
IBDY
IBHR
IRLG
NSPEC
NSE
ITEST
METFM
AVET
Type
integer
integer
integer
integer
integer
integer
integer
integer
integer
real
Description
Starting year of the CALPUFF run (two digits)
Starting month
Starting day
Starting hour (00-23)
Length of the run (hours)
Total number of species modeled
Number of species emitted
Flag to stop run after the setup phase (1 = stops the
program, 2 = continues with execution after setup)
Meteorological data format
1 = CALMET unformatted file (CALMET DAT)
2 - ISC2 ASCH file (ISCMETJDAT)
3 = AUSPLUME ASCII file (PLMMET DAT)
Averaging time (minutes)
(PG - o, is adjusted by the equation (AVET/60.0)"
Default
Value
-
-
-
-
-
5
3
2
1
60.0
t\calpun\jul95\«ect4.wph
4-36

-------
                                    Table 4-6 (Continued)
                         CALPUFF Control File Inputs - Input Group 2
                                       Technical Options
Variable
Type
Description
Default
Value
     MGAUSS



     MCTADJ




     MCTSG



     MSLUG


     MTRANS
integer




integer



integer


integer
     MTIP
integer
     MSHEAR     integer
     MSPLTT


     MCHEM
integer


integer
     MWET
integer
Ccmtrol variable determining die vertical distribution
used in the near field (See Section 2.L1).
(0 * uniform, 1 • Gaussian)

Terrain adjustment method (See Section 2.6.2).
0 = no adjustment
1 = ISC-type of terrain adjustment
2 * simple, CALPUFF-type of terrain adjustment

CALPUFF subgrid scale complex terrain module
(CTSG) flag (See Section 2.6.1).
(0 = CTSG. not modeled, 1 » CTSG modeled)

Near-field puffs are modeled as elongated 'slugs* ?
(0 = no, 1  - yes)  (See Section 2.1).

Transitional plume rise modeled ? (see Section 2.4.1).
(0 = only final rise computed, 1 - transitional rise
computed)  Note:  Transitional plume rise is always
computed for sources subject to building downwash
effects.

Stack tip downwash modeled ? (See Section 2.4.2).
0 = no (Le., no stack tip downwash)
1 = yes (Le., use stack tip downwash)

Vertical wind shear above stack top modeled in plume
rise ? (See Section 2.4J5).
(0 = no, 1 = yes)

Puff splitting allowed ? (See Section 2.2.4).
(0 = no, 1 = yes)

Chemical mechanism flag (See Section 2.8).
0 = chemical transformation not modeled
1 = transformation rates computed internally
    (MESOPUFF H scheme)
2 = user specified  transformation rates used
(If MCHEM = 2, the user must prepare a file
(CHEMDAT) with a diurnal cycle of transformation
rates)

Wet removal modeled ? (See Section 2.9).
(0 = no, 1 = yes)
1


1
0

1
i:\cajpuff\jul95\ied4.wph
                           4-37

-------
                                    Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 2
                                      Technical Options
     Variable
Type
Description
Default
 Value
     MDRY       integer      Dry deposition modeled ? (See Section 2.7).
                              (0 * no, 1 » yes)
                              Note:  The method used to determine dry deposition
                              velocities is specified by the user on a spedes-by-
                              species basis in Input Group 3.

     MDISP       integer      Method used to compute the horizontal and vertical
                              dispersion coefficients (See Section 22).
                              1 = computed from values of o. and  ow from
                                 the SIGMAJ3AT file
                              2 - computed from o, and ow which  are
                                 calculated internally from the
                                 micrometeorological variables (m, w., L,
                                 etc)
                              3 = PG dispersion coefficients used in RURAL
                                 areas (computed using the ISCST
                                 multi-segment approximation) and MP
                                 coefficients used in URBAN areas
                              4 = same as 3 except PG coefficients computed
                                 using the MESOPUFF H equations
                              5 = CTDM  sigmas used for stable and neutral
                                 conditions for unstable conditions, sigmas are
                                 computed as in MDISP  = 1. MDISP = 5
                                 assumes that oy and ov are read from
                                 SIGMA.DAT file.
     MROUGH    integer
     MPARTL     integer
     MREG
integer
PG oy and o, adjusted for surface roughness ?
(0 = no, 1 = yes) (See Eqns.(2-73) to (2-75)).

Partial plume penetration of elevated inversion?
(0 = no, 1 = yes) (Sec Section 2.43).

Test options in control file to see if they conform to
regulatory values?
(0 = no, 1 = yes (US EPA),
2 - yes (USA visibility application),
3 = yes (Victorian EPA)
   0


   0


   0
i:\calpufl\jul95\tect4.wph
                           4-38

-------
                                  Table 4-6 (Continued)
                            Control File Inputs - Input Group 3
                                       Species List
       Input Group 3 consists of two parts. The first part is a list of the species names and the
second part contains a table with three integer flags for each species. These flags indicate if a
pollutant is modeled (0»no, l«yes), emitted (0=no, l=yes), and dry deposited (0-no, 1-yes,
treated as a gas with the resistance model, 2*yes, treated as a particle with the resistance model,
or 3=yes, user-specified deposition velocities used).

       However, the user must first specify the species names to be modeled.  Each species is
entered on a separate line with ! CSPEC « XXX ! .'END!, where XXX is a species name (up to
12 characters in length), and the variable delimiter and group delimiter (!END!) appears on the
line. For example, a five-species SOr NOX run would be:
       INPUT GROUP: 3 - Species List
! CSPEC = SO2 !
! CSPEC = 804 !
! CSPEC - NOX !
! CSPEC = HNO3 !
! CSPEC = NO3 !
{END!
!END!
!END!
!END!
•END!
       The chemical transformation scheme in CALPUFF is designed to simulate the conversion
of SO2 - SO; and NOX - HNO3 - NO;.  Therefore, the five pollutants in CALPUFF are labeled
as SO2, SO4, NOr HNO3, and NO;.  However, by setting the appropriate flags controlling the
various technical options (chemical transformation, deposition, etc.), other reactive or non-reactive
pollutants can be simulated.

       The user has control over which species are to be emitted and dry deposited in a particular
run. If the dry deposition flag is set equal to 3 for any pollutant, a  file called VD.DAT must be
made available to the model. This file contains a diurnal cycle of 24 user-specified deposition
velocities for each pollutant flagged  (see Section 4.2.5).
i:\calpufl\jul9i\iec44.wph                           4-39.

-------
                                   Table 4-6 (Continued)
       The format of the species list table is:
INPUT GROUP: 3 - Species Get
SPECIES
NAME
!  SO2
!  SO4
!  NOX
!  HN03
!  NO3

!END!
 MODELED
(0-NO, 1-YES)
 EMITTED
(0-NO, 1-YES)
    DRY
 DEPOSITED
(0-NO,
1-COMPUTED-GAS
2-COMPUTED-PARTICLE
3-USER-SPEOFIED)
t\calpu£r\jul95\s«cl4.wph
                                4-40

-------
                                    Table 4-6 (Continued)
                        CALPUFF Control Ffle Inputs - Input Group 4
                                  Grid Control Parameters
Variable
NX
NY
Type
integer
integer
Description
Number of grid cells in
meteorological grid
Number of grid cells in

the X direction of the
the Y direction of the
Default
Value
-
-
                              meteorological grid

     DGRIDKM    real        Grid spacing (km) of the meteorological grid

     XORIGKM    real        Reference X coordinate (km) of the southwest corner of
                              grid cell (1,1) of the meteorological grid

     YORIGKM    real        Reference Y coordinate (km) of the southwest corner of
                              grid cell (1,1) of the meteorological grid

     IUTMZN      integer     Zone of coordinates

     XLAT         real        Reference latitude (deg.) of the center of the modeling
                              domain (used in solar elevation angle calculations)

     XLONG       real        Reference longitude (deg.) of the center of the modeling
                              domain

     XTZ          real        Reference time zone of the center of the modeling
                              domain (PST=8, MST=7, CST-6, EST=5)

     NZ            integer     Number of vertical layers

     ZFACE        real array   Cell face heights (m) for the meteorological grid (NX +
                              1 values must be entered).  Note:  Cell center (grid point)
                              height of layer "i" is ((ZFACE(i+l) + (ZFACE(i))/2).

     IBCOMP       integer     X index of lower left comer of the computational grid
                              (1 s IBCOMP & NX)

     JBCOMP       integer     Y index of lower left corner of the computational grid
                              (1 s JBCOMP 
-------
                                 Table 4-6 (Continued)
                      CALPUFF Control Ffle Inputs - Input Group 4
                                Grid Control Parameters
    Variable
Type
Description
Default
 Value
    IECOMP     integer     X index of upper right corner of the computational
                           grid
                           (1 * ffiCOMP i NX)

    JECOMP     integer     Y index of upper right comer of computational grid
                           (1 i JECOMP $ NY)

    LSAMP      integer     Flag indicating if an array of gridded receptors (Le.,
                           sampling grid) is used
                           (T - yes, F - no)

    IBSAMP     integer     X index of lower left corner of the sampling grid
                           (ffiCOMP s IBSAMP 2 ffiCOMP)

    JBSAMP     integer     Y index of tower left corner of the sampling grid
                           (JBCOMP * JBSAMP * JECOMP)

    IESAMP     integer     X index of upper right corner of the sampling grid
                           (IBCOMP s IESAMP * IECOMP)

    JESAMP     integer     Y index of upper right corner of the sampling gird
                           (JBCOMP * JESAMP t JECOMP)

    MESHDN    integer     Nesting factor of the sampling grid
                           (MESHDN i  1).  The grid spacing of the sampling
                           grid is DGRIDKM/MESHDN. The number of
                           sampling grid  points is NXSAM * NYSAM, where
                             NXSAM =  MESHDN * (IESAMP - IBSAMP) + 1
                             NYSAM =  MESHDN * (JESAMP - JBSAMP) + 1
t\calpufl\jul95\««14.wph
                         4-42

-------
                                     Table 4-6 (Continued)
                         CALPUFF Control File Inputs - Input Group 5
                                        Output Options
     Variable
Type
Description
Default
 Value
     ICON        integer     Control variable for creation of an output disk file            1
                              (CONCDAT) mnfaimng concentration fields (species
                              stored in this file are controlled by the output species
                              table described below).
                              (0 = do not create CONCDAT,
                               1 - create CONCDAT)

     IDRY        integer     Control variable for creation of an output disk file            1
                              (DF1XDAT) containing dry flux fields.  (The  species
                              stored in this file are controlled by the, output species
                              table in Input Group 5 described below.)
                              (0 - do not create DFLXJDAT,
                               1 - create DFLXDAT)

     IWET        integer     Control variable for creation of an output disk file            1
                              (WFUCDAT) containing wet flux fields. (The species
                              stored in this file are controlled by the output species
                              table hi Input Group 5 described below.)
                              (0 - do not create WFLXDAT,
                               1 - create WFLX.DAT)

     IVIS          integer     Control variable for creation of an output disk  file           0
                              containing relative humidity data required for visibility
                              applications

     ICPRT        integer     Control variable for printing of concentration fields to        0
                              the output list file (CALPUFF.LST).
                              (0 = do not print any dry fluxes,
                               1 - print dry fluxes indicated in output species
                                   table)

     IDPRT        integer     Control variable for printing of dry flux fields to the          0
                              output list file (CALPUFRLST).
                              (0 = do not print any dry fluxes,
                               1  = print dry fluxes indicated in output species
                                   table)

     IWPRT       integer     Control variable for printing of wet flux fields to the          0
                              output list file (CALPUFF.LST).
                              (0 = do not print any wet fluxes,
                               1  = print wet fluxes indicated in output species
                                   table)
i:\cripufl\jul95\iecM.wph
                          4-43

-------
                                    Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 5
                                       Output  Options
     Variable
             Type
                        Description
Default
 Value
ICFRQ
IDFRQ
                  integer     Printing interval for
             integer
                             Concentrations are printed every TCFRQ" hours.
                             (Used only if ICPRT -= L)

                             Printing interval for the dry flax fields.  Dry fluxes are
                             printed every TDFRQ" hours. (Used only if IDPRT
     IWFRQ      integer     Printing interval for the wet flux fields. Wet fluxes are
                             printed every 1WFRQ" hours.  (Used only if IWPRT
                             -L)

     IMESG      integer     Control variable determining if messages tracking the
                             progress of the run are written to the screen (0 = not
                             written, 1 = written).
LDEBUG

NPFDEB
NN1
NN2
logical

integer
integer
integer
Control variable for activation of "debug" write
statements
Number of puffs to write in debug option (used only if
LDEBUG = T)
Tune period (hour) to begin debug output (used only
if LDEBUG = T)
Time period (hour) to stop debug output (used only if
                                                                                  F


                                                                                  1


                                                                                  1


                                                                                  10
                             LDEBUG = T)
i:\calpiifl\jul9S\Mct4.wph
                                        4-44

-------
                                  Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 5
                                     Output Options
       In addition to the variable described above, Input Group 5 also contains a table of species
with a series of flags indicating if the pollutant's concentration and wet/dry flux fields are to be
printed to the output list file (CALFUFF15T) and/or stored in the output disk files (CONC.DAT,
DFLX.DAT, and WFLX.DAT).

       The format of the species output table is shown below.  A value of 0 indicates "no", and a
value of 1 indicates "yes".


       SPECIES LIST FOR OUTPUT OPTIONS
        	CONCENTRATIONS	    	DRY FLUXES	    	WETFLUXES	
SPECIES
 NAME   PRINTED?   SAVED ON DISK?  PRINTED?  SAVED ON DISK?  PRINTED?       SAVED ON DISK?
ISO2
4SO4
!NOX -
THNO3 -
!N03 -
1
0
0
0
0
1
0
0
0
o
0
0
0
0
0
0
0
0
0
0 _

,
f
(
»
                                                           0              0    !
                                                           0              0    !
                                                           0              0    !
                                                           0              0    t
                                                           0              0    !
!END!
i:\calpufl\jul95\sect4.wph                           4-45

-------
                                     Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 6
                        Subgrid Scale Complex Terrain (CTSG) Inputs
       Variable
Type
                      Description
Default
 Value
       NHILL

       NCTREC


       MHILL
integer


integer
XHILL2M
ZHILL2M

XC
YC
THETAH
ZGRID
RELIEF
EXPO1
EXPO2
SCALE1
SCALE2
AMAX1
AMAX2
real

real
real
real
real
real
real
real
real
real
real
real
real
(Input Group 6a - General CTSG Parameters)

 Number of subgrid scale terrain features

 Number of special subgrid scale complex terrain receptors

 Terrain data for CTSG hills input in CTDM format ? (0
 = bin data created by CTDM processors and read from a
 HELLDAT file;
 1 = hill data created by OPTHILL & input below in
 Subgroup (6b)).

 Factor to convert horizontal dimensions to meters (used
 only if MHILL - 1)

 Factor to convert vertical dimensions to meters
 (used only if MHILL = 1)

     (Input Group 6b - Hill Information)

 UTM X coordinate (km) of the center of the hill on the
 meteorological grid

 UTM Y coordinate (km) of the center of the hill on the
 meteorological grid

 Orientation of the major axis of the hill (in degrees)
 clockwise from north

 Height (m) of the "zero-plane" of the grid above mean sea
 level

 Height (m) of the crest of the hill above the grid elevation

 Hill shape exponent for the major axis of the hill

 Hill shape exponent for the minor axis of the hill

 Horizontal length scale of the hill along the major axis

 Horizontal length .scale of the hill along the minor axis

 Maximum allowed axis length of the major axis of the hill

 Maximum allowed axis length of the minor axis of the hill
   0

   0
                                                                                    1.0
                                                                                    1.0
i:\ralpufl\jul95\tecM.wph
                           4-46

-------
                                    Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 6
                        Subgrid Scale Complex Terrain (CTSG) Inputs
The variables in Input Group 6b are entered for each of the "NHILL" subgrid scale hills treated
in the model run. The data for each hfll " treated as a separate input subgroup, and therefore
must end with an input group terminator (Le.. {END!). The format of Input Group 6b is shown
below.
Subgroup («b)
   HILL INFORMATION


HILL     XC  YC   THETAH ZORID RELIEF   EXPO 1 EXPO 2 SCALE 1  SCALE 2  AMAX1  AMAX2
 MO.      (km)  (km)   (de(.)    (m)   (m)     (m)    (m)     (•)      (•)    (m)     (m)

 1 ! HILL - 170.5. 3841.0 , «9. ,    1310. ,  300. ,   L91 ,   L24  ,   1523.  ,   2896. ,   2000,   1500. !   !END!
 2 ifflLL- 173.0, 3839X1, 49. ,    1310. .  230. ,   LSO ,   L50  ,   3000.  ,   1000. ,   4000,   2000.!   !END!
Note that the hfll number is an optional user comment which is outside of the delimiters
containing the required data.  The data for each hill must follow the opening delimiter and
"HLLL=".  The data for each hill is followed by a closing delimiter and an input group
terminator (i.e.( SEND!).
t\calpufl\jul95\tec(4.wph                             4-47

-------
                                     Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 6
                        Subgrid Scale Complex Terrain (CTSG) Inputs
     Variable
I>pe
Description
                                              Default
                                               Value
                              (Input Group 6c - CTSG Receptor Data)
     XRCT        real        UTM X coordinate (km) on the meteorological grid
                              system of a CTSG receptor

     YRCT        real        UTM Y coordinate (km) on the meteorological grid
                              system of a CTSG receptor
     ZRCT        real        Height (m) of the ground above mean sea level at the
                              CTSG receptor
     XHH         real        Hill number associated with this CTSG receptor
        The variables in Input Group 6c are entered for each of the "NCTREC" complex terrain
receptors in the model run. The data for each receptor is treated as a separate input subgroup, and
therefore must end with an input group terminator (i.e.. !END!). The format of Input Group 6c
is shown below.
Subgroup («c)
  COMPLEX TERRAIN RECEPTOR INFORMATION
         XRCT  YRCT   ZRCT
         (km)   (km)     (m)
! CTREC • 1705,   3840.0
! CTREC - 169.0,   3840.3
! CTREC - 1705,   3841.0
! CTREC- 173.5,   3840.0
! CTREC - 1715,   3840.0
    1430.
    1430.
    1580.
    1525.
    1430.
                              XHH
1.
1.
1.
2.
2.
!END!
!END!
!END!
!END!
!END!
** The data for each CTSG receptor must follow an opening delimiter and •CTREO". The data for each receptor h followed by a doting delimiter and
an input group terminator (U., !END!).
fc\cajpufl\jul95\iect4.wph
                           4-48

-------
                                     Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 7
                              Dry Deposition Parameters - Gases

        Input Group 7 consists of a table containing the following five parameters which are
required by the resistance deposition model for computing deposition velocities for gases:

               Pollutant diffusivity (cm2/s)  (see Eqn. 2-182)
               Aqueous phase dissociation constant, a.  (see Eqn. 2-186)
               Pollutant reactivity (see Eqn. 2-184)
               Mesophyll resistance, rm (s/cm)  (see Eqn. 2-181)
               Henry's Law coefficient, H (dimensionless)  (see Eqn. 2-186)

        These parameters must be specified for each pollutant with a dry deposition flag of "1" in
the species list (Input Group 3) indicating the use of the resistance model for a gas.

        The format of the input table is shown below:
INPUT CROUP: 7 - Cbemial pinmeten for diy depotition of gua
SPECIES  DiFFUsrvrry  ALPHA STAR  REACTIVITY    MESOPHYLL RESISTANCE   HENRYS LAW COEFFICIENT
 NAME    (on"2/f)                                  ((/on)                 (dimenuonjo.)
!SO2 -    0.1509   ,    1.00E3   ,     8.0    ,           0.0      ,               4.e-2
!NOX  •    0.1656   ,    1.00   ,      8.0    ,           5.0      ,               33
! HNO3 •    0.1628   ,    1.00   ,     18.0    ,           0.0      ,               S.e-8

SEND!
i:\calpufl\juJ95\sect4.wph                             4-49

-------
                                   Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 8
                            Dry Deposition Parameters - Particles
       Input Group 8 consists of a table containing the geometric mass mean diameter
(microns) and the geometric standard deviation (microns) required by the resistance deposition
model for computing deposition velocities for paniculate matter.

       These parameters must be specified for each pollutant with a dry deposition flag of "2" in
the species list (Input Group 3) indicating the use of the resistance model for a pollutant
deposited as paniculate matter.

       The format of the input table is shown below:
INPUT GROUP: 8-Size puameten to dtydepodUon of particles
SPECIES   GEOMETRIC MASS MEAN   GEOMETRIC STANDARD
NAME       DIAMETER              DEVIATION
            (miaou)                (micron.)
!SO4   -       0.48       ,            100   !
!NO3  -       0.48       ,            2.00   !
!END!
fc\calpufl\jul95\iecU.wph                            4-50

-------
                                     Table 4-6 (Continued)
                         CALPUFF Control File Inputs - Input Group 9
                           Miscellaneous Dry Deposition Parameters
     Variable
Type
Description
                                                    Default
                                                     Value
     RCUTR      real


     RGR         real


     REACTR     real
     IVEG
integer
Reference cuticle resistance (s/on)
(see Eqn. 2-184)

Reference ground resistance (s/cm)
(see Eqn. 2-185)

Reference pollutant reactivity
(see Eqn. 2-184)

Flag specifying the state of vegetation in unirrigated
areas
   1 = vegetation is active and unstressed

   2 = vegetation is active and stressed

   3 = vegetation is inactive
                                                      30.


