W**"*"*" Ei'titon
AERSCREEN User's Guide
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EPA-454/B-15-005
July 2015
AERSCREEN User's Guide
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Air Quality Assessment Division
Air Quality Modeling Group
Research Triangle Park, North Carolina
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Preface
This document provides a description of AERSCREEN, the screening version of AERMOD.
Included in the document are descriptions of inputs, processing methodology in AERSCREEN,
and outputs. This document represents a revision to the previous AERSCREEN User's Guide,
EPA document number EPA-454/B-11-001.
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Acknowledgements
AERSCREEN and the AERSCREEN User's guide The AERSURFACE User's Guide has been
developed by the Air Quality Modeling Group within EPA's Office of Air Quality Planning and
Standards and AERSCREEN Workgroup, with input from the AERMOD Implementation
Workgroup. The AERSCREEN code was initially developed by James Haywood, Michigan
Department of Environmental Quality.
in
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Contents
Preface ii
Acknowledgements iii
Figures vi
Tables ix
1. Overview of AERSCREEN 1
1.1 Description of AERSCREEN 2
1.1.1 Changes to AERSCREEN 3
1.2 Description of MAKEMET 5
1.3 Differences with SCREENS 8
2. AERSCREEN features 9
2.1 Source inputs 9
2.1.1 Point, capped stacks and horizontal stack sources 9
2.1.2 Flares 13
2.1.3 Volume sources 14
2.1.4 Rectangular area sources 15
2.1.5 Circular area sources 16
2.1.6NOx to NO2 conversion 17
2.1.7 Other inputs 18
2.2Downwash 18
2.3 Meteorology and surface characteristics 21
2.4 Terrain 25
2.6 Inclusion of discrete distances 29
2.7 Other inputs 31
2.8 Fumigation options 32
2.9 Optional debug file 33
2.10 Non-default name for output file 34
2.11 Error checking 34
3. AERSCREEN Program Execution 36
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3.1 Data input and validation 37
3.2 Meteorological data files 43
3.3 BPIPPRM execution 45
3.4 Source elevation calculation 45
3.4 Receptor network 46
3.5 PROBE 46
3.6 FLOW SECTOR 47
3.6.1 Rectangular area sources 48
3.6.2 Non-rectangular area sources 52
3.7 REFINE 55
3.8 Fumigation 56
3.8.1 Selection of meteorological data 56
3.8.2 Inversion break-up fumigation 57
3.8.3 Shoreline fumigation 57
3.8.4 AERSCREEN run option 59
3.9 Outputs 59
4. Example run 61
4.1 Processing and log file 65
4.2 AERSCREEN output 83
5. References 96
Appendix A. Input parameters and invalid responses A-l
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Figures
Figure 1. User prompts for MAKEMET 6
Figure 2. AERSCREEN.INP and prompts inputs for point sources 11
Figure 3. AERSCREEN.INP and prompts inputs for capped stack sources 12
Figure 4. AERSCREEN.INP and prompts inputs for horizontal stack sources 13
Figure 5. AERSCREEN.INP and prompts inputs for flare sources 14
Figure 6. AERSCREEN.INP and prompts inputs for volume sources 15
Figure 7. AERSCREEN.INP and prompts inputs for rectangular area sources 16
Figure 8. AERSCREEN.INP and prompts inputs for circular area sources 16
Figure 9. AERSCREEN.INP and prompts inputs for NOx to NO2 conversion 18
Figure 10. AERSCREEN.INP and prompts inputs for building inputs 20
Figure 11. Stack and building orientation for a building oriented 90 degrees to north and stack
oriented 45 degrees to north 21
Figure 12. AERSCREEN.INP and prompts inputs for meteorological and surface characteristics
data 23
Figure 13. AERSCREEN.INP and prompts inputs for terrain data 26
Figure 14. Example formats ofdemlist.txt 29
Figure 15. AERSCREEN.INP and prompts inputs for including discrete distances 30
Figure 16. Sample distances in a discrete distances text file 30
Figure 17. AERSCREEN.INP and prompts inputs for other inputs 31
Figure 18. AERSCREEN.inp and prompt inputs for fumigation 33
Figure 19. AERSCREEN.inp and prompt inputs for fumigation 33
Figure 20. AERSCREEN.INP and prompts inputs for output filename 34
Figure 21. AERSCREEN processing and stages 36
Figure 22. AERSCREEN start screen 37
Figure 23. AERSCREEN validation page 39
Figure 24. Submenus for changing source parameters for a) point, capped or horizontal stack, b)
volume, c) rectangular area, d) circular area, and e) flare sources 40
Figure 25. Building downwash submenus for a) building downwash included and b) building
downwash not included 41
Figure 26. Terrain submenus for a) terrain heights included, b) terrain heights not included and
c) rectangular area sources 42
Figure 27. Meteorological data submenu 42
Figure 28. Fumigation submenus for various fumigation options 43
Figure 29. Meteorological file creation for monthly 12 sector AERSURFACE output 44
Figure 30. Sequence of AERMOD runs in PROBE for different surface characteristics
combinations 47
Figure 31. Receptor radials for rectangular area sources 49
Figure 32. ME pathway in the AERMOD runstream with WRDOTATE keyword and values for
various angles 50
Figure 33. AERMOD run sequences for rectangular area source for seasonal 12 sector surface
characteristics 51
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Figure 34. Receptor placement for point (including capped and horizontal stacks), flare, volume,
or circular area sources inFLOWSECTOR 52
Figure 35. AERMOD sequence for seasonal 12 sector surface characteristics when processing
terrain and/or building downwash 53
Figure 36. Flow vector (solid arrow) of 10 degrees and associated upwind surface roughness
sector for three surface roughness sectors (0 to 90, 90 to 225, 225 to 0) 53
Figure 37. Receptor skipping notification during FLOWSECTOR run, with notification of
missing elevations in AERMAP, and total number of receptors skipped for FLOWSECTOR and
REFINE 55
Figure 38. Plane view of building and stack orientation for example AERSCREEN run 62
Figure 39. a) land use pattern and sectors used for surface characteristics and b) terrain. The
circle represents the 1 km radius from the source 64
Figure 40. Contents ofdemlist.txt for terrain processing 64
Figure 41. Contents ofdiscrete_receptors.txt 65
Figure 42. Initial AERSCREEN title, units, and source type prompts 65
Figure 43. Source parameter inputs 66
Figure 44. Initial building downwash prompts 67
Figure 45. Building parameter inputs 67
Figure 46. Terrain parameter prompts 68
Figure 47. Meteorological parameter prompts and inputs 69
Figure 48. Fumigation prompts 69
Figure 49. Debug option input 70
Figure 50. Output filename prompt and response 70
Figure 51. Data validation page 71
Figure 52. InputdatainAERSCREEN.LOG 72
Figure 53. Surface characteristics processing and meteorological files creation 73
Figure 54. AERMAP processing and elevation of source 74
Figure 55. AERSCREEN.LOG records for AERMAP processing for FLOWSECTOR 74
Figure 56. Status of AERMAP processing for FLOWSECTOR 75
Figure 57. AERSCREEN.LOG summary of AERMAP.OUT warning and error messages 75
Figure 58. Partial AERMAP output for FLOWSECTOR 76
Figure 59. AERSCREEN processing during FLOWSECTOR 77
Figure 60. Partial AERMOD.INP file used in FLOWSECTOR for 20 degree flow vector 78
Figure 61. AERSCREEN.LOG partial output of AERMOD.OUT checks for FLOWSECTOR. 79
Figure 62. Status of AERMAP processing for REFINE 80
Figure 63. Partial AERMOD.INP file for REFINE processing 81
Figure 64. REFINE messages 81
Figure 65. Fumigation and final AERSCREEN messages 82
Figure 66. Overall maximum, maximum ambient boundary concentration, and maximum
inversion break-up fumigation concentration statistics 83
Figure 67. AERSCREEN_EXAMPLE.OUT section with source and building information 84
Figure 68. FLOWSECTOR results in AERSCREEN_EXAMPLE.OUT 85
Figure 69. Meteorological data associated with maximum FLOWSECTOR concentration and
ambient boundary concentration 87
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Figure 70. Summary of maximum concentrations by distance in
AERSCREEN_EXAMPLE.OUT 88
Figure 71. Maximum concentration impact, ambient boundary, and inversion break-up
fumigation concentration summaries in AERSCREEN_EXAMPLE.OUT 89
Figure 72. Output of aerscreen_example_max_conc_distance.txt 90
Figure 73. Partial output of aerscreen_example_concentrations.txt 91
Figure 74. Partial output ofaerscreen_example_fumigate_debug.txt showing effective plume
height calculations 92
Figure 75. Partial output ofaerscreen_example_fumigate_debug.txt showing concentration
calculations 93
Figure 76. Header portion of new AERSCREEN.INP file 95
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Tables
Table 1. MAKEMET prompts and example values for the first month and surface roughness
sector and last month and surface roughness sector for monthly 12 sector AERSUKFACE output.
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Table 2. Variables listed in max_conc_distance.txt 60
Table 3. Inputs for example AERSCREEN run 61
Table 4. Seasonal surface characteristics by sector 63
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1. Overview of AERSCREEN
AERSCREEN is a screening-level air quality model based on AERMOD (U.S. EPA, 2004a).
The AERSCREEN model consists of two main components: 1) the MAKEMET program which
generates a site-specific matrix of meteorological conditions for input to the AERMOD model;
and 2) the AERSCREEN command-prompt interface program. AERSCREEN interfaces with
MAKEMET for generating the meteorological matrix, but also interfaces with AERMAP (U.S.
EPA, 2004b) and BPIPPRM (Schulman et al. 2000; U.S. EPA, 2004d) to automate the
processing of terrain and building information respectively, and interfaces with the AERMOD
model utilizing the SCREEN option to perform the modeling runs. AERSCREEN interfaces
with version 09292 and later versions of AERMOD and will not work with earlier versions of
AERMOD. The AERSCREEN program also includes averaging time factors for worst-case 3-
hr, 8-hr, 24-hr and annual averages.
The screening mode of the current version of AERMOD, which is controlled by the SCREEN
option on the CO MODELOPT card, forces the model calculations to represent values for the
plume centerline, regardless of the source-receptor-wind direction orientation. This option is
included in AERMOD to facilitate the use of the model in a screening mode to estimate worst-
case impacts. Since the screening option in AERMOD is designed to be used with a non-
sequential meteorological data file representing a matrix of conditions, currently generated by
the MAKEMET program, the SCREEN option also forces the use of the NOCHKD option even
if NOCHKD is not included on the MODELOPT card. The NOCHKD option suspends the
checks made within AERMOD for proper date sequences in the surface and profile
meteorological input data files. The SCREEN option also restricts the averaging period options
to 1-hour averages only on the CO AVERTEVIE card.
Given these two basic components of AERSCREEN, the AERMOD model can be run in a
screening mode by either: 1) using the AERSCREEN command-prompt interface; or 2) using the
stand-alone MAKEMET program to generate the matrix of meteorological conditions and
running AERMOD directly with the SCREEN option. The first approach automates much of the
processing for the user, including building and terrain processing, while the second approach
gives the user more flexibility for defining the receptor network to be used in the screening
analysis and may be more appropriate in certain situations, especially in very complex terrain
settings. These two options for running AERMOD in a screening mode will not necessarily
produce the same results. This is because the results for the stand-alone application of
AERMOD with MAKEMET-generated meteorology will be determined by the user-specified
receptor network, whereas the AERSCREEN program performs a more precise search to isolate
the receptor distance with the highest impact, similar to the automated distance option in
SCREENS (U.S. EPA, 1995). In general, the AERSCREEN program should produce slightly
more conservative results than stand-alone AERMOD with MAKEMET data, depending on the
receptor resolution used for the latter.
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Before running AERSCREEN, users should consult and become familiar the following:
AERMOD User's Guide and addenda (U.S. EPA, 2004a)
AERMAP User's Guide and addenda (U. S. EPA, 2004b)
AERMET User's Guide [for surface characteristics tables] (U.S. EPA, 2004c)
BPIPPRM User's Guide (U.S. EPA, 2004d)
Guideline on Air Quality Models (Appendix W) (U.S. EPA, 2005)
AERSURFACE User's Guide (U.S. EPA, 2008)
AERMOD Implementation Guide (U.S., EPA, 2009)
Screening Procedures for Estimating the Air Quality Impact of Stationary Sources (U.S.
EPA, 1992)
The above documents and other support documents can be found at the AERMOD modeling
page of the Support Center for Regulatory Atmospheric Modeling (SCRAM) page at:
http://www.epa.gov/scramOOl/dispersion_prefrec.htm#aermod and the Guideline on Air Quality
Models (hereafter referred to as Appendix W) can be found at:
http://www.epa.gov/scram001/guidance/guide/appw 05.pdf
1.1 Description of AERSCREEN
As stated above, AERSCREEN is an interactive command-prompt application that interfaces
with MAKEMET for generating the meteorological matrix, but also interfaces with AERMAP
and BPIPPRM to automate the processing of terrain and building information, and interfaces
with the AERMOD model utilizing the SCREEN option to perform the modeling runs. The
AERSCREEN program also includes averaging time factors for worst-case 3-hr, 8-hr, 24-hr and
annual averages. The AERSCREEN program is currently limited to modeling a single point
(vertical uncapped stack), capped stack, horizontal stack, rectangular area, circular area, flare, or
volume source.
Inputs or options to AERSCREEN are:
Source parameters for point, rectangular area, circular area, volume, capped stack,
horizontal stack or flare sources
Building downwash information for point, capped stack, horizontal stack, and flare
sources
Ability to model NOx to NO2 conversion
o Plume Volume Molar Ratio (PVMRM) (Hanrahan, 1999a and 1999b) or
o Ozone Limiting Method (OLM)
o Input of representative ozone background concentration
Ability to use terrain heights for source and receptors via AERMAP
Specify ambient minimum and maximum temperatures for MAKEMET
Specify minimum wind speed and anemometer height for MAKEMET
Specify surface characteristics for input to MAKEMET by the following methods:
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o user-defined single values for albedo, Bowen ratio, and surface roughness (no
temporal or spatial variation in surface characteristics)
o AERMET seasonal tables (temporal variation only)
o Values listed in an external file, either an AERSURFACE (U.S. EPA, 2008)
output file or surface characteristics listed in an AERMET stage 3 input file
Probe distance (maximum downwind distance) of receptors
Use of flagpole receptors and define flagpole height
Specify urban or rural source and urban population if urban source
Minimum ambient distance for ambient air receptors
Up to ten discrete receptor distances in a user supplied text file
Plume fumigation due to inversion break-up
Shoreline fumigation of plume
Performs error checks on AERSCREEN inputs, AERMOD output and/or AERMAP
output
Calculate maximum concentration by distance
Debug option to output intermediate output from PROBE or FLOWSECTOR as well as
intermediate fumigation calculations.
Search routine to find overall worst case scenario (maximum 1-hour concentration)
AERSCREEN automatically provides impacts for other averaging periods using scaling ratios.
The averaging period ratios currently implemented in AERSCREEN are as follows (SCREENS
factors are shown for comparison):
3-hour fixed ratio of 1.00 0.90
8-hour fixed ratio of 0.90 0.70
24-hour fixed ratio of 0.60 0.40
Annual fixed ratio of 0.10 0.08
For area sources (rectangular and circular), the averaging factors are based on guidance in
Section 4.5.4 of the EPA screening guidance document (U.S. EPA, 1992). For area sources, the
3, 8, and 24-hour average concentrations are equal to the 1-hour average calculated by
AERMOD in screening mode. No annual average concentration is calculated.
1.1.1 Changes to AERSCREEN
The original version of AERSCREEN is version 11060. Following is a list of changes since that
version.
Version 11076
1. Modified subroutine MAKETERRAIN to change the variable XDIST to always be 1.1
times the probe distance for the DOMAINXY keyword that goes into AERMAP. In
version 11060, for the FLOWSECTOR stage of AERSCREEN, XDIST was set to 1.1
times the probe distance while in FLOWSECTOR it is set to 1.1 times the final distance.
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In complex terrain, this change in DOMAINXY can affect hill height scales, affecting
concentrations.
Version 11126
1. Modified subroutine MAKETERRAIN to accommodate the 12-character source
identifier for AERMAP version 11103.
2. Modified subroutine READINP to set the discrete receptor use flag to N and discrete
receptor file to "NA" when the discrete receptor data section is missing in
AERSCREEN.INP
Version 14147
1. Modified subroutines MAKETERRAIN and MAKEGRID to include a new variable,
REFDIST for calculating receptors for the REFINE stage. Previously, the variable
NUMPT was used in these subroutines to represent the number of receptor points for the
PROBE and FLOWSECTOR stages and distance for the REFINE stage. REFDIST was
created to avoid confusion with different meanings of NUMPT. REFDIST is also set to
the probe distance if REFDIST exceeds the probe distance.
2. Modified subroutine MAKEINPUT to eliminate a blank line as the first line of the
AERMOD input file. This makes AERSCREEN compatible with AERMOD version
14134 and later due to the skipping of blank lines in AERMOD (see miscellaneous
change #3 of AERMOD MCB #10).
3. Modified subroutine FINDMAX to read the AERMOD version number from
AERSCREEN.FIL so that it is independent of the AERMOD version. Previous versions
of AERSCREEN read the version number using a fixed format that changed with
AERMOD 12345. AERSCREEN no longer uses a fixed format to read the version
number and is flexible for later AERMOD versions.
4. Modified subroutine READINP to set the discrete receptor use flag DISCFLAG to N
instead of setting the logical variable DISCDAT to N. Previous versions of
AERSCREEN were setting the wrong variable (DISCDAT).
Version 15181
1. Added subroutines FUMINP, FUMIGATE, INVMAX, SHORELINE, SHOREMAX,
RECALCPLUME, and TIBL to support inversion break-up and shoreline fumigation
calculations
2. Added subroutine SUBSETMET to create matrix of hours with meteorological conditions
of F stability and stack top wind speed of 2.5 m/s for fumigation calculations.
3. Added fumigation inputs including distance to shoreline, optional direction to shoreline,
and option to run or not run full AERSCREEN in subroutine READINP.
4. Added fumigation error check flags to subroutine CHECKDAT.
5. Modified subroutine VALIDATE AND WRITETOLOG to add fumigation options
6. Added optional debug option to output PROBE, FLOWSECTOR, and fumigation
calculations.
7. Updated subroutine PLUMEHGT to include plume height calculations for stable
conditions.
8. Updated subroutine MAKEMET2 to include optional u* adjustment prompt for
MAKEMET. At this time, this prompt is always set to no (do not include adjustment).
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9. Eliminated numerous system calls of copying and deleting files by using write statements
and close statements. This is to make code more portable across operating systems.