                                                      10.


                                                      8.


                                                      1
i:\calpufl\jul95\iect4.wph
                          4-51

-------
                                   Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 10
                                Wet Deposition Parameters
       Input Group 10 consists of a table containing pollutant-dependent values of the
scavenging coefficient, X, defined by Equation (2-197), for both liquid and frozen precipitation
types.  The format of the input table is shown below.
INPUT GROUP: 10 - Wet Depoution Parameters
    PoDuUnt

    !  SO2
    !  SO4
    !  NOX
    !  HN03
    !  NO3
-• scavengings
Liquid Pncip.
3Oe-S
10.0e-5
0.0
6.0e-5
10.0e-5
Frozen PPBC^.
0.0 !
3.0e-5 !
0.0 !
0.0 !
3.0e-5 !
!END!
i:\olpuH\jul95\Kcl4.wph
4-52

-------
                                    Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 11
                                    Chemistry Parameters
     Variable
Description
Default
 Value
     MOZ         integer     Control variable for the input of hourly ozone data           1
                             used in the ^tfanmil transformation module
                             (Used only if MCHEM = 1)
                                0 » use a constant background ozone value
                                    in chemistry calculation
                                1 * use hourly ozone concentrations from
                                    the OZONE.DAT data file

     BCKO3       real       Background ozone concentration in ppb                   80.
                             (Used only if MCHEM-1 and MOZ - 0 or if
                             (MOZ-1 and all hourly ozone data are missing))

     BCKNH3      real       Background ammonia concentration in ppb                10.

     RNTTE1       real       Nighttime SO2 loss rate in percent/hour                   02
                             (k, in Eqn. 2-192)

     RNTTE2       real       Nighttime NO, loss rate in percent/hour                  2.0
                             (ka in Eqn. 2-193)

     RNTTE3       real       Nighttime HNO3 formation rate in percent/hour            2.0
                             (k3 in Eqn. 2-194)
i:\calpufl\juI95\tect4.wph
               4-53

-------
       JSUP
                                    Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 12
                                    Dispersion Parameters
Variable
Type
Description
Default
Value
       SYTDEP    real
        MHFTRZ   integer
integer
        CONK1     real
        CONK2     real
        IURB1,      integer
        IURB2
        XMXLEN   real


        XSAMLEN  real


        MXNEW    integer



        MXSAM    integer



        SL2PF       real
Horizontal size of a puff (m) beyond which the         550
time-dependent dispersion equation of Heffter
(1965)

Use Heffter formulas for o, ? (0 =  no; 1 = yes).        1
If yes, the distance at which the Heffter formula
will be applied for o, is determined by whin oy
switches to Heffter's eqn. (see SYTDEP).

Stability class used to determine dispersion rates         6
for puffs above the boundary layer (e.g, 6 = F
stability)

Vertical dispersion constant for stable conditions        0.01
(k, in Eqn. 2-173)

Vertical dispersion constant for neutral/unstable        0.10
conditions (k2 m £4°- 2-173)

Land use categories associated with urban areas.        10,19
If MDISP = 3 or 4, MP dispersion coefficients are
used when puff is over land use type IURB1
through IURB2

Maximum length of an emitted slug (in met. grid        1.0
units)

Maximum travel distance of a slug or puff (in met.       5.0
grid units) during one sampling step

Maximum number of puffs or slugs  released from        99
one source during one time step (serves as a cap if
XMXLEN is specified too small)

Maximum number of sampling steps during one          5
time step for a puff or slug (serves as a cap if
XSAMLEN is specified too small)

Slug-to-puff transition criterion factor (max.            100.
oy/slug length before transition to puff)
PLXO(6)
real
array
Wind speed profile power-law exponents for
stabilities A-F
0.07, 0.07,
0.10, 0.15,
035, 0.55
i:\calpufl\juI9S\tect4.wph
                         4-54

-------
                                   Table 4-6 (Continued)
                       CALPUFF Control Ffle Inputs - Input Group 12
                                   Dispersion Parameters
Variable
PTGO(2)
SYMIN
SZMIN
SVMIN
SWMDSf
WSCALM
Type
real
array
real
real
real
real
real
Description
Potential temperature gradient (deg. k/m) for
stability classes E and F
Minimum 0y (m) a OCW puff Of slug
Minimum o, (m) a new puff or slug
Minimum turbulence ov (m/s)
Minimum turbulence ov (m/s)
Minimum wind speed allowed for non-calm
Default
Value
.020, .035
0.01
0.01
050
0.016
LO
        XMAXZI    real

        XMINZI     real
conditions. Wind speeds less than WSCALM will
be considered as "calm* by the model  WSCALM
is also used as the minimum speed returned from
the power law extrapolation of the wind speed
toward the surface.

Maximum mixing height (m)

Minimum mixing height (m)
3000.

 20.
i:\calpufl\jul9S\tecM.wph
              4-55

-------
                                     Table 4-6 (Continued)
                        CALPUFF Control File Inputs - Input Group 13
                                   Point Source Parameters
   Variable
Type
Description
Default
 Value
   Input Group 13a - General Data
   NPT1         integer     Number of point sources with constant stack and emission
                            parameters
   NPT2         integer     Number of point sources with arbitrarily-varying emission
                            parameters (If NPT2 > 0, the-point source emissions file
                            PTEMARB X>AT must be provided)
               13b - Point Source Data for Sources with Constant Stack and Emissions

                            X coordinate (km) of the stack on the meteorological grid
                            Y coordinate (km) of the stack on the meteorological grid
                            Stack height  (m)
                            Stack base elevation (m) above mean sea level
                            Stack diameter (m)
                            Stack gas exit velocity (m/s)
                            Stack gas exit temperature (deg. K)
                            Building downwash flag
                               0. = building downwash not modeled,
                               1. = building downwash modeled
   EMS         real array  Emission rate (g/s) of each modeled species
                            Note: *NSPEC" values must be entered
Input Group
Parameters
XUTM
YUTM
HSTAK
SELEV
DIAM
EXTTW
EXTTT
BDOWN
13b-l
real
real
real
real
real
real
real
real
       The variables in Input Group 13b are entered for each of the "NPT1" point sources with constant
emission parameters.  The data for each source is treated as a separate input subgroup, and therefore, must
end with an input group terminator (i.e.. !END!1. The format of Input Group 13b is shown below.
i:\calpufl\jul95\tect4.wph
                             4-56

-------
                                         Table 4-6 (Continued)
                          CALPUFF Control File Inputs - Input Group 13
                                       Point Source Parameters
Sobgmp(13.)

   NMberofpoatt

   Number of point
                         (NFT1)   No default
                     with
    (IfNFn >0, the variable point
    source emissions are read from
    the flic PTEMARRDAT)
                parasvten (NFT2)   No default
                                                 !  NPT1 • 1!
                                                 !  NPT2-0!
SEND!
Subgroup (13b)
        POINT SOURCE DATA FOR SOURCES WITH CONSTANT EMISSION PARAMETERS*
Source X Y Stack Base Stack
No. Coordinate Coordinate Height Elevation Diameter

1
2
3

!X -
!X -
!X •
(km)
168.1,
172.1,
180,1,
(km)
3839.0,
384LO,
3869A
(m) (m) (m)
40, 25.0, 1.0,
20.5 0.0, 22,
85.0 0.0, 46.
Exk
Velocity
(m/s)
0.001,
3.5,
12.0,
Edt
Temp.
(*»K)
250,
283,
350,
b
BMfr

0. ,
L ,
t ,
EmWon
Rates
((/•)
L667 !
0.9 !
22.9 !
c

!END!
!END!
!END!
    Data for each source receptor are treated as a separate
    input subgroup and therefore must end with an input group terminator.
   0. • No building downwash modeled, 1. • downwash modeled
   NOTE must be entered as a REAL number (Le, with decimal point)
    'NSPEC* emission rates must be entered (one for every pollutant).
    Enter emission rale of zero for secondary pollutants.
Note that the source number is an optional user comment which is outside of the delimiter
containing the required source data.  The data for each source must follow an opening delimiter
and "X=". The data for each source is followed by a dosing delimiter and an input group
terminator.
i:\calpufl\jul95\sect4.wph
                                                 4-57

-------
                                   Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 13
                                  Point Source Parameters
Variable
Type
Description
Default
Value
                             (Input Group 13c - Building Dimension Data)
     WIDTH      real array   Array of 36 direction-specific building widths (m) for
                             flow vectors from 10°-360° in 10° increments
     HEIGHT     real array   Array of 36-direction-specific building heights (m) for
                             flow vectors from 10°-360° in 10° increments
       The variables in Input Group 13c are entered for each point source for which
IDOWN=1 in Input Group 13b.  The data for each point source f Le.. 36 widths and 36 heights)
is treated as a separate input subgroup and therefore must end with an input group terminator
(Le.. !END!).  The format of Input Group 13c is shown below.
Subgroup (Be)
       BUILDING DIMENSION DATA FOR SOURCES SUBJECT TO DOWNWASH
Source
 No.    Effective building width and height (in meten) every 10 degree
 2     ! WIDTH - 36 • 12.0 !
 2     ! HEIGHT - 36 • 22 £ <
!END!
 3     ! WIDTH - 20 • 0.0,45 5, 48.5, 523,13 • 0.0 !
 3     ! HEIGHT - 20 • 0.0, 78.0, 78.0, 78.0,13 • 0.0 !
!END!
Note that the source number is an optional user comment which is outside of the delimiters.
The data for each source must follow an opening delimiter and either "WIDTH=" or
"HEIGHT-". The data for each source is followed by a closing delimiter and an input group
terminator (i.e., !END!).


i:\caIpufl\jul9S\sect4.wph                            4-58

-------
                                    Table 4-6 (Continued)
                       CALPUFF Control File Inputs - Input Group 14
                                   Area Source Parameters
     Variable      Type      Description                                         Default
    	                                                   Value
     (Input Group 14a • General Area Source Data)
     NAR1       integer     Number of area sources with constant emission
                             parameters
     NAR2       integer     Number of buoyant area sources with arbitrary varying
                             emission parameters

     (Input Group 14b - Area Source Data for Sources with Constant Emissions)
     XUTM       real       X coordinates (km) of each vertex of the .area source
                             on the meteorological grid
     YUTM       real       Y coordinate (km) of each vertex of the area source
                             on the meteorological grid
     HTEFF      real       Effective height (m) of the area source
     AELEV      real       Base elevation (m) above mean sea level
     SIGZI       real       Initial vertical dispersion coefficient (oj, in meters, of
                             the area source
     EMIS        real array   Emission rate (g/s) of each modeled species
                             Note: "NSPEC values must be entered
       The variables in Input Group  14b are entered for each of the "NAR1" area sources with
constant emissions. The data for each source is treated as a separate input subgroup, and therefore.
must end with an input group terminator tie.. !END!). The format of Input Group 14 is shown
below.
i:\calpuffl\jul9S\iect4.wph                            4-59

-------
                                             Table 4-6 (Continued)
                             CALPUFF Control File Inputs - Input Group 14
                                            Area Source Parameters
Subgroup (14.)
Number of polygon ire* sources with
             i parameters (NAR1)       No debut          ! NAJU - 0 !
!END!
Subgroup (Mb)
       AREA SOURCE DATA FOR SOURCES WITH CONSTANT EMISSION PARAMETERS
                                  b
Source       Eflfrt.  Base   Initial   Emission
 No.        Height Elevation  Sigma z  Rates
            (m)    (m)    (m)    (g/s/m"2)
 1    ! X -   1.0,   0.0,    2.5,    0.85,0.0!  !END!
 2    ! X -   L5,   0.0,    3.0,    L15,0.0!  !END!
   Data for each «ource are treated as a separate input subgroup
   and therefore must end with an input group terminator.
   b
    Emission rates must be entered for every pollutant (*NSPEC* values).
    Enter emission rate of zero for secondary pollutants.
Subgroup (14c)


       COORDINATES (UTM-km) FOR EACH VERTEX(4) OF EACH POLYGON
Source                                      a
 No.     Ordered list of X followed by list of Y, grouped by source
  1  !   X • 0.500, 0.510, 0.510, OJOO  !
  1  !   Y - 1.600,1.600,1.610,1.610  !
!END!
  2  !   X - 0.750, 0.760, 0.760, 0.750  !
  2  !   Y - 1.800, 1.800, 1.810, 1.810  !
SEND!

   a
    Data for each source are treated as a separate input subgroup
    and therefore must end with an input group terminator.
i:\calpufl\jul9S\sect4.wph                                     4-60

-------
                                    Table 4-6 (Continued)
                        CALPUEF Control File Inputs - Input Group 15
                                   Line Source Parameters
     Variable
Type
Description
Default
 Value
     (Input Group 15a - General Line Source Data)
     NLINES
     MXNSEG
integer
integer
XL
HBL
WBL
WML
DXL
FPRIMEL
real
real
real
real
real
real
Number of buoyant line sources
Maximum number of line segments into which each
line may be divided (if MSLUG=1); Actual number of
virtual points which will be used to represent each line
(ifMSLUG-0)
Average line source length (m)
Average height of line source (m)
Average building width (m)
Average line source width (m)
Average deviation between building (m)
Average buoyancy parameter (
     (Input Group 15b - Buoyant Line Source Data) - repeated for each line source
     XBEGL      real       Beginning X coordinate (km)
     YBEGL      real       Beginning Y coordinate (km)
     XENDL      real       Ending X coordinate (km)
     YENDL      real       Ending Y coordinate (km)
     HTL         real       Release height (m)
     ELEVL      real       Base elevation (m)
     QL          real       Emissions rate (g/s) of each pollutant
i:\calpuff\jul9S\iecl4.wph
                          4-61

-------
                                   Table 4-6 (Continued)
                      CALPUFF Control File Inputs - Input Group 16
                                 Volume Source Parameters
     Variable
•type
Description
Default
 Value
     (Input Group 16a - General Volume Source Data)

     NVL1        integer     Number of volume sources with constant emission
                            parameters

     GRIDVL     integer     Gridded volume source data used?
                            (0 - no, 1 = yes - read from file VOLENLDAT)

     VEFFHT     real       Effective height (m) of emissions in gridded volume
                            source file

     VSIGYI       real       Initial oy (m) of emissions in gridded volume source
                            file

     VSIGZI       real       Initial ox (m) of emissions in gridded volume source
                            file
     Input Group 16b - Volume Source Data for Sources with Constant Emissions
     data (repeated for each volume source (NVL1))

                            X coordinate (km) of center of volume source

                            Y coordinate (km) of center of volume source

                            Effective height (m) of volume source

                            Base elevation (m) of volume source

                            Initial oy (m) of volume source

                            Initial a, (m) of volume source

                            Emission rates (g/s)  of each pollutant from volume
                            source
XVOL
YVOL
HTVOL
ELEVOL
SYVOL
SZVOL
QVOL
real
real
real
real
real
real
real
fc\calpufl\jul9S\sed4.wph
                          4-62

-------
                                   Table 4-6 (Concluded)
                       CALPUFF Control File Inputs - Input Group 17
                           Non-Gridded (Discrete) Receptor Data
     Variable      Type       Description                                        Default
                                                                                Value

     (Input Group 17a - General Discrete Receptor Data)
     NREC       integer     Number of non-gridded receptors
     (Input Group 17b • Discrete Receptor Data)
     XUTM       real        X coordinate (km) of the discrete receptor on the
                             meteorological grid
     YUTM       real        Y coordinate (km) of the discrete receptor on the
                             meteorological grid  •
     ELEV       real        Ground elevation (m) above mean sea level of the
                             receptor
    The variables in Input Group 17b are entered for each of the "NREC" discrete receptors.  The
data for each receptor is treated as a separate input subgroup, and therefore, must end with an
input group terminator (Le., !END!). The format of Input Group 17b is shown below.
Subgroup (17b)
      NON-GRIDDED (DISCRETE) RECEPTOR DATA1

Receptor
No.
1 !X •
2 !X -
3 !X -
X
Coordinate
(km)
180.t
195.1,
2115,
Y
Coordinate
(km)
38592,
3862,2,
38772,
Ground
Elevation
(m)
22.0
65.0
105.0



! !END!
! !END!
! !END!
  Data tor each receptor are treated at a Mparate input subgroup
  and therefore mint end with an input group terminator.
       Note that the receptor number is an optional user comment which  is outside of the
delimiter.  The data for each receptor must follow an opening delimiter and "X=". The data for
each receptor is followed by a closing delimiter and an input group terminator (Le., !END!).
i:\calpun\jul95\iect4.wpb                             4-63

-------
4.2.2   Meteorological Data Files

       Three types of meteorological data files can be used to drive the CALPUFF model In
order to take full advantage of the capabilities of the model to simulate the effects spatially-
varying meteorological fields, gridded fields of winds, temperatures, mixing heights, and other
meteorological variables can be input into CALPUFF through the CALMET.DAT file. The
format and contants of this file is described in Section 4.22.1.

       Alternatively, CALPUFF will also accept single station meteorological data in the ISC2
format or AUSPLUME data. The ISC2 meteorological data file (ISCMET.DAT) is described in
Section 4222, and the AUSPLUME file (PLMMETDAT) is described in Section 4223.  It
should be noted that three header records must be added to the standard ISC2 or AUSPLUME
files for use with CALPUFF.
4.22.1  CALMET.DAT

       The CALMET.DAT file contains gridded meteorological data fields required to drive the
CALPUFF model  It also contains certain geophysical fields, such as terrain elevations, surface
roughness lengths, and land use types, used by both the CALMET meteorological model and
CALPUFF.  Although the input requirements of CALPUFF are designed to be directly
compatible with CALMET, meteorological fields produced by other meteorological models can
be substituted for the CALMET output as long as the required variables are produced and the
output is reformatted to be consistent with the CALMET.DAT file specifications described in
this section.
                          CALMETJ)AT File - Header Records

       The CALMET.DAT file consists of a set of up to fourteen header records, followed by a
set of hourly data records.  The header records contains a descriptive title of the meteorological
run, information including the horizontal and vertical grid systems of the meteorological grid,
the number, type, and coordinates of the meteorological stations included in the CALMET run,
gridded fields of surface roughness lengths, land use, terrain elevations, leaf area indexes, and a
pre-compute field of the closest surface meteorological station number to each grid point.

       The actual number of header records may vary because, as explained below, records
containing surface, upper air, and precipitation station coordinates are not included if these

c\
-------
stations were not included in the run.  A description of each variable in the header records is
provided in Table 4-7.

       The following variables stored in the CALMET.DAT header records are checked in the
setup phase of the CALPUFF model run to ensure compatibility with variables specified in the
CALPUFF control file:  number of grid cells in the X and Y directions, grid size, reference
UTM or Lambert conformal coordinates of the grid origin, and UTM zone of the grid origin.

       Sample FORTRAN write statements for the CALMET.DAT header records are:
       Header record 1 - Run title
       write(iunit)TITLE

       Header record 2 - General run and grid information
     2 NUSTA,NPSTA^40WSTA^LU JWATUWAT2.LCALGRD

c —    Header record 3 - Vertical cell face heights (nz+1 values)
       write(iunh)CLABlJDUM^FACEM

c —    Header records 4 and 5 - Surface station coordinates
       if(nssta.ge.l)then
         write(iunit)CLAB24DUM,XSSTA
         write(iunit)CLAB3JDUM,YSSTA
       endif

c —    Header records 6 and 7 — Upper air station coordinates
       if(nusta.ge.l)then
         write(iunit)CLAB4,IDUHXUSTA
         write(iunit)CLAB5,IDUM,YUSTA
       endif

c —    Header records 8 and 9 - Precipitation station coordinates
       if(npsta.ge.l)then
         write(iunit)CLAB7,IDUM,YPSTA
       endif

c —    Header record 10 - Surface roughness lengths
       write(iunit)CLAB8^DUM^O

c —    Header record 11 - Land use categories
       write(iunit)CLAB9,IDUMJLANDU

c —    Header record 12 — Terrain elevations
       write(iunit)CLAB10,IDUM,ELEV
t\caJpufl\jul»S\iecU22.wph                          4-65

-------
      Header record 13 - Leaf area indexes
      write(iunk)CLABll^DUKpaAI

      Header record 14 - Nearest surface station to each grid point
      writc(iunit)CLAB12JDUM^TEARS

      where the following declarations apply:
      rea!ZFACEM(nz+l)PCSSTA(nssta),YSSTA(iissta)pCUSTA(nusta),YUSTA(nusta)
      real XPSTA(npsta),YPSTA(npsta)
      real ZO(nxlny)^LEV(in^iy)lXLAI(nx,ny)
      integer ILANDU(nxjiy),NEARS(iixjiy)
      character*80 TITLE(3)
      character's VER^VEL,C1AB1,CLAB2,C1AB3,CLAB4,CLAB5,CLAB6
      character's CLAB7,C1AB8,CL^9,CLAB10,CLAB11,CLAB12
      logical LCALGRD
t\
-------
                                           Table 4-7
                             CALMET.DAT file - Header Records
Header
Record No.
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Variable No.
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Variable
TITLE
VER
LEVEL
IBYR
IBMO
IBDY
ffiHR
ffiTZ
IRLG
IRTYPE
NX
NY
NZ
DGRID
XORIGR
YORIGR
IUTMZN
Type'
char*80
array
char*8
char*8
integer
integer
integer
integer
integer
integer
integer
integer
integer
integer
real
real
real
integer
Description
Array with three 80-character lines of the user's
title of the CALMET run
CALMET model version number
CALMET model level number
Starting year of CALMET run
Starting month
Starting day
Starting hour
Base time zone (e.g^ 05=EST, 06=CST,
07=MST, 08=PST)
Run length (hours)
Run type (0=wind fields only, l=wind and
micrometeorological fields). IRTYPE must be
run type 1 to drive CALGRID or the CTSG
option of CALPUFF
Number of grid cells in the X direction
Number of grid cells in the Y direction
Number of vertical layers
Grid spacing (m)
X coordinate (m) of southwest corner of grid
cell (1,1)
Y coordinate (m) of southwest corner of grid
cell (1,1)
UTM zone of coordinates (0 if using a Lambert
 •char*80 = Character*80
  char*8 =  Character'8
                                                       conformal projection)
t\calpufl\jul9S\iecM22.wph
4-67

-------
                                   Table 4-7 (Continued)
                            CALMET.DAT file - Header Records
Header Variable No.
Record No.
2 17
2 18
2 19
2 20
2 21
2 22
2 23
2 24
2 25

3 1
3 2
3 3

4" 1
4b 2
4" 3

Variable
IWFCOD
NSSTA
NUSTA
NPSTA
NOWSTA
NLU
IWAT1
IWAT2
LCALGRD

CLAB1
IDUM
ZFACEM

CLAB2
IDUM
XSSTA

Type*
integer
integer
integer
integer
integer
integer
integer
integer
logical

char*8
integer
real
array
char*8
integer
real
array
Description
Wind field module used (0= objective
analysis, 1= diagnostic model)
Number of surface meteorological stations
Number of upper air stations
Number of precipitation stations
Number of over water stations
Number of land use categories
Range of land use categories
Corresponding to water surfaces (IWAT1 or
IWAT2, inclusive)
Flag indicating if special meteorological
parameters required by CALGRID are
contained in the file (LCALGRD must be
TRUE to drive CALGRID or the CTSG
option of CALPUFF)
Variable label ('ZFACE')
Variable not used
Heights (m) of cell faces (NZ + 1 values)

Variable label ('XSSTA')
Variable not used
X coordinates (m) of each surface met.
station
 1 char*8 = Character's
 b Included only if NSSTA > 0
fc\calpufl\jul95\sect422.wph
4-68

-------
                                    Table 4-7 (Continued)
                            CALMET.DAT file - Header Records
Header
Record No.
5"
5-
5"
6e
6C
6C
r
r
r
8"
8"
; 8"
9"
9"
9"
10
10
10
Variable No.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Variable
CLAB3
IDUM
YSSTA
CLAB4
IDUM
XUSTA
CLAB5
rouM
YUSTA
CLAB6
IDUM
XPSTA
CLAB7
IDUM
YPSTA
CLAB8
IDUM
zo
Type'
char*8
integer
real
array
char*8
integer
real
array
char*8
integer
real
array
char*8
integer
real
array
char*8
integer
real
array
char*8
integer
real
array
Description
Variable label fYSSTA')
Variable not used



Y coordinates (m) of each surface met. station
Variable label CXUSTA')
Variable not used
X coordinates (m) of each upper air met.
station
Variable label CYUSTA')
Variable not used
Y coordinate (m) of each upper air met.
station
Variable label ('XPSTA')
Variable not used








X coordinate (m) of each precipitation station
Variable label fYPSTA')
Variable not used


Y coordinate (m) of each precipitation station
Variable label ('ZO')
Variable not used
Gridded field of surface roughness lengths
for each grid cell


(m)
 1 char*8 = Character*8
 b Included only if NSSTA > 0
 c Included only if NUSTA > 0
 d Included only if NPSTA > 0
L-\calpufl\jul95\(ecM22.wph
4-69

-------
                                  Table 4-7 (Concluded)
                           CALMET.DAT file - Header Records
Header
Record No.
11
11
11
12
12
12
13
13
13
14
14
14
Variable No.
1
2
3
1
2
3
1
2
3
1
2
3
Variable
CLAB9
IDUM
ILANDU
CLAB10
IDUM
ELEV
CLAB11
IDUM
XLAI
CLAB12
IDUM
HEARS
Type"
char'8
integer
integer
array
char*8
integer
real
array
char*8
integer
real
array
char*8
integer
integer
array
Description
Variable label (ILANDU')
Variable not used
Gridded field of land use category for
each grid cell
Variable label CELEV)
Variable not used
Gridded field of terrain elevations for
each grid cell
Variable label (
-------
                            CALMETJ)AT File - Data Records

       The CALMET.DAT data records indude hourly fields of winds and meteorological
variables. In addition to the regular CALMET output variables, CALGRID and the subgrid
scale complex terrain (CTSG) module of CALPUFF require additional three-dimensional fields
(air temperature and/or vertical velocity).  The presence of these fields in the CALMET output
file is flagged by the header record logical variable, LCALGRD, having a value of TRUE.

       The data records contain three-dimensional gridded fields of U, V, and W wind
components and air temperature, two-dimensional fields of PGT stability class, surface friction
velocity, mixing height, Monin-Obukhov length, convective velocity scale, and precipitation rate
(not used by CALGRID), and values of the temperature, air density, short-wave solar radiation,
relative humidity, and precipitation type codes (not used by CALGRID) defined at the surface
meteorological stations. A description of each variable in the data records is provided in
Table 4-8.

       Sample FORTRAN write statements for the CALMET.DAT data records are:

c —   Write U, V, W wind components
         —  Loop over vertical layers, k
               write(iiiiiit)CLABU^DATHR((U(y,k),i= l^x) j
               write(hinit)CLAB V,NDATHR((V(y ,k),i
       -  End loop over vertical layers
c —    Write 3-D temperature field
       if(LCALGRD.and.irtype.eq.l) then
         —  Loop over vertical layers, k
       endif
               write(iunit)CLABT,NDATHR((ZTEMP(ij,k)4=l,nxm) j = l,nym)

             End loop over vertical layers
i\caJpufl\juM3\iect422.wph                         4-7 J

-------
       Write 2-D meteorological fields
       if(irtype.cq.l) then

             writc(iunit)CLABSC,hfDATHR,IPGT
             wril«r(iunk)CLABUS^DATHR,USTAR
             write(iunk)ClABL>NDATHRrEL
             write(iuiik)CLABWSjroATHR,WSTAR
             writc(iuiiit)ClABRMM^fDATHRtRMM
       endif
       Write 1-D variables defined at surface met stations
       if(irtype.eq.l) then

             writc(iunit)CLABTIsNDATHR,TEMPK
             write(iunit)CLABDJ«)ATHIUlHO
             write(iunit)CLABQ^DATHR,QSW
             writc(iunit)CLABRH^JDATHR,IRH  .
             write(iunit)CLABPQNDATHIUPCODE

       endif
where the following declarations apply:

       real U(nx^iy^iz),V(nx^iy,nz),W(nx,ny,nz)
       real ZTEMP(mgiy^iz)
       real USTAR(nx,ny)^I(nx,ny),EL(nx,ny)
       real WSTAR(nx,ny),RMM(nx,ny)
       real TEMPK(ossta),RHO(nssta),QSW(nssta)
       integer IPGT(nx^iy)
       integer IRH(nssta),IPCODE(nssta)
       character's CLABU, CLABV, CLABW, CLABT, CLABSC, CLABUS, CLABZI
       character'8 CLABL, CLABWS, CLABRMM, CLABTK, CLABD, CLABQ, CLABRH
       character'8 CLABPC
t\calpufl\iiiI9S\sed422.wph                         4-72

-------
                                          Table 4-8
                              CALMETJDAT file - Data Records
      Record   Variable   Variable    Type*       Description
       Type      No.     Name	
        1         1      CLABU    char*8      Variable label (TJ-LEVnx', where nx
                                                indicates the layer number)

        1         2      NDATHR  integer      Year, Julian day and hour in the form
                                                YYJJJHH

        1         3      U          real array    U-component (m/s) of the winds at each grid
                                                point
        2         1      CLABV    char*8     Variable label CV-LEVxxx", where xxx
                                               .indicates the layer .number)

        2         2      NDATHR   integer     Year, Julian day and hour in the form
                                               YYJJJHH

        2         3V          real array   V-component (m/s) of the winds at each grid
                                               point
        3"         1      CLABW    char*8     Variable label CWFACExxx"), where xxx
                                               indicates the layer number)

        S6         2      NDATHR   integer     Year, Julian day and hour in the form
                                               YYJJJHH

        3b         3      W          real array   W-component (m/s) of the winds at each grid
                                               point

     (Record types 1,2,3 repeated NZ tunes (once per layer) as a set)
     4"       1         CLABT     char*8     Variable label (T-LEVxxx', where xxx
                                               indicates the layer number)

     4b       2         NDATHR   integer     Year, Julian day and hour in the form
                                               YYJJJHH

     4"       3         ZTEMP     real array   Air temperature (deg. K) at each grid point

     (Record type 4 repeated NZM times (once per layer))
     1 char*8 = Character's
     b Record types 3 and 4 are included only if LCALGRD is TRUE
t\c^pufl\ju»S\tecl422.wph                           4-73

-------
                                   Table 4-8 (Continued)
                             CALMET.DAT file - Data Records
Record
Type
5
5
5
6
6
6
7
7
7
8
8
8
9
9
9
10
10
10
Variable
No.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Variable
Name
CLABSC
NDATHR
IPGT
CLABUS
NDATHR
USTAR
CLABZI
NDATHR
ZI
CLABL
NDATHR
EL
CLABWS
NDATHR
WSTAR
CLABRMM
NDATHR
RMM
Type'
char*8
integer
integer
array
char*8
integer
real array
char*8
integer
real array
char*8
integer
real array
char*8
integer
real array
char*8
integer
real array
Description
Variable label ('IPGT)
Year, Julian day and hour in the form
PGT stability class at each grid point
Variable label (TJSTAR')
Year, Julian day and hour in the form
Surface friction velocity (m/s)
Variable label ('ZI')
Year, Julian day and hour in the form
Mixing height (m)
Variable label ('EL')
Year, Julian day and hour in the form
Monin-Obukhov length (m)
Variable label (WSTAR')
Year, Julian day and hour in the form
Convective velocity scale (m/s)
Variable label ('RMM')
Year, Julian day and hour in the form
Precipitation rate (mm/hr). Not used


YYJJJHH


YYJJJHH


YYJJJHH


YYJJJHH


YYJJJHH


YYJJJHH
byCALGRJJD.
  * char*8 = Character's
t\aUpuff\jul95\secl422.wph
4-74

-------
                                     Table 4-8 (Concluded)
                              CALMET.DAT file - Data Records
Record
Type
11
11
11
12
12
12
13
13
. 13
- 14
14
14
15
15
15
Variable
No.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Variable Name
CLABTK
NDATHR
TEMPK
CLABD
NDATHR
RHO
CLABQ
NDATHR
QSW
CLABRH
NDATHR
IRH
CLABPC
NDATHR
IPCODE
Type'
char*8
integer
real array
char*8
integer
real array
char*8
integer
real array
char*8
integer
integer
array
char*8
integer
integer
array
Description
Variable label (TEMPK')
Year, Julian day and hour in the form
Temperature (deg. K) at each surface
Variable label ('RHO')
Year, Julian day and hour in the form


YYJJJHH
met. station

YYJJJHH
Air density (kg/m3) aLeach surface met station
Variable label ('QSW)
Year, Julian day and hour in the form

YYJJJHH
Short-wave solar radiation (W/m2) at each surface
met station
Variable label ('IRH')
Year, Julian day and hour in the form

YYJJJHH
Relative humidity (percent) at each surface met.
station
Variable label ('IPCODE')
Year, Julian day and hour in the form

YYJJJHH
Precipitation type code (not used by CALGRID)
 ' char*8 = Character's
i:\calpufl\jul95\iecl422.wph
4-75

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4.2.2.2 ISCMET.DAT

       CALPUFF can be driven by a single-station ISC2-type of meteorological file.  However,
the header records of the standard ISC2 data file must be modified to provide some additional
information required by CALPUFF. In addition, the ISCMET.DAT file used by CALPUFF can
accommodate an extended data record, provding variables not found in a standard ISC2 data
record.

       CALPUFF is normally run with a full three-dimensional wind field and temperature
field, as well as two-dimensional fields of mixing heights and other meteorological variables (see
CALMET.DAT in Section 4.2.2.1). However, in some near-field applications, when spatial
variability of the meteorological fields may not be significant, the single-station data file may be
used. The model uses the data in the ISCMET.DAT file to fill the 2-D or 3-D arrays with the
scalar values read from the file. For example, the ISCMET.DAT header records contain a
single value of land use, and the hourly data records contain single values of mixing height and
temperature. In single-station mode, CALPUFF assigns the single value of each variable read
from the ISCMET.DAT file to all grid points, resulting in a spatially uniform gridded field.
However, the model does not assume the meteorological conditions are steady-state, which
allows the important effects of causality to be simulated even with the single-station
meteorological data.  For example, the time required for plume material to reach a receptor is
accounted for in the puff formulation, and curved trajectories and variable dispersion and
stability conditions over multiple hours of transport will result even when using the single-station
meteorological data.  However, in general, the preferred mode for most applications of
CALPUFF is to use the spatially variable fields generated by CALMET.

       The minimum data required in the ISCMET.DAT file includes hourly values of the
vector flow direction, wind speed, temperature, stability class, and mixing height (urban or
rural). In addition, if dry or wet deposition are being modeled, or if turbulence-based dispersion
coefficients are to be computed based on micrometeorological parameters, hourly values of the
surface friction velocity (u.), Monin-Obukhov length (L), a  time-varying surface roughness length
(z0), displacement height, precipitation rate, and precipitation type code can be entered on an
extended record.  If chemical transformation is being modeled, hourly values of short-wave solar
radiation and relative humidity can also be included.  In addition, hourly values of the potential
temperature lapse rate (d6/dz) and power law profile exponent (p) can be entered.  Non-
missing values of the basic meteorological variables (i.e., vector wind direction, wind speed,
temperature, stability class, and mixing height) must be provided for all applications.  The data
fields for the extended record variables (u., L, etc.) may be left blank if the CALPUFF options
are set so that they are not needed (e.g., no wet or dry deposition, no chemical transformation,
no computation of turbulence-based dispersion coefficients).  However, if the CALPUFF model

i\aUpufl\jul9S\sect422.wph                          4-76

-------
options are set to require them, the model assumes that valid values of the extended record
variables will be provided for every hour. Hie only exceptions are d8/dz and p, which can be
entered for some hours and not others.  If values of d6/dz or p are missing (Le., blank) for a
given hour, the model will use its default or user-specified stability-dependent values (see the
PLXO and PTGO variables in Input Group 12 of the control file).

       Sample ISCMET.DAT files are shown in Tables 4-7(a) and 4-7(b).  Part (a) of the table
shows the "base" data record (Le., an ISC2 meteorological data record). The extended data
record is shown in Part (b) of the table.  Table 4-8 lists the contents of the ISCMET.DAT
header records, and Table 4-9 describes the data records.

       The ISCMET.DAT header records are not part of the standard ISC2 ASCII
meteorological data file, so they must be added to an existing ISC2 data file before running
CALPUFF. The header  records contain: (1) an 80-character title of the data set; (2) the
starting date and hour of the data in the file; and (3) the anemometer height, surface roughness
length, land use type, elevation, and leaf area index of the modeling region. The starting date
and time in the header record allows checks in the setup phase of the model to be conducted to
verify that the model starting date is at or after the start of the data in the file. The
anemometer height is required in the vertical power law extrapolation of the wind speed. The
roughness length is used if turbulence-based dispersion coefficients are selected, and in the
calculation of dry deposition velocities. The land use category is used to determine if urban or
rural dispersion coefficients are appropriate when the Pasquill-Gifford/McElroy-Pooler
dispersion coefficients are used. Also see the variables IURB1 and IURB2 in Input Group 12
of the control file.  They define the range of land use categories that are to be considered urban
(i.e., if the value of the land use category in the ISCMET.DAT file is between IURB1 and
IURB2, inclusive, the modeling domain will be consider urban).  Otherwise, it will be considered
rural. The leaf area index is only used by the model if dry deposition velocities are being
computed (see Section  2.7). However, all of the header record variables must be present in the
ISCMET.DAT file, even if the model options will result in them not being used.

       The elevation on the ISCMET.DAT header record is used to fill the 2-D terrain
elevation array in CALPUFF. This  array is used to determine, through interpolation, the
elevation of the gridded receptors generated by the model as an option. Because a single value
is available in the ISCMET.DAT file, all of the gridded receptors will be assigned this elevation.
Receptor-specific elevations are assigned to each discrete receptor by the user in the CALPUFF
control file (see Input Group 17).
L-\calpiifl\jiiRS\KcU22.wph                          4-77

-------
                                                 Table 4-7
                                        Sample ISCMET.DAT files
                                          (a) Base Data Records
Austin ,TX Meteorological data -  10 hrs - Base ISC2 data only
90 1 1 1
10.06 0.25 2 0.0 3.0
90 1 1 81.0000 3.0866 280.9 5 881.S
90 1 2 98.0000 1.5433 279.8 6 904.6
90 3 114.0000 2.5722 279.8 5 927.8
90 4 113.0000 4.1155 280.4 4 951.0
90 5 103.0000 3.0866 279.8 5 974.2
90 6 102.0000 5.1444 280.4 4 997.4
90 7. 105.0000 4.6300 280.4 4 1020.6
90 1 8 73.0000 2.5722 280.4 4 1043.8
90 1 9 117.0000 4.1155 280.9 4 1067.0
90 1 110 141.0000 3.6011 283.73 1090.2
TTTT^ T T TT T
yr dy UO vect US Temp rural
•to hr stab zi
Austin ,TX meteorological data - 10 hrs -
90 1 1 1
10.06 0.25 2 0.0
90 1 1
90 1 2
90 1 3
90 1 4
90 1 5
90 1 6
90 1 1 7
90 1 1 8
90 1 1 9
90 1 110
T T T t
yr dy
mo hr
81.0000
98.0000
114.0000
113.0000
103.0000
102.0000
105.0000
73.0000
117.0000
H 1.0000
T
UD vect
3.0
3.0866
1.5433
2.5722
4.1155
3.0866
5.1444
4.6300
2.5722
4.1155
3.6011
T
US
: iyr.imo.iday,ihr(1-24) (begin)
: anemht(m),zO(m),ilandu,elev(m),xlai
53.0
53.0
53.0
951.0
53.0
997.4
1020.6
1043.8
1067.0
1090.2
T
urban
zi
(b) Extended Data Records
Extended data records
: iyr,imo,iday,ihr(1-24) (begin)
: anenht(m)(zO(m)
280.9 5
279.8 6
279.8 5
280.4 4
279.8 5
280.4 4
280.4 4
280.4 4
280.9 4
283.7 3
T T
Tenp
881.5
904.6
927.8
951.0
974.2
997.4
1020.6
1043.8
1067.0
1090.2
T
rural
stab zi
53.0
53.0
53.0
951.0
53.0
997.4
1020.6
1043.8
1067.0
1090.2
T
urban
zi
0.33
0.17
0.28
0.45
0.33
0.56
0.50
0.28
0.45
0.39
T
u*
, i landu,elev(n) ,xlai
355.
122.
259.
655.
355.
1025.
-1005.
-355.
-395.
-148.
T
L
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
t
zo
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
t
zd
0
0
0
0
0
1
0
1
2
0
T
P
code
0.0
0.0
0.0
0.0
0.0
.25
0.0
.75
2.64
0.0
T
prec
amt
                                                                                          .020  .35
                                                                                          .035  .55
                                                                                               .30
                                                                                               .15
                                                                                          .022
                                                                                               .18
                                                                                               .17

                                                                                               .22
                                                                                               .12
                                                                                             T    t
                                                    0. 77
                                                    0. 68
                                                    0. 72
                                                    0. 74
                                                    0. 75
                                                    0. 73
                                                   70. 71
                                                   120. 65
                                                   180. 68
                                                   240. 62
                                                    t   t
                                                   SW  rh
                                                   rad.  X
    i:\calpuff\jul95\sect422.wph
4-78

-------
                                            Table 4-8
                              ISCMET.DAT File - Header Records
               Records 1-3.  Title, stfl't'ng date, geophysical data.
Record
1
2
2
2
2
3
3
3
3
3
frJ^tnnc
1-80
*
*
*
•
*
*
*
*
*
Variable
TITLE
IBYR
ffiMO
ffiHR
IBHY
ANEMHT
ZOIN
ILANDUIN
ELEVIN
XLAIIN
Type
character*80
integer
integer
integer
integer
integer
real
integer
real
real
Description
Title of file.
Begining year of data.
Beginning month.
Beginning day.
Beginning hour (1-24).
Anemometer height (m).
Roughness length (m).
Land use category.
Elevation (m).
Leaf area index (LAI)
        * Free formatted input
t\calpufl\jul9S\iecM22.wph
4-79

-------
                                         Table 4-9
                             ISCMETJDAT FUe - Data Records
                                   (One record per hour)

                           Records 4,5,6»~ Hourly meteorological data.
Columns

1-2
3-4
5-6
7-8
9-17
18-26
27-32
33-34
35-41
42-48

49-57
58-67
68-75
76-80
81-84
85-91
92-101
102-106
107-115
116-118
Variable
Base
IY
IM
ID
m
FVEC
WSPD
TMPK
KST
RMIX
UMIX

USTR
XMON
ZOM
ZDISP
IPC
PMMHR
DTHTD
FLAW
QSWRAD
IRH
Type
Pata
integer
integer
integer
integer
•- real
real
real
integer
real
real
nded data
real
real
real
real
integer
real
real
real
real
integer
Description

Year of data in record
Month
Day
Hour (ISC2 convention .(1-24))
Flow vector (deg.)
Wind speed (m/s)
Temperature (deg. K)
Stability class (1-6)
Rural mixing height (m)
Urban m faring height (m)

Friction velocity (m/s)
Monin-Obukhov length (m)
Surface roughness length (m)
Displacement height (m)
Precipitation type code (see Table 2-11)
Precipitation rate (mm/hr)
Potential temperature lapse rate (deg. K/m)
Wind speed power law exponent
Short-wave solar radiation (W/m2)
Relative humidity (%)
i:\calpufl\jul95\tect422.wph
4-80

-------
4.22.3 PLMMETDAT

       In addition to the capability to use three-dimensional wind fields generated by CALMET,
a single-station meteorological file can also be used by CALPUFF as its source of meteorological
data.  The single station data can be in the form of the ISC2 meteorological data file (see Section
4222) or the AUSPLUME (Lorimer, 1976) type of data file. The standard AUSPLUME data file
must be modified by adding three header records at the beginning of the file to provide additional
information required by CALPUFF.