1.2 Description of MAKEMET
The MAKEMET program generates a matrix of meteorological conditions, in the form of
AERMET-ready surface (AERSCREEN.sfc) and profile (AERSCREEN.pfl) files, based on user-
specified surface characteristics, ambient temperatures, minimum wind speed, and anemometer
height. See the AERMET User's Guide (U.S. EPA, 2004c) for file formats. The current version
of MAKEMET also allows the user to specify the minimum wind speed to include in the matrix
and the anemometer height as well. Beginning with version 15181, MAKEMET has the
capability to include the adjustment to surface friction velocity, u*, that is also a part of
AERMET. These options have been included to facilitate comparisons of AERSCREEN
estimates to estimates from AERMOD in a refined mode to eliminate differences that may be
due to either the minimum wind speed in the refined data or the anemometer height. The
suggested default values for routine application of MAKEMET are 0.5 m/s for the minimum
wind speed and 10 meters for the anemometer height.
MAKEMET allows the user to specify more than one set of surface characteristics and ambient
temperatures, such as for seasonal or monthly variations, and will concatenate the resulting
meteorological matrices into single surface and profile files. For AERSCREEN, this option is
not used and separate files are created for seasonal or monthly variations in surface
characteristics. No variation in minimum and maximum temperature is done in MAKEMET.
MAKEMET also allows the user to specify a single wind direction or a range of wind directions
for the meteorological matrix. This option may be useful for applications involving building
downwash to ensure that building dimensions for all sectors are included in the screening
analysis (the treatment of building downwash in the AERSCREEN program is described in
Section 3.2.2). However, in AERSCREEN processing, the wind direction is set to a single
direction of 270 degrees.
MAKEMET can be run from the command-prompt, with the prompts in Figure 1 for user input.
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ENTER SFC MET FILE NAME
ENTER PFL MET FILE NAME
ENTER MIN. WS (M/S)
ENTER ANEMHT (M)
ENTER OPTION TO ADJUST U* (Y=adjust,N=no adjustment)
ENTER NUMBER OF WIND DIRECTIONS
If the user enters one for the number of wind directions
ENTER WIND DIRECTION
Otherwise
ENTER STARTING WIND DIRECTION
ENTER CLOCKWISE WIND DIRECTION INCREMENT
ENTER MIN AND MAX AMBIENT TEMPS IN KEL VIN
ENTER ALBEDO
ENTER BO WEN RATIO
ENTER SURFACE ROUGHNESS LENGTH IN METERS
DO YOU WANT TO GENERATE ANOTHER MET SET THAT WILL BE
APPENDED TO CURRENT FILE?
[TYPEEITHER "Y" OR "y"FOR YES; OR HIT "ENTER" TO EXIT
If ("Y" or "y") then the program loops through prompts 7 through 10 for each additional data set (e.g. seasonal).
Figure 1. User prompts for MAKEMET.
The MAKEMET program has a long complex history, dating back over 10 years. Suffice it to
say that the version of MAKEMET supplied with AERSCREEN operates in the following
manner. As mentioned earlier, MAKEMET generates a matrix of meteorological conditions for
application of AERMOD in a screening mode and output the results in the form of AERMOD-
ready surface and profile meteorological data files. The matrix is generated based on looping
through a range of wind speeds, cloud covers, ambient temperatures, solar elevation angles, and
convective velocity scales (w* for convective conditions only) for user-specified surface
characteristics (Z0, Bo, r). For stable cases, the mechanical mixing height (Z;m) is calculated
based on the friction velocity, u*. A loop through Z;m factors (multiplied times the initial value
calculated form u*) is also included to account for smoothing of Z;m that occurs with refined
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AERMET data. Stable transition cases with solar angle greater than zero but less than the
critical solar angle (ACRIT) are also included in the matrix.
The program calculates u*, Monin-Obukhov length (L), and Z;m for each combination in the
matrix, and also calculates the convective mixing height (Z;c) based on w* for convective cases.
The program uses subroutines from AERMET (U.S. EPA, 2004c) to calculate boundary layer
parameters for each combination in the matrix. The program generates a log file, called
MAKEMET.LOG, which summarizes the inputs selected for that run, and the number of "hours"
in the final screening matrix for each set of surface characteristics. An effort has been made to
optimize the MAKEMET program for AERMOD screening applications by eliminating
combinations that are unnecessary in terms of identifying worst-case impacts, based on a wide
range of tests comparing screening to refined AERMOD estimates (which are briefly
summarized below). The number of "hours" per set of surface characteristics will typically be
around 300-400, but will vary depending on the user inputs. The number will tend to be larger
for applications with lower surface roughness due to the internal checks made to eliminate
unnecessary combinations.
MAKEMET uses the following scheme to assign dates for each of the "hours" in the
meteorological matrix. The default starting year for the data is 10, and the year is incremented
by 10 for each additional data set generated. Thus, for seasonal data files, the first season date
will start with a T, second season will start with a '2', etc. The hour is used to distinguish
between stable and convective conditions, with hours 01 through 11 indicating stable hours, and
hours 12 through 24 indicating convective hours. Note that for monthly data sets and/or for large
numbers of wind directions (greater than 36), duplicate dates may be generated. A warning
message is written to the log file in these cases. AERMOD will still run since the NOCHKD
option is invoked, but determining which conditions produced the worst-case results could
become problematic. In addition to the required variables for input to AERMOD, the surface file
generated by MAKEMET also includes five columns of integer variables that provide the loop
indices for each of the loops in the met matrix corresponding to each "hour" of screening
meteorology. These indices can be used to analyze the frequency of occurrence for various
combinations within the meteorological matrix resulting in the controlling (highest)
concentration.
AERSCREEN provides three options for surface characteristics inputs for generating the
screening meteorology. One option allows for user-specified surface characteristics - albedo,
Bowen ratio, and surface roughness (no spatial or temporal variation), the second option is to use
seasonally varying surface characteristics for generic land use classifications based on Tables 4-
1, 4-2, and 4-3 of the AERMET User's Guide (U.S. EPA 2004c). The third option is to input the
name of an external file such as an AERSURFACE (U.S. EPA, 2008) output file or AERMET
stage 3 input file that contains surface characteristics. Monthly, seasonal, and annual output for
one sector or multiple sectors is allowed with the third option. AERSCREEN will setup and run
the MAKEMET program to generate the screening meteorological data for input to AERMOD.
AERSCREEN will run MAKEMET for each combination of temporal period and spatial sector
of the surface characteristics. If AERSURFACE output is used, AERSCREEN does not call
AERSURFACE, so the user must run AERSURFACE prior to running AERSCREEN.
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1.3 Differences with SCREENS
The three areas where AERSCREEN deviates significantly from SCREENS and will, thus, be
the most difficult for first time users are:
1) Building wake effects - AERSCREEN utilizes all the advantages of PRIME (Schulman
et al., 2000) including stacks detached from the building. This requires three additional
pieces of information from the user beyond the normal building height and dimensions.
The additional information is orientation of the maximum dimension relative to north,
angle relative to north of the stack and, distance between the stack and building center.
AERSCREEN will use this information to setup and run the BPIPPRM program and extract
the information needed for the AERMOD model. More downwash details can be found in
Section 2.2.
2) Meteorology - AERSCREEN provides three options for generating the screening
meteorology. One option allows for user-specified surface characteristics - albedo,
Bowen ratio, and surface roughness (no temporal or spatial variation) - the second option
is to use seasonally varying surface characteristics for generic land use classifications
based on Tables 4-1, 4-2, and 4-3 of the AERMET User's Guide. The third option is to
use surface characteristics listed in an external file such as an AERSURFACE output file
or AERMET stage 3 input file. The user enters the name of the file. The user also
specifies the overall minimum and maximum ambient temperatures. AERSCREEN will
setup and run the MAKEMET program to generate the screening meteorological data for
input to AERMOD. More details about meteorology can be found in Section 2.3.
3) Terrain - AERSCREEN provides the option for incorporating terrain impacts on the
screening analysis. The user must create a file called demlist.txt. The first line of this
file describes the type of terrain file being used. The file type must be DEM or NED.
DEM refers to any DEM file type and NED refers to National Elevation Dataset. The
third line of the file lists the location of the NAD conversion files and the fourth line
begins the list of terrain files with each file on a separate line. When AERSCREEN is
run, the user will be prompted to provide the source coordinates and associated NAD
datum. AERSCREEN will then setup the necessary input file for AERMAP, run
AERMAP, and extract the information needed for the AERMOD model. More terrain
processing details can be found in Section 2.4
Given the use of surface characteristics and terrain, it is important that the user know the exact
coordinates of the source, i.e., stack or center location of volume or area source.
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2. AERSCREEN features
As noted in Section 1.1, AERSCREEN has many features and options available to the user. In
this section, the features and inputs to the restart file, AERSCREEN.INP, are described. When
running AERSCREEN from a restart file, the file must be named AERSCREEN.INP or
AERSCREEN will automatically begin prompting the user for data. The prompts used to enter
the data interactively are described in each relevant section as well. Prompts are not necessarily
shown in the order in which they appear but in the order for the parameters shown in
AERSCREEN.INP for each data section. The prompts described are based on metric units.
When processing data from the input file, all units are assumed to be metric. Some variables
listed below are not requested when using the prompts to enter data, but are automatically
defaulted, such as when processing a rectangular area source, volume source, or circular area
source. In the case of a rectangular area source, terrain use and downwash are automatically set
to "no" and the user is not prompted for the choice of terrain processing and source coordinates.
For all three source types, downwash is automatically set to "no" and downwash information is
not requested. When reading data from the input file, if one of the data sections (source,
building, terrain, meteorology, etc.) is missing, AERSCREEN will notify the user and stop
processing. Also, if the source data is listed after the building, terrain, or miscellaneous data,
AERSCREEN will alert the user and stop processing. This is done because the source type is
needed to determine if parameters must be reset in the building or terrain sections, such as
resetting building downwash to "no" if an area or volume source is being processed. Also, if
data is missing or invalid (such as negative emission rate) when reading AERSCREEN.INP,
AERSCREEN alerts the user and stops processing.
2.1 Source inputs
AERSCREEN can be used for a single point, flare, capped stack, horizontal stack, volume,
rectangular area source, or circular area source. Below are listed the source types with required
input variables and example values from the first line of the AERSCREEN.INP file. Building
downwash is allowed for the point, capped stack, horizontal stack, and flare sources but not for
volume or area (rectangular or circular) sources. Terrain processing is allowed for all sources
except rectangular area sources. For all source types, emission rates are in g/s or Ib/hr. For area
source types, AERSCREEN calculates the emission rate per unit area, the required input for
AERMOD.
2.1.1 Point, capped stacks and horizontal stack sources
Stack parameters for point (vertical stacks with no caps), capped stacks, and horizontal stacks are
the same. Point sources are denoted by the term "** STACK DATA "in the input file in the line
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above the source parameters. Capped stacks are denoted by the term "** POINTCAP DATA" in
the input file and horizontal stacks are denoted by the term "** POINTHOR DATA" in the input
file. Source inputs for these three source types are, with English and metric units in parentheses:
emission rate (Ib/hr or g/s)
stack height (feet or meters)
stack diameter (inches or meters)
stack temperature (degrees Fahrenheit or Kelvin)
and stack velocity (ft/s or m/s) or flow rate (ACFM)
Note that stack velocity can be input as ft/s or m/s, regardless of using English or metric units for
other parameters. AERSCREEN.INP and prompt inputs (shown in italics) are shown in Figures
2 through 4 for point, capped stack and horizontal stacks, respectively. If a stack temperature of
zero (Fahrenheit or Kelvin) or negative stack temperature is entered, the entered temperature will
be used as a difference between the stack and ambient temperature. A negative number, such as
-10, implies that the stack is 10 degrees warmer than the ambient temperature. For capped and
horizontal stacks, AERMOD uses the BETA option on the MODELOPT keyword in the
AERMOD runstream file, AERMOD.INP, to invoke the algorithms for those source types.
10
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AERSCREEN.INP point source inputs
** STACK DAT A Rate Height Temp. Velocity Diam. Flow
** 0.1896E+01 5.0902 353.7056 13.2662 0.6096 8204.
Point source prompts inputs
If the user enters "P" or "p" for point source:
Enter Emission Rate (g/s):
Enter Stack Height (meters):
Enter Stack Diameter (meters):
Enter Stack Temperature (K)
Enter 0 for ambient temperature
or a negative number for temperature difference ((K))
between stack temperature and ambient temperature:
Option (1) - Exit Velocity (m/s)
Option (2) - Exit Velocity (ft/s)
Option (3) - Flow Rate (ACFM)
Enter Option for Flow Rate or Exit Velocity:
If the user chooses option 1, the prompt is:
Enter Exit Velocity (m/s):
If the user chooses option 2, the prompt is:
Enter Exit Velocity (ft/s):
If the user chooses option 3, the prompt is:
Enter Flow Rate (ACFM):
Figure 2. AERSCREEN.INP and prompts inputs for point sources.
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AERSCREEN.INP capped stack source inputs
** POINTCAP DATA Rate Height Temp. Velocity Diam. Flow
** 0.1896E+01 5.0902 353.7056 13.2662 0.6096 8204.
Capped stack source prompts inputs
If the user enters "S" or "s" for capped stack source:
Enter Emission Rate (g/s):
Enter Stack Height (meters):
Enter Stack Diameter (meters):
Enter Stack Temperature (K)
Enter 0 for ambient temperature
or a negative number for temperature difference ((K))
between stack temperature and ambient temperature:
Option (1) - Exit Velocity (m/s)
Option (2) - Exit Velocity (ft/s)
Option (3) - Flow Rate (ACFM)
Enter Option for Flow Rate or Exit Velocity:
If the user chooses option 1, the prompt is:
Enter Exit Velocity (m/s):
If the user chooses option 2, the prompt is:
Enter Exit Velocity (ft/s):
If the user chooses option 3, the prompt is:
Enter Flow Rate (ACFM):
Figure 3. AERSCREEN.INP and prompts inputs for capped stack sources.
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AERSCREEN.INP horizontal stack source inputs
** POINTHOR DATA Rate Height Temp. Velocity Diam. Flow
** 0.1896E+01 5.0902 353.7056 13.2662 0.6096 8204.
Horizontal stack source prompts inputs
If the user enters "H" or "h" for horizontal stack source:
Enter Emission Rate (g/s):
Enter Stack Height (meters):
Enter Stack Diameter (meters):
Enter Stack Temperature (K)
Enter 0 for ambient temperature
or a negative number for temperature difference ((K))
between stack temperature and ambient temperature:
Option (1) - Exit Velocity (m/s)
Option (2) - Exit Velocity (ft/s)
Option (3) - Flow Rate (ACFM)
Enter Option for Flow Rate or Exit Velocity:
If the user chooses option 1, the prompt is:
Enter Exit Velocity (m/s):
If the user chooses option 2, the prompt is:
Enter Exit Velocity (ft/s):
If the user chooses option 3, the prompt is:
Enter Flow Rate (ACFM):
Figure 4. AERSCREEN.INP and prompts inputs for horizontal stack sources.
2.1.2 Flares
Flare sources are denoted by the term "** FLARE DATA" in the input file in the line above
the source parameters. Flare source inputs are, with English and metric units:
emission rate (Ib/hr or g/s)
stack height (feet or meters)
total heat release rate (cal/sec)
radiative heat loss fraction
The heat loss fraction can be user selected or the SCREENS default value of 0.55. For
information about heat loss fractions, see Leahey and Davies (1984). AERSCREEN will process
13
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the flare in AERMOD as a POINT source type. For the exit velocity and exit temperature,
AERSCREEN defaults these values to 20 m/s and 1,273 K, respectively as done in SCREENS
(U.S. EPA, 1995). The stack diameter and effective stack height used in AERMOD are
calculated from the inputs as:
D = 9.88 x 1(T4 x JHR x (1 - HL) (1)
heff = HS + 4.56 x 1(T3 x HROA78 (2)
Where D is effective stack diameter, HR is the heat release rate, HL is the heat loss fraction, Heff
is effective stack height and Hs is the stack height entered by the user.
AERSCREEN.INP and prompt inputs (in italics) are shown in Figure 5.
AERSCREEN.INP flare source inputs
FLARE DATA Rate Height Heat HeatLoss
0.1000E+03 35.0000 0.1000E+08 0.550
Flare source prompts inputs
If the user enters "F" or "f" for flare source:
Enter Emission Rate (g/s):
Enter Flare Stack Height (meters):
Enter Total Heat Release Rate (cal/sec):
Enter Radiative Heat Loss Fraction -
for default value of 0.55:
Figure 5. AERSCREEN.INP and prompts inputs for flare sources.
2.7.3 Volume sources
Volume sources are denoted by the term "** VOLUME DATA" in the input file in the line
above the source parameters. Volume source inputs are, with English and metric units:
emission rate (Ib/hr or g/s)
release height, i.e. center of volume (feet or meters)
initial lateral dimension of the volume (feet or meters)
initial vertical dimension of the volume (feet or meters)
AERSCREEN.INP and prompt inputs (in italics) are shown in Figure 6.
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AERSCREEN.INP
** VOLUME DATA Rate
** 0.1000E+03
Height
2.0000
volume source inputs
Syinit Szinit
1.5000 3.0000
Volume source prompts inputs
If the user enters "V" or "v" for volume source:
Enter Emission Rate (g/s):
Enter Center of Volume Height (meters):
Enter Initial Lateral Dimension (meters):
Enter initial Vertical Dimension (meters):
Figure 6. AERSCREEN.INP and prompts inputs for volume sources.
2.1.4 Rectangular area sources
Rectangular area sources are denoted by the term "** AREA DATA" in the input file in the line
above the source parameters. Rectangular area source inputs are, with English and metric units:
emission rate (Ib/hr or g/s)
release height above ground (feet or meters)
long and short dimensions of area (feet or meters)
initial vertical dimension of plume (feet or meters)
As previously noted, the emission rate is in g/s or Ib/hour, not emission rate per unit area as
entered in AERMOD input files. AERSCREEN automatically calculates the emission rate per
unit area to input into AERMOD. The angle of the source relative to north is automatically set to
0 degrees. Note that the long dimension of the area source is in the x-direction and short
dimension in the y-direction. AERSCREEN.INP and prompt inputs (in italics) are shown in
Figure 7. For rectangular area sources, AERMOD uses the non-default FASTAREA keyword on
the MODELOPT keyword in the CO pathway of the AERMOD.INP file.
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AERSCREEN.INP rectangular area inputs
AREA DATA Rate Height Length Width Angle Szinit
0.1000E+03 2.0000 500.0000 200.0000 0.0 1.50
Rectangular area source prompts inputs
If the user enters "A" or "a" for rectangular area source:
Enter Emission Rate (g/s):
Enter Release Height Above Ground (meters):
Enter Long Side of Area Source (meters):
Enter Short Side of Area Source (meters):
Enter Initial Vertical Dimension (meters):
Figure 7. AERSCREEN.INP and prompts inputs for rectangular area sources.