       CALPUFF is normally run with a full three-dimensional wind field and temperature field,
as well as two-dimensional fields of mixing heights and other  meteorological variables  (see
CALMET.DAT  in Section 422.1).   However, in some near-field  applications, when  spatial
variability of the meteorological fields may not be significant, the single-station data file may be
used.  The model uses the data in the PLMMET.DAT file to fill the 2-D or 3-D arrays with the
scalar values read from the file. For example, the PLMMET.DAT header records contain a single
value  of land use, and  the hourly  data records contain single values of  mixing height and
temperature. In single station mode, CALPUFF assigns the single value of each variable read from
the PLMMET.DAT file to all grid points, resulting in a spatially uniform gridded field.  However,
the model does  not assume the meteorological conditions are steady-state, which allows the
important effects of causality to be simulated even with the single-station meteorological data. For
example, the time required for plume material to reach  a receptor is accounted  for in the puff
formulation, and curved trajectories and variable dispersion and stability conditions over multiple
hours of transport will result even when using the single-station meteorological data.  However, in
general, the preferred mode for most applications of CALPUFF is to use the spatially variable fields
generated by CALMET.

       The PLMMET.DAT file includes the basic hourly data required by CALPUFF, including
the wind  direction,  wind  speed, temperature, stability  class, and mixing height.  Note  that
PLMMET.DAT uses wind direction in the usual meteorological convention (Le., winds from the west
blowing toward the east has a value of 270°), while ISCMET.DAT uses/tow vector (Le., winds from
the west toward the east have a vector direction of 90°). The PLMMET.DAT format contains two
data fields that are not used by CALPUFF (oe and a chemical decay constant). If turbulence data
are available, they should be entered through  the use of  the SIGMA.DAT data file (see Section
4.2.9).  Also, CALPUFF contains several options for modeling chemical transformation that do not
involve the use of a decay constant (see section 2.8).

       The PLMMET.DAT format does not allow for micrometeorological variables, such as the
surface friction velocity and Monin-Obukhov  length, or  precipitation  data to be entered.  The

t\calpufl\jul95\«ecM22.wph                         4-gl

-------
CALMET.DAT or ISCMET.DAT formats should be used if the selected CALPUFF options require
these parameters.

       A sample PLMMET.DAT file is shown in Table 4-10.  A description of the contents of the
header records is provided in Table 4-11, and the data records are described in Table 4-12.  The
header records are not part of the standard AUSPLUME meteorological data file, and must be
added by the user. The data record format is identical to the standard AUSPLUME format

       The header records contain: (1) an 80-character title of the data set; (2) the starting date
and hour (1-24) of the data in the file; and  (3) the anemometer height, surface roughness length,
land use type, elevation, and leaf area index of the modeling region. The starting date and time in
the header record allows checks in the setup phase of the model to be conducted to verify that the
model starting date is at  or after the start of the data in the file.  The anemometer height is
required in the vertical power law extrapolation of the wind speed. The roughness length  is used
if turbulence-based dispersion coefficients are selected, and  in the calculation of dry deposition
velocities. The land use category is used to  determine if urban or rural dispersion coefficients are
appropriate when the Pasquill-Gifford/McElroy-Pooler dispersion coefficients are used. Also see
the variables IURB1 and IURB2 in Input Group 12 of the control file.  They define the range of
land use categories that are to be considered urban (Len if the value of the land use category in the
PLMMET.DAT file is between IURB1 and IURB2, inclusive, the modeling domain will be consider
urban). Otherwise, it will be considered rural. The leaf area index is only used by the model if dry
deposition velocities are being computed (see Section 2.7).  However, all of the header record
variables must be present in the PLMET.DAT file, even if the model options will result in them not
being used.

       The elevation on the PLMMET.DAT header record is used to fill the 2-D terrain elevation
array in CALPUFF.  This array is used to determine, through interpolation, the elevation of the
gridded receptors generated by the model as an option.  Because a single  value is available in the
PLMMET.DAT file, all of the gridded receptors will be assigned this elevation. Receptor-specific
elevations are assigned to each discrete receptor by the user in the CALPUFF control file (see Input
Group 17).
fc\calpufl\juB5\«ect422.wph                          4-82

-------
SMple PUMET.DAT data file.
94 1 1 1
Nin.
                                               Table 4-10
                                       Sample PLMMET.DAT file
us'1.0 m/t
     : iyr,iM,
-------
                                           Table 4-11
                             PLMMET.DAT File - Header Records
               Records 1-3. Title, starting date, geophysical data.
Record
1
2
2
2
2
3
3
3
3
3
Columns
1-80
*
*
*
*
*
*
*
*
*
Variable
TITLE
IBYR
ffiMO
ffiHR
IBHY
ANEMHT
ZOIN
DLANDUIN
ELEVIN
XLAIIN
Type
character'80
integer
integer
integer
integer
integer
real
integer
real
real
Description
Title of file.
Rfgming ycpr r»f data.
Beginning month-
Beginning day.
Beginning hour.
Anemometer height (m).
Roughness length (m).
Land use category.
Elevation (m).
Leaf area index (LAI)
       * Free formatted input
i\c»lpuff\jul9S\sec*422.wph
4-84

-------
                                          Table 4-12
                              PLMMET.DAT File - Data Records
                                    (One record per hour)

                            Records 4,5,6^.  Hourly meteorological data.
Columns
1-2
3-4
5-6
7-8
9-11
12-16
17-20
21-22
23-27
"28-32

33-37
-38-42
43-52

Variable
IY
IM
ID
IH
TMPC
WSPD
IWD
KST
ZMK
SIGTHA

PLEXP
PTGDF
DECAY

Type
integer
integer
integer
integer
real
real
integer
integer
real
real

real
real
real

Description
Year of data in record
Month
Day
Hour (1-24 hour dock)
Temperature (deg. C)
Wind speed (m/s)
Wind direction (deg.)
Stability class
Mixing height (m)
o,(deg.). Not used by CALPUFF. Use SIGMAJDAT file
for turbulence measurements. See Section 4.2.9.
Wind speed power law exponent
Potential temperature gradient (deg. K/m)
Decay constant (s'1). Not used by CALPUFF. See
Section 2£ for chemical transformation options.
L\calpufl\jiil9S\iect422.wph
4-85

-------
4.23   Point Source Emissions File With Arbitrarily Varying Emissions (PTEMARBDAT)

       The PTEMARB.DAT file contains point source emissions data for sources with detailed,
arbitrarily varying emissions parameters.   In the  PTEMARB.DAT file, values for the  stack
parameters and emission rates can be specified for each time step in the run.  Plume rise is
computed within the CALPUFF model for each source.

       PTEMARB.DAT is a sequential, unformatted data file consisting of three header records
(see Table 4-13), followed by a set of data records containing time-invariant source information.
The time-invariant records contain the stack height, diameter, coordinates, and optional descriptive
codes for each source.  The time varying emissions and stack parameter data follow in subsequent
records.  One data record per source is required  for each time period  (e.g.,usuaUy at hourly
intervals).

       The data in the PTEMARB.DAT file is independent of the horizontal and vertical grid
systems being used  in  the model.  The horizontal coordinates are  specified  in terms of the
meteorological grid projection (UTM or Lambert conformal coordinates).  The vertical layers
receiving the emissions of the source are based on the plume rise of the source computed internally
by the model. However, the PTEMARB.DAT file does contain time-dependent data specifying the
emission parameters for a particular time period.
i\calpufl\jul95\«ecM22.wph                         4-86

-------
                         PTEMARB .DAT FUe • Header Records

       The header records of the PTEMARB.DAT file contain the number of sources, starting and
ending time periods of data in the file, and a list of the emitted species. Sample Fortran read
statements are:
      READ(iunk)FNAME2^SRC2^SE2JUTMZ2,mDAT2^BTIM2JEDAT2,
     1 IETIM2,VRS2^ABEL2

      READ(iunit)CSLST2
      READ(iunit)XMWEM2


where the following declarations apply:

      CHARACTER*12 FNAME2,VRS2,LABEL2,CSLST2(nse2)
      REAL XMWEM2(nse2)
i:\calpufl\jul95\iec»422.wph                        4-g7

-------
                                       Table 4-13
                    PTEMARB.DAT - Header Record 1 - General Data
No.
1
2
3
4
5
6
7
8
9
10
Variable
FNAME2
NSRC2
NSE2
IUTMZ2
EBDAT2
IBTIM2
IEDAT2
IETIM2
VRS2
LABEL2
Type'
C*12
integer
integer
integer
integer
integer
integer
integer
C*12
C*12
Description
Data set name
Number of sources in the file
Number of species emitted
UTM zone in which source coordinates are specified
(enter 0 if using Lambert confbrmal coordinates)
Date of beginning of data in the file (YYJJJ, where
YY=year, JJJ= Julian day)
Hour of beginning of data in the file
(00-23, LST)
Date of end of data in the file
(YYJJJ, where YY=year, JJJ=Julian day)
Hour of end of data in the file
(00-23, LST)
Data set version
Data set label
Sample
Values
PTEMARB
10
3
11
84220
00
84224
23
Base Case
Major pts.
  C*12 = Character*!!
L\aUpufl\jul95\Kd422.wph
4-88

-------
                                  Table 4-13 (Continued)
                      PTEMARB.DAT - Header Record 2 - Species List
NO:
i
2
1>pc'
ۥ12
C*12
PcscfiutioD
Species identifier for species 1
Species identifier for species 2
Sample Values
SO2
S04
   NSE2      C*12       Species identifier for specks "NSE2"                NOX
   " "NSE2" elements of CSLST2 array
   1 C*12 = Character*12
t\calpufl\jul95\iect422.wph

-------
                                 Table 4-13 (Concluded)
                  PTEMARB.DAT - Header Record 3 - Molecular Weights
No."
1
2
T>pe-
real
real
Description
Molecular weight for species 1
Molecular weight for species 2
Sample Values
64. SO2
96. S04
   NSE2      real        Molecular weight for species "NSET               30. (NOX as NO)
   ' "NSE2" elements of XMWEM2 array
L-\calpufl\iiil95\tect422.wph                          4-90

-------
                           PTEMARBJUT File - Data Records


      The FTEMARB.DAT file contains two types of data records.  A set of time-invariant
records (see Table 4-14) are read after the header records. These records specify the time-
invariant source parameters, including the source coordinates, stack height, and diameter. A set
of time-varying data follows (see Table 4-15). The time-varying records contain the stack
temperature, exit velocity, flow rate, and emission rate for each species.

      Sample Fortran read statements for time-invariant data records are:

   —Loop over sources

      READ(iunit)CID,TIDATA

   —End loop over sources
where the following declarations apply:

      CHARACTER'16 CID

      REAL TIDATA(7)

      Sample Fortran read statements for time-varying data records are:

         — Loop over time periods
            READ(iunit)ffiDAT,ffiTIMJEDAT,IETIM

            	Loop over sources

                  READ(iunit)CID,TEMPK,VEXIT,VOLFLOW,QEMIT

            	End loop over sources

            End loop over time periods
where the following declarations apply:

       CHARACTER*16 CID
       REAL QEMTT(nse2)
i:\calpiifi\juI93\tect42Zwph                         4-91

-------
                                         Table 4-14
                   PTEMARB.DAT - Time-Invariant Data Record Contents
                                 (Repeated for each source)
No.
1
2
Variable
CED
TIDATA(1)
1>pe'
C*16
real
Description
^rmrff wtmtifvv l\t\ rtiarflrtm = A owwvlicl
Easting UTM or Lambert conformal coordinate
                 TIDATA(2)      real
4
5
6
7
8
TIDATA(3)
TIDATA(4)
TIDATA(5)
TIDATA(6)
TIDATA(7)
real
real
real
real
real
(km) of the source
Northing UTM or Lambert conformal coordinate
(km) of the source
Stack height (m)
Stack diameter (m)
Stack base elevation (m)
User defined flag (e.g^ industry code)
User defined flag (e.g, fuel code)
       C*16 = Character*16
i:\calpuff\jul9S\iect422,wph
4-92

-------
                                      Table 4-15
                  PTEMARB.DAT - Time-Varying Data Record Contents
             (First record of "NSRC2"+1 records required for each time period)
No. Variable
1 IBDAT
2 IBTIM
3 ffiDAT
4 ffiTIM
1>pc'
integer
integer
integer
integer
Description
Beginning date for which data in fh«$ set
where YY-ycar, JJJ= Julian day)

is valid (YYJJJ,
Beginning hour for which data in this set is valid
(00-23, LSI)
Ending date for which data in this set is
YY=year, JJJ=Julian day)
Ending hour for which data in this set is
valid (YYJJJ, where
valid (00-23, LST)
Example:
      Data Valid for 1 hour:
           ffiDAT=89183JBTIM=00 JEDAT=89183JETIM=00
           IBDAT=89183.IBTIM » 01JEDAT=89183.IETIM=01
           ffiDAT=89183,ffiTIM=02,IEDAT=89183,IETIM=02

      Data Valid for 3 hours:
           IBDAT * 89183.IBTIM=OO^EDAT=89183 JETTM=02
           IBDAT=89183JBTIM=03JEDAT=89183.IETIM=05
           IBDAT=89183,IBTIM=06JEDAT=89183,IETIM=08
t\oUpufl\jul95\iect422.wph
4-93

-------
                                Table 4-15 (Concluded)
                  PTEMARB.DAT - Time-Varying Data Record Contents
                                (Next "NSRC2" records)
No.
1
2
3
4
Next
NSE2
Variable
cn>
TEMPK
vExrr
VOLFLOW
QEMTT
Type'
C*16
real
real
real
real array
Description
Source identifier (must match values
records)
Exit temperature (deg. K)
Exit velocity (m/s)
Volumetric flow rate (m3/s)
Emission rates (g/s) for each species
in Header Record 2

in time-invariant



in the order specified
 *C*16 = Character*16
fc\calpufl\jul95\secl422.wph                         4-94

-------
4.2.4   Buoyant Area Source Emissions File With Arbitrarily Varying Emissions
       (BAEMARB.DAT)

       The BAEMARB JDAT file contains buoyant area source emissions data for sources with
detailed, arbitrarily varying emissions parameters.  This file can be generated from the output of
the Forest Service's Emissions Production Model (EPM) using a reformatting and preprocessing
program provided with CALPUFF.  In the BAEMARBDAT file, values for the source
parameters and emission rates can be specified for each time step in the run.  Plume rise is
computed within the CALPUFF model for each source using the numerical plume rise
algorithm described in Section 2.4.6.

       BAEMARB.DAT is a free-formatted ASCII data file consisting of three header records
(see Table 4-16), followed by a set of data records containing source information. The time-
invariant data records contain character source identifiers. The time varying emissions and
source parameter data follow in subsequent records.  One data record per source is required for
each time period (e.g.,usually at hourly intervals).

       The data in the BAEMARB.DAT file are independent of the horizontal and vertical grid
systems being used in the model.  The horizontal coordinates are specified in terms of UTM or
Lambert conformal coordinates. The vertical layers receiving the emissions of the source are
based on the plume rise of the source computed internally by the model. However, the
BAEMARB.DAT file does contain time-dependent data specifying the emission parameters for
a particular time period.
t\calpun\jul95\sect422.wph                         4-95

-------
                         BAEMARBDAT File - Header Records

       The header records of the BAEMARB.DAT file contain the number of sources, starting
and ending time periods of data in the file, and a list of the emitted species. Sample Fortran
read statements are:
    1 IETIM3,VRS3,LABEL3

     READ(iunit,*)CSLST3
     READ(iunit,*)XMWEM3

where the following declarations apply:

     CHARACTER'12 FNAME3,VRS3,LABEL3,CSLST3(nse3)
     REAL XMWEM3(nse3)
i;\caJpufl\}ul95\«ect422.wph                         4-96

-------
                                         Table 4-16
                     BAEMARB.DAT - Header Record 1 - General Data
No.
1
2
3
4
5
6
7
8
9
10
Variable
FNAME3
NSRC3
NSE3
IUTMZ3
IBDAT3
IBTIM3
IEDAT3
IETIM3
VRS3
LABELS
"type'
C*12
integer
integer
integer
integer
integer
integer
integer
C*12
C*12
Description
Data set name
Number of sources in the file
Number of species emitted
UTM zone in which source coordinates are specified
(rn^r 0 5$ ^King 1 ^mh^rf rnnfnrmfll mfw^inaf^)
Date of beginning of data in the file (YYJJJ, where
YY«year, JJJ-Julian day)
Hour of beginning of data in the file
(00-23, LST)
Date of end of data in the file
(YYJJJ, where YY=year, JJJ= Julian day)
Hour of end of data in the file
(00-23, LST)
Data set version
Data set label
Sample
Values
BAEMARB
10
3
11
84220
00
84224
23
Base Case
Burn#l
 * C*12 = Character*12
L\c«lpufl\jul95\iect422.wph
4-97

-------
                                  Table 4-16 (Continued)
                     BAEMARB.DAT - Header Record 2 - Species List
No.'
1
2
Type'
C*12
C*12
Description
Species identifier for species 1
Species identifier for species 2
Sample Values
PM
PM10
   NSE3      C*12        Species identifier for species "NSE3"               PM25
   ' -NSE3" elements of CSLST3 array
   * C*12 = Character*12
r\calpufl\jul95\iect422.wph                           4-98

-------
                                    Table 4-16 (Concluded)
                   BAEMARB.DAT - Header Record 3 - Molecular Weights
              No."      TyP6*      Description                     Sample Values

              1         real        Molecular weight for species 1           200.

              2         real        Molecular weight for species 2           200.
              NSE3     real        Molecular weight for species            200.
                                   "NSE3"
              ' "NSE3" elements of XMWEM3 array
i\calpufl\jul95\iect422.wph                            4-99

-------
                           BAEMARB .DAT FUe - Data Records


      The BAEMARB.DAT file contains two types of data records. A set of time-invariant
records (see Table 4-17) are read after the header records. These records specify the time-
invariant source names.  A set of time-varying data follows (see Table 4-18).  The time-varying
records contain the coordinates of four vertices that define the perimeter of the source, effective
release heights, temperature, heat flux, and an emission rate for each species. Note that the
four vertices must be centered in sequence around the perimeter; all four V coordinates
followed by all four V coordinates.

      Sample Fortran read statements for time-invariant data records are:

     -Loop over sources

      READ(iunit,*)C3D

     -End loop over sources

where the following declarations apply:

      CHARACTER'16 CID

      Sample Fortran read statements for time-varying data records are:

         	Loop over time periods
            READ(iumt,*)ffiDAT,IBTIM,IEDAT,IETIM

              —Loop over sources

                  READ(iunit,*)CID,VERTX,VERTY,HT,TEMPK,QHFLX,QEMIT

              — End loop over sources
         	End loop over time periods

where the following declarations apply:

       CHARACTER*16 CID
       REAL VERTX(4),VERTY(4)
       REAL QEMIT(nse3)
t\calpufl\jul95\iec»422.wph                         4-100

-------
         No.
                                          Table 4-17
                   BAEMARB.DAT • Time-Invariant Data Record Contents
                                  (Repeated for each source)
Variable      Type'        Description
                 C3D
             C*16        Source identifier (16 characters - 4 words)
        C*16 - Character*16
i:\calpufl\iiil9S\iect422.wpb
                       4-101

-------
                                      Table 4-18
                  BAEMARB.DAT - Time-Varying Data Record Contents
             (First record of "NSRC3"+1 records required for each time period)
No.
1
2
3
4
Variable
ffiDAT
IBTIM
ffiDAT
ffiTIM
Type'
integer
integer
integer
integer
Description
Beginning date for which data in this set is valid (YYJJI,
where YY=year, JJJ= Julian day)
Beginning hour for which data in this set is valid
(00-23, LST)
prtjing date for which data in this set is valid (YYJJJ, where
YY=year, JJJ= Julian day)
Ending hour for which data in this set is valid (00-23, LST)
Example:
      Data Valid for 1 hour
           IBDAT=89183,IBTIM=00,IEDAT=89183.IETIM=00
           IBDAT=89183 JBTIM=OUEDAT=89183.IETIM=01
           IBDAT=89183,IBTIM=02,ffiDAT=891834ETIM=02

      Data Valid for 3 hours:
           ffiDAT=89183,IBTIM=OOJEDAT=89183,ffiTIM=02
           ffiDAT=89183.IBTIM=03.IEDAT=89183,ffiTIM=05
           IBDAT=89183,ffiTTM=06,ffiDAT=89183,IETIM=08
L\calpufl\jiiI95\Kc(422.wph
4-102

-------
                                   Table 4-18 (Concluded)
                   BAEMARB.DAT - Time-Varying Data Record Contents
                                   (Next "NSRC3" records)
    No.
     10
     11
     12
 -Next
 NSE3
Variable
HT
TEMPK
QHFLX
QEMTT
 "C»16 = Character*16
Typef
Description
1
2-5
6-9
cn>
VERTX
VERTY
C*16
real array
real array
Source identifier (must match values in tune-invariant
records)
X-coordinate (km) of each of the four vertices defining the
perimeter of the area source
Y-coordinate (km) of each of the four vertices defining the
            perimeter of the area source
real         Effective height (m) of the emissions above the ground
real         Temperature (deg. K)
real         Total heat flux (kW)
real array    Emission rates (g/s) for each species in the order specified
            in Header Record 2
L-\calpufi\jiil$S\McM22.wpb
                               4-103

-------
4.2.5   Volume Source Emissions File (VOLEM.DAT) with Arbitrarily Varying Emissions

       Time independent volume source data are contained in the CALPUFF control file
(CALPUFF.INP). The VOLEM.DAT emissions file contains time-dependent volume source
emissions data. VOLEMDAT is a sequential, unformatted data file containing one two-
dimensional grid for each emitted species modeled by CALPUFF for each time step.  There are
three header records with information describing the grid system, dates and time of data in the
file, species names, and molecular weights.

       The total emission rate for each pollutant is specified for the grid column. Individual
source information is not stored in the file, so plume rise is not computed by CALPUFF for the
VOLEM.DAT emissions. The effective height and initial vertical and horizontal plume
dimensions (ay oz) are specified by the user in the control file (CALPUFF.INP) for the gridded
area source inventory.
                             VOLEM File - Header Records

       The header records contain information regarding the horizontal grid system, species
emitted, molecular weights, and dates of the data contained in the file (see Table 4-19).  These
data are checked by CALPUFF in the setup phase of the model run to ensure the parameters
are compatible with those specified in the CALPUFF control file. Any mismatch in the
specifications results in an error message and termination of the run.

       Sample Fortran read statements for the header records are:

        READ(iunit)FNAME4,IGTYP4,NX4^rY4,DELX4,DELY4pCORIG4,YORIG4,IUTMZ4,
         1 NSE4JBDAT4,IBTIM4,ffiDAT4,IETIM4,VRS4^ABEL4

         READ(iunit)CSLST4
         READ(iunit)XMWEM4

where the following declarations apply:

         CHARACTER*^ FNAME4,VRS4,LABEL4,CSLST4(nse4)
         REAL XMWEM4(iise4)
t\calpufl\jiil9S\sect422.wpb                        4-104

-------
                                         Table 4-19
              VOLEM - Header Record 1 - General Grid, Species, and Date Data
No.
- 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Variable
FNAME4
IGTYP4
NX4
NY4
DELX4
DELY4
XORIG4
YORIG4
IUTMZ4
NSE4
ffiDAT4
IBTIM4
IEDAT4
IETIM4
VRS4
LABEL4
Type'
C*12
integer
integer
integer
real
real
real
real
integer
integer
integer
integer
integer
integer
C*12
C*12
Description
Data set name
Horizontal grid type (always - 1 for CALPUFF runs)
Number of grid ceOs in the X direction
Number of grid cells in the Y direction
Grid spacing (km) in the X direction
Grid spacing (km) in the Y direction
Reference X coordinate (km) of the southwest corner
of grid cell (LI)
Reference Y coordinate (km) of the southwest corner
of grid cell (U)
UTM zone of horizontal coordinates (enter 0 if using
Lambert conformal coordinates)
Number of species emitted
Date of beginning of data in file (YYJJJ, where
YY=year, JJJ= Julian day)
Hour of beginning of data in file (00-23, LST)
Date of end of data in file (YYJJJ, where YY=year,
JJJ= Julian day)
Hour of end of data in file (00-23, LST)
Data set version
Data set label
Sample
Values
VOLEM
1
30
30
5.
5.
168.000
3930.000
11
3
84220
00
84224
23
Base Case
'84 -KERN
  •C*12 = Character*12
i:\calpufl\jiil95\ieci422.wph
4-105

-------
                                   Table 4-19 (Continued)
                          VOLEM - Header Record 2 - Species List
No.
1
2
Type*
C*12
C«12
Description
Species identifier for species 1
Species identifier for species 2
Sample
Values
SO2
SO4
       NSE4    C*12       Species identifier for species "NSE4"                NOX
       * "NSE4" elements of CSLST4 array
       •C*12 = Character*12
t\calpuff\jul95\sect422.wph                           4-106

-------
                                  Table 4-19 (Concluded)
                      VOLEM - Header Record 3 - Molecular Weights
No.
1
2
•**
real
real
Description
Molecular weight for species 1
Molecular weight for species 2
Sample
Values
64. (SO2)
%. (SO4)
       NSE4    real       Molecular weight for species "NSE4"                30. (NOX)
       • "NSE4" elements of XMWEM1 array
fc\calpiifl\juSS\iecM22.wph                          4-107

-------
                            VOLEMDAT File • Data Records
      The VOLEMDAT file contains a set of "NSE4"+1 records for each time period (e.g.,
hour). The first data record of each set defines the time period over which the emissions data
in the following records are valid. The next "NSE4" records each contain a species identifier and
a two-dimensional gridded field of emissions.  See Table 4-20 for a description of the variables
in the VOLEM.DAT data records.

      Sample Fortran read statements for a set of data records are:

         	   Loop over time periods (e-g. Hours)
                 —  Loop over species

                     READ(iunit)CSPEC,QEMIT

                	  End loop over species

               End loop over time periods
where the following declarations apply:


       CHARACTER'12 CSPEC

       REAL QEMIT(iix4,ny4)
L\calpufl\jul95\«ect422.wph
4-108

-------
                                     Table 4-20
                            VOLEM - Data Record Contents
                                (Record 1 of each set)
No.
1
2
3
4
Variable
ffiDAT
IBTIM
ffiDAT
ffiTIM
Type-
integer
integer
integer
integer
Description
Beginning date for which data in this set is valid
(YYJJJ, where YY-year, JJJ-Julian day)
Beginning time for which data in this set is valid (00-
23.LST)
Ending date for which data in this set is valid (YYJJJ,
where YY«year, JJJ= Julian day)
Ending time for which data in this set is valid (00-23,
LST)
Example:
      Data Valid for 1 hour
           ffiDAT=89183^BTIM=004EDAT=89183,IETIM=00
           ffiDAT=89183,ffiTIM=01JEDAT=89183,IETIM=01
           KDAT=89183,IBTIM=02,IEDAT=89183,IETIM=02

      Data Valid for 3 hours:
           IBDAT=89183.IBTIM=OO.IEDAT=89183,ffiTIM=02
           IBDAT=89183,mTIM=03^EDAT=89183,IETIM=05
           IBDAT=89183.IBTIM=06 JEDAT=89183,IETIM=08
t\olpufl\jul95\«ct422.wph
4-109

-------
                                  Table 4-20 (Concluded)
                             VOLEM - Data Record Contents
                           (Records 2, 3,... "NSE4"+1 of each set)
    No.         Variable     Type*      Description
    1           CSPEC      C*12       Species identifier (up to 12 characters)
    Next        QEMTT     real array   Volume source emission rate (g/s) of species CSPEC"
    NX4*NY4                          for each grid column (QEMTT (nx4,ny4)
    •C»12 = Character*12
t\calpufl\jul95\«ec«422.wph                           4-110

-------
4.2.6   User-Specified Deposition Velocity Data Ffle (VDDAT)

       The CALPUFF model requires that the user specify the method for determining dry
deposition velocities for each species.  In Input Group 3 of the control file, one of the following
flags must be specified for each pollutant.

       0  -   no dry deposition (deposition velocities set to zero)
       1  -   resistance model used - pollutant deposited as a gas
       2  =   resistance model used - pollutant deposited as a particle
       3  =   user-specified deposition velocities used

       Note that different methods can be used for different pollutants in the same CALPUFF
run.

       If any species are flagged as using "user-specified" deposition velocities, CALPUFF reads
a formatted user-prepared data file with a 24-hour diurnal cycle of deposition velocities for each
species flagged.  The 24  values correspond to hours 01-24 (LST) of the simulated day. Twenty-
four values must be entered for each flagged pollutant, even if the model run is for less than a
full diurnal cycle. The units of the deposition velocities are m/s.

       An example of a user-specified VD.DAT file is shown in Table 4-21.  The VD.DAT file
uses a control file format (see Section 4.22). All text outside the  delimiters (!) is considered as
user comment information and is echoed back but otherwise ignored by the input module.  Each
data line consists of a delimiter followed by the species name, 24 deposition velocities, and a
terminating delimiter. The data may extend over more than one line.  The line being continued
must end with a comma. The control file format allows the use of repetition factors (e.g., 3 *
1.0 instead of 1.0, 1.0, 1.0). The order in which the species are entered in the file is not
important. However, the file must end with an input group terminator (i.e., !END!).

       The model checks that values have been entered for each species flagged as using user-
specified deposition velocities. An error message is printed and execution of the run is
terminated if any values are missing. The run will also terminate with an error message from
the input routine if too many values are entered (i.e., more than 24 values for a particular
pollutant). The species names must match those used in the chemical mechanism of the model.
t\calpufl\jul95\ieetC2.wph                          4-111

-------
                                               Table 4-21
                  Sample User-Specified Deposition Velocity File for Two Species
                DEPOSITION VELOCITY FILE (VD.OAT)



VD.DAT contains 24-hour diurnal cycle of deposition velocities for each species flagged as using user-specified
values in the control  file  (CALPUFF.INP).

The first value correspond  to  the period fro* 0:00  to 1:00. and the 24th value corresponds to 23:00-0:00.

NOTE: Units are in «/s.
SPECIES
 NAME                  Deposition Velocities («/s)
I  HN03       =        5*1.5e-2, 4*1.7e-2. 3*1.8e-2.  3*1.9e-2. 3*1.7e-2, 6*1.5e-2
I  S02        «        5*0.8e-2. 13*1.Oe-2, 6*0.Be-2
!END!
t\calpuff\jul9S\ied422.wph                              4-112

-------
4.2.7  Hourly Ozone Data File (OZONE.DAT)

       If the MESOPUFF n chemical mechanism is used to simulate the chemical
transformation of SO2 - SOJ and NO, - HNO3 - NO,, estimates of background ambient ozone
concentration levels are required to compute the hourly conversion rates. CALPUFF provides
two options for the user to provide these data: (1) a single, typical background value
appropriate for the modeling region, or (2) hourly ozone data from one or more ozone
monitoring stations. The selection of Option 2 requires that a file called OZONE.DAT be
created with the necessary data.

       OZONE.DAT is a sequential, formatted data file containing three types of records:
single header record, time-invariant data records, and hourly ozone data records. A sample
OZONE.DAT file is shown in Table 4-22. The header record contains information on the
number of stations in the data set, the time period of the data, and descriptive information
regarding the file. The time-invariant records contain the coordinates of each of the ozone
stations.  The time-varying data consists of hourly ozone concentrations at each of the ozone
stations.
i-\c«Ipufl\jul95\iect422.wph                        4-113

-------
                                         Table 4-22
                       Sample Hourly Ozone Data File (OZONE.DAT)


                      'OZONE'. 3. 11, 80001, 0, 80002, 0.  'TEST DATA'.  'V1.0'
'STATION 1'
'STATION 2'
'STATION 3'
80.
80.
80.
80.
80.
80.
80.
80,
80,
80,
80.
80.
80,
80,
80,
80.
80.
80.
80.
80,
80.
80,
80.
80.
80.
001.
001.
001.
001.
001.
001.
001.
001.
001.
001,
001,
001,
001,
001.
001,
001.
001.
001,
001,
001,
001,
001.
001.
001,
002,
«
9
ff
o.
1.
2.
3.
4.
5.
6,
7.
8.
9.
10,
11.
12.
13,
1*.
15.
16.
17.
18,
19.
20,
21.
22,
23.
00,
168.000, 3840.000
200.000, 3880.000
180.000, 3860.000
9999 • i
9999 • 4
68..
66..
Tyyy» f
9999.,
9999 • «
9999««
69..
72..
74.,
87..
102.,
109.,
120.,
116.,
103.,
98..
89.,
9999 • t
QQOQ
yyyy. 9
9999 u i
9999* i
9999.,
9999.,
62..
9999* (
61.,
9999m i
9999*g
9999m 9
9999. t
9999m i
68..
75.,
.78..
85..
99..
105..
118..
116.,
100.,
90..
82..
oooo
yyyy. f
9999m g
9999. g
9999.,
9999» t
QQQQ
yyyy. ,
50.
TVTT»
9999.
9999.
53.
9999*
9999*
9999m
60.
65.
69.
74.
84.
92.
102.
95.
97.
88.
83.
80.
78.
74.
69.
69.
68.
L\calpufl\jul95\«ect422,wph                           4-114

-------
                          OZONE DAT File - Header Record
       The header records of the OZONE.DAT file contain the name, version, and label of the
data set, the number of ozone stations, and starting and ending tune periods of data in the file
(see Table 4-23). A sample Fortran read statement for the header record is:
       1 ffiIIMO,VRSOZJABOZ

where the following declaration applies:

       CHARACTER*12 FNAMEO.VRSOZMBOZ.
fc\calpufl\ju»5\iecl422.wph                         4-115

-------
                                         Table 4-23
                       OZONE .DAT - Header Record - General Data
No.
1
2
3
Variable
FNAMEO
NOZSTA
ITUMOZ
1>pe'
C*12
integer
integer
Description
Data set name
Number of ozone stations in the file
UTM zone in which ozone station coordinates are
Sample
Values
OZONE
3
11
  4    IBDATO

  5    IBTTMO
  6    IEDATO

  7    IETIMO
  8    VRSOZ
  9    LABOZ
          specified (enter 0 if using Lambert conformal
          coordinates)
integer    Date of beginning of data in the file (YYJJJ, where    80001
          YY=year, JJJ«=JuUan day)
integer    Hour of beginning of data in the file (00-23, LST)      00
integer    Date of end of data in the file (YYJJJ, where         80002
          YY=year, JJJ=Julian day)
integer    Hour of end of data in the file (00-23, LST)          00
C*12      Data set version                                  Test Data"
C*12      Data set label                                    "V1.0"
       = Character*12
t\aUpufl\jul95\»ect422.wph
                       4-116

-------
                            OZONE.DAT File - Data Records


      The OZONE.DAT file contains two types of data records.  A set of time-invariant records
are read after the header records.  These records specify the coordinates of each ozone station
(see Table 4-24).  A set of time-varying data follows, which contain the hourly ozone
concentration (in ppb) for each station (see Table 4-25).

      Sample Fortran read statements for time-invariant data records are:

      I	  Loop over stations
            READ(iunit,*)CID,XOZ,YOZ
        —  End loop over stations
where the following declaration applies:
      CHARACTERS CID
      Sample Fortran read statements for time-varying data records are:
            Loop over hours

                 READ(iunit,*)IYRJJUL,IHR,OZCONC

            End loop over hours
where the following declaration applies:


      REAL OZCONC(nozsta)
i: \calpufl\jul95\sect422. wph                         4-117

-------
                                         Table 4-24
                    OZONE.DAT - Time-Invariant Data Record Contents
                                 (Repeated for each station)
            No.      Variable    Type*     Description	
             1       (3D       C*16      Station identifier (16 characters « 4 words)
             2       XOZ       real       X coordinate (km) of the ozone station
             3       YOZ       real       Y coordinate (km) of the ozone station
        «C*16 = Character*16
t\calpiiff\jul95\iect422.wph                           4-118

-------
                                         Table 4-25
                     OZONE.DAT - Time-Varying Data Record Contents
                                    (One record per hour)
    No.          Variable     Type*      Description
    1            IYR        integer     Year of data (two digits)
    2            UUL       integer     Julian day
    3            IRH        integer     Hour of data (00-23 LSI)
    Next         OZCONC   real array  Ozone concentration (ppb) at each ozone station (in the
    "NOZSTA"                           same order as the station coordinates in the time-
                                        invariant records)
i:\calpufl\jul95\sect422.wph                          4-119

-------
4.2.8   User-Specified Chemical Transformation Rate Data File (CHEM.DAT)

       If chemical conversion is to be considered by CALPUFF, the user must specify a
variable in the control file, MCHEM, which determines how chemical transformation rates are
computed.  The options for MCHEM are:

       0 =   chemical transformation is not modeled
       1 =   the MESOPUFF n chemical scheme is used to compute transformation rates
       2 =   user-specified 24-hour cycles of transformation rates are used

       If MCHEM is set equal to 2, CALPUFF reads a formatted user-prepared data file with
24-hour diurnal cycles  of transformation rates klt k* k} (described  in Section 2.8). The nature of
the equilibrium relationship assumed between pollutants 4 and 5 (e.g., HNO3 and NO 3)
precludes the use of a  user-specified conversion rate between these pollutants. If NO3 is being
modeled, the NH4NO3 dissociation constant is determined as a function of temperature and
relative humidity as described in Section 2.8.1.

       A sample user-specified CHEM.DAT file is shown in Table 4-26.  The CHEM.DAT file
uses a control file format (see Section 42.2). All text outside the delimiters (!) is considered as
user comment information and  is  echoed back but otherwise ignored by the input module. Each
data line consists of a delimiter followed by the species name, 24 conversion rates, and a
terminating delimiter.  The data may extend over more than one line.  The line being continued
must end with a comma. The control file format allows the use of repetition factors (e.g., 3 *
1.0 instead of 1.0, 1.0,  1.0). The order in which the species are entered in the file is not
important.  However, the file must end with an input group terminator (i.e., !END).

       The model checks  that the proper number of values have been  entered for each
conversion rate.  An error message is printed and execution of the run is terminated if any
values are missing. The run will also terminate with an error message  from the input routine if
too many values are entered (i.e., more than 24 values).
t\a]puff\jiil9S\MCt422.wph                         4-120

-------
                                               Table 4-26
          Sample User-Specified Chemical Transformation Rate Data File (CHEM.DAT)
                         CHEMICAL TRANSFORMATION RATE FILE (CHEM.DAT)



 CHEM.DAT contains a 24-hour diurnal cycle of chearical trantfonaation
 rates for the cheatical  transformation of S02 to S04. and NOx to HN03/PAN.

          k1 « S02 to S04 transformation rate(percent/hour)

          k2 » NOx to HN03 * PAN transfonnation rate (percent/hour)

          k3 « NOx to HN03 (only) transfomation rate (percent/hour)

 The first value correspond to the period from 0:00 to 1:00, and the 24th value corresponds to 23:00-0:00.