2.1.5 Circular area sources
Circular area sources are denoted by the term "** AREACIRC DATA" in the input file in the
line above the source parameters. Circular area source inputs are, with English and metric units:
emission rate (Ib/hr or g/s)
release height above ground (feet or meters)
radius of circle (feet or meters)
initial vertical dimension of plume (feet or meters)
As with rectangular area sources, the emission rate is in g/s or Ib/hour, not emission rate per unit
area. AERSCREEN.INP and prompt inputs (in italics) are shown in Figure 8. For circular area
sources, AERMOD uses the non-default FASTAREA keyword on the MODELOPT keyword in
the CO pathway of the AERMOD.INP file.
AERSCREEN.INP circular area source inputs
** AREACIRC DATA Rate Height
** 0.1000E+03 2.0000
Radius
250.0000
Circular area source prompts
NVerts
20
inputs
Szinit
1.50
If the user enters "C" or "c" for circular area source:
Enter Emission Rate (g/s):
Enter Release Height Above Ground (meters):
Enter Radius of AREACIRC Source (meters):
Enter Initial Vertical Dimension (meters):
Figure 8. AERSCREEN.INP and prompts inputs for circular area sources.
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2.1.6 NOx to NO2 conversion
Beginning with version 11060, AERSCREEN allows the option to include NOx to NO2
conversion either by using the Plume Volume Molar Ratio Method (PVMRM) or the Ozone
Limiting Method (OLM). See Section 2.4 of the AERMOD User's Guide Addendum for more
information about PVMRM and OLM and Hanrahan (1999a and 1999b) for background on
PVMRM.
When entering data via the prompts, the user is asked to enter an option for modeling NOx to
NO2 conversion:
1. No chemistry or pollutant is not NO2
2. Use Ozone Limiting Method (OLM)
3. Use Plume Volume Molar Ratio Method (PVMRM)
If option two or three is chosen, the user is prompted for the NO2/NOx in-stack ratio (AERMOD
card CO NOSTACK) and a representative ozone background concentration (AERMOD card CO
OZONEVAL). The NO2/NOX in-stack ratio can range from zero to one and units of the
background concentration can be parts per million (ppm), parts per billion (ppb) or micrograms
per cubic meter (|j,g/m3). For PVMRM the NO2EQUIL ratio is set at the default value of 0.9.
For OLM use, since only one source is being modeled, the OLMGROUP keyword is not needed.
When entering data via AERSCREEN.INP, the user can specify NOx to NO2 conversion by
setting the appropriate keywords in the CO pathway of the AERMOD runstream file portion of
AERSCREEN.INP. PVMRM or OLM must be included on the MODELOPT keyword string,
POLLUTE) must be NO2, NO2STACK must be specified with a ratio, and the background
ozone concentration and units must be specified using OZONEVAL. Figure 9 shows the inputs
using AERSCREEN.INP or interactive prompts.
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AERSCREEN.INP NOx to NOi chemistry inputs
MODELOPT CONC SCREEN OLM
POLLUTID NO2
NO2STACK 0.9000
OZONEVAL 0.4000 UG/M3
MODELOPT CONC SCREEN PVMRM
POLLUTID NO2
NO2STACK 0.9000
OZONEVAL 0.4000 UG/M3
NOx to NOi chemistry prompts inputs
Enter an option for modeling NO2 chemistry
1) No chemistry or pollutant is not NO2
2) Use Ozone Limiting Method (OLM)
3) Use Plume Volume Molar Ratio Method (PVMRM)
If the user enters "2" or "3"
Enter in-stack NO2/NOx ratio ( 0 to 1.0):
Enter concentration units for representative ozone concentration
1) Micrograms per cubic meter (ugm/m^3)
2) Parts per million (ppm)
3) Parts per billion (ppb)
Enter ozone concentration:
Figure 9. AERSCREEN.INP and prompts inputs for NOx to NOi conversion.
2.1.7 Other inputs
Other inputs in the source input prompts are urban/rural classification and minimum ambient
distance. These are discussed in more detail in Section 2.7.
2.2 Downwash
Several parameters are needed by AERSCREEN for input into BPIPPRM. These are:
Include downwash (Y=use building downwash, N=no downwash)
Option to use an existing BPIPPRM input file or,
Building height (feet or meters)
Maximum building horizontal dimension (feet or meters)
Minimum building horizontal dimension (feet or meters)
Degrees from North of maximum building horizontal dimension (0-179 degrees)
Degrees from North of stack location relative to building center (0-360 degrees)
Distance between stack and building center (feet or meters)
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Building parameter data are denoted by the term "** BUILDING DATA" in the input file in the
line above the building dimensions. These inputs are listed in the second block of data of
AERSCREEN.INP (Figure 10) and must be entered in the AERSCREEN.INP file after the
emissions data or AERSCREEN will stop processing. The order of variables is as listed above.
Prompts for building downwash are also shown in Figure 10. When entering data via the
prompts, building prompts will only appear when processing point, capped stack, horizontal
stacks, or flare sources. Building dimensions are in feet or meters. Angles are in degrees
relative to North (0 to 360 degrees). An example building/stack configuration is shown in Figure
11. When entering building parameters, either through the building data line or prompts shown
in Figure 10, the parameters are for a single tier rectangular or square shaped building. If the
user wishes to use downwash for multiple buildings, tiers, or more complicated geometries, the
user can enter a BPIPPRM input filename at the prompts ("Use pre-existing BPIPPRM input
file") or in the CO pathway of the AERSCREEN input file using the TITLETWO keyword. If a
BPIPPRM input filename is entered, AERSCREEN will use the parameters from the file but will
not overwrite parameters from the building data block. If a pre-existing BPIPPRM input file is
used, the process, line 2 of the BPIPPRM input file, must be set to 'P' or 'p' for PRIME
downwash and only one stack located within the file or AERSCREEN will abort.
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AERSCREEN.INP building inputs on BUILDING DATA line
** BUILDING DATA BPIP Height Max dim. Min dim. Orient. Direct. Offset
** Y 34.0000 120.0000 60.0000 90.0000 26.6000 45.0000
AERSCREEN.INP building BPIPPRM input filename line
CO STARTING
TITLEONE flare
TITLETWO BUILDING.INP
** REFINE STAGE 3
MODELOPT CONG SCREEN
AVERTIME 1
POLLUTID OTHER
RUNORNOT RUN
CO FINISHED
Building prompts inputs
Include Building Downwash? (y/n):
If user enters "y" or "Y":
Use pre-existing BPIPPRM input file? (y/n):
If user enters "y" or "Y" for pre-existing BPIPPRM input file:
Enter user created BPIPPRM input file:
If user enters "n" or "N" for pre-existing BPIPPRM input file:
Enter Building Height (meters):
Enter Maximum Horizontal Building Dimension (meters):
Enter Minimum Horizontal Building Dimension (meters):
Enter Maximum Building Dimension Angle to True North (0-179 degees):
Enter Direction of Stack from Building Center (0 - 360 degrees):
Enter Distance Between Stack and Building Center (meters):
If user enters "n" or "N" for building downwash use then no prompts are processed.
Figure 10. AERSCREEN.INP and prompts inputs for building inputs.
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Stack to building
center distance
O)
O)
13
CO
Angle of stack
from north
Max dimension of
) building is oriented
90° to north
Min dimension
Max dimension
Figure 11. Stack and building orientation for a building oriented 90 degrees to north and
stack oriented 45 degrees to north.
2.3 Meteorology and surface characteristics
For inputs to MAKEMET, the user enters the following:
Minimum and maximum ambient air temperatures (Fahrenheit or Kelvin)
Minimum wind speed (m/s)
Anemometer height (m)
Surface characteristics type (user-entered, AERMET tables, or surface characteristics
listed in an external file)
When entering data via the prompts, the user can choose to enter default values for temperatures,
wind speed, and anemometer height (see Figure 12). If using non-default values for
temperatures, the record minimum and maximum temperatures for the area containing the source
should be entered. If using a non-default value for the minimum wind speed, a wind speed less
than 0.5 m/s is allowed. When entering surface characteristics, if the user chooses to utilize user-
21
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entered single value surface characteristics, the user will be prompted for those values. If the
user chooses to use AERMET seasonal tables, the user will be prompted for land use type and
surface moisture (average, dry, or wet). If the user chooses to use an external file, i.e.
AERSUKFACE output or AERMET stage 3 input file, the user will be prompted to enter the
name of the file. If the filename contains spaces or the pathname contains spaces, the pathname
should be entered in quotations. If the surface characteristics are in a file that is not an
AERSURFACE file or AERMET stage 3 input file, the format should follow that as outlined in
the AERMET User's Guide, Section 4.7.7 (U.S. EPA, 2004c). After entering the filename,
AERSCREEN will check for its existence and if it does not exist, the user will be re-prompted
for the filename. AERSCREEN will also check the file for format and valid values for surface
characteristics and if the format is incorrect or surface characteristics are not valid, the user will
be re-prompted for the surface characteristics type (user, AERMET tables, or external file) when
entering data from the prompts. If the data is entered from AERSCREEN.INP and the file is
missing, the format is incorrect or surface characteristics are not valid, AERSCREEN will alert
the user and stop processing.
AERSCREEN will also alert the user if the ambient temperatures exceed current world record
temperatures (183 K and 331 K), Bowen ratio is less than -10 or greater than 10, and if the
surface roughness is less than 0.001 (but positive) or greater than two meters. If surface
roughness is less than 0.001 and not negative, AERSCREEN automatically resets the value to
0.001 and notifies the user. In the case of these warnings, AERSCREEN will use the entered
values but warns the user that they may exceed reasonable values.
If the user uses the AERSCREEN input file to enter the meteorological parameters, the inputs are
as follows in the third block of data of the input file and the data section is denoted by "**
MAKEMET DATA" in the input file. The order of the MAKEMET data line relative to the
other data sections is unimportant. In the AERSCREEN.INP file, temperatures are in degrees
Kelvin. For prompts based input, temperatures are in degrees Fahrenheit or Kelvin. Regardless
of the units convention, wind speeds are in m/s and anemometer height is in meters. The
AERSCREEN.INP and prompts inputs are shown in Figure 12.
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AERSCREEN.INP meteorological inputs
Prompts inputs
Enter Min & Max Ambient Temperatures (K) or
to default to 250 31 OK...
Enter Minimum Temperature (K):
If user enters a number for minimum temperature:
Enter Maximum Temperature (K):
Enter Minimum Wind Speed or to default to 0.5 m/s...
Enter Anemometer Height or to default to 10.0 meters...
1) Single user specified values
2) AEKMET seasonal tables
3) External file
Enter surface characteristics option:
If the user enters 1
Enter Albedo:
Enter Bowen Ratio:
Enter Surface Roughness Length (m):
If the user enters 2
1) Water
2) Deciduous Forest
3) Coniferous Forest
4) Swamp
5) Cultivated Land
6) Grassland
7) Urban
8) Desert Shrubland
Enter Dominant Surface Profile:
1) Average Moisture
2) Wet Conditions
3) Dry Conditions
Enter Dominant Climate Profile:
If user enters 3
Enter filename containing surface characteristics.
Enclose filename -with quotes if path or filename includes spaces...
Figure 12. AERSCREEN.INP and prompts inputs for meteorological and surface
characteristics data.
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The parameters in the input file are:
Minimum temperature
Maximum temperature
Minimum wind speed
Anemometer height
Land use type for surface characteristics
o 0 = user-entered surface characteristics
o 1 = water
o 2 = deciduous forest
o 3 = coniferous forest
o 4 = swamp
o 5 = cultivated land
o 6 = grassland
o 7 = urban
o 8 = desert shrub land
o 9 = use external file of surface characteristics
Climatology type ( for land use of 1 through 8)
o 1 = average moisture
o 2 = wet conditions
o 3 = dry conditions
User defined albedo (not used/requested if land use type is 1 through 9)
User defined Bowen ratio (not used/requested if land use type is 1 through 9)
User defined surface roughness (not used/requested if land use type is 1 through 9)
External surface characteristics filename (not used/requested if land use type is 0 through
8)
When determining surface characteristics, the user should consider the location of the source
(stack or center of volume or area source). Often in emission inventories, the location given for
a source is not the actual location of the source, but an average of sources in a facility or location
of an address. The user should verify coordinates of a stack, volume, or area source. The exact
location of the source is important in determining surface characteristics, especially when using a
tool such as AERSURFACE. Inaccurate source locations can lead to inaccurate surface
characteristics estimations, especially surface roughness. When determining surface
characteristics for the source, regardless of method (user-entered, AERMET tables, or
AERSURFACE), the user is highly encouraged to review Section 3.1 of the AERMOD
Implementation Guide (U.S. EPA, 2009) and if using AERSURFACE, to review the
AERSURFACE User's Guide (U.S. EPA, 2008).
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2.4 Terrain
For terrain processing in AERMAP, the user enters the following:
Include terrain processing (yes=include terrain, no=do not include terrain effects)
Probe distance (meters)
Include discrete receptor distances (discussed in Section 2.6) (beginning with version
11060)
Flagpole receptors (discussed in Section 2.7)
Source elevation or use AERMAP to determine source elevation
Source coordinates (geographic or UTM)
NAD datum (NAD 27 or 83)
UTM zone (if UTM coordinates entered)
If the user is processing a rectangular area source, the only inputs the user enters via the prompts
are probe distance, use of discrete receptor distances (version 11060), flagpole receptors, and
source elevation. The user will not have the choice of using AERMAP for source elevation
determination. If flat terrain is being processed for any source type, the user cannot use
AERMAP for source elevation determination. When entering data via the prompts and
processing terrain, the user has the choice of inputting geographic coordinates (latitude and
longitude) or UTM coordinates, as well as the NAD datum of the coordinates , North American
Datum of 1927 (NAD 27) or North American Datum of 1983 (NAD 83). If the user enters
geographic or UTM coordinates with NAD 27 datum, AERSCREEN converts the coordinates to
UTM coordinates with NAD 83 datum. If the user enters geographic coordinates with NAD 83,
AERSCREEN converts the coordinates to UTM coordinates with NAD 83 datum and writes
those to the AERSCREEN.INP file. If the terrain files read in AERMAP are NAD datum 27 and
not datum 83, AERMAP will do the necessary conversions to NAD 27 for terrain processing in
AERMAP. For more information about the NAD conversion process see the AERMAP User's
Guide (U.S. EPA, 2004b).
If geographic to UTM conversion is performed, AERSCREEN will write the converted NAD 83
UTM coordinates to the new AERSCREEN.INP file with a message that the latitude and
longitude coordinates were converted to UTM coordinates. AERSCREEN will also write a
message to the input file if coordinates were switched from NAD 1927 to NAD 1983. When
entering data using the AERSCREEN.INP file, coordinates must be in UTM coordinates. If the
coordinates are indicated to be in NAD 1927, AERSCREEN will convert to NAD 1983 UTM
coordinates and notify the user. Coordinates should only be in NAD 1927 if the user manually
changed the coordinates and NAD in AERSCREEN.INP. The variables are as follows in the
fourth line of the AERSCREEN input file (Figure 13). Terrain data is denoted by the term "**
TERRAIN DATA" in the input file. Prompts are also shown in Figure 13.
25
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AERSCREEN.INP inputs
TERRAIN DATA Terrain UTM East UTM North Zone Nada Probe PROFBASE Use AERMAP ele\
N 406672.0 3698970.8 12 1 5.0 18.30 N
Prompts inputs
Include Terrain Heights? (y/n):
If user enters "y" or "Y":
Enter Maximum Distance (m) to probe
for default (10000 m):
If user enters "n" or "N":
Enter Maximum Distance (m) to probe
for default (5000 m):
Enter stack elevation (m) or
for AERMAP derived elevation:
If the user enters "n" or "N" for terrain or source is a rectangular area source:
Enter source elevation (m) or
for default 0 m:
If user enters "y" or "Y" for terrain:
Enter coordinate type:
LATLONfor latitutde & longitude or
UTM for UTM coordinates
If the user enters LATLON:
Enter Source Latitude (North positive) (xx.xxxx):
Enter Source Longitude (West negaitive) (xxx.xxxx):
If the user enters UTM:
Enter Source UTM Easting (xxxxxx.x):
Enter Source UTM Northing (xxxxxxx.x):
The following prompt is shown for UTM coordinates:
Enter Source UTM Zone (xx):
Option (1) - North American Datum of 1927
Option (4) - North American Datum of 1983
Enter Option for Applicable UTM Nada:
Figure 13. AERSCREEN.INP and prompts inputs for terrain data.
26
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Input parameters in AERSCREEN.INP are:
Terrain flag (Y=use terrain, N=do not use terrain)
UTM X coordinate
UTM Y coordinate
UTM zone
NAD datum of source location
Probe distance in meters
Source elevation (feet or meters)
Override source elevation with AERMAP value (Y=yes, N=no)
When the probe distance is entered, AERSCREEN checks to see if the probe distance is a
multiple of 25 meters. If the distance is not a multiple of 25, the probe distance is reset to the
next distance that is greater than the entered probe distance and is a multiple of 25.
AERSCREEN alerts the user of the change. For example, if the entered probe distance is 1,031
m, AERSCREEN will reset the distance to 1,050 m. This is done because the receptor spacing
between zero and 5 km is 25 m and a multiple of 100 between 5 km and the probe distance. The
reset makes it easier to perform the calculations.
If the user enters the source coordinates as latitude and longitude, the UTM zone will not be
requested and is determined by AERSCREEN. If not processing terrain, the user can enter the
actual elevation for the source or choose a default of zero. The user will not be prompted for
AERMAP override of user-entered source elevation.
When entering data via the prompts, the prompt for terrain processing and overriding of source
elevation with AERMAP will appear for all source types except rectangular area sources. The
other prompts will appear for all sources.
The name(s) of the terrain input file(s) that AERMAP reads are input into AERSCREEN by a
file called demlist.txt, which is to be located in the same directory as the AERSCREEN
executable or local folder in which the user is working. The demlist.txt file is not created by
AERSCREEN but the user must create the file prior to running AERSCREEN. If terrain is to be
processed, AERSCREEN will check for the existence of this file and if it is not present,
AERSCREEN will stop processing. The general format of the file and three examples are shown
in Figure 14. The general format is that the first line contains either "NED" or "DEM" (the case
can be lower or upper case) as the first three characters to denote the file type. The rest of the
line is for informational purposes and not read by AERSCREEN. The second line is a delineator
between the file type and the file list, usually a series of dashes. The third line is to specify the
location of the grid files (conus.las, conus.los, etc.) that will be used for NAD conversion (from
27 to 83 or vice versa). The location is specified by starting the line with "NADGRIDS"
followed by the pathname of the files. If the pathname contains spaces, the entire pathname
should be enclosed in quotations. Beginning with AERSCREEN version 11060, a trailing "\" is
no longer necessary at the end of the pathname. In Figure 14a, AERSCREEN will accept
27
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"c:\grid filesV or "c:\grid files". If the files are in the current working directory1, the rest of the
line after "NADGRIDS" can be the full path of the current working directory, blank, or \.
However, if the files are not in the working directory, AERSCREEN will stop processing.
Regardless of the NAD datum of the coordinates, the field will be read by AERSCREEN and
input into AERMAP. If the line beginning with NADGRIDS is not in the demlist.txt file,
AERSCREEN will notify the user and stop processing.
Finally beginning with the fourth line, is the list of the files to be read into AERMAP, each file
on a separate line. If the filename or pathname of the file contains spaces, the filename or
pathname must be enclosed in quotations. For NED files only, the units of the terrain data can be
included. The units are:
FEET for units of feet
DECI-FEET or DECIFEET for units of decifeet
DECA-FEET or DECAFEET for units of decafeet
METERS for meters
DECI-METERS or DECIMETERS for units of decimeters
DECA-METERS or DECAMETERS for units of decameters
Note that the units are not case sensitive, so lower-case text is allowed. If no units are entered,
i.e. blank after the filename, the units are understood to be meters and AERMAP will give a non-
fatal warning to the user when AERMAP is executed. If units are included, when AERSCREEN
creates the AERMAP.INP file, the TIFFDEBUG keyword will be added to the DATAFILE line
in the AERMAP.INP file.
In Figure 14a, a single National Elevation Data (NED) file called ned_file.tif is to be read into
AERMAP with units of meters by default. Also, the NADGRIDS files are located in a folder
with spaces in the pathname so the filename is in quotations. Figure 14b gives an example of a
NED file whose pathname contains spaces, so the name is enclosed in quotations. The units of
the terrain are specified to be meters. Figure 14b also shows that the location of the grid files
used for NAD conversion. Figure 14c shows a list of DEM files that will be processed in
AERMAP with NAD grid files located in the current working directory. Note that units cannot
be included with DEM files.
Users are encouraged to use NED data as DEM data is static and no longer updated. NED data is
more up to date and is regularly updated.
1 Current working directory refers to the directory or folder that a DOS prompt is working in when using a DOS
window or to the folder that the AERSCREEN executable is in when double clicking the AERSCREEN executable
icon.
28
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NED : Must be either DEM or NED
NADGRIDS "c:\grid filesV
ned file.tif
NED : Must be either DEM or NED
NADGRIDS c:\aermap\grids
"test dir\ned file.tif" meters
DEM : Must be either DEM or NED
NADGRIDS
testOI .dem
test02.dem
testOS.dem
Figure 14. Example formats of demlist.txt.
If terrain is to be included, users should consult the AERMOD Implementation Guide,
specifically sections 4.3, 4.4, and 4.5 (U.S. EPA, 2009) as well as the AERMAP User's Guide
and addendum (U.S. EPA, 2004b).
2.6 Inclusion of discrete distances
Beginning with version 11060, AERSCREEN allows for the input of up to ten discrete receptor
distances that are not part of the regularly spaced receptor network created by AERSCREEN
(See Section 3.4). These could include distances to specific locations near a source such as a
monitor, school, residential area, etc. AERSCREEN will read all of the locations input by the
user but will only process receptors that are between the ambient distance and probe distance.
Discrete receptor use is entered in AERSCREEN.INP via the 6th data line in AERSCREEN.INP
(Figure 15) or during the terrain processing prompts when entering via the prompts. If the user
wishes to include discrete distances, the distances should be entered into a simple text file. The
user will also be prompted for the filename of distances. The distances listed in the file can be in
29
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several units: meters, feet, kilometers, or miles and is independent of whether other data (source
inputs, meteorology, etc.) are in metric or English units. To define the units, the first line of the
text file should be the line "units: "followed by the units of the distances. An example file is
shown in Figure 16 with distances listed in meters. The format of the units line is not case
sensitive but it must be the first line of the file. Distances can be entered as:
FEET or FT for feet
METERS for meters
KILOMETERS, KILO-METERS, or KM for kilometers
MILES for miles
If the units line is present but no distance units are entered, i.e. the line is just "units: ", then
AERSCREEN will assume distance units of meters. When entering the filename from
AERSCREEN.INP, if the file does not exist, or the number of receptors exceeds ten, or no units
line is listed, AERSCREEN will alert the user and stop processing. If entering the filename
using prompts and one of the conditions above is met, AERSCREEN will alert the user and re-
prompt for a filename.
If the discrete receptor data line is not in AERSCREEN.INP, AERSCREEN will assume no
discrete receptor distances will be used in modeling. The user can then include discrete receptor
use in the data validation phase of AERSCREEN.
AERSCREEN
.INP inputs
** DISCRETE RECEPTORS Discflag Receptor file
** Y "discrete rec.txt"
Prompts
Include up to 10 discrete receptors (y/n) ?
If user enters "y" or "Y":
Enter name of file with discrete receptors.
Enclose filename with quotes if path or filename includes
inputs
spaces...
Figure 15. AERSCREEN.INP and prompts inputs for including discrete distances.
units: meters
26.0
35.1
111.5
427.35
535.0
Figure 16. Sample distances in a discrete distances text file.
30
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2.7 Other inputs
Other inputs or options used by AERSCREEN are:
units of inputs (metric or English),
urban/rural classification
urban population if urban
minimum ambient distance (feet or meters)
use of flagpole receptors
flagpole receptor height (feet or meters)
These variables in the sixth line of the AERSCREEN input file are shown in Figure 15 and are
denoted by the term "** UNITS/POPULATION." This line must be listed after the source input
line. While entering data via prompts, the English or metrics unit prompt is before any other
prompts, while the urban/rural and ambient distance prompts occur during the source input
processing. The flagpole receptor prompts occur in the terrain inputs processing.
AERSCREEN.INP inputs
Prompts inputs
English or Metric Units? (EorM):
Rural or Urban? (R or U):
Enter Population of Urban Area:
Enter Minimum Distance (meters) to Ambient Air -
for default (1 m):
Use Flagpole receptors? (y or n):
If user enters "y" or "Y":
Enter Flagpole receptor height (meters)
Figure 17. AERSCREEN.INP and prompts inputs for other inputs.
31
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Inputs in AERSCREEN.INP are:
Units of data (M=metric, E=English)
Urban/rural flag (U=urban, R=Rural)
Population for urban source
Minimum ambient distance
Use Flagpole receptors
Flagpole receptor height (ignored if flagpole receptors = no)
If the units flag in AERSCREEN.INP is set to "E" AERSCREEN will stop processing and notify
the user that the flag is not set to "M." for metric. The user can enter the data in English units
when entering data from the prompts but AERSCREEN will change the units flag to metric and
convert the variables from English to metric units during processing. When AERSCREEN
creates the AERSCREEN.INP file from prompt-entered data, there will be a comment in the new
input file that units were converted from English to metric.
For minimum ambient air distances for non-volume sources, when entering data with English
units, the default value listed will be 3.3 feet, or 1 meter. For volume sources, the ambient
distance must be greater than or equal to 2.15 times the initial lateral dimension, 2.15oy plus one
meter. In AERMOD, receptors with source-receptor distances less than 2.15oy plus one meter
are not included in concentration calculations. When entering data via the prompts, the default
value that is listed will be 2.15oy plus 1 m (or equivalent in feet). If the user chooses the default
value by hitting , that will be the ambient distance. If the user enters a different value
from the listed default value, it must be greater than or equal to the default value listed.
Otherwise, the user will receive a message that the value reset to 2.15oy plus 1 m. When
obtaining the ambient distance from AERSCREEN.INP, AERSCREEN will compare that value
against 2.15oy plus 1 m and if the entered value is less than 2.15oy plus 1m, it is reset to 2.15oy
plus 1 m. If the user does not wish to use the reset value, it change be changed at the validation
page but must be greater than or equal to 2.15oy plus 1m.
When the source is a non-volume source and the ambient distance is less than 1 meter in the
AERSCREEN.INP, the distance will be reset to 1 meter and AERSCREEN will alert the user. If
the user enters a distance less than 1 meter using the prompts, the distance will be reset to 1 m
and the user will be alerted.
2.8 Fumigation options
Beginning with version 15181, AERSCREEN will calculate fumigation due to inversion break-
up and coastal fumigation for point sources with release heights (above ground level) 10 m or
more in height. The fumigation equations are taken from SCREENS (U.S. EPA, 1995) and
follow the methodology of Turner (1970). The inputs to AERSCREEN.INP are:
Calculate inversion break-up fumigation (Y=calculate fumigation, N=do not calculate
fumigation)
Calculate shoreline fumigation (Y=calculate fumigation, N=do not calculate fumigation)
32
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Minimum distance to shoreline in meters (less than 3,000 m)
Optional direction to shoreline from source (0-360 degrees or -9 for no specified
direction)
For shoreline fumigation, the user also enters the minimum distance to the shoreline from the
source and the user has the option to specify the direction from the source to the shoreline when
using spatially varying surface characteristics for MAKEMET. This option allows AERSCREEN
to use appropriate surface characteristics corresponding to the upwind direction from the source
to shoreline. For the fumigation options, the source is considered rural, no downwash effects are
included, and no terrain effects are included. The inputs for fumigation are shown in Figure 18.
AERSCREEN.INP inputs
** FUMIGATION Inversion Break-up Shoreline Distance Direct Run
AERSCREEN
** FUMIGATION Inversion Break-up Shoreline Distance Direct Run
AERSCREEN
** N N 0.00 0.0 Y
Prompts inputs
Apply inversion break-up fumigation (y/n):
Apply shoreline fumigation (y/n):
Enter minimum distance to shoreline (m):
Enter optional direction to shoreline (0 - 360 degrees) or enter -9 or for no specific direction:
Run AERSCREEN (y/n):
Figure 18. AERSCREEN.inp and prompt inputs for fumigation.
2.9 Optional debug file
Beginning with version 15181, AERSCREEN allows for the option to output a debug file that
contains all intermediate output from the stages of AERSCREEN (PROBE and FLOWSECTOR)
described in Section 3.5 and 3.6 of this guide. When fumigation options are selected, the debug
option will also output the meteorological variables and iterations of the fumigation calculations.
The inputs for the debug option are shown in Figure 19.
AERSCREEN.INP inputs
** DEBUG OPTION
* *
Debug
N
Prompts inputs
Enter Y or y to turn on
the debug option or
to not use the debug option
Figure 19. AERSCREEN.inp and prompt inputs for fumigation.
33
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2.10 Non-default name for output file
The default output files for AERSCREEN are AERSCREEN.OUT and max_conc_distance.txt.
The default name for the optional debug file is concentrations.txt and fumigate_debug.txt for
fumigation output. AERSCREEN.OUT lists the inputs and various outputs of the AERSCREEN
run. The file max_conc_distance.txt, lists the maximum concentration by distance. Beginning
with AERSCREEN version 11060, the user can choose different names other than the defaults.
The filename must have an ".out" extension. The user can specify a filename within the current
working folder or a complete path. If a complete pathname is entered, AERSCREEN will check
to make sure that the target folder or directory exists. If the folder does not exist, the user must
re-enter the filename. The filename that is used for output file is also used to construct the
maximum concentration by distance file as well the debug files. The prefix (including folder
name) of the new output file is used for the maximum concentration file and debug files. The
prefix (including folder name) is also used to copy the final AERSCREEN.INP file and
AERSCREEN.LOG files to new files that have the same prefix as the output file. The user can
change the filename using prompts or by the seventh data line beginning with "** OUTPUT
FILE" followed by the output filename. Figure 20 shows the AERSCREEN.INP inputs and
prompts inputs. If the output file option is not listed in AERSCREEN.INP, AERSCREEN will
assume the default AERSCREEN.OUT for the filename and the user can change the filename
during the data validation phase of AERSCREEN.
AERSCREEN.INP inputs
** OUTPUT FILE "AERSCREEN.OUT"
Prompts inputs
Enter name of AERSCREEN output file
Enter to use default name AERSCREEN.OUT
Filename should include .out or .OUT extension
If filename contains spaces, enter entire filename in quotations
Figure 20. AERSCREEN.INP and prompts inputs for output filename.
2.11 Error checking
When entering data via the AERSCREEN.INP file or via prompts, AERSCREEN will check for
invalid responses for flags (use downwash, terrain, urban/rural, etc.) and numeric values (stack
height, building height, etc.). When processing input from the AERSCREEN.INP file, any flags
or parameters found to be invalid or outside a realistic data range (minimum ambient temperature
is greater than maximum ambient temperature), AERSCREEN lists error messages for the
parameters to the AERSCREEN.LOG file and stops AERSCREEN processing to allow the user
to correct the values in the AERSCREEN.INP file. Examples would be a character other than
"Y", "y", "N", or "n" for the building downwash flag or a negative building height for
34
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downwash. If processing input data from the prompts, AERSCREEN will re-prompt the user for
a valid response. For the two examples listed above, AERSCREEN would re-prompt the user
for responses. Appendix A lists the input parameters, reasons for invalid values, and actions
taken by AERSCREEN.
When entering data from AERSCREEN.INP, AERSCREEN checks to make sure that the
emissions data is listed before the building, terrain, and miscellaneous data lines. If the
emissions data line is listed after one of the other three lines, AERSCREEN notifies the user and
stops processing.
AERSCREEN also checks for the presence of several files, if applicable:
Demlist.txt (when processing terrain)
BPIPPRM input file (if processing downwash and filename is entered)
External surface characteristics file (if isurf equals 9)
Discrete receptor file (if processing discrete receptors)
If these files are not found, AERSCREEN issues a message and stops processing. Note that if
demlist.txt does not exist, AERSCREEN stops processing, regardless of whether data is being
entered via prompts or AERSCREEN.INP. AERSCREEN will also check if the pathname of the
output file is valid. If the folder or directory does not exist, AERSCREEN issues a message and
stops processing. AERSCREEN also checks for the presence of the AERMOD and MAKEMET
executables in the current working folder. If one of those executables is not present,
AERSCREEN issues a warning and prompts the user for the location of the executable.
AERSCREEN will copy the executable from the entered locations to the current working folder.
If processing downwash, AERSCREEN will check for the presence of the BPIPPRM executable
and the AERMAP executable if processing terrain. If those are not present, AERSCREEN will
issue a warning, prompt the user for the locations of the executables, and copy them to the
current working folder.
35
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3. AERSCREEN Program Execution
The AERSCREEN program can be run from the command-prompt or by double-clicking on the
AERSCREEN.EXE from Windows Explorer. The user should make sure that demlist.txt, the
AERMOD, MAKEMET, and if necessary the AERMAP and BPIPPRM executables are in the
current working directory. General AERSCREEN processing is shown in Figure 21. If a restart
file generated from a previous run (called 'AERSCREEN.INP') is present in the folder, then the
user will be asked to continue with the restart file or enter data via the prompts (Figure 22a). If
there is no restart file, the prompts will begin automatically (Figure 22b).
User actions input and Vi
alidate data
Generate meteorological files and run BPIPPRM and AERMAP for source if
necessary; Generate receptor network
Program actions
., ^ Is there a sc
No ^ ..
1 u rce-rece ptor\.
action ^> Yes
idency? ,-"""""^
^^ terrain and/or downwash
or rectangular area
source, execute
FLOWSECTOR
FINF «
Inversion break-up
jtput « shoreline fumigation
Figure 21. AERSCREEN processing and stages.
36
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AERSCREEN 15181
RESTART file title: POINT, FLAT, DOWNWASH
Continue with RESTART File? :
OR
Start a NEW Run? :
Enter choice:
AERSCREEN 15181
AERSCREEN.INP does not exist
User must enter data
INITIAL INFORMATION
Enter Title:
Figure 22. AERSCREEN start screen.
3.1 Data input and validation
If the user chooses the restart file, AERSCREEN goes directly into the user validation page. The
user should carefully review the data to ensure accurate inputs. If processing terrain, particular
attention should be paid to the coordinates to ensure that any NAD conversions were successful.
Also on the validation page, the user will have the option of rerunning the same inputs or
selectively modifying specific components, such as building or terrain information (Figure 23).
For example, if changes are to be made to building parameters, the user chooses option 2 and a
list of further options will appear (Figure 25). The user can change individual parameters
without having to re-enter all the parameters. The option to re-enter all parameters is a choice as
well. Changes to individual parameters are available for source, meteorological, and terrain
parameters as well. Some options cannot be changed without changing another parameter first.
These include changing urban population for a rural source or surface characteristics (i.e. user
defined values when AERMET tables are chosen). Figure 24 shows the list of choices for
various source types, Figure 25 shows the choices for building parameters, Figure 26 lists the
37
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choices for terrain processing, Figure 27 lists the choices for meteorological processing and
Figure 28 lists the fumigation options. For each submenu, once the desired changes are made,
the user can hit to return to the validation page. Some changes will automatically return
the user to the validation page, such as choosing option 1 in Figure 25a for building downwash
or turning the debug option on or off.
Note, that if the user chooses to change source data, the source type cannot be changed; only
parameters for the source type from the AERSCREEN.INP file or from the prompts. For
example, the user cannot change the source from point to rectangular area. For building data, if
the user is running AERSCREEN for an area source, rectangular or circular, or a volume source
(which do not use building downwash) and chooses option 2 from the validation page,
AERSCREEN will give the message that building parameters cannot be changed due to source
type and return to the validation page. The same is true for changing terrain data when running a
rectangular area source. The user may also change parameters in the AERSCREEN.INP file
before running AERSCREEN, instead of modifying the data using the prompts.
38
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AERSCREEN 15181
DATA ENTRY VALIDATION -
METRIC ENGLISH
** STACKDATA **
Emission Rate:
Stack Height:
Stack Diameter:
Stack Temperature:
Exit Velocity:
Stack Flow Rate:
Model Mode:
BUILDING DATA
User defined BPIPPRM input file:
BUILDING.INP
TERRAIN DATA
Probe distance: 10000 . meters
No flagpole receptors
Using discrete receptors in
** FUMIGATION DATA **
No fumigation reguested
** METEOROLOGY DATA **
Min/Max Temperature: 270.0 / 310.0 K
Minimum Wind Speed: 0.5 m/s
Anemometer Height: 10.000 meters
DEBUG OPTION OFF
AERSCREEN output file:
AERSCREEN FLAT DW.OUT
1 - Change Source Data;
2 - Change Building Data;
3 - Change Terrain Data;
4 - Change Meteorology Data;
5 - Change Fumigation Data;
6 - Change Title;
7 - Change Debug Option;
8 - Change Output Filename;
9 - Stop AERSCREEN;
- or -
Hit to Start Run
Figure 23. AERSCREEN validation page.