                  TRANSFORMATION RATE (percent/hour)
 ! K1          *   7*0.2, 0.4, 0.8, 1.2,  1.6. 3*2.0,   1.6,  1.2,  0.8,  0.4, 6*0.2 !
 I K2          «   7*2.0, 4.0, 8.0,12.0,15.0, 3*20.0, 15.0, 12.0,  8.0,  4.0, 6*2.0 I
 I K3          «   7*2.0, 3.0, 6.0, 8.0,11.0, 3*15.0, 11.0,  8.0,  6.0,  3.0, 6*2.0 I
 I END!
i:\calpufl\juB5\iect422.wph                              4-121

-------
42.9   Site-Specific Turbulence Data (SIGMA.DAT)

       CALPUFF provides several options for computing the dispersion coefficients, oy and oz.
In Input Group 2 of the control file, the user specifies a value for the dispersion method flag,
MDISP:

       1  =   dispersion coefficients computed from values of ov and ow read from a data file
              (SIGMA.DAT),

       2  =   dispersion coefficients determined from internally computed values of ov and ow
              based on similarity scaling relationships,

       3  =   PG coefficients (computed using the ISCST multi-segment approximation) used
              for rural areas and MP coefficients used in urban areas,

       4  =   same as 3 except that the PG coefficients are computed using the MESOPUFF n
              equations.

       Section 2.2.1 contains more information on these options.  If Option 1 is selected, the
user must prepare a data file with hourly values of ov and 
-------
                                            Table 4-27
                    Sample Site-Specific Turbulence Data File (SIGMA.DAT)
             •SIGMA', 80001, 0, 80002, 0, 'BASE CASE', 'OnsitelOm'
                                                                0.01
                                                                0.01
                                                                O01
                                                                0.01
                                                                0.02
                                                                0.02
                                                                0.04
                                                                0.04
                                                                0.05
                                                                0.05
                                                                0.07
                                                                0.07
                                                                0.08
                                                                0.08
                                                                0.08
                                                                0.10
                                                                0.10
                                                                0.12
                                                                0.12
                                                                0.14
                                                                0.14
                                                                026
                                                                026
                                                                028
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
80,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
001,
002,
01,
02,
03,
04,
05,
06,
07,
08,
09,
10,
11,
12,
13,
H
15,
16,
17,
18,
19,
20,
21,
22,
23,
00,
0.52,
0.54,
057,
0.61,
0.64,
0.64,
0.65,
0.68,
0.70,
0.72,
0.73,
0.93,
LOS,
1.18,
123,
1.12,
L12,
0.99,
0.93,
0.89,
0.87,
0.76,
0.71,
0.63,
L-\
-------
                           SIGMA.DAT File - Header Record

       The header record of the SIGMA.DAT file contains the name, version, and label of the
data set, and the starting and ending time periods of the data in the file (see Table 4-28). A
sample Fortran read statement for the header record is:

             READ(iunit)FNAMES^DATS^BTIMS^EDATSJETIMS,VRSSMBELS

where the following declaration applies:

             CHARACTER*^ FNAMES, VRSS, 1ABELS
fc\calpufl\jiil9S\iecM22.wph                        4-124

-------
                                          Table 4-28
                         SIGMA.DAT - Heater Record - General Data
No.
1
2
3
4
5
6
7
Variable
FNAMES
ffiDATS
IBTIMS
ffiDATS
ffiTIMS
VRSS
LABELS
Type'
C*12
integer
integer
integer
integer
C*12
C*12
Description
Data set name
Date of beginning of data in the file (YYJJJ, where
YY«=year and JJJ= Julian day)
Hour of beginning of data in the file (00-23, LST)
Date of end of data in the file (YYJJJ, where
YY=year and JJJ= Julian day)
Hour of end of data in the file (00-23, LST)
Data set version
Data set label
Sample
Values
SIGMA
80001
00
80002
00
Base Case
OnsitelOm
   C*12 = Character*12
i:\calpufl\jul95\Md42Zwph
4-125

-------
                             SIGMA.DAT File - Data Records
     The SIGMAJDAT file contains one data record per hour.  Each record contains values for
ov and o^ in m/s (see Table 4-29). Preferably, the measurement height of o¥ and ow should be
at or near the height of the stack being modeled. The values of ov and ow provided in the
SIGMAJDAT file are used in Eqns. (2-39) and (2-40)  to compute oy and az (see Section 2.2.1).
A sample read statement for the hourly data records is:
   —  Loop over hours

        READ(iunit/)IYRJJUUHR,SIGV,SIGW

   L—  End loop over hours
t\calpufl\juJ95\iecM22,wph                          4-126

-------
                                          Table 4-29
                      SIGMAJDAT - Time-Varying Data Record Contents
                                    (One record per hour)
        No.
Variable     Type'
Description
         1       IYR         integer     Year of data (two digits)
         2       UUL        integer     Julian day
         3       MR         integer     Hour of data
         4       SIGV        real        Standard deviation (m/s) of the horizontal crosswind
                                         component of the wind (OT)
         5       SIGW        real        Standard deviation (m/s) of the vertical component of
                                         the wind (ov)
t\calpuff\jul95\«ect422.wph
                           4-127

-------
4.2.10  CTDMPLUS Terrain Feature Description - for CTSG (TERRAIN)

       CALPUFF allows two ways of specifying the characteristics of terrain features modeled
by CTSG. The first is by means of the OPTfflLL processor described in Section 4.1. The
second approach allows the use of the terrain preprocessing programs provided with
CTDMPLUS (Mills et aL, 1987).  If a user is familiar with the terrain preprocessor, then this
may be the preferred option because the standard terrain ffle used in CTDMPLUS can be used
in CALPUFF without modification. CTDMPLUS subroutines that read and process the terrain
data have been incorporated in CALPUFF.

       Table 4-30 illustrates a typical TERRAIN file for one hill.  This  one is defined by
ellipse/polynomial shapes determined for a range of 10 "critical elevations" from 25 m to 115 m
above the base of the hill. After the header record, the first group of 10 records provides the
ellipse parameters at each "critical elevation", and the second group of 10 records provides the
parameters for the corresponding inverse polynomial shape profile fit to the portion of the hill
above it. Refer to Mills et al. (1987) for more detailed information.
i\calpuff\jul9S\«ed422.wph                         4-128

-------
                                        Table 4-30
                    Sample CTDMPLUS Terrain Feature File (TERRAIN)
      1 10        125.             CISC T«>t Mill
25.
35.
45.
55.
65.
75.
85.
95.
105.
115.
25.
35.
45.
55.
65.
75.
85.
95.
105.
115.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
1132.
980.
855.6
748.6
653.4
565.8
482.6
400.
313.8
213.8
2.5
2.4
2.6
2.7
2.5
2.8
2.8
2.9
2.0
2.0
566.
490.
427.8
374.3
326.7
282.9
241.3
200.
156.9
106.9
2.5
2.4
2.5
2.6
2.4
2.6
2.5
2.0
2.0
2.0










540.
500.
460.
420.
380.
340.
300.
260.
107.
53.5










270.
250.
230.
210.
190.
170.
150.
130.
53.5
26.8
i:\alpiifl\jul9S\iecM2Zwpli                          4-129

-------
43    CALPUFF Output Files

43.1   Concentration File (CONCDAT)

       The CONC.DAT file is an unformatted data file containing gridded fields of time
averaged concentrations predicted by CALPUFF.  The creation and contents of the CONCDAT
file are controlled by user-specified inputs in Input Group 7 of the control file (see Section
4.2.2).  The control file variable ICON must be set equal to one in order to create the
CONCDAT file.

                           CONCDAT File - Header Records

       The CONC.DAT file consists of five header records followed by a set of data records.
The header records contain information describing the version of the model used in the run
creating the file, horizontal and vertical grid data, a user-input title, a list of the species
combinations stored in the output file, and receptor information (see Table 4-31).

       Sample FORTRAN read  statements for the header records are:

       READ(iunk)CMODEL,VER4£VELJBYRJBJUL»IBHR,
       2 IBSAMP^SAMP,IESANIP^ESAMP>IESHDN^TS,NAREAS,W)REQNCTREC,LSGRro,
       3 NSPOUT
       READ(iunit)TTnJE
       READ(iunit)CSOUT
       READ(iunit)XREC,YREC,ZREC
       READ(iunit)XRCT,YRCT,ZRCT,IHILL

where the following declarations apply:

       Character'80 TITLE(3)
       Character*15 CSOUT(NSPOUT)
       Character*12 CMODEL,VER,LEVEL

       Real XREC(NDREC),YREC(NDREC)^REC(NDREC)
       Real XRCT(NCTREC),YRCT(NCTREC),ZRCr(NCrREC)

       Integer IHILL(NCTREC)
t\calpufl\juI9S\iect422.wph                        4-130

-------
                                        Table 4-31
               Unformatted CONC.DAT file - Header Record 1 - General Data
No.
1
2
3
4
5
6
7
8
9
-• 10
„ 11
* 12
13
14
15
16
17
18
19
Variable
CMODEL
VER
LEVEL
ffiYR
IBJUL
IBHR
IRLG
IAVG
NXM
NYM
DXKM
DYKM
IONE
mCOMP
IECOMP
JBCOMP
JECOMP
ffiSAMP
JBSAMP
Type'
C*12
C*12
C*12
integer
integer
integer
integer
integer
integer
integer
real
real
integer
integer
integer
integer
integer
integer
integer
Description
Model name
Model version number
Model level number
Starting year of the run
Starting Julian day
Starting hour (00-23)
Length of run (hours)
Averaging time (hours) of output concentrations
Number of grid points in meteorological grid (X
direction)
Number of grid points in meteorological grid (Y
direction)
Grid spacing (km) in the X direction
Grid spacing (km) in the Y direction
Number of receptor layers (must be equal to one for
CALPUFFruns)
Start of computational grid in X direction
End of computational grid in X direction
Start of computation grid in the Y direction
End of computational grid in Y direction
Start of sampling grid in X direction
End of sampling grid in X direction
Sample
Values
CALPUFF
3.0
950715
80
183
8
5
1
20
20
5.
5.
1
1
20
1
20
1
20
 *C*12 = Character*12
i\calpufl\jul95\»e
-------
                                  Table 4-31 (Continued)
              Unformatted CONC.DAT file - Header Record 1 - General Data
No.
20
21
22
23
24
25
26
27
Variable
ffiSAMP
JESAMP
MESHDN
NPTS
NAREAS
NDREC
NCTREC
LSGRID
Type
integer
integer
integer
integer
integer
integer
integer
logical
Description
Start of sampling grid in Y direction
End of sampling grid in Y direction
Sampling grid spacing factor
Number of point sources
Number of area sources
number of discrete receptors
Number of complex terrain receptors
Sampling grid flag (T = gridded receptors,
Sample
Values
1
20
1
2
0
0
0
T
                             F = no gridded receptors)
  28   NSPOUT     integer   Number of output species
t\calpufl\ju»5\iect422.wph
4-132

-------
                                    Table 4-31 (Continued)
                  Unformatted CONCDAT file - Header Record 2 - Run Title
        No.
Variable
           Description
                 TITLE (3)   C*80
                        User-specified run title (three fines of up to 80
                        characters/line)
                        Header Record 3 - List of Species in Output File
     No.
Variable
Type'
Description
     1-NSPEC    CSOUT      C*15       Species name (characters 1-12) and layer (characters 13-
                 array                   15) of concentrations stored in the output file. For
                                         example, *SO2        1" indicates SO2 concentrations
                                         in Layer 1; "DIOXINP    1* indicates dioxin in
                                         particulate form in Layer 1. CALPUFF concentrations
                                         are always computed at ground-level, so therefore are
                                         labeled as Layer 1.
     *C*80 = Character*80
     C*15 = Character*15
i:\calpufl\iul95\Kd422. wph
                           4-133

-------
                                Table 4-31 (Concluded)
                          Header Record 4 - Discrete Receptors
                             (Included only if NDREC > 0)
No.
1
2
3
Variable
XREC
YREC
ZREC
Type
real array
real array
real array
Description
X-coordinate (km) of each discrete receptor
Y-coordinate (km) of each discrete receptor
Ground level elevation (m) of each discrete receptor
                      Header Record 5 - Complex Terrain Receptors
                            (Included only if NCTREC >  0)   .
No.
1
2
3
4
Variable
XRCT
YRCT
ZRCT
IHILL
Type
real array
real array
real array
integer
array
Description
X-coordinate (km) of each complex terrain receptor
Y-coordinate (km) of each complex terrain receptor
Ground level elevation (m) of each complex terrain
receptor
Hill number associated with this receptor
i:\calpiiff\jul9S\iecM22.wph
4-134

-------
                          CONCDAT File - Data Records


     The CONCDAT data records consist of a set of "NSPOUT+1" records for each hour of
the CALPUFF run (NSPOUT is the number of output species in the CALPUFF run).  The first
record of each set contains the date and hour of the data in the records which follow it The
next "NSPOUT" records contain the predicted concentrations in g/m3, for each species, flagged
for output in the control file.  See Table 4-32 for a description of the variables.


     Sample FORTRAN read statements for the data records are:

 —  LOOP OVER OUTPUT SPECIES

     GRIDDED RECEPTOR CONCENTRATIONS
     IF(LSGRID)READ(iunit)CSPECG,CONCG

     DISCRETE RECEPTOR CONCENTRATIONS
     IF(NDREC.GT.O)READ(iunit)CSPECD,CONCD

     COMPLEX TERRAIN RECEPTOR CONCENTRATIONS
     IF(NCTRECGTJ))READ(iunU)CSPECCT,CONCCT

 —  END LOOP OVER OUTPUT SPECIES

where the following declarations apply:

     Character*15 CSPECG.CPSECD.CSPECCT
     Real CONCG(nxg,nyg),CONCD(NDREC),CONCCT(NCTREC)
and
    nxg = IESAMP - IBSAMP+1
    nyg = JESAMP - JBSAMP+1
fc\oUpufl\jul9S\iect422.wph                       4-135

-------
                                         Table 4-32
                        Unformatted CONC.DAT File - Data Records
                                   (Record 1 of each set)
No.
1
2
3
Variable
NYR
NJUL
NHR
•type
integer
integer
integer
Description
Year of concentration data (two digits)
Julian day of data
Hour (00-23) of data
                                    (Next Data Record)
                            (Included only if LSGRID = TRUE)
   No.
Variable
Description
                  CSPECG     C*15
   Next           CONCG     real array
   NXG*NYG
                       Species name (characters 1-12) and layer (characters 13-
                       15) of the concentrations in this record. For example,
                       "SO2       1" indicates SO2 concentrations in
                       Layer 1; "DIOXINP     1* indicates dioxin in
                       particulate form in Layer 1. (Note:  Layer is always " 1"
                       in CALPUFF output, but can be up to NZ in
                       CALGRID.)

                       "IAVG" - hour averaged concentrations (g/m3) for each
                       sampling grid point
    C*15 = Character*15
i:\calpufl\jul95\iect422.wph
                          4-136

-------
43.2   Dry Flux File (DFLX.DAT)

       The DFLX.DAT file is an unformatted data file containing gridded fields of time
averaged dry deposition fluxes predicted by CALPUFF. The creation and contents of the
DFLX.DAT de are controlled by user-specified inputs in Input Group 7 of the control file (see
Section 42.1).

       The control file variable IDRY must be set equal to one in order to create the
DFLX.DAT file. The species saved in the output file are also controlled by the user by setting
flags in the output species table in Input Group 7 of the control file.  The model checks that
only deposited species are flagged for output into the DFLX.DAT file. The effects of dry
deposition on ambient concentrations can be evaluated without saving the dry fluxes in the
output file if the actual values of the deposition fluxes are not of interest.

                            DFLXJ)AT File - Header Records ~

       The DFLX.DAT file consists of five header records followed by a set of data records.
The header records contain information describing the version of the model used in the run
creating the file, horizontal and vertical grid data, a user-input run title, and a list of the
deposited species stored in the output file, and receptor information (see Table 4-33).

       Sample FORTRAN read statements for the header records are:
       2
       3NDFOUT
       READ(iunit)TTTLE
       READ(iunit)CDFOUT
       READ(iunit)XREC,YREC,ZREC
       READ(iumt)XRCT,YRCT,ZRCT,IHILL

where the following declarations apply:

       Character«80 TTTLE(3)
       Character*15 CDFOUT(NDFOUT)
       Character*12 CMODEL.VERO-EVEL

       Real XREC(NDREC),YREC(NDREC)^REC(NDREC)
       Real XRCT(NCTREC),YRCT(NCTREC),ZRCT(NCTREC)
       Integer IHILL(NCTREC)
L\calpu0\juJ9S\tect432,wph                         4-137

-------
                                        Table 4-33
               Unformatted DFLX.DAT file - Header Record 1 - General Data
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Variable
CMODEL
VER
LEVEL
ffiYR
IBJUL
IBHR
IRLG
IAVG
NXM
NYM
DXKM
DYKM
IONE
ffiCOMP
IECOMP
JBCOMP
JECOMP
IBSAMP
JBSAMP
Type"
C*12
C*12
C*12
integer
integer
integer
integer
integer
integer
integer
real
real
integer
integer
integer
integer
integer
integer
integer
Description
Model name
Model version number
Model level number
Starting year of the run
Starting Julian day
Starting hour (00-23)
Length of run (hours)
Averaging time (hours) of output concentrations
Number of grid points in meteorological grid (X
direction)
Number of grid points in meteorological grid (Y
direction)
Grid spacing (km) in the X direction
Grid spacing (km) in the Y direction
Layer number (always 1 for deposition fluxes)
Start of computational grid in X direction
End of computational grid in X direction
Start of computational grid in Y direction
End of computational grid in Y direction
Start of sampling grid in X direction
End of sampling grid in X direction
Sample
Values
CALPUFF
3.0
950715
80
183
8
5
1
20
20
5.
5.
1
1
20
1
20
1
20
   C*12 = Character*12
L\calpufi\jul9S\sect432.wph
4-138

-------
                                   Table 4-33 (Continued)
                Unformatted DFLX.DAT file - Header Record 1 - General Data
No.
20
21
' 22
23
24
25
26
27
Variable
DESAMP
JESAMP
MESHON
NPTS
NAREAS
NDREC
NCTREC
LSGRID
Type'
integer
integer
integer
integer
integer
integer
integer
logical
Description
Start of sampling grid in Y direction
End of sampling grid in Y direction
Sampling grid spacing factor
Number of point sources
Number of area sources
Number of discrete receptors
Number of complex terrain receptors
Sampling grid flag (T = gridded receptors,
Sample
Values
1
20
1
2
0
0
0
T
  28    NDFOUT
          F = no gridded receptors)

integer    Number of dry deposited species stored in the output
          file
L-\calpufl\jul95\«ecl432.wph
                      4-139

-------
                                   Table 4-33 (Continued)
                 Unformatted DFLX.DAT file - Header Record 2 • Run Title
        No.      Variable     Type*      Description	

         1       TITLE(3)    C*80       User-specified run title (three lines of up to 80
                                        characters/line)
                   Header Record 3 - List of Species-Layers in Output File
        No.       Variable     Type       Description
   1-NDFOUT     CDFOUT    C*15       Species name (characters 1-12) and variable flag
                  array                   (characters 13-15) of data stored in the output file. The
                                         variable flag for dry fluxes is" DP. For example,
                                         "SO2        DP" corresponds to SO2 dry fluxes.
    C*80 = Character*80
    C*15 = Character*15
L\calpufl\jul95\«ect432.wph                           4-140

-------
                                   Table 4-33 (Concluded)
                            Header Record 4 - Discrete Receptors
                                (Included only if NDREC > 0)
No.
1
2
3
Variable
XREC
YREC
ZREC
Type-
real array
real array
real array
Description
X-coordinate (km) of each discrete receptor
Y-coordinate (km) of each discrete receptor
Ground level elevation (m) of each discrete receptor
                        Header Record 5 - Complex Terrain Receptors
                               (Included only if NCTREC >  0)
        No.
Variable
Type
Description
         1
         2
         3
XRCT
YRCT
ZRCT

BULL
real array   X-coordinate (km) of each complex terrain receptor
real array   Y-coordinate (km) of each complex terrain receptor
real array   Ground level elevation (m) of each complex terrain
           receptor
                              integer
                              array
           Hill number associated with this receptor
i:\aUpufl\juJ9S\tect432.wph
                          4-141

-------
                           DFLX.DAT File • Data Records


      The DFLX.DAT data records consist of a set of "NDFOUT+1" records for each hour of
the CALPUFF runs (NDFOUT is the number of species flagged as being stored in the output
file). The first record of each set contains the date and hour of the data in the records which
follow it The next "NDFOUT" records contain predicted one-hour averaged dry deposition
fluxes in g/m2/s for each relevant species (see Table 4-34).