39
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Enter number of parameterto change or
to return to validation page
Point Source
1) Emission rate
2) Stack height
3) Stack diameter
4) Stack temperature
5) Exit velocity
6) Urban/Rural
7) Urban population
8) Distance to ambient air
9) N02 chemistry
10) N02/N0x in stack ratio
11) Ozone concentration
12) Update all parameters
Enter number of parameterto change or u
to return to validation page
Volume Source
1) Emission rate
2) Center of volume height
3) Initial lateral dimension
4) Initial vertical dimension
5) Urban/Rural
6) Urban population
7) Distance to ambient air
8) N02 chemistry
9) NCG/NOx in stack ratio
10) Ozone concentration
11) Update all parameters
Enter number of parameterto change or
to return to validation page
Rectangular area source
1) Emission rate
2) Release height
3) Long side dimension
4) Short side dimension
5) Initial vertical dispersion parameter
6) Urban/Rural
7) Urban population
8) Distance to ambient air
9) N02 chemistry
10) NCQ/NOx in stack ratio
11) Ozone concentration
12) Update all parameters
Enter number of parameterto change or d
to return to validation page
Circular area source
1) Emission rate
2) Release height
3) Radius
4) Initial vertical dispersion parameter
5) Urban/Rural
6) Urban population
7) Distance to ambient air
8) N02 chemistry
8) NCQ/Nox in stack ratio
10) Ozone concentration
11) Update all parameters
Enter number of parameterto change or e
to return to validation page
Flare Source
1) Emission rate
2) Stack height
3) Total heat release rate
4) Heat lossfraction
5) Urban/Rural
6) Urban population
7) Distanceto ambient air
8) N02 chemistry
9) N02/Nox in stack ratio
10) Ozone concentration
11) Update all parameters
Figure 24. Submenus for changing source parameters for a) point, capped or horizontal
stack, b) volume, c) rectangular area, d) circular area, and e) flare sources.
40
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Enter number of parameterto change or
to return to validation page
Pre-existing BPIPPRM input filename must be
re-entered if it is to be used (Option 2)
1) Do not include building downwash
2) BPIPPRM input filename
3) Building height
4) Maximum horizontal dimension
5) Minimum horizontal dimension
6) Maximum building dimension angle to North
7) Angle of stackfrom building center
8) Distance between stack and building center
9) Update all parameters
Enter number of parameterto change or
to return to validation page
Pre-existing BPIPPRM input filename must be
re-entered if it is to be used (Option 2)
1) Include building downwash
2) BPIPPRM input filename
3) Building height
4) Maximum horizontal dimension
5) Minimum horizontal dimension
6) Maximum building dimension angle to North
7) Angle of stackfrom building center
8) Distance between stackand building center
9) Include building downwash and update all parameters
Figure 25. Building downwash submenus for a) building downwash included and b)
building downwash not included.
41
-------
Enter number of parameter to change or
to return to validation page
1) Do not include terrain heights
2) Probe distance
3) Use flagpole receptors
4) Flagpole receptor height
5) Source elevation input (user entered or AERMAP)
6) Input coordinate type and coordinates (LATLON or
UTM), UTM zone, and NAD
7) Include discrete receptors
8) Filename of discrete receptor list
9) Update all parameters
Enter number of parameterto change or
to return to validation page
1) Include terrain heights
2) Probe distance
3) Use flagpole receptors
4) Flagpole receptor height
5) Source elevation input (user entered or AERMAP)
6) Input coordinatetype and coordinates (LATLON or
UTM), UTM zone, and NAD
7) Include discrete receptors
8) Filename of discrete receptor list
9) Include terrain heights and update all parameters
Enter number of parameterto change or
to return to validation page
1) Probe distance
2) Use flagpole receptors
3) Flagpole receptor height
4) Source elevation input
5) Include discrete receptors
6) Filename of discrete receptor list
7) Update all parameters
a
b
c
Figure 26. Terrain submenus for a) terrain heights included, b) terrain heights not
included and c) rectangular area sources.
Enter number of parameter to change or
to return to validation page
1) Use default min and max temperatures
2) Minimum temperature
3) Maximum temperature
4) Minimum wind speed
5) Anemometer height
6) Input surface characteristics
7) User albedo
8) User Bowen ratio
9) User surface roughness length
10) landuse
11) Moisture
12) AERSURFACE output file
13) Update all parameters
Figure 27. Meteorological data submenu.
42
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g
Figure 28. Fumigation submenus for various fumigation options.
If the user chooses to run from the restart file, while reading the file, AERSCREEN may
automatically change some of the options in the file, depending on other options. If the source
being modeled is a rectangular area source and the terrain flag is set to "y" or "Y" then the
terrain flag is reset to "N." For rectangular area sources, circular area sources, or volume
sources, if the BPIP flag is set to "Y" or "y" in the input file then the BPIP flag is set to "N" and
no downwash is calculated. If the user enters data using prompts instead of the
AERSCREEN.INP file, the validation page will appear after all prompts have been processed for
the source, building, terrain, and meteorological data.
3.2 Meteorological data files
After reading the input file or prompt inputs, and prompting the user for any changes,
AERSCREEN processes the surface characteristics and runs MAKEMET to create the
AERMOD meteorological input files (.sfc, and .pfl files). MAKEMET is run for each temporal
period /spatial sector combination of surface characteristics. Depending on the temporal
resolution and number of spatial sectors of the surface characteristics, one surface and one
profile file (annual, 1 sector) to a maximum of 144 (monthly, 12 sector) surface files and 144
profile files are created, one for each temporal period/spatial sector combination (Figure 29). In
the meteorological files naming convention, the first set of 2-digit numbers refers to the temporal
period of the surface characteristics, which ranges from 1 to 12. If processing annual surface
characteristics, the number would be "01" and if processing seasonal or monthly surface
characteristics, the number would be range from "01" to "04" for seasonal output and "01" to
"12" for monthly output. The second set of numbers in the filenames is the number of spatial
sectors for surface roughness. This can range from "01" to "12" for one sector to 12 sectors.
In Figure 26, aerscreen_01_01.sfc and aerscreen_01_01.pfl use surface characteristics for
January, sector 1; aerscreen_01_02.sfc and aerscreen_01_02.pfl use surface characteristics for
43
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January, sector 2 and so on with aerscreen_12_12.sfc and aerscreen_12_12.pfl using surface
characteristics for December, and sector 12.
Creating
Creating
Creating
Creating
Creating
Creating
met
met
met
met
met
met
files
files
files
files
files
files
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 12
01
02
03
04
05
12
. sf c
. sf c
.sfc
.sfc
.sfc
.sfc
&
&
&
&
&
&
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 01
aerscreen 12
01
02
03
04
05
12
.pfl
.pfl
.pfl
.pfl
.pfl
.pfl
Figure 29. Meteorological file creation for monthly 12 sector AERSURFACE output.
The input parameters to MAKEMET, which are normally entered using prompts, are written to a
text file called prompts.inp by AERSCREEN and then "piped" to the MAKEMET call by
AERSCREEN with the call system command, "makemet < prompts.inp." Using the
MAKEMET prompts shown in Figure 1 as a guide, AERSCREEN assigns the names for the
surface and upper air meteorological files requested in the first two prompts shown in Figure 1
based on the file naming convention described above. The minimum wind speed and
anemometer height are assigned the values entered by the user. The number of wind directions
is automatically set to 1 by AERSCREEN and the wind direction is set to 270 degrees. The
minimum and maximum temperatures are assigned the values entered by the user. The albedo,
Bowen ratio and surface roughness length are assigned the values for the particular
temporal/spatial combination being processed. The final prompt, "DO YOU WANT TO
GENERATE ANOTHER MET SET THAT WILL BE APPENDED TO CURRENT FILE?
[TYPE EITHER "Y" OR "y" FOR YES; OR HIT "ENTER" TO EXIT]" is set not to generate
another file. An example for monthly, 12 sector AERSURFACE output is shown in Table 1.
44
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Table 1. MAKEMET prompts and example
roughness sector and last month and surface
AERSURFACE output.
values for the first month and surface
roughness sector for monthly 12 sector
MAKEMET prompt
ENTER SFC MET FILE NAME
ENTER PFL MET FILE NAME
ENTER MIN. WS (M/S)
ENTER ANEM HT (M)
ENTER OPTION TO ADJUST U* (Y=adjust,N=no
adjustment)
ENTER NUMBER OF WIND DIRECTIONS
ENTER WIND DIRECTION
ENTER MIN AND MAX AMBIENT TEMPS IN
KELVIN
ENTER ALBEDO
ENTER BOWEN RATIO
ENTER SURFACE ROUGHNESS LENGTH IN
METERS
DO YOU WANT TO GENERATE ANOTHER MET
SET THAT WILL BE
APPENDED TO CURRENT FILE?
[TYPE EITHER "Y" OR "y" FOR YES; OR HIT
"ENTER" EXIT]
Value (month 1, sector 1)
aerscreen 01 Ol.sfc
aerscreen 01 Ol.pfl
User input minimum wind
speed
User input anemometer
height
N
1
270
User entered temperatures
Albedo for month 1, sector
1
Bowen ratio for month 1,
sector 1
Surface roughness for
month 1, sector 1
N
Value (month 12, sector 12)
aerscreen 12 12.sfc
aerscreen 12 12.pfl
User input minimum wind
speed
User input anemometer
height
N
1
270
User entered temperatures
Albedo for month 12, sector
12
Bowen ratio for month 12,
sector 12
Surface roughness for month
12, sector 12
N
3.3 BPIPPRM execution
If downwash is to be considered, BPIPPRM inputs are calculated and written to a BPIPPRM
input file or the user entered input file is used. For either method, BPIPPRM is executed to
create the projected building dimensions for input into AERMOD. If a user-entered file is used
and the processing flag (line 2) of the BPIPPRM input file is not a "P" or "p" then BPIPPRM
will abort and AERSCREEN will notify the user and stop processing. Beginning with
AERSCREEN version 11060, AERSCREEN also checks to make sure only one stack is listed in
the BPIPPRM input file. If more than one stack is listed, AERSCREEN will stop processing and
notify the user.
3.4 Source elevation calculation
If terrain is being used, AERSCREEN calls AERMAP to get the source location's elevation.
The source elevation, user-entered or AERMAP calculated, can be used as the source elevation
in the SO pathway of the AERMOD runstream file, AERMOD.INP, and as the station elevation,
keyword PROFBASE in the ME pathway of the AERMOD input file. If the user has chosen to
45
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replace the input source elevation, either from the restart file or via prompts, AERSCREEN will
use the AERMAP elevation as the source location's elevation. If the user chose to keep the input
elevation, AERSCREEN will calculate a percent difference between the user-entered elevation
and the AERMAP calculated elevation and write the difference to the AERSCREEN log file.
3.4 Receptor network
An array of receptor distances is also created including the minimum ambient distance,
automatically calculated distances (as described in steps 1 and 2 below), and any discrete
receptor distances. The probe distance is set to the user-specified probe distance, or reset probe
distance (as described in Section 2.4). Depending on the probe distance, there may be two
receptor spacing values:
1. 25 meters from zero to 5 km
2. From 5 km to the final probe distance, the spacing is the greater of 25 m or a spacing
calculated by: (probe distance - 5,000 m)/100 where 100 represents 100 receptors
For example, if the user enters a probe distance of 12, 500 m, the receptor spacing from zero to
5,000 m is 25 m and the spacing from 5,000 to 12,500 is 75 m (7,500 m/100).
Receptors located at distances less than the minimum ambient distance, either discrete or
automatically calculated, are not included in the set of receptors. Also, any discrete receptor
distances that exceed the probe distance are not included. Discrete receptors that are also equal
to any distance in the automatic array are not included to avoid duplicate receptors. Receptor
distances are relative to x=0 and y=0. For point, capped stacks, horizontal stacks, and flare
sources, x=0 and y=0 represent the stack or flare location. For volume and circular area sources,
x=0 and y=0 represent the center of the source.
There are three main routines in AERSCREEN: PROBE, FLOWSECTOR and REFINE as
shown in Figure 19. There are two optional fumigation routines FUMIGATE and SHORELINE
used to calculate maximum concentrations due to inversion break-up fumigation and shoreline
fumigation respectively. PROBE is executed when there is no source-receptor direction
dependency (no terrain, no building downwash, and the source is not a rectangular area source).
FLOWSECTOR is executed when there is a source-receptor direction dependency (terrain and/or
building downwash, or source is a rectangular area source). REFINE is executed after PROBE
or FLOWSECTOR. FUMIGATE and SHORELINE are executed, if chosen, after REFINE.
Details about each section and the final output of AERSCREEN are described in each of the
following sections.
3.5 PROBE
PROBE executes AERMOD for each combination of temporal periods and spatial sectors. For
example, if user defined surface characteristics are used (annual, 1 spatial sector), AERMOD is
46
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executed once (Figure 30a). If monthly, 12 spatial sector AERSUKFACE output is used, then
AERMOD is executed 144 times, 12 months x 12 sectors (Figure 30b).
Running probe for Annual sector 1
a
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for January
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
Running probe for December
sector 1 ,
sector 2 "
sector 3
sector 4
sector 5
sector 6
sector 7
sector 8
sector 9
sector 10
sector 1 1
sector 12
sector 1
sector 2
sector 3
sector 4
sector 5
sector 6
sector 7
sector 8
sector 9
sector 10
sector 1 1
sector 12
Figure 30. Sequence of AERMOD runs in PROBE for different surface characteristics
combinations.
AERSCREEN reads the output from AERMOD for each run and the highest concentration and
its distance from the source are stored in arrays that will be used to find the highest overall
concentration in REFINE. AERSCREEN also retains the high first high (H1H) 1-hour
concentration for each receptor. These concentrations are later used in determining the
maximum concentration by downwind distance.
3.6 FLOW SECTOR
FLOWSECTOR is executed when there is a source-receptor direction dependency (terrain and/or
building downwash, or rectangular area source).
If terrain is to be used, AERSCREEN checks for the presence of output from a previous
AERMAP run. If there is output available, AERSCREEN checks the following against the same
parameters in the current AERSCREEN run:
source location
probe distance
minimum ambient distance
47
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receptor spacing
number of receptors
NAD datum
UTM zone
Type (DEM or NED files), number and names of terrain input files
If all of the above parameters match between the existing AERMAP output and the
current AERSCREEN run, AERSCREEN then checks the receptor coordinates in the
previous AERMAP run to ensure the distances and directions match the receptor spacing
of the current run and that all 36 radial directions are included. This step is done in case
the file was changed or corrupted without the user's knowledge or if different discrete
receptors are used, but the number of receptors has not changed.
If any of the above parameters differ, AERMAP will be executed to create new receptor
elevations. If all parameters match, the user is prompted to decide to use the elevations from the
previous output, or to run AERMAP to create new elevations. If the older AERMAP output is
for a source type different than the one being processed in the current run, the user may want to
consider re-running AERMAP. AERSCREEN sets the ANCHORXY, x=0 and y=0 to the source
location and receptor locations are relative to this location. For volume and circular area
sources, this represents the center of the source. For point and flare sources, this is the stack
location.
If AERMAP is run in FLOW SECTOR, AERSCREEN will calculate a domain for the receptor
grid to include with the DOMAINXY keyword in the AERMAP.INP file that AERSCREEN
generates to run AERMAP. This will speed up processing, especially if large terrain files are
used. For FLOW SECTOR, the domain is 1.1 times the probe distance.
After running AERMAP for the receptor elevations, AERSCREEN checks the AERMAP.OUT
file for any warnings or errors. If any are found, they are written to the AERSCREEN log file
and AERSCREEN stops processing.
3.6.1 Rectangular area sources
For rectangular area sources, the angle of the diagonal is calculated from the center to the corner
of the rectangle. Next, radials are calculated every five degrees, beginning with 0 degrees up to
the nearest 5 degrees past the diagonal. For example, if the diagonal of the source was found to
be 26 degrees, radials are calculated for 0, 5, 10, 15, 20, 25, and 30 degrees, as shown in Figure
31.
48
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400 r
300
200
§ 100
-100
-200
30 deg.
diagonal
-400 -300 -200 -100
0 100 200
X distance
300
400
500
600
Figure 31. Receptor radials for rectangular area sources.
For each one of these radials, receptors are placed out to the probe distance at the calculated
spacing(s). For each radial, the WDROTATE keyword is used in the ME pathway of the
AERMOD runstream input file with the value set to the angle of the radial (0, 5, 10, etc.). See
Figure 32 for examples.
49
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ME STARTING
SURFFILE AERSCREEN.SFC FREE
PROFFILE AERSCREEN.PFL FREE
SURFDATA 11111 2010 SCREEN
UAIRDATA 22222 2010 SCREEN
PROFBASE 18.3 METERS
MEWDROTATE 0.0
ME FINISHED
ME STARTING
SURFFILE AERSCREEN.SFC FREE
PROFFILE AERSCREEN.PFL FREE
SURFDATA 11111 2010 SCREEN
UAIRDATA 22222 2010 SCREEN
PROFBASE 18.3 METERS
MEWDROTATE 10.0
ME FINISHED
ME STARTING
SURFFILE AERSCREEN.SFC FREE
PROFFILE AERSCREEN.PFL FREE
SURFDATA 11111 2010 SCREEN
UAIRDATA 22222 2010 SCREEN
PROFBASE 18.3 METERS
MEWDROTATE 5.0
ME FINISHED
ME STARTING
SURFFILE AERSCREEN.SFC FREE
PROFFILE AERSCREEN.PFL FREE
SURFDATA 11111 2010 SCREEN
UAIRDATA 22222 2010 SCREEN
PROFBASE 18.3 METERS
MEWDROTATE 15.0
ME FINISHED
Figure 32. ME pathway in the AERMOD runstream with WKDOTATE keyword and
values for various angles.
The WDROTATE keyword rotates the wind to be along the radial being processed in AERMOD
because the wind direction in the meteorological files is 270 degrees. Receptor x and y
coordinates are also calculated based on the angle of the radial, i.e. for the 10 degree radial at 50
m x=49.24 m, y=8.68 m. AERMOD is run for each of the radials for each surface characteristic
temporal/spatial sector combination. In the example in Figure 28, for annual surface
characteristics for the whole 360 degree sector, AERMOD is executed seven times, once for each
radial. For seasonal surface characteristics for 2 spatial sectors, AERMOD is executed 56 times,
once for each radial for each season and sector. For monthly surface characteristics with the
maximum 12 sectors for surface roughness, AERMOD is executed 1,008 times, once for each
radial, month, and surface roughness sector. Figure 33 shows sample AERMOD run sequences
for seasonal, 12 sector surface characteristics for a rectangular area source with six radials. First,
winter surface characteristics for sector 1 are used for each of the six radials. Next, winter
surface characteristics for sector 2 are used for each of the six radials. This process is followed
for each season and surface characteristic sector finishing with autumn sector 12 surface
characteristics. For each temporal/sector combination, AERSCREEN then determines the worst
case concentration, associated radial, and meteorology to be used later in the REFINE stage.
50
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Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Winter
surface roughness
wind
wind
wind
wind
wind
wind
flow
flow
flow
flow
flow
flow
sector
sector
sector
sector
sector
sector
surface roughness
wind
wind
wind
wind
wind
wind
flow
flow
flow
flow
flow
flow
sector
sector
sector
sector
sector
sector
surface roughness
wind
wind
wind
wind
wind
wind
flow
flow
flow
flow
flow
flow
sector
sector
sector
sector
sector
sector
sector 1
1
2
3
4
5
6
sector 2
1
2
3
4
5
6
sector 12
1
2
3
4
5
6
Autumn
surface roughness
wind
wind
wind
wind
wind
wind
flow
flow
flow
flow
flow
flow
sector
sector
sector
sector
sector
sector
sector 12
1
2
3
4
5
6
Figure 33. AERMOD run sequences for rectangular area source for seasonal 12 sector
surface characteristics.
51
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3.6.2 Non-rectangular area sources
For non-rectangular area sources, FLOWSECTOR arranges receptors along 36 radials from the
source, every 10 degrees, shown below in Figure 34. AERMOD is executed for each temporal
period (annual, seasonal, or monthly) of the surface characteristics (Figure 35). However, it is
not executed for each surface roughness sector. Instead, for each radial, AERSCREEN
determines the upwind surface roughness sector of the radial being processed. That is,
AERSCREEN determines the sector that contains the direction 180 degrees from the radial being
processed. That is done because the radial is considered in the direction of the flow while
surface characteristics are for the sector from which the wind is blowing, i.e. upwind. Figure 36
shows which sector is used for the 10 degree flow vector (solid black arrow) for three sectors
from AERSURFACE output. In this case, the upwind direction of 10 degrees, 190 degrees
(dashed black arrow), is contained in the 90 to 225 surface roughness sector.
600
400
200
-200
-400
-600
340
3^0
360
210
200
190
-600
-400
-200
200
400
600
Figure 34. Receptor placement for point (including capped and horizontal stacks), flare,
volume, or circular area sources in FLOWSECTOR.
52
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Processing Winter
Processing wind flow sector 10
Processing wind flow sector 20
Processing wind flow sector 30
Processing wind flow sector 40
Processing wind flow sector 360
Processing Spring
Processing wind flow sector 10
Processing Autumn
Processing wind flow sector 10
Processing wind flow sector 20
Processing wind flow sector 30
Processing wind flow sector 40
Processing wind flow sector 360
Figure 35. AERMOD sequence for seasonal 12 sector surface characteristics when
processing terrain and/or building downwash.
Figure 36. Flow vector (solid arrow) of 10 degrees and associated upwind surface
roughness sector for three surface roughness sectors (0 to 90, 90 to 225, 225 to 0).
53
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If building downwash is considered, projected building dimensions calculated by BPIPPRM for
the flow direction being modeled are included in the AERMOD run. If terrain is processed,
AERSCREEN will find the appropriate receptors (based on distance and direction) from the
AERMAP output and include the appropriate terrain data in the AERMOD input file.
AERSCREEN also checks to ensure the receptor coordinates match the specified distance and
direction. If they do not, AERSCREEN will issue an error and stop processing. Since
AERSCREEN generates the receptor elevations via AERMAP, this should not happen, unless
the AERMAP output file became corrupted during processing. When extracting the appropriate
receptors, if any receptors have a missing elevation, i.e. -9999.0, AERSCREEN will skip those
receptors and they will not be included in the AERMOD run for that particular direction.
AERSCREEN will notify the user of how many receptors were skipped for the particular
AERMOD run (Figure 37a). If any receptors did have missing elevations, the warning messages
for those receptors will appear in the AERSCREEN.LOG file for the AERMAP quality
assurance check (Figure 37b). AERSCREEN will notify the user of the total number of
receptors skipped for FLOWSECTOR at the end of the AERSCREEN run (Figure 37c). If the
user finds that receptors have been skipped due to missing elevations, the user may want to
check the input terrain files for gaps or other irregularities or reconsider the probe distance, as
this can affect the final maximum 1-hour concentration from AERSCREEN.
54
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RunningAERMOD
Processing Winter
Processing wind flow sector 10
AERMOD Fin ish es Su ccessfully for FLOWSECTOR stage 2 Winter sector 10
0 receptors skipped due to missing elevations
Processin g win d flow sector 150
AERMOD Finishes Successfully for FLOWSECTOR stage 2 Winter sector 150
8 receptors skipped due to missing elevations
Processing wind flow sector 160
AERMOD Finishes Successfully for FLOWSECTOR stage 2 Winter sector 160
7 receptors skipped dueto missing elevations
RunningAERMAP for FLOWSECTOR
*** AERMAP Finishes Successfully*** for stage 2
******** WARNING MESSAGES *******
OU W400 7265 FIND4:Receptor Location Outside Range of Profiles, IREC= 2997
OUW410 7265 MAIN:Receptor Elevation is Missing (-9999.0), IREC= 2997
OU W400 7265 FIND4:Receptor Location Outside Range of Profiles, IREC= 2998
OUW410 7265 MAIN;Receptor Elevation is Missing (-9999.0), IREC= 2998
OUW410 7265 MAIN:Receptor Elevation is Missing (-9999.0).
51 receptors have missing elevations
and will be skipped in AERMOD processing
IREC= 4210
AERSCREEN Finished Successfully
But with Warnings
51 receptors skipped for FLOWSECTOR
0 receptors skipped for REFINE
Check log file for details
Figure 37. Receptor skipping notification during FLOWSECTOR run, with notification of
missing elevations in AERMAP, and total number of receptors skipped for
FLOWSECTOR and REFINE.
For each AERMOD run in FLOWSECTOR, the maximum concentration, downwind distance,
and terrain (if applicable) are stored for later use in REFINE. The stored concentrations are
concentrations for each radial and temporal period of the surface characteristics.
3.7 REFINE
REFINE finds the maximum concentration and associated distance and date output from PROBE
or FLOWSECTOR. If output is from PROBE or a rectangular area source from
FLOWSECTOR, REFINE uses the meteorological files for the temporal period and surface
55
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roughness sector of the maximum concentration. If output is from FLOW SECTOR for non-
rectangular area sources, REFINE finds the upwind surface characteristic sector of the flow
direction of maximum concentration as in Figure 36. REFINE then uses the meteorological files
for the appropriate temporal and surface characteristics sector. Receptor spacing becomes one,
two, or five meters, depending on maximum concentration distance, to refine the output. For
rectangular area sources, the receptors are placed along the radial associated with the maximum
concentration. Any discrete receptors supplied by the user are not included in the REFINE
AERMOD run. If building downwash is used, building dimensions based on the flow direction
of maximum concentration are used. If terrain is used, REFINE will rerun AERMAP with the
new receptors in the flow direction of the maximum concentration output from FLOWSECTOR.
As in FLOWSECTOR, REFINE will create a domain to be used with the DOMAINXY keyword
in AERMAP. After running AERMAP, REFINE then runs AERMOD using the new receptors
and appropriate meteorological, building and terrain data. As with FLOWSECTOR, if any
receptors have a missing elevation, they will be skipped, and the user will be notified of how
many were skipped (see Figure 37c for example).
3.8 Fumigation
The optional fumigation calculations, inversion break-up and shoreline fumigation are based on
the equations implemented in SCREENS (U.S. EPA, 1995). The inversion break-up calculations
are based on procedures described in Turner (1970). Fumigation calculations are only made for
point type sources, including flares, with release heights 10 m or more above ground level.
3.8.1 Selection of meteorological data
Before fumigation calculations are performed, AERSCREEN determines the appropriate hours
to use from the meteorological data created by MAKEMET. For the fumigation calculations, the
fumigations are based on assumptions of F stability and a stack top wind speed of 2.5 m/s (U.S.
EPA, 1995). Also, for the fumigation calculations AERSCREEN assumes the source is a rural
source, ignores building downwash, and ignores terrain effects.
AERSCREEN reads the meteorological data files that are created as described in Section 3.2 of
this document. Using various meteorological variables, AERSCREEN determines a stability
class (A, B, C, D, E, or F) and stack top wind speed. For those hours that meet the criteria of F
stability and stack top wind speed of 2.5 m/s, AERSCREEN calculates an array of variables that
will be needed for the fumigation calculations.
If no hours meet the stability and wind speed criteria, AERCREEN issues a notice that no hours
meeting the criteria and fumigation calculations are not performed. Otherwise, AERSCREEN
proceeds with the calculations.
56
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3.8.2 Inversion break-up fumigation
Inversion break-up fumigation in AERSCREEN uses the inversion break-up fumigation
equations from SCREENS (U.S. EPA, 1995) which are based on Turner (1970). For the
fumigation calculations, the distance to maximum fumigation is based on an estimate of the time
required for the mixing layer to develop from the top of the stack to the top of the plume is
calculated by:
Xmax = (upacp/K)(A0/Az)(/ii - hMht ~ hs}/2\ (3)
where:
Xmax=distance to maximum concentration (m)
u= stack top wind speed (2.5 m/s)
pa=ambient air density (1205 g/m3 at 20°C)
cp=specific heat of air at constant pressure (0.24 cal/gK)
R=net rate of sensible heating of an air column by solar radiation (67 cal/m2/s)
A0/Az=potential temperature gradient (0.035 K/m for F stability)
h;=height of the top of the plume (he + 2oze) where he is the plume centerline height (m)
hs=physical stack height or release height (m)
Gze=vertical dispersion parameter incorporating buoyancy induced dispersion (m)
and the maximum concentration is calculated as:
Xf = Q/[(2ii}0*u(aye + he/Q)(he + 2aze}\ (4)
where:
Xf=maximum ground level concentration due to inversion break-up fumigation (|j,g/m3)
Q=emission rate in g/s
u=stack top wind speed (2.5 m/s)
aye=horizontal dispersion parameter incorporating buoyancy induced dispersion (m)
Other parameters are defined as in Equation 3. To calculate Xmax, AERSCREEN uses an
iterative approach to solve Equation 3, beginning with an initial value of 5,000 m. This iteration
is done for each hour of appropriate meteorology. Once Xmax is found, Xf is calculate for the
hour using Equation 4. After all hours have been processed, the highest value of Xf is the
maximum ground level concentration.
3.8.3 Shoreline fumigation
AERSCREEN will calculate shoreline fumigation for sources within 3 km of the coastline.
Again, AERSCREEN incorporates the calculations from SCREEN (U.S. EPA 1995). The
assumptions in the calculations are described in Section 3.8.1 above, F stability and onshore flow
57
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of 2.5 m/s at stack top. The maximum ground-level shoreline fumigation concentration is
assumed to occur where the top of the stable plume intersects the top of the well-mixed thermal
internal boundary layer (TIBL). The TIBL height for rural flat terrain as a function of inland
distance can be estimated by:
hT = Ax°* (5)
where:
hT=TIBL height (m)
A= TIBL factor containing physics needed for TIBL parameterization (including heat flux)
(m1/2) set to 6 (U.S. EPA, 1995).
x=inland distance (m)
As with the inversion break-up fumigation, the distance to the maximum concentration due to
shoreline fumigation is an iterative process for each hour. The distance, Xmax is found by:
Xmax = [(he + 2aze)/6j2 - xs (6)
Where xs is the shoreline distance and all other variables are defined as in Section 3.8.2. The
maximum concentration at Xf is found by:
Xf = Q/[(2n)°-5u(aye + he/Q)(he + 2aze)\ (7)
Where
Xf=maximum ground level concentration due to shoreline break-up fumigation (|j,g/m3) and all
other variables defined as above.
Before proceeding with the shoreline fumigation calculations, AERSCREEN determines if any
of the meteorological hours determined in Section 3.8.1 or hours that match upwind surface
characteristics from the shoreline have a plume height above the TIBL height by calculating the
distance at which the effective stack height is equal to the TIBL height and taking the difference
with the shoreline distance to calculate xo:
x0 = (he/6~)2-xs (8)
If xo is less than zero for all relevant hours then the plume is considered to be below the TIBL
height for the shoreline distance xs and no shoreline fumigation calculations will be performed at
all. If xo is greater than zero for any relevant hour then shoreline fumigation calculations will
proceed.
As with inversion break-up fumigation, to calculate Xmax for shoreline fumigation AERSCREEN
uses an iterative approach to solve Equation 6, beginning with an initial value of equal to xo
(Equation 8) that is calculated for the particular hour being processed. This iteration is done for
each hour of appropriate meteorology. Once Xmax is found, Xf is calculate for the hour using
Equation 7. After all hours have been processed, the highest value of Xf is the maximum ground
level concentration for shoreline fumigation.
58
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3.8.4 AERSCREEN run option
Beginning with version 15181, when the interest is only in the fumigation concentrations,
AERSCREEN allows the option of skipping the screening modeling portion of AERSCREEN
(PROBE, FLOWSECTOR, and REFINE) to save processing time.
3.9 Outputs
AERSCREEN creates the file AERSCREEN.OUT or user-supplied output filename which
contains the following: source information, output from either PROBE or FLOWSECTOR,
meteorology associated with the maximum concentration output from PROBE or
FLOWSECTOR, maximum concentrations by distance, REFINE output (final maximum
concentration and maximum concentration at the minimum ambient distance), and optional
fumigation results. See Section 4 for example output. AERSCREEN also outputs a file called
max_conc_distance.txt, or name based on the user-supplied output filename, that contains the
highest concentration by distance, independent of worst case meteorology and flow direction,
with associated meteorology for the concentrations. These concentrations were calculated in
PROBE or FLOWSECTOR. Also included in the file is the overall maximum concentration
output from REFINE. This concentration is denoted by an asterisk in the file. The format of this
file is shown in Table 2. If the optional debug output is chosen a file containing PROBE or
FLOWSECTOR results is created and has a similar format to the max_conc_distance.txt file
with the exception that for AREA sources, the individual diagonal angles are listed. If
fumigation options are chosen along with the debug option, a fumigation debug file will be
created with the intermediate fumigation calculations. AERSCREEN also copies the
AERMOD.INP file from the REFINE AERMOD run to the file AERSCREEN.INP, containing
the inputs to AERSCREEN entered via prompts or a previous AERSCREEN.INP file with any
changes that were made during AERSCREEN processing2. AERSCREEN also copies the
AERSCREEN.INP and AERSCREEN.LOG files to new files with names based on the user-
supplied filename.
2 If at any time, AERSCREEN aborts during PROBE, FLOWSECTOR, or REFINE, the user may be able to copy
the current AERMOD.INP file to AERSCREEN.INP to avoid re-entering data.
59
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Table 2. Variables listed in max cone distance.txt.
Variable
Concentration
Distance
Elevation
Flow
Season/Month
Zo sector
Date
HO
U*
W*
DT/DZ
ZICNV
ZIMCH
M-O LEN
ZO
Bo wen
Albedo
REFWS
HT
REFTA
HT
Description
Maximum 1-hour screening concentration (|ig/m3). A concentration with a
preceding asterisk is the overall maximum concentration.
Distance (m) from source of maximum 1-hour concentration
Elevation (m) of maximum 1-hour concentration
Flow vector (degrees) associated with maximum 1-hour concentration
Season/Month of maximum 1-hour concentration (can be annual, season, or
month)
Surface roughness sector number of maximum 1-hour concentration
Date of maximum 1-hour concentration
Heat flux (W/m2)of hour of maximum 1-hour concentration
Friction velocity (m/s) of hour of maximum 1-hour concentration
Convective velocity (m/s) of hour of maximum 1-hour concentration
Lapse rate (K/m) of hour of maximum 1-hour concentration
Convective mixing height (m) of hour of maximum 1-hour concentration
Mechanical mixing height (m) of hour of maximum 1-hour concentration
Monin-Obukhov length (m) of hour of maximum 1-hour concentration
Surface roughness length (m) of hour of maximum 1-hour concentration
Bowen ratio of hour of maximum 1-hour concentration
Albedo of hour of maximum 1-hour concentration
Wind speed (m/s) of hour of maximum 1-hour concentration
Anemometer height (m) of hour of maximum 1-hour concentration
Temperature (K) of hour of maximum 1-hour concentration
Height of Temperature (m) of hour of maximum 1-hour concentration
60
-------
4. Example run
This section will show an example AERSCREEN run for a point source with building downwash
and terrain. Inversion break-up fumigation will also be selected as well as the output of a debug
file. Table 3 gives a summary of the AERSCREEN inputs and Figure 38 shows the
building/stack orientation. Table 4 lists the seasonal surface characteristics and Figure 39 shows
the land use and terrain for the example. Figure 40 lists the inputs for demlist.txt and Figure 41
lists the discrete receptor file contents.
Table 3. Inputs for example AERSCREEN run.
Parameters
Source
Building
Meteorology
Terrain
Discrete
receptors
Other inputs
Fumigation
Debug option
Output file
Inputs
Source type
Stack height
Emission rate
Stack diameter
Stack exit temperature
Stack exit velocity
Include building downwash
Building height
Maximum horizontal dimension
Orientation of maximum building dimension to North
Minimum horizontal dimension
Direction of stack from North
Distance from stack to building center
Minimum temperature
Maximum temperature
Minimum wind speed
Anemometer height
Source of surface characteristics
Include terrain
Coordinate type
Source latitude
Source longitude
NAD
Probe distance
Source elevation
Override input elevation with AERMAP derived value
Use five discrete receptors, units in meters
Input units
Rural/urban
Input population
Minimum ambient distance
Use flagpole receptors
Inversion break-up
Shoreline fumigation
Yes
Use non-default name
Input values
POINT
20m
Ig/s
0.5m
300 K
15m/s
Yes
34m
120m
90°
60m
26.6°
67m
261.4
313.1
1.5 m/s
10m
AERSURFACE (aersurface 12.out)
Yes
Latitude and longitude (LATLON)
35. 891400° N
78.781940° W
83
1km
126.8
No
discrete_receptors.txt
Metric
Urban
2400000
30m
No
Yes
No
aerscreen_example.out
61
-------
o
<£>
N '
stack
26.6C
120m
Figure 38. Plane view of building and stack orientation for example AERSCREEN run.
62
-------
Table 4. Seasonal surface characteristics by sector.
Variable
Albedo
Bowen
ratio
Surface
roughness
Season
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Sector
1
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.089
0.118
0.143
0.123
2
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.011
0.016
0.022
0.016
3
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.025
0.032
0.038
0.032
4
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.029
0.036
0.043
0.036
5
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.032
0.04
0.048
0.041
6
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.034
0.042
0.049
0.042
7
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.031
0.038
0.045
0.038
8
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.013
0.019
0.025
0.019
9
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.115
0.141
0.163
0.142
10
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.244
0.289
0.335
0.311
11
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.391
0.458
0.509
0.478
12
0.15
0.14
0.15
0.15
0.85
0.63
0.36
0.84
0.305
0.379
0.435
0.405
63
-------
a
Legend
^B .'.".: .'-
j H^h rtwtMy reader*.*
irtr an5eort.it!
]M
j^B Row oops
j^B Urban/cecreaftonai grasses
- ..... ." :
H Enwfger* hnbxcous
Legend
Wgh MS 30KT3
Figure 39. a) land use pattern and sectors used for surface characteristics and b) terrain.
The circle represents the 1 km radius from the source.
NED :
NADGRIDS A
NED 22944813\NED 22944813.tif
Figure 40. Contents ofdemlist.txt for terrain processing.
64
-------
units: METERS
53
105
201
503
702
Figure 41. Contents ofdiscrete_receptors.txt.
4.1 Processing and log file
Below in Figures 42 through 47 are the prompts and inputs for the source, building information,
terrain data and meteorological data. In Figure 39, the initial prompts are shown. Since there is
no existing AERSCREEN.INP file, AERSCREEN alerts the user that AERSCREEN.INP does
not exist and the user must enter the data. The user enters a title, whether the inputs are in
English or metric units, and the source type (point, volume, etc.).