      Sample FORTRAN read statements for the data records are:

  -  LOOP OVER DRY DEPOSITED SPECIES STORED ON DISK

     GRIDDED RECEPTOR DRY FLUXES
       IF(LSGRID)READ(iunit)CDFG^>FLXG

     DISCRETE RECEPTOR DRY FLUXES
       IF(NDREC.GT.O)REXVD(iunit)CDFD4>FLXD

     COMPLEX TERRAIN RECEPTOR DRY FLUXES
       IF (NCTRECGT.O)READ(iunU)CDFCr,DFLXCT

 —  AND LOOP OVER DRY DEPOSITED SPECIES STORED ON DISK


where the following declarations apply:


     Character*15 CDFG.CDFD.CDFCT
     Real DFLXG(nxg,nyg),DFLXD(NDREC) ,DFLXCT(NCTREC)
and
    nxg = IESAMP - ffiSAMP+1
    nyg = JESAMP - JBSAMP+1
i:\calpufl\jul9S\iect432.wph                      4-142

-------
                                         Table 4-34
                        Unformatted DFLX.DAT File - Data Records
                                   (Record 1 of each set)
No.
1
2
3
Variable
NYR
NJUL
NHR
Type'
integer
integer
integer
Description
Year of dry flux data (two digits)
Julian day of data
Hour (00-23) of data
                                    (Next Data Record)
                            (Included only if LSGRID = TRUE)
   No.
Variable
Type
Description
                  CDFG       C*15
   Next           DFLXG      real array
   NXG*NYG
                       Species name (characters 1-12) and variable flag
                       (characters 13-15) of the data in this record.  For
                       example, "SO2       DP corresponds to SO2 dry flux.

                       "IAVG" - hour averaged dry deposition fluxes (g/m'/s)
                       for each gridded receptor
    C*15 = Character*15
I:\calpufl\jul95\jecl432-wph
                         4-143

-------
433   Wet Flux File (WFLX.DAT)

       The WFLX.DAT file is an unformatted data file containing gridded fields of time
averaged wet deposition fluxes predicted by CALPUFF. The creation and contents of the
WFLXJDAT file are controlled by user-specified inputs in Input Group 7 of the control file (see
Section 4.2.1).

       The control file variable IWET must be set equal to one in order to create the
WFLX.DAT file. The species saved in the output file are also controlled by the user by setting
flags in the output species table in Input Group 7 of the control file.  The model checks that
only deposited species are flagged for output into the WFLX.DAT file. The effects of wet
deposition on  ambient concentrations can be evaluated without saving the wet fluxes in the
output file if the actual values of the deposition fluxes are not of interest.

                           WFLXJ3AT  File - Header Records

       The WFLX.DAT file consists of five header records followed by a set of data records.
The header records contain information describing the version of the model used in the  run
creating the file, horizontal and vertical grid data, a user-input run title, and a list of the
deposited species stored in the output file, and receptor information  (see Table 4-35).

       Sample FORTRAN read statements for the header records are:

       READ(iunit)CMODELiVER4-EVEUBYR4BJUUBHR,IRLG,
       2 IBSAMP,JBSAMP,IESAMP,JESAMP,MESHDN^
       3NWFOUT
       READ(iunit)TITLE
       READ(iunit)CWFOUT
       READ(iunit)XREC,YREC,ZREC
       READ(iunit)XRCT,YRCT,ZRCT,IHILL

where the following declarations apply:

       Character*80 TTTLE(3)
       Character*15 CWFOUT(NWFOUT)
       Character*12 CMODEL>VER,LEVEL

       Real XREC(hfDREC),YREC(NDREC)^REC(NDREC)
       Real XRCT(NCTREC),YRCT(NCTREC),ZRCT(NCTREC)
       Integer IfflLL(NCTREC)
t\calpufl\jul95\iect432.wph                        4-144

-------
                                        Table 4-35
               Unformatted WFLX.DAT file • Header Record 1 - General Data
No.
1
2
3
4
5
6
7
8
9
10
*. 11
12
* 13
14
15
16
17
18
Variable
CMODEL
VER
LEVEL
IBYR
IBJUL
IBHR
IRLG
IAVG
NXM
NYM
DXKM
DYKM
IONE
IBCOMP
IECOMP
JBCOMP
JECOMP
IBSAMP
Type'
C*12
C*12
C*12
integer
integer
integer
integer
integer
integer
integer
real
real
integer
integer
integer
integer
integer
integer
Description
Model name
Model version number
Model level number
Starting year of the run
Starting Julian day
Starting hour (00-23)
Length of run (hours)
Averaging time (hours) of output concentrations
Number of grid points in meteorological grid (X
direction)
Number of grid points in meteorological grid (Y
direction)
Grid spacing (km) in the X direction
Grid spacing (km) in the Y direction
Layer number (always 1 for deposition fluxes)
Start of computational grid in X direction
End of computational grid in X direction
Start of computational grid in Y direction
End of computational grid in Y direction
Start of sampling grid in X direction
Sample
Values
CALPUFF
3.0
950715
80
183
8
5
1
20
20
5.
5.
1
1
20
1
20
1
 1 C*12 = Character*12
i:\calpufl\jul95\sect43Xwph
4-145

-------
                                  Table 4-35 (Continued)
               Unformatted WFLX.DAT file - Header Record 1 - General Data
No.
19
20
21
22
23
24
25
26
27
Variable
JBSAMP
IESAMP
JESAMP
MESHON
NPTS
NAREAS
NDREC
NCTREC
LSGRID
Type-
integer
integer
integer
integer
integer
integer
integer
integer
logical
Description
End of sampling grid in X direction
Start of sampling grid in Y direction
End of sampling grid in Y direction
Sampling grid spacing factor
Number of point sources
Number of area sources
Number of discrete. receptors
Number of complex terrain receptors
Sampling grid flag (T = gridded receptors,
F = no gridded receptors)
Sample
Values
20
1
20
1
2
0
0
0
T
  28   NWFOUT    integer
Number of wet deposited species stored in the output
file
i:\calpufl\jul9S\KCt43Zwph
             4-146

-------
                                    Table 4-35 (Continued)
                 Unformatted WFUCDAT file - Header Record 2 - Run Title
        No.      Variable     Type*      Description

         1       TTTLE(3)    C*80      User-specified run title (three lines of up to 80
                                        characters/line)
                    Header Record 3 - List of Species-Layers in Output File
   No.            Variable     Type       Description
   1-NWFOUT    CWFOUT   C*15      Species name (characters 1-12) and wet flux flag
                  array                   (characters 13-15) of data stored in the output file.  The
                                         wet flux flag is " WF. For example, "SO2         WF
                                         corresponds to SO2 wet fluxes.
   1 C*80 - Character'80
    C*15 = Character*15
t\calpufl\jul9S\iect432.wph                           4-147

-------
                                  Table 4-35 (Concluded)
                               Unformatted WFIJCDAT File
                           Header Record 4 - Discrete Receptors
                               (Included only if NDREC > 0)
No.
1
2
3
Variable
XREC
YREC
ZREC
Type*
real array
real array
real array
Description
X-coordinate (km) of each discrete receptor
Y-coordinate (km) of each discrete receptor
Ground level elevation (m) of each discrete receptor
                       Header Record 5 - Complex Terrain Receptors
                              (Included only if NCTREC > 0)
       No.
Variable
Type
Description
         1
         2
         3
XRCT
YRCT
ZRCT

IHILL
real array   X-coordinate (km) of each complex terrain receptor
real array   Y-coordinate (km) of each complex terrain receptor
real array   Ground level elevation (m) of each complex terrain
           receptor
                              integer
                              array
           Hill number associated with this receptor
fc\calpufl\jul9S\iect432.wph
                         4-148

-------
                           WFLXJUT FUe - Data Records

       The WFLX.DAT data records consist of a set of "NWFOUT+1" records for each hour
of the CALPUFF runs (NWFOUT is the number of species flagged as being stored in the
output file). The first record of each set contains the date and hour of the data in the records
which follow it The next "NWFOUT" records contain predicted one-hour averaged wet
•deposition fluxes in g/m2/s for each relevant species (see Table 4-36).

       Sample FORTRAN read statements for the data records are:

     i— LOOP OVER WET DEPOSITED SPECIES STORED ON DISK
         GRIDDED RECEPTOR WET FLUXES
             IF(LSGRID)READ(iunit)CWFG,WFLXG
         DISCRETE RECEPTOR WET FLUXES
            IF(NDREC.GT^)READ(iunU)CWFD,WFLXD
         COMPLEX TERRAIN RECEPTOR WET FLUXES
             IF (NCTRECGT^))READ(iunit)CWFCT,WFLXCT
     — END LOOP OVER WET DEPOSITED SPECIES STORED ON DISK
where the following declarations apply:
     Character*15 CWFG,CWFD,CWFCT
     Real WFLXG(nxg,nyg),WFLXD(NDREC),WFLXCT(NCTREC)
and
     nxg = IESAMP-IBSAMP+1
     nyg = JESAMP - JBSAMP+1
L-\calpufl\jul9S\secM32.wph                       4-149

-------
                                        Table 4-36
                       Unformatted WFLX.DAT File - Data Records
                                   (Record 1 of each set)
No.
1
2
3
Variable
NYR
NJUL
NHR
Type?
integer
integer
integer
Description
Year of wet flux data (two digits)
Julian day of data
Hour (00-23) of data
                                    (Next Data Record)
                            (Included only if LSGRID = TRUE)
   No.
Variable
1>pe
Description
                 CWFG
   Next          DWLXG
   NXG'NYG
            C*15       Species name (characters 1-12) and wet flux flag
                       (characters 13-15) of the data in this record. For
                       example, "SO2      WP corresponds to SO2 wet
                       fluxes.

            real array   "IAVG" - hour averaged wet deposition fluxes (g/mj/s)
                       for each gridded receptor
   ' C*15 = Character*15
t\c»lpufl\juJ95\«ecl432.wph
                          4-150

-------
                                   Table 4-36 (Concluded)
                        Unformatted WFUCDAT File - Data Records
                                    (Next Data Record)
                               (Included only if NDREC > 0)
    No.
Variable
           Description
                CWFD
    Next
    NDREC
WFLXD
C*15       Species name (characters 1-12) and wet flux flag
           (characters 13-15) of the data in this record. For
           example, "SO2      WP corresponds to SO2 wet
           fluxes.


real array   "IAVG" - hour averaged weLdeposition fluxes (g/m2/s)
           for each discrete receptor
                                    (Next Data Record)
                              (Included only if NCTREC > 0)
   No.
 Variable
 Type
Description
                  CWFCT
   Next          WFLXD
   NCTREC
             C*15       Species name (characters 1-12) and wet flux flag
                        (characters 13-15) of the dat&in this record. For
                        example, "SO2       WF" corresponds to SO2 wet
                        fluxes.

             real array   "IAVG" - hour averaged wet deposition fluxes (g/m3/s)
                        at each complex terrain (CTSG) receptor
      *15 = Character*15
fc\calpufl\jul95\sect432.wph
                           4-151

-------
4.4    CALPOST Postprocessing Program

       The CALPOST program is a postprocessor designed to produce ranked tabulations of
averages of selected concentration (or wet/dry deposition flux) data obtained from the
CALPUFF or CALGRID models. Its capabilities and options include:

              Option to produce tables of the "top-50" average concentration/deposition data
              (includes time and receptor information) for specified averaging times.

              Option to produce tables of the "top-N" (user specifies the number N) average
              concentration/deposition data at each receptor for specified averaging times.

              Option to produce a table of the annual (or length-of-run) average
              concentration/deposition at each receptor.

              Option to print concentration/deposition averages for selected days.

              Option to print tables of the number of exceedances of user-specified threshold
              values for each averaging time at each receptor.

              Option to produce plot files containing the "top N" concentrations or deposition
              fluxes at each receptor or the number of exceedances of the user-specified
              thresholds at each receptor.

              User-selected processing periods.

              User-selected chemical species.

              User-selected layer from which concentration data are obtained.

              Option to include gridded receptors, discrete receptors, and complex terrain
              receptors in any combination.

              Option to scale all concentration/deposition data by means of a linear function of
              the form: a*X + b (where X is concentration or deposition, and a,b are user-
              supplied scaling factors).

              User-specified averaging time.

i:\calpufl\jul95\tect432.wph                         4-152

-------
       The user-specified inputs to CALPOST are read from the control file: CALPOSTJNP.
The program reads the concentration/deposition flux data from an unformatted data file called
MODELDAT that is generated by the CALPUFF model (or CALGRID). CALPUFF abo
generates a file containing relative humidity data, called VISB.DAT, which is read by CALPOST
if the visibility options in CALPOST are selected
      The CALPOST control file uses the same irelf-docuingntfrig control fite format as
CALPUFF. See Section 4.2.1 for a description of the control file input conventions. A
description of each input variable is shown in Table 4-38.  A sample input file is presented in
Table 4-39. A sample output list file is shown in Table 4-40.

      CALPOST generates an output list file, called CALPOSTXST, and a set of optional plot
files containing the "top N" highest concentrations at each receptor.  A second set of optional
plot files cnmaias the number of eacceedances of user-specified threshold values at each receptor
and averaging time. The format of the plot files (Receptor X, Y, value 1, vahies2, etc.) is
suitable for direct input into many of the popular PC-based graphics packages.

      As with CALPUFF and CALMET, CALPOST also contains a parameter file, called
PAKAMS.PST, in which all of the array dimensions related to the number of gridded, discrete,
and complex terrain receptors, the number of "top N" tables allowed, and the Fortran unit
numbers associated with each  input and output file are specified. If the user needs for a
particular application to increase the number of discrete receptors, for example, beyond the
current maximum, a change to the value of the discrete  receptor parameter in PARAMSJPST
will automatically re-size all arrays related to this parameter upon recompilation of the
CALPOST code.
                                        4-153

-------
                                        Table 4-37
                             CALPOST Input and Output Files
  Unk*   File Name
Type
Format
                Description
   in2    CALPOSTJNP    input
   inl    MODELDAT     input
             formatted
                Control file containing i

                CALFUFF output file
                modeled concentration or
                flux data
   in3    VISBDAT
input
   iol    CALPOST1ST    output
unformatted
formatted
                CALPUFF output file r***mmina
                relative humidity data (required only
                for viability application*)
                             List file nminmtng CALPOST
                                other generated
           Optional Plot Files • Top N* concentrations or dcposuian fluxes at cadi rcceptor
mapl
map3
map24
mapn
mapr
UTOPN.MAP
L3TOPN.MAP
L24TOPNJvIAP
LNTOPNAiAP
LRAVGMAP
output
output
output
output
output
formatted
formatted
formatted
formatted
formatted
1-hour averaged values
3-hour averaged values
24-hour averaged values
User-specified averaging time
Length of run averaged values
            Optional Plot Files - Number of CTceedances of user-specified threshold values
  maplz   L1EXCMAP      output        formatted
  map3z   L3EXCMAP      output        formatted
 map24x   L24EXCMAP     output        formatted
  mapnx   LNEXCMAP     output        formatted
                             1-hour averaged threshold
                             3-hour averaged threshold
                             24-hour averaged threshold
                             User-specified averaging time threshold
       * See the parameter file, PARAMS.PST, for the numerical values of the unit numbers.
t\
-------
                                             Table 4-38
                         CALPOST Control Ffle Inputs (CALPOSTJNP)
Variable
ISYR
ISMO
ISDY
ISHR
NHRS
ASPEC
Type
atfffj
•^M^AM
integer
diancter'12
Description
Starting year of data to proem (two digits)
flf flfi •••!•) BBQQtll
Starting day
Starting hour (0-23). Uses ending hour convention (eg,
Unnv 1 mmtmm* tn *!•« 	 * - ^ JL*M« 4WV1 1 ^V>\
uour i reten to tne penoo nom uruu - uuu).
Number of hours to process
Name of "species' to process**
Deb*
-
    HAVER    integer
       A

       B
real

real
Code
                                     ocess
                                 layer of concentrations (always "1* when
                                 entrations front CALPUFF, "-I" for dry
deposition fluxes, and *•? for net deposition fluxes)

Multiplicative «"d™g factor (not applied if                00
A - B - OO)
Additive factor (r« appbui if A « B = 00))              QjO
LG
LD
LCT
BEXTBK
RHFRAC
RHMAX

NAVG
L1T50
L3T50
L24T50
LNT50
LRT50
" Sample value*
logical
logical
logical
real
real
real

integer
logical
logical
logical
logical
logical
of ASPEC SO2,
Gridded receptors processed 1
Discrete receptors processed ?
CTSG complex terrain receptors processed ?
Background light extinction coefficient (I/mm)
Percentage of particles ffrftf^ ty r^lativr humiditv
** « • •
Maximum relative humidity (%) used in the particle
growth equation
User-specified averaging time (hours)
Generate top 50 table for 1-hr averages ?
Generate top 50 table to 3-hr averages ?
Generate top 50 table for 24-hr averages ?
Generate top 50 table for NAVG-hr averages ?
Generate top 50 table for length-of-nm averages ?
STM, NOX, HNfn, Kim nr fnr vicihilifv olrnfet^nr- ppXT (\l^t^tt«M\r» „
F
F
F
.
-
-

0
T
T
T
F
T
aeffideat). BEXTS
(contribution of tutftte to the ligbt-extinction coefficient), BEXTN (conthbution of nitrate), BEXTSN (cootribution of both saltee and
nitrate), BEXTRH (lignt-extinctioa coefficient of the background aerosol at ambient relative humidity.
L-\calpufl\jiiR5\wMSZ.vpk
                               4-155

-------
                                 Table 4-38 (Concluded)
                     CALPOST Control File Inputs (CALPOSTJNP)
  Variable
 Description
   NTOP
  ITOP(4)
array
L1TOPN
L3TOPN
L24TOPN
LNTOPN
LRAVG
THRESH1
THRESH3
THRE3H24
THRESHN
logical
logkal
logical
logical
logical
real
real
teal
real
   LMAP     logical
 Number of "top" values at each receptor (most be * 4)
 Specific ranks of "top* Tabes reported (e^, values of 1,
 2, 5 and 48 would produce the highest, 2nd highest, 5th
 receptor)
 Produce top N* table for 1-hr averages ?
 Produce top N* table for 3-hr averages ?
 Produce top N* table for 24-hr avenges ?
 Produce top N" table for NAVG-hr averages ?
-Produce top N" table for length-of-run averages ?

 Exceedance threshold* for 1-hr averages
 Exceedance threshold* for 3-hr averages
 Exceedance threshold* for 24-hr averages
 Exceedance threshold* for NAV-o-L.  ..~
 Generate PLOT files for each top N* table and
 exceedance table selected above ?
                                                                                  F
                                                                                  F
                                                                                  F
                                                                                  F
                                                                                  F

                                                                                  -LO
                                                                                  -LO
                                                                                  -LO
                                                                                  -LO
  LECH1    logical
  LECH3    logical
  LECH24    logical
  LECHN    logical
 LDEBUG   logical

IECHO(366)  integer array
 Output 1-hr averages for selected days ?                 F
 Output 3-hr averages for selected days ?                 F
 Output 24-hr averages for selected days ?                F.
 Output NAVG-hr averages for selected days ?            F
 Activate special debug output statements ?               F

 Arrays of days selected to print data for averaging times   366*0
 selected with  LECHL LECH3, LECH24, LECHN
 variables (0= do not print day, 1=print day)
 ' Value of -LO inactivates threshold exceedance option.
                                          4-156

-------
                                               Table 4-39
                          Sample CALPOST Control Ffle (CALPOSTJNP)
CALPOST TEST CASE
Pollutant: 802
Griddad receptor rut
Central rut control  paraaatsrs

  Starting data:  Taar  (1ST!) - Mo dafault    I IStt  •  87  I
                  Month  (ISMO) -- Ho dafault    I ISNO  *   1  I
                    Day  (ISOY) •- >o dafault    I ISOY  •   1  I
                    •our (ISM) •• Ho dafault    I ISMft  •   1  I

     Nuaber of hour* to preens (MtS)  -  No default    I NHRS  • 8760 I

            Species  to procass (ASPEC)  —  No dafault    I ASPEC • $02  I
 Exaaples:  $02, SM, NOX, HNQ3, N03, or for visibility calculations:
            KXT (light-extinction coaffieiant).
            BEXTS (contribution of aulfata to tha light axtinction coaffieiant)
            KXTN (contribution of nitrata to tha light extinction coaffieiant)
            BEXTSN (contribution of both aulfata and nitrata)
            KXTM (light-extinction  coaffieiant of tha-background aerosols*.
                    tha aabiant ralativa huaidity)

Concentration and scaling factors

      Layar/dapoaition code  (ILATEt) — Dafault: 1      I I LAYER • 1 I
        •1"  for CALPUFF concantrations,
        ••1" for dry deposition fluxas.
        *-<- tor uat deposition fluxas.