Command Prompt - aerscreen
H S3
flERSCREEN 15181
flERSCREEN.INP does not exist
User must enter data
INITIAL INFORMATION
Enter Title: Example stack
English or Metric Units? : n
POINT, UOLUME, flREfl, flREflCIRC, FLflRE, POINTCflP,or POINTHOR Source?
: p
Figure 42. Initial AERSCREEN title, units, and source type prompts.
After the initial prompts, the user then enters source parameters (Figure 43). The stack
parameters, stack height, inner stack diameter, stack exit temperature, stack velocity units, and
stack velocity. The user also enters if the source is urban or rural, and the urban population if an
urban source. The user then enters the minimum distance to ambient air, i.e. ambient boundary.
Values entered are as described in Table 3.
65
-------
Command Prompt - aer^creen.exe
AERSCREEN 15181
SOURCE INFORMATION
Enter Emission Rate (g/s): 1.0
Enter Stack Height (meters): 20.0
Enter Stack Diameter (meters}: 0.5
Enter Stack Temperature
Enter 0 for ambient temperature
or a negative number for tenperature difference «1O)
between stack temperature and ambient temperature: 300
Option <1> - Exit Uelocity
Option <2> - Exit Uelocity
Option <3> - Flou Rate
Enter Option for Flow Rate or Exit Uelocitii: 1
Enter Exit Uelocity : 15
Rural or Urban? : u
Enter Population of Urban Area: 2400000
Enter Minimum Distance to Ambient Air
for default <1 m>: 30
Enter an option for modeling N02 chemistry
1) No chemistry or pollutant is not N02
2> Use Ozone Limiting Method
3> Use Plume Uolume Molar Ratio Method
Figure 43. Source parameter inputs.
After source parameters have been entered, the user enters the building parameters for building
downwash effects (Figures 44 and 45). In Figure 44, the initial prompts are shown. The user is
prompted to include downwash if desired and if so, the user is prompted if an existing BPIPPRM
input file is to be used. If the answer is yes to downwash but no to an existing BPIPPRM file,
the user is then prompted for the building dimensions, building orientation, and stack orientation
relative to the building (Figure 45). The inputs are building height, maximum horizontal
dimension, minimum horizontal dimension, angle of maximum horizontal dimension to North,
angle of stack from North, and distance between stack and building center. Building dimensions
are shown in Table 3 and Figure 38.
66
-------
Command Prompt - aer:creen.exe
flERSCREEN 15181
BUILDING DOUHUflSH INFORMflTION
Include Building Dounuash? : y
Use pre-existing BPIPPRM input file? <.y/n>- n
Figure 44. Initial building downwash prompts.
Command Prompt - aerscreen.exe
flERSCREEN 15181
BUILDING DOUNUflSH INFORMATION
Enter Building Height : 34
Enter Maximum Horizontal Building Dimension : 120
Minimum Horizontal Building Dimension (meters>: 60
Enter Maximum Building Dimension Angle to True North (0 179 degees): 90
Enter Direction of Stack from Building Center <0 360 degrees): 26.6
Enter Distance Between Stack and Building Center : 67
Figure 45. Building parameter inputs.
The next set of inputs is for terrain (Figure 46). The user is prompted if terrain is to be used.
The user is then prompted for the probe distance with a default of 10 km available. Note, that
the terrain input file or files (NED or DEM), must encompass the probe distance. Following the
probe distance, the user is prompted for the use of discrete receptors and then the user is
prompted for the use of flagpole receptors and if so, the flagpole height. After the flagpole
information, the source elevation is input by the user. This can be an elevation or the user can hit
to use AERMAP to calculate elevation. In this case, the user has entered 126.8 m. Note
if terrain is not used, this is the last prompt in the terrain section of inputs. If terrain is to be
used, the user enters the coordinate type and coordinates. The NAD datum is also entered by the
user. If coordinates are UTM coordinates, the user will be prompted for the UTM zone. Since
geographic coordinates are used in this example, the UTM zone is determined by AERMAP.
67
-------
Command Prompt - aer5creen.exe
AEFSCFEEN 1E181
TEFFAIN HEIGHT INFOFMATION
Include Terrain Heights? f.y/n~>- y
Enter Maxinun Distance (m) to probe
for default <10000 m>: 1000
Include up to 10 discrete receptors ? y
Enter name of file with discrete receptors.
Enclose filenane uith quotes if path or filename includes spaces.
discrete_receptors.txt
Use Flagpole receptors? : n
Enter source elevation or
for flEFMflP derived elevation: 126.8
Enter coordinate type:
LfllLON for latitude & longitude or
UTM for UTM coordinates
latIon
Enter Source Latitude (North positive) : 35.8914
Enter Source Longitude : -78.78194
Option <1> - North American Datum of 1927
Option <4> - North American Datum of 1983
Enter Option for Applicable UTN Nada:
Figure 46. Terrain parameter prompts.
The meteorological parameters are the next inputs by the user (Figure 47). The user enters the
minimum and maximum air temperatures for the AERSCREEN run or accepts defaults of 250
and 310 K. The user then enters the minimum wind speed and anemometer height. For this
example, a minimum of 1.5 m/s was selected for the wind speed and the default 10 m
anemometer height was entered. After the anemometer height, the surface characteristics type,
user-entered single values (option 1), AERMET seasonal tables (option 2), or use of an external
file (option 3) is chosen. Option 3, an external file, is chosen by the user and the user then enters
the filename. The file is in the same folder as the current working directory so no pathnames are
necessary. Figures 48 and 49 show the fumigation inputs and debug selection respectively.
After processing the debug option, the user is prompted for the name of the output file (Figure
50).
68
-------
Command Prompt- aerscreen.exe
flEFSCREEN 15181
MflKEMET METEOROLOGY
Enter Min & Max finbient Temperatures
Or to default to 250 310 K...
Enter Minimum Temperature : 261.4
Enter Maximum Temperature : 313.1
Enter Minimum Uind Speed or to default to 0.5 m/s... 1.5
Enter Anemometer Height or to default to 10.0 meters...
1> Single user specified values
2> flERMET seasonal tables
3> External file
Enter surface characteristics option: 3
Enter filename containing surface characteristics
Enclose filename with quotes if path or filename includes spaces...
or to return to the surface characteristics option selection
aersurface_J.2.out
Figure 47. Meteorological parameter prompts and inputs.
Command Prompt - aerscreen
AERSCREEN 15181
FUMIGATION
Source is an urban source, will assume rural for fumigation calculations
Apply inversion break-up fumigation : y
Apply shoreline fumigation : n
Figure 48. Fumigation prompts.
69
-------
Command Prompt - aer^creen
flERSCREEN 15181
Enter V or y to turn on the debug option or to not use the debug option
Figure 49. Debug option input.
Command Prompt - aerscreen
flERSCREEN 15181
enter nane of aerscreen output file
enter to use default nane aerscreen.out
filename should include .out or .out extension
if filenane contains spaces, enter entire filename in quotations
aerscreen_exanple.out
Figure 50. Output filename prompt and response.
Finally after the output file options, the validation page is displayed to the user listing all input
parameters for the source, building downwash, terrain, and meteorological data (Figure 51). The
source and building parameters are listed in both metric and English units as well as the
minimum and maximum temperatures, source elevation and probe distance. AERSCREEN also
displays the UTM and geographic coordinates for the source with the message that coordinates
were converted from geographic to UTM coordinates. Coordinates are displayed in NAD datum
of 1983. If coordinates were initially entered in NAD 1927 datum, those coordinates would be
listed as well with the message that coordinates were switched from NAD 27 to NAD 83 with
the NAD 27 geographic and UTM coordinates listed as well. The validation page indicates that
inversion break-up fumigation calculations will be performed and that the urban source will be
assumed to be rural for fumigation. Meteorological data are listed followed by the message that
the debug option is on and the name of the output file. The options listed below the output
filename can be used to change parameters for the source, building, terrain, meteorological data,
fumigation options, run title, debug option, and output filename. If options 1 through 6 are
chosen, the user then sees a sub-menu of parameters to choose (See Section 3). If the user is
ready to proceed, the user enters and AERSCREEN begins processing the data. After
choosing to run AERSCREEN, the same data as seen on the validation page is written to the
AERSCREEN.LOG file (Figure 52).
70
-------
Command Prompt - aerncreen
DflTfl j
METRIC
*» STACKDATA «*
VALIDATION -
ENGLISH
Emission Rate:
Stack Height:
Stack Diameter:
Stack Temperature:
Exit Uelocity:
Stack Flow Rate:
Model Mode:
Population:
Dist to Ambient Air
** BUILDING DATA
1.0000 g/s
20.00 meters
0.500 neters
300.0 1C
15.000 n/s
6240 fiCFM
URBAN
2400000
30.0 neters
7.937 lb/hr
65.62 feet
19.69 inches
80.3 Deg F
49.21 ft/s
Building Height: 34.0 neters
Max Building Dimension: 120.0 neters
Min Building Dimension: 60.0 neters
Building Orientation: 90.0 degrees
Stack Direction: 26.6 degrees
Stack Distance: 67.0 neters
98. feet
111.5 feet
393.7 feet
196.9 feet
219.8 feet
** TERRAIN DflTfl **
Input coordinates switched fron geographic to UTM
Source Longitude: -78.78194 deg 700198. Easting
Source Latitude: 35.89140 deg 3974176. Northing
UTM Zone: 17 Reference Datun: 4 to Start Run
Figure 51. Data validation page.
71
-------
Start date and time 06/26/15 11:01:14
AERSCREEN 15181
DATA ENTRY VALIDATION -
METRIC ENGLISH
** STACKDATA **
Emission Rate: 1.0000 g/s
Stack Height: 20.00 meters
Stack Diameter: 0.500 meters
Stack Temperature: 300.0 K
Exit Velocity: 15.000 m/s
Stack Flow Rate: 6240 ACFM
Model Mode: URBAN
Population:
** BUILDING DATA **
Building Height: 34.0 meters
Max Building Dimension: 120.0 meters
Min Building Dimension: 60.0 meters
Building Orientation: 90.0 degrees
Stack Direction: 26.6 degrees
** TERRAIN DATA **
Input coordinates switched from geographic to UTM
Source Longitude: -78.78194 deg 700198. Easting
Source Latitude: 35.89140 deg 3974176. Northing
UTM Zone: 17 Reference Datum: 4 (NAD 83)
Source Base Elevation: 126.8 meters 416.0 feet
** FUMIGATION DATA **
Urban source, assume rural for fumigation
Inversion break-up fumigation reguested
** METEOROLOGY DATA **
Min/Max Temperature: 261.4 / 313.1 K 10.9 / 103.9 Deg F
Minimum Wind Speed: 1.5 m/s
Anemometer Height: 10.000 meters
AERSCREEN output file:
aerscreen_example.out
*** AERSCREEN Run is Ready to Begin
Terrain to be used,AERMAP will be run
Figure 52. Input data in AERSCREEN.LOG.
72
-------
After data validation, AERSCREEN reads the AERSURFACE output file and lists the surface
characteristics (Figure 53).
SURFACE CHARACTERISTICS & MAKEMET
Obtaining surface characteristics . . .
Using seasonal surface characteristics for 12 spatial sector (s)
Sector Start End
1 0 30
2 30 60
3 60 90
4 90 120
5 120 150
6 150 180
7 180 210
8 210 240
9 240 270
10 270 300
11 300 330
12 330 0
Season Sector
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Spring
Spring
Autumn
Autumn
Creating met
Creating met
Creating met
Creating met
************
1
2
3
4
5
6
7
8
9
10
11
12
1
2
11
12
files
files
files
files
*****
Albedo
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.14
0.14
0.15
0.15
aerscreen
aerscreen
aerscreen
aerscreen
**********
Bo
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.63
0.63
0.84
0.84
01 01
01 02
04 11
04 12
******
zo
0.089
0.011
0.025
0.029
0.032
0.034
0.031
0.013
0.115
0.244
0.391
0.305
0.118
0.016
0.478
0.405
. sfc & aerscreen 01 01
. sfc & aerscreen 01 02
.sfc & aerscreen 04 11
.sfc & aerscreen 04 12
******************
.pfl
.pfl
.pfl
.pfl
Figure 53. Surface characteristics processing and meteorological files creation.
73
-------
AERSCREEN then runs AERMAP for the source and determines the percent difference between
the user-entered source elevation and the AERMAP derived elevation (Figure 54). The
AERMAP elevation will not be used by AERSCREEN. AERSCREEN also lists any fatal error
or warning messages from AERMAP. In this case warning messages about the use of default
elevation units of meters for the NED file are displayed. For the example case, the difference
between the AERMAP elevation, 120.98 m, and the user-entered elevation, 126.8 m, differ by
4.59%.
Running AERMAP for source
*** AERMAP Finishes Successfully *** for stage 0
******** WARNING MESSAGES ********
OU W473 26 NEDCHK:Default elevation units of METERS used; NED file: 1
AERMAP elevation, 120.98 differs from user entered elevation, 126.80 by 4.59^
Figure 54. AERMAP processing and elevation of source.
Once AERMAP has been run for the source, AERSCREEN then begins the FLOWSECTOR
stage and executes AERMAP for the receptors (Figure 55). While processing the receptors,
AERMAP writes the processing status to the screen (Figure 56). Once AERMAP is completed
for all receptors for all thirty-six directions, AERSCREEN checks the AERMAP.OUT file for
any warnings or errors (Figure 57).
Buildings and/or terrain present or rectangular area source, skipping probe
FLOWSECTOR started 06/26/15 11:03:13
***************************************************
Running AERMAP for FLOWSECTOR
Figure 55. AERSCREEN.LOG records for AERMAP processing for FLOWSECTOR.
74
-------
Command Prompt - aerscreen.exe
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Processing
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
Receptor
628 of
629 of
630 of
631 of
632 of
633 of
634 of
635 of
636 of
637 of
638 of
639 of
643 of
641 of
642 of
643 of
644 of
645 of
646 of
647 of
648 of
649 of
650 of
651 of
652 of
653 of
654 of
655 of
656 of
657 of
658 of
659 of
660 of
661 of
662 of
663 of
664 of
665 of
666 of
667 of
668 of
669 of
670 of
671 of
672 of
673 of
674 of
675 of
676 of
677 of
678 of
679 of
680 of
681 of
682 of
683 of
684 of
685 of
Figure 56. Status of AERMAP processing for FLOWSECTOR.
*** AERMAP Finishes Successfully *** for stage 2
******** WARNING MESSAGES ********
OU W473 1462 NEDCHK:Default elevation units of METERS used; NED file:
1
Figure 57. AERSCREEN.LOG summary of AERMAP.OUT warning and error messages.
75
-------
Figure 58 shows partial AERMAP output for FLOWSECTOR. It is from this output that
AERSCREEN will extract the receptor elevations for AERMOD processing in FLOWSECTOR.
Receptor spacing for this example was 25 m since the probe distance was less than 5 km.
Summing across all 36 radials, excluding receptors less than the minimum ambient distance,
including the ambient distance, discrete receptors, and the source location, results in 1,621 total
receptors. Also listed in the output is information that will be used for later AERSCREEN runs
to determine if AERMAP needs to be rerun for FLOWSECTOR. This includes the UTM
coordinates, probe distance (meters), receptor spacing, UTM zone, NAD datum, number of NED
files and number of receptors. Coordinates, probe distance, receptor spacing, UTM zone, and
NAD datum are listed in the line after "** Example stack."
* *
**
**
* *
* *
**
**
* *
* *
RE
AERMAP -
Example
700198
A total
A total
DOMAINXY
VERSION 11103
stack
.4 3974175.8
of 1
of 1621
699098
ANCHORXY 0
Terrain
ELEVUNIT
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
DISCCART
heights were
METERS
0.
5.
8.
9.
13.
17.
18.
21.
26.
30.
34.
34.
39.
1000.
NED files
receptors
0
were
were
.2 3973075.
.0
0.
extracted by
00
21
68
20
02
36
23
71
05
39
73
90
07
0.
29.
49.
52.
73.
98.
103.
123.
147.
172.
196.
197.
221.
5
0
25.0
used
processed
25.0
17 701298.2
700198.2
06/26/15
11:03:14
17 4
3975275.5 17
3974175.5 17 4
default
00
54
24
19
86
48
40
10
72
34
96
95
58
120.
119.
119.
119.
120.
120.
120.
120.
120.
119.
117.
117.
117.
98
75
60
84
82
82
81
73
36
77
76
69
96
120
119
119
119
120
120
120
120
120
120
120
120
117
98
75
60
84
82
82
81
73
36
36
49
49
96
Figure 58. Partial AERMAP output for FLOWSECTOR.
Once AERMAP has been run for all receptors, AERSCREEN processes each flow vector every
10 degrees from 10 degrees to 360 degrees. The appropriate building dimensions and
meteorological files are used for each flow vector. During processing, AERSCREEN notifies
the user what season or month and flow vector is being processed (Figure 59). A sample
AERMOD.INP file is shown in Figure 60 with projected building dimensions and receptors for a
particular flow vector. Note that the y-coordinate for each receptor is reset to 0. After
AERMOD is executed for each flow vector, AERSCREEN checks the AERMOD.OUT file and
notifies the user of any warning or error messages for that flow vector (Figure 61).
76
-------
Command Prompt- aerscreen
AERSCREEN 15181
DERIUING WORST CflSE FLOW SECTOR
Processing Winter
Processing Spring
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
Process
wind flow
uind flow
wind flow
uind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
wind flow
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
Processing wind flow sector 10
Processing wind flow sector 20
Figure 59. AERSCREEN processing during FLOWSECTOR.
77
-------
SO STARTING
LOCATION SOURCE POINT 0.0 0.0 126.80
SRCPARAM SOURCE 0.1000E+01 10.000 300.000 15.000 0.500
BUILDHGT SOURCE 36*34.00
BUILDWID SOURCE 36*133.28
BUILDLEN SOURCE 36*97.42
XBADJ SOURCE 36*-115.27
YBADJ SOURCE 36*7.70
URBANSRC SOURCE
SRCGROUP ALL
SO FINISHED
RE STARTING
** Fence line receptor
DISCCART 30.0 0.0 120.90 120.90
** Automatic receptors
DISCCART 50.0 0.0 120.84 120.84
DISCCART 53.0 0.0 120.88 120.88
DISCCART 75.0 0.0 121.31 121.31
RE FINISHED
Figure 60. Partial AERMOD.INP file used in FLOWSECTOR for 20 degree flow vector.
78
-------
Running AERMOD
Processing Winter
*****************************************************
Processing wind flow sector 10
AERMOD Finishes Successfully for FLOWSECTOR stage 2 Winter sector 10
0 receptors skipped due to missing elevations
******** WARNING MESSAGES ********
*** NONE ***
*****************************************************
*****************************************************
Processing wind flow sector 360
AERMOD Finishes Successfully for FLOWSECTOR stage 2 Autumn sector 360
0 receptors skipped due to missing elevations
******** WARNING MESSAGES ********
*** NONE ***
FLOWSECTOR ended 06/26/15 11:05:28
Figure 61. AERSCREEN.LOG partial output of AERMOD.OUT checks for
FLOWSECTOR.
After FLOWSECTOR, AERSCREEN enters the REFINE subroutine and calculates the overall
maximum concentration and its associated distance, flow vector, projected building dimensions,
terrain and meteorology. AERSCREEN then reruns AERMAP (Figure 62) and AERMOD with
refined receptor spacing using the terrain, projected building dimensions, and meteorology of the
maximum concentration's flow vector. The receptors include the minimum ambient receptor
and receptors near the maximum concentration with 1 to 5 m spacing. See Figure 63 for the
partial AERMOD.INP file used in REFINE. Messages from AERSCREEN.LOG for REFINE
are shown in Figure 64. The maximum concentration is along the 160 degree flow vector.
79
-------
Command Prompt - aerscreen
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Now Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Now Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
Now Processing Receptc
+Nou Processing Receptc
"-Now Processing Receptc
+Nou Processing Receptc
Now Processing Receptc
Nou Processing Receptc
-Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
'Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
+Nou Processing Receptc
Nou Processing Receptc
1-ssH
36 of
37 of
38 of
39 of
40 of
41 of
42 of
43 of
44 of
45 of
46 of
47 of
48 of
49 of
50 of
51 of
52 of
53 of
54 of
55 of
56 of
57 of
58 of
59 of
60 of
61 of
62 of
63 of
64 of
65 of
66 of
67 of
68 of
69 of
70 of
71 of
72 of
73 of
74 of
75 of
76 of
77 of
78 of
79 of
80 of
81 of
82 of
83 of
84 of
85 of
86 of
87 of
88 of
89 of
90 of
91 of
92 of
93 of
94 of
95 of
96 of
97 of
98 of
99 of
100 Of
101 Of
102 of
103 of
Figure 62. Status of AERMAP processing for REFINE.
80
-------
so
so
RE
STARTING
LOCATION
SRCPARAM
BUILDHGT
BUILDWID
BUILDLEN
XBADJ
YBADJ
URBAN SRC
SRCGROUP
FINISHED
STARTING
SOURCE
SOURCE
SOURCE
SOURCE
SOURCE
SOURCE
SOURCE
SOURCE
ALL
POINT 0.0 0.0 126.80
0.
36*
36*
36*
36*
36*
1000E+01 20.000 300.000 15.000 0.500
34.00
133.28
97.42
-2.68
-48.68
** Fence line receptor
**
RE
DISCCART
Refined
DISCCART
DISCCART
DISCCART
DISCCART
FINISHED
30
.00 0.00 121.70 121.70
receptors
125
126
127
128
.00 0.00 120.82 120.82
.00 0.00 120.79 120.79
.00 0.00 120.76 120.76
.00 0.00 120.73 120.73
Figure 63. Partial AERMOD.INP file for REFINE processing.
REFINE started 06/26/15 11:05:28
***************************************************
Running AERMAP for REFINE
*** AERMAP Finishes Successfully *** for stage 3
******** WARNING MESSAGES ********
OU W473 123 NEDCHK:Default elevation units of METERS used; NED file:
AERMOD Finishes Successfully for REFINE stage 3 Winter sector 160
0 receptors skipped due to missing elevations
******** WARNING MESSAGES ********
*** NONE ***
REFINE
ended 06/26/15 11:05:30
Figure 64. REFINE messages.
After REFINE, the inversion break-up fumigation calculations begin (Figure 65) and the final
messages are written to the AERSCREEN.LOG file. AERSCREEN ends and notifies the user
that AERSCREEN ended successfully with warnings and gives the end time.
81
-------
FUMIGATE started 06/26/15 11:05:31
Calculating maximum distance of fumigation concentration
**********************************************
AERSCREEN Finished Successfully
But with Warnings
Source coordinates switched from lat/lon to UTM
0 receptors skipped for FLOWSECTOR
0 receptors skipped for REFINE
Check log file for details
***********************************************
Ending date and time 06/26/15 11:05:55
Figure 65. Fumigation and final AERSCREEN messages.
AERSCREEN also outputs the overall maximum 1-hour concentration, maximum 1-hour
ambient boundary concentration, and maximum 1-hour inversion break-up fumigation
concentration with scaled 3, 8, 24-hour, and annual average concentrations (Figure 66). Also
listed are the distances, flow vectors direction, and receptor elevations relative to the source
elevation. For the example case, the overall maximum 1-hour concentration was 215.6 |ig/m3 at
171m toward 160° and the receptor's elevation was 6.12 m below the source or 122.68 m. The
maximum ambient boundary concentration was 149.4 |ig/m3 north of the source at an elevation
of about 118.93 m or 7.87 m below the source elevation. The maximum concentration due to
inversion break-up was 759.5 |ig/m3 at a distance of 100 m from the source.
82
-------
Command Prompt
flERSCREEN 15181
Calculating nax concentrations by distance
Writing debug file...
CflLCULflTION
PROCEDURE
ELEUflTED TERRfllN
MflXIMUM
1-HOUR
CONC
SCflLED
3-HOUR
CONC
SCflLED
8-HOUR
CONC
SCflLED
24-HOUR
CONC
SCftLED
ANNUAL
CONC
DISTANCE FROM SOURCE 171.00 meters directed toward 160 degree:
RECEPTOR HEIGHT -6.12 meters
IMPACT AT THE
AMBIENT BOUNDARV 149.4 149.4 134.5 89.65 J
DISTANCE FROM SOURCE 30.00 meters directed toward 360 degree:
RECEPTOR HEIGHT -7.87 meters
FUMIGATION
PROCEDURE
MflXIMUM
1-HOUR
CONC
AERSCREEN FUMIGATION SUMMflRV
INUERSION BREflK-UP
DISTANCE FROM SOURCE
SCALED
3-HOUR
CONC
100.00 meters
SCftLED
8-HOUR
CONC
SCflLED
24-HOUR
CONC
SCALED
ANNUAL
CONC
«* Restart file is written to "flERSCREEN.INP" *»
** Output is written to
flERSCREEN.OUT
flERSCREEN Finished Successfully
But with Warnings
Source coordinates switched from lat/lon to UTM
0 receptors skipped for FLOUSECTOR
0 receptors skipped for REFINE
Check log file for details
Figure 66. Overall maximum, maximum ambient boundary concentration, and maximum
inversion break-up fumigation concentration statistics.
4.2 AERSCREEN output
Output from AERSCREEN is written to AERSCREEN_EXAMPLE.OUT. Following are
sections with explanations.
The first section shown lists information also shown in the log file, emissions inputs, terrain
information (input terrain file and probe distance), and building inputs in both metric and English
units (Figure 67).
83
-------
AERSCREEN 15181 / AERMOD 14134
TITLE: Example stack
*****************************
SOURCE EMISSION RATE:
STACK HEIGHT:
STACK INNER DIAMETER:
PLUME EXIT TEMPERATURE:
PLUME EXIT VELOCITY:
STACK AIR FLOW RATE:
STACK BASE LONGITUDE:
STACK BASE LATITUDE:
STACK BASE UTM ZONE:
REFERENCE DATUM (NADA) :
STACK BASE ELEVATION:
RURAL OR URBAN:
POPULATION:
DIGITAL ELEVATION MAP ( S )
INITIAL PROBE DISTANCE =
STACK PARAMETERS *
1.0000 g/s
20. 00 meters
0.500 meters
300.0 K
15.000 m/s
6241 ACFM
-78.7819 deg
35.8914 deg
126. 80 meters
URBAN
2400000
NED 22944813\NED
1000. meters
***************
7.937
65.92
19.69
80.3
49.21
700198.
3974176.
17
4
416.01
22944813.tif
3281.
*********************** BUILDING DOWNWASH PARAMETERS **********
BUILDING HEIGHT:
MAX BUILDING DIMENSION:
MIN BUILDING DIMENSION:
BUILDING ORIENTATION TO NORTH:
STACK DIRECTION FROM CENTER:
STACK DISTANCE FROM CENTER:
34 . 0 meters
120. 0 meters
60 . 0 meters
90 . degrees
27. degrees
67 . 0 meters
111.5
393.7
196.9
219.8
06/26/15
11:05:31
************
Ib/hr
feet
inches
Deg F
ft/s
Easting
Northing
feet
feet
************
feet
feet
feet
feet
Figure 67. AERSCREEN_EXAMPLE.OUT section with source and building information.
The next section gives information about the results of FLOW SECTOR (Figure 68). The header
for the section gives the receptor spacing, 25 m. Next, follows the flow sectors from 10 to 360
degrees. Included for each sector are the projected building width and length output from
BPIPPRM, the x and y building adjustments from BPIPPRM, the maximum 1-hour
concentration (|j,g/m3), the downwind distance from the source, and the elevation of the receptor
relative to the source (receptor - source). Concentrations are written in with the "G" FORTRAN
descriptor with 4 significant digits. The sector followed by an "*" indicates that this is the
highest concentration sector or "worst case sector." In this case it is flow sector 160° with a
concentration of approximately 201.2 |j,g/m3 at 175 m from the source. The relative receptor
84
-------
elevation is -5.95 m, meaning the receptor is at an elevation of approximately 125.8 m. The
temporal period associated with the maximum concentration is winter.
25 meter rece
FLOW
LOW SECTOR ANALYSIS **************************-
ptor spacing: 30. meters - 1000. meters
BUILD BUILD
SECTOR WIDTH LENGTH
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
* = worst
128
133
133
130
123
111
97
79
0
0
0
111
123
130
133
* 133
128
120
128
133
133
130
123
111
97
79
0
0
0
111
123
130
133
133
128
120
case
.60
.28
.92
.49
.10
.96
.42
.93
.00
.00
.00
.96
.10
.49
.92
.28
.60
.00
.60
.28
.92
.49
.10
.96
.42
.93
.00
.00
.00
.96
.10
.49
.92
.28
.60
.00
flow
79.93
97.42
111.96
123.10
130.49
133.92
133.28
128.60
0.00
0.00
0.00
133.92
130.49
123.10
111.96
97.42
79.93
60.00
79.93
97.42
111.96
123.10
130.49
133.92
133.28
128.60
0.00
0.00
0.00
133.92
130.49
123.10
111.96
97.42
79.93
60.00
sector
XBADJ
-104.17
-115.27
-122.86
-126.73
-126.74
-122.90
-115.32
-104.25
0.00
0.00
0.00
-62.99
-49.72
-34.94
-19.10
-2. 68
13.83
29.91
24.25
17.85
10.90
3.63
-3.76
-11.03
-17.96
-24.35
0.00
0.00
0.00
-70.94
-80.77
-88.16
-92.86
-94.75
-93.75
-89.91
YBADJ
19
7
-3
-15
-26
-36
-46
-53
0
0
0
-66
-65
-61
-55
-48
-39
-30
-19
-7
3
15
26
36
46
53
0
0
0
66
65
61
55
48
39
30
14
70
97
53
61
88
04
79
00
00
00
88
18
49
94
68
95
00
14
70
97
53
61
88
04
79
00
00
00
88
18
49
94
68
95
00
t
MAXIMUM IMPACT RECEPTOR
1-HR CONG DIST HEIGHT TEMPORAL
(ug/m3)
127.8
117.7
83.83
62.52
60.34
89.96
94.09
167.1
59.91
59.40
58.83
173.8
171.9
177.1
195.4
201.2
196.7
132.6
147. 6
158.4
199.8
194.1
172. 6
148.0
164.7
170.7
65.81
65.65
65.65
157.1
121.8
122.8
100.4
64.08
106.1
149.4
(m)
53
30
30
150
150
75
75
53
325
350
325
75
100
125
150
175
175
100
105
125
125
150
125
200
150
105
400
375
375
75
100
100
100
150
30
30
(m)
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
-7
-6
-5
-4
-4
-4
-4
-4
-4
-4
-4
-4
-5
-6
-6
-5
-6
-5
-5
-5
-5
-6
-7
-13
-19
-21
-13
-21
-23
-15
-12
-11
-11
-8
-8
-7
02
27
90
95
48
81
63
78
04
28
65
63
31
10
32
95
76
14
17
34
69
42
80
12
31
97
94
22
80
94
98
30
07
70
58
87
PERIOD
WIN
WIN
SUM
SPR
SPR
WIN
SPR
SPR
WIN
WIN
WIN
SPR
SPR
SPR
WIN
WIN
SPR
WIN
SPR
SPR
SUM
WIN
WIN
WIN
WIN
SUM
WIN
WIN
WIN
SPR
WIN
SUM
WIN
SPR
WIN
SPR
Figure 68. FLOWSECTOR results in AERSCREEN_EXAMPLE.OUT.
Next, follows meteorological inputs and meteorology used to calculate the overall worst case
scenario (Figure 69). Listed first are the inputs: minimum and maximum temperatures (K),
minimum wind speed and anemometer height. Also listed is the dominant season and surface
roughness sector associated with the worst case concentration. For this case it is winter and
roughness sector 12 with beginning direction 330° and ending with 0° (or 360°). Note that this is
85
-------
the sector of the upwind direction of the worst case scenario. Shown below the season and
sector are the surface characteristics for that season and sector.
Next, follows the meteorological parameters used to predict the worst case concentration at the
ambient boundary (Figure 69): year, month, day, Julian date, hour, heat flux, u*, w*, lapse rate,
convective mixing height, mechanical mixing height, Monin-Obukhov length, surface roughness,
Bowen ratio, albedo reference wind speed, anemometer height, temperature, and temperature
measurement height (2 meters). The surface characteristics listed should match those listed in
association with the dominant season and sector in the AERSUKFACE output file or
AERSCREEN.LOG file. After the meteorological parameters, the final plume rise is also
shown with stack top wind speeds. After that are listed the meteorological parameters and plume
height of the maximum concentration at the ambient boundary. Plume heights do not include
down wash effects.
86
-------
MAKEMET METEOROLOGY PARAMETERS
MIN/MAX TEMPERATURE:
MINIMUM WIND SPEED:
ANEMOMETER HEIGHT:
SURFACE CHARACTERISTICS INPUT: aersurface_12.out
0)
ALBEDO:
BOWEN RATIO:
ROUGHNESS LENGTH:
METEOROLOGY CONDITIONS USED TO PREDICT OVERALL MAXIMUM IMPACT
DT/DZ ZICNV ZIMCH M-0 LEN ZO BOWEN ALBEDO REE WS
HT REE TA HT
10.0 287.2 2.0
WIND SPEED AT STACK HEIGHT (non-downwash): 1.8 m/s
STACK-TIP DOWNWASH ADJUSTED STACK HEIGHT: 20.0 meters
ESTIMATED FINAL PLUME RISE (non-downwash): 10.7 meters
ESTIMATED FINAL PLUME HEIGHT (non-downwash): 30.7 meters
YR MO DY JDY HR
10 06 10 14 12
HO U* W* DT/DZ ZICNV ZIMCH M-0 LEN ZO BOWEN ALBEDO REF WS
34.75 0.239 1.200 0.020 1913. 268. -37.7 0.038 0.63 0.14 3.00
HT REF TA HT
10.0 313.1 2.0
WIND SPEED AT STACK HEIGHT (non-downwash): 3.3 m/s
STACK-TIP DOWNWASH ADJUSTED STACK HEIGHT: 20.0 meters
ESTIMATED FINAL PLUME RISE (non-downwash): 6.9 meters
ESTIMATED FINAL PLUME HEIGHT (non-downwash): 26.9 meters
Figure 69. Meteorological data associated with maximum FLOWSECTOR concentration
and ambient boundary concentration.
87
-------
After the meteorological parameters, follows a summary of maximum concentrations by distance
(Figure 70). The concentrations shown are not necessarily in the same direction as the overall
maximum concentration shown in the flow sector analysis, i.e., the maximum 30 m
concentration may not be directed toward 180. Details about the concentrations' meteorology
can be found in the file aerscreen_example_max_conc_distance.txt, whose format is listed in
Table 1. The maximum concentration and its distance, 175 m (shown in red in Figure 70) found
from FLOWSECTOR should be listed in the table and in
aerscreen_example_max_conc_distances.txt.
*************
DIST
(m)
30.00
50.00
53.00
75.00
100.00
105.00
125.00
150.00
175.00
200.00
201.00
225.00
250.00
275.00
300.00
325.00
350.00
375.00
400.00
425.00
450.00
475.00
500.00
*********** AERSCREEN AUTOMATED DISTANCES **********************
OVERALL MAXIMUM CONCENTRATIONS BY DISTANCE
MAXIMUM
1-HR CONG
(ug/m3)
149.4
166.9
167.1
173.8
181.5
180.7
199.8
199.5
201.2
193.8
193.8
126.5
117.4
115.4
113.1
110.7
108. 6
112.2
116.1
120.5
125.0
130.1
132.0
RECEPTOR
HEIGHT
(m)
-7.87
-4.82
-4.78
-4. 63
-5.30
-5.43
-5.69
-5.73
-5.95
-6.47
-6.47
-6.50
-5.87
-5.92
-6.01
-6.13
-13.95
-15.03
-14.10
-11.78
-9.54
-7.34
-6.94
DIST
(m)
503.00
525.00
550.00
575.00
600.00
625.00
650.00
675.00
700.00
702.00
725.00
750.00
775.00
800.00
825.00
850.00
875.00
900.00
925.00
950.00
975.00
1000.00
MAXIMUM
1-HR CONG
(ug/m3)
132.1
131.7
130.2
128.5
127.4
123.5
123.0
124.6
126.4
126.2
124.8
121.3
116. 6
112. 6
108.9
105.2
101.7
97.01
92.22
88.78
86.55
84.33
RECEPTOR
HEIGHT
(m)
-6.91
-7.24
-7.94
-8. 66
-8.91
-10.77
-10.40
-8.89
-7.54
-7.55
-7.63
-8.42
-9.28
-9.90
-10.43
-11.04
-11. 64
-13.40
-16.03
-17.60
-17.23
-16.96
Figure 70. Summary of maximum concentrations by distance in
AERSCREEN EX AMPLE. OUT.
The final section of the output file lists the results of REFINE and fumigation calculations
(Figure 71). The REFINE result is the overall maximum concentration in the direction of the
worst case scenario found in FLOWSECTOR, using the same surface characteristics (winter, 90
to 120 degrees sector). In addition to the 1-hour concentration calculated by AERMOD, the
scaled 3-hr, 8-hr, 24-hr, and annual concentrations are calculated by AERSCREEN and output.
Also output is the distance of the maximum concentration and its direction. Similar output is
listed for the maximum concentration at the minimum ambient distance. The maximum 1-hour
88
-------
inversion break-up fumigation concentration is listed along with the scaled 3-hr, 8-hr, 24-hr, and
annual concentrations.
AERSCREEN MAXIMUM IMPACT SUMMARY
MAXIMUM