      Scaling factors of the fDTK     --  Defaults:      I > « 0.0    I
            X(new) « X(old) * A * B         A •  0.0      I B • 0.0    I
        (HOT applied if A * B » 0.0)         B •  0.0

Receptor Information

               Gridded receptors processed (LG)  7        I LG  * T    I
              Discrete receptors processed (ID)  ?        I LD  • F    I
  CTSG Coaplex terrain receptors processed (LCT) ?       I LCT « F    I

Visibility Parameters
    Background light extinction coefficient  (I/an)
                             (BEXTBK)  •-  No default   I BEXTBK > 50.  !
    Percentage of particles affected by relative timidity
                             (RHFRAC)  —  No default   I RHFRAC =  0.  I
    Naxisui relative huaidity (X) used  in  particle growth eqn.
                              (RHNAX)  —  No default   I RHMAX  * 98.  I

Averaging tiae and TOP SO Table control

    User-specified everaging tiae
                               (MAVG)  ••  No default    I   NAVG *  1 I
 -   Top 50 table for 1-hr averages
                              (L1T50)  -•  No default    !  L1T50 * T  I
    Top 50 table for 3-hr averages
                              (L3T50)  -  No default    I  L3T50 * F  I
    Top 50 table for 24-hr averages
                             (L24T50)  --  No default    ! L24T50 « F  I
    Top 50 table for NAVG-hr averages
                              (LNT50)  --  No default    I  LNT50 = F  !
    Top 50 table for length of nxi averages
                              (LRT50)  --  No default    !  LRT50 = F  I
fc\«*ufl\j«BS\ieaaZ.wpli                               4-157

-------
                                        Table 4-39 (Concluded)
                          Sample CALPOST Control File (CALPOSTJNP)
TOP *n" Table control
    Nuaber of "top" values at cadi receptor
                               (MTOP) — No dtfault
               (NTOP autt be <» 4)
       !  NTOP • 4
    Spacific ranks of "top" values reported
                    (ITOP(4) array) -- le default I  I TOP • 1, 2, 5. 15 I
                (•TOP values Bust be. entered)
    Top on" table for  1-hr averages   U1TOPN)
    Top "n" table for  3-hr averages   (LSTOPN)
    Top "n" table for 24-hr averages   (L24TOPN)
    Top "n" table for NAVG-hr averages (LMTOPN)
    Top "n" table for length of run averages (LRAVG)
       L1TCPM
       L3TOPN
      124TOPH
       LNTOPN
        LtAVC
Threshold Exceedance control
    Counts will be tabulated for each average that
    exceeds a specified non-negative threshold.
                                 Default » -1.0

    Threshold for  1-hr averages   (TWESN1)
    Threshold for  3-hr averages   (THRESM3)
    Threshold for 24-hr averages  (TMXESN24)
    Threshold for MAVG-hr averages (TMKSW)

Output Options
I   THRESH1  «  0.1    I
I   THRESH3  « -1.0    I
I  THRESH24  «  0.01   I
!   THRESHN  • -1.0    I
     Special Output (LIMP):
     Plot files can be created for selected Top-n and Exceedance tables.
     They follow a record  format of [x,y,val1.val2....]  so that  NAPS of
     these values can be produced with little effort.  Each type of
     data is placed in its own file.  The mating convention for  these
     files is adopted fro* the Top-N control variables,  so that
        Top 3-hr values are  listed in                 :  L3TOPN.NAP
        Length-of-run averages are in                 :  LRAVC.NAP
        Exceedances of the 24-hour threshold are in   :  L24EXC.NAP
     A NAP-file will be created for each control variable set to "T",
     if LMAP is also "T-.
                                           (LMAP)      I  LMAP

     Standard Output to List  File:
     Output 1-hr averages for selected days (LECH1)       LECH1
     Output 3-hr averages for selected days (LECH3)       LECH3
     Output 24-hr averages for selected days (LECH24)     LECH24
     Output MAVG-hr averages  for selected days (LECHN)    LECHH
     Output selected information for debugging (LOEBUG)   LDEBUG
                   T  I
     Days selected for output  IECHO(366)
     (366 values aust be entered)
  ! 1ECHO  = 366 * 0 I
      (END!
 t\calpafl\jiiB3\iecM32.w|*
  4-158

-------
                                              Table 4-40
                          Sample CALPOST Output File (CALPOSTJ-ST)
                                           (Partial Listing)
                                            CALPOST  Version  3.0  Uv*l  950531
                           S02          1

             TOP-SO    1-HOUR AVERAGE  OHCEMTRATION VALUES

             TEAR  MY NOUR(0-23) RECEPTOR  TYPE   OONCENTRATIOl   COORDINATES (ka)
             87  187
             87  187
             87  187
             87  169
             87  224
             87  320.
             87  205
             87  187
             87  156
             87  215
             87  230
             87  188
             87  249
             87  140
             87  187
             87  151
             87  188
             87  168
             87  218
             87  249
             87  151
             87    4
             87  215
             87  344
             87    7
             87  224
             87  103
             87  170
             87  215
             87   70
             87  224
             87  169
             87  247
             87    7
             87  121
             87  187
             87  319
             87  201
             87  312
             87  313
             87   93
             87  274
             87   31
             87  263
             87  114
             87  224
             87  103
 7
 6
 5
 5
 7
 5
20
19
 8
18
19
 0
 3
 3
21
21
 2
22
20
 4
20
 2
20
 5
 2
 6
 4
 6
21
 5
 4
 6
21
 4
 4
 9
 4
 7
 5
 5
 0
21
 0
23
 4
 5
 1
(4.
(4.
(4,
(4.
(4,
(4.
( 4.
(4.
(4.
(4,
(5.
(5,
(4.
(5.
< 4.
(5.
C 3.
(5.
( 5.
(4,
(5,
<5.
( 5.
( 5.
C 4.
< 4.
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( 4.
4.
4.
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5,
5.
4.
( 4,
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( 4,
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( 4,
< 4,
( 5,
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( 4,
( 4,
4)
4)
4)
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4>
4)
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4)
4)
4)
5)
4)
5}
5)
5)
4)
4)
4)
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4)
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5)
6
G
6
6
G
6
6
G
G
G
G
G
G
G






G
G
G
G
G
G
G
G
G
G
G
G
G
6
G
G
G
G
G
G
G
G
G
G
G
G
G
 .98066*00
 .97786*00
 .81406*00
 .75426*00
 .73346*00
 .72656*00
 .71996*00
 .71296*00
 .66896*00
 .66786*00
 .66476*00
 .58496*00
 .57856*00
 .56926*00
 .56446*00
 .53626*00
 .52476*00
 .52086*00
 .46956*00
 .43996*00
 .42816*00
 .41436*00
 .31846*00
 .25706*00
 .24266*00
 .23666*00
 .21346*00
 .20906*00
 .19096*00
 .18476*00
 .18406*00
 .11776*00
 .11006*00
 .10276*00
 .10246*00
 .08996*00
 .07196*00
 .03946*00
 .00236*00
 .00236*00
9.73956-01
9.53996-01
9.51556-01
9.47566-01
9.29386-01
9.0212E-01
8.9583E-01
•0.150
-0.150
•0.150
•0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150 '
0.150
0.150
-0.150
0.150
-0.150
0.150
0.150
0.150
0.150
-0.150
0.150
0.150
0.150
0.150
-0.150
•0.150
0.150
-0.150
0.150
-0.150
-0.150
-0.150
0.150
0.150
0.150
-0.150
-0.150
0.150
-0.150
-0.150
0.150
-0.150
-0.150
0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150
•0.150
-0.150
•0.150
0.150
0.150
0.150
' 0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150
0.150
-0.150
-0.150
-0.150
0.150
-0.150
0.150
0.150
0.150
-0.150
-0.150
-0.150
0.150
-0.150
-0.150
-0.150
-0.150
-0.150
-0.150
0.150
-0.150
-0.150
-0.150
0.150
0.150
-0.150
0.150
0.150
0.150
c\cataa\jaBS\iec*422.vph
                       4-159

-------
                                  Table 4-40 (Continued)
                      Sample CALPOST Output File (CALPOSTXST)
                                      (Partial Listing)
                                      CALPOST  Version  3.0  Ltvtl 950531
                                               S02         1

4 RANKED     1-HOUR AVERAGE  CONCENTRATION VALUES AT EACH GRIDOED RECEPTOR  Sw16c-0"i vS" =$£', -6J
5.61736-01 (87, 77, 4)
5.30136-01 (87,237.18)
3.68246-01 (87.187,19)
2.38326-01 (87,230,20)
1.79876-01 (87,232,17)
2.1082E-01 (87.193,20)
3.00296-01 (87,188, 4)
7.30716-01 (87,188, 4)
1.97786*00 (87.187. 6)
1.71296*00 (87,187,19)
6.6343E-01 (87,321. 0)
1.9711E-01 (87. 13, 2)
1.81396-01 (87,360, 5)
1.87046-01 (87,181, 9)
2.8236E-01 (87,220. 8)
6.7587E-01 (87,205,21)
1.58496*00 (87,188, 0)
1.31846*00 (87.215.20)
5.16566-01 (87,269, 3)
2.28136-01 (87, 51, 3)
1.84206-01 (87,227,23)
2.06136-01 (87,265, 7)
2.28066-01 (87, 11, 1)
4.13216-01 (87.151,21)
5.8829E-01 (87,156, 5)
3.64366-01 (87,222, 5)
2.77956-01 (87,103, 4)
5 RANK
1.9975E-01 (87,349, 3)
1.61596-01 (87.169, 5)
1.21416-01 (87,128,21)
1.68236-01 (87.201, 0)
1.8382E-01 (87, 84. 7)
1.6457E-01 (87, 29, 1)
1.82796-01 (87,296, 6)
1.4789E-01 (87,319, 0)
1.8414E-01 (87.276, 6)
2.3857E-01 (87,249. 4)
1.9363E-01 (87, 33, 6)
2.7294E-01 (87,201, 4)
2.7548E-01 (87,188,20)
2.23996-01 (87,348, 6)
1.65786-01 (87,248,20)
1.62436-01 (87,304. 6)
1.8794E-01 (87, 76, 2)
2. 19636-01 (87,133. 4)
4.3739E-01 (87.249, 4)
4.43026-01 (87,201, 4)
5.14886-01 (87.181,18)
3.5855E-01 (87,215,18)
2.23326-01 (87. 93. 4)
1.76876-01 (87.304. 5)
1.99916-01 (87.121,19)
2.6788E-01 (87.181, 8)
7.2638E-01 (87.225, 7)
1.81406*00 (87,187, 5)
1.66896*00 (87,156, 8)
6.01326-01 (87,230,21)
1.94006-01 (87.360, 2)
1.77956-01 (87.155.18)
1.7676E-01 (87.108,19)
2.7479E-01 (87,205, 6)
6.60296-01 (87,181, 6)
1.56926*00 (87,140, 3)
1.21346*00 (87,103. 4)
3.6877E-01 (87,103, 2)
2.2109E-01 (87,214,18)
1.6752E-01 (87.103, 6)
2.0613E-01 (87,264, 7)
2.14556-01 (87, 75. 1)
3.4788E-01 (87,188, 0)
5.2152E-01 (87.218,23)
3.44106-01 (87,218,22)
2.70256-01 (87.201, 7)
c\calpafl\faBS\«ecM32.wph
4-160

-------
                                         TabU 4*40 (Contlnuad)
                                SaipU CALPOST Output Fit* (CALPOST.LST)
                                           (Partial  Listing)
                                           CALPOST  version  3.0  Laval  950531
  1 • RAMK RICHEST VALUES FOR PERIOD

Multiply all valuas by 10 •*  -3
*
7
6
: s
4
3
2
1
-
154
216
206
294
202
180
208
217
175
176
240
305
383
224
315
193
274
349
370
715
648
589
333
227
200
231
720
1720
1981
777
303
228
217
259
520
1470
1665
811
387
190
154
190
328
589
726
421
228
232
182
180
251
330
240
336
208
177
160
175
188
194
240
216
190
163

1
2 • RANK
2
3
4
RICHEST VALUES FOR
Multiply all valuta fay
8

7

6

5

4

3

2

1

152
*
192
+
181
*
206
»
177
+
148
+
189
*
211
*
1
170
•
172
*
228
*
294
4
382
*
194
4
309
*
184
*
2
180
4
238
4
368
4
530
*
562
+
583
4
280
*
190
*
3
1C **
181
4
197
*
663
4
1713
*
1978
4
731
4
300
4
211
*
4
5
6
7
8
PERIOD
-3
184
*
228
*
517
4
1318
4
1585
*
676
*
282
4
187
*
5

145
4
176
*
278
4
364
4
588
«
413
4
228
*
206
*
6

173
*
143
4
249
«
293
«
211
*
235
4
206
+
175
*
7

121
*
137
+
178
^
189
4-
150
+
188
+
177
*
142
*
8
                                                4-161

-------
                                  Table 4-40 (Continued)
                     Sample CALPOST Output File (CALPOST.LST)
                                     (Partial Listing)
                                      CALMST  Vtrsion  3.0  Ltwl  950531
                                              S02         1

       COUfTS OF   1-HOUR AVERAGE  COWEMTRATIOi EXffEDFBCFS AT EACH GRIOOED RECEPTOR


MJMBER OF AVERAGES  >  0.10006*00
8

7

6

5

4

3

2

1

24
*
43
•*•
41
*
20
+
15
+
8
4
8
+
27
»
26
+
55
*
88
«•
38
+
24
•
25
*
54
*
59
*
40
•
57
«
106
•»
96
4
31
•
106
»
122
*
101
^
21
*
55
+
185
*
556
+
459
*
334
•*
153
+
96
+
12
+
38
*
185
+
463
*•
596
+
256
+
85
*
53
*
11
+
14
*
37
+
172
+
232
+
112
+
70
+
46
<*•
8
*
16
+
22
*
33
»
59
*
77
*
59
*
28
*
4
+
9
+
11
*
19
^
21
*
32
•»•
35
+
20
*
                                           4-162

-------
                                   5. REFERENCES
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 l:\alpufl\jaBS\-ctS.wpfc                           5-1

-------
Brighton, P.W.KL, 1978:  Strongly stratified flow past three-dimensional obstacles. Quart JJi
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Britter, RJL, J.CR. Hunt and KJ. Richards, 1981: Airflow over a two-dimensional hflk  Studies
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Brest, RA. and J.C Wyngaard, 1978: A model study of the stably stratified planetary boundary
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Calvert, J.G., F. Su, J.W. Bottenheim and OP. Strausz, 1978: Mechanism of the homogeneous
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Caughey, SJn 1981:  Observed characteristics of the atmospheric boundary layer.  In:
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Ching, J.JLS, JM. Godowitch, J.F. Clarke and A.H. Auer, 1983: Urban scale variations of
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Douglas, S. and R. Kessler, 1988: User's guide to the diagnostic wind model California Air
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l:\calpufl\jul95\iosS.wpti                            5.2

-------
EPA, 1992:   User's guide for the Industrial Source Complex (BC2) dispersion models. VoL I -
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EPA, 1993b:  User's guide to the Building Profile Input Program (BPIP). US. Environmental
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EPA, 1995:   Testing of meteorological and dispersion  models for use in regional air quality
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Forrest, J., R.W. Garber and L. Newman, 1981:  Conversion rates in power plant plumes based
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Fowler, D. and MR Unsworth, 1979: Turbulent transfer of sulphur dioxide to a wheat crop.
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Geller, M. and E. Ng, 1971: Tables of Integrals of the Error Functions — II: Additions and
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Gifford, FA^ Jr. 1976: Turbulent Diffusion-Typing schemes: A Review. Nud. Saf., 17, 6846.

Hales, J.M., D.C. Powell and T.D. Fox, 1977:  STRAM-An Air Pollution Model Incorporating
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Hanna, S.R., GA. Briggs, J. Deardorff, B.A. Egan, FA.  Gifford and F. PasquilL 1977:  AMS
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I:\aJpufl\jul95\iecb.wp6                           5.3

-------
Hanna, S.R. and J.C Chang, 1991: Modifications of the Hybrid Plume Dispersion Model
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Hanna, S.IL, LL, Schuhnan, RJ. Paine, J.E. Pleim and M. Baer, 1985: Development and
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Hanna, S.R, J.C Weft* and RJ. Paine, 1986: Plume model development and evaluation. Report
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Hicks, B.B., 1985:  Behavior of turbulence statistics in the invective boundary layer. /. Cfim.
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Hosker, RP., 1974: A comparison of estimation procedures for overwater plume dispersion.
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Hosker, R.P., 1984: Flow and diffusion near obstacles. In:  Atmospheric Science and Power
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Hosker, R.P., Jr. and SJE. Lindberg, 1982:  Review: Atmospheric deposition and plant
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Hoult, D.P. and J.C. Weil, 1972: A turbulent plume in a laminar crossflow.  Atmos. Environ., 6,
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Huber, A.H. 1977:  Incorporating building/terrain wake effects on stack effluents.  Preprint
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I:\alp«fl\juBS\«ctS.wpb                          5-4

-------
Huber, AJL and WJL Snyder, 1976r Building wake effects on sboct stack effluents.  Preprint
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Huber, AIL and WJL Snyder, 1982: Wind tunnel investigation of the effects of a rectangular-
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Hunt, J.GIL, 1982: Diffusion in the stable boundary layer. In: Atmospheric Turbulence and Air
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Hunt, J.CR. and RJ. Mulhearn, 1973: Turbulent dispersion from sources near two-dimensional
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Hunt, J.CR. and WJL Snyder, 1980: Experiments on stably and neutrally stratified flow over a
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Irwin, J.S., 1979: Scheme for estimating dispersion parameters as a function of release height
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Kessler, R.C., 1989: User's Guide.  Systems Applications, Inc. Version of the Colorado State
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Lamb, R.G., 1981:  Diffusion in the convective boundary layer. In: Atmospheric Turbulence and
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LeMone, M., 1978: The marine boundary layer.  In: Proceedings of Workshop on the Planetary
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L\eUpufl\juBS\iea5.wpb                           5.5

-------
Levme, S.Z. and SJS. Schwartz, 1982: In-cioud and below-doud of scavenging of nitric acid
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Lorimer, G., 1986:  The AUSFLUME Gaussian plume dispersion model Environmental
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Ludwig, F.L, LS. Gasiorek and FLE. Ruff, 1977:  Simplification of a Gaussian puff model for
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McElroy, J.L. and F. Pooler, 1968:  The St Louis dispersion study.  U.S. Public Health Service,
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Moller U. and G.  Shumann, 1970:  Mechanisms of transport from the atmosphere to the earth's
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I:\alpafl\jul9S\iectS.wph                           5-6

-------
Nieuwstadt, F.TAL, 1984:  Some aspects of the turbulent stable boundary layer. Bound. Layer
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L\nlp«fl\j.B5\»
-------
Rfrtnumn, BJL, 1982:  Application of the two-thirds law to plume rise from industrial-sized
      sources. Atmospheric Environ., 16, 2575-2579.

Schulman, T~T- and S.R. Hanna, 1986: Evaluation of downwash modifications to the Industrial
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t\ealpafl\juB5\»a3.»ph                           5-g

-------
Scire, J.S. and LL, s**nii*^«, 1981: Evaluation of the BLP and ISC models with SF4 tracer
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       Research Triangle Park, NC, 12 p.

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I:\olpufl\juB5\ieaS.wp*                          5. 10

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I:\olpufl\iuB5\i««5.«p*                          5-11

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                  ("Please read Instruction* on reverse before completing';
    EPA-454/B-95-006
    A User's Guide  for the CALPDFF Dispersion Model
                                                            1BDMTDATE
                                                               July 1995
                                                                    > OtOAMZATON CODE
 7. AUIMOMB
                                                                     OtOAMZATKMIBOKTNO.
                                                                         NO.
    USDA Forest Service
    Ft. Collins, CO   80526
                                                             u. coNTBAcrauirr NO.
                                                                LAG DW12544201
    U.S. Environmental Protection Agency
    Office of Air Quality Planning and Standards
    Emissions, Monitoring and Analysis Division
    Research Triangle Park,  RC  27711
                                  u. TYK or UKrr AND i
                                     Final Report
                                  14.
                                           AOENCYCOOE
        TAinr Norat
    SPA Project Officer:
John S. Irwin
 14. ABSTRACT


       This report describes  the CALPUFF dispersion model and associated processing
 programs.   The CALPUFF model described in this  report reflect improvements to the model
 including 1)  new modules to  treat buoyant rise  and dispersion from'area sources  (such-
 as  forest fires), buoyant  line sources, and volume sources, 2) an  improved treatment of
 ron^1«r terrain, 3) additional model switches to facilitate its use  in regulatory
 applications, 4) an enhanced treatment of wind  shear through puff  splitting, and 4) an
 optional PC-based GUI.  CALPUFF has been coupled to the Emissions  Production Model
 (EPM)  developed by the Forest Service through an interface processor.   BPM provides
 time-dependent emissions and heat release data  for use in modeling controlled burns and
 wildfires.
                                   KEY WORDS AND DOCUMENT ANALY8S
                  Dcacurois
                                                        ENDED TOMS
   Air  Pollution
   Long Range Transport
   Dispersion Modeling
                    Dispersion Modeling
                    Meteorology
                    Air Pollution Control
11. oisnuii/noK STATEMENT

   Release  Unlimited
                  19. SBCuwnr CLASS at^*m
                   Unclassified
21. NO. OF PAGES
   338
                                            20. SECURITY CLASS 
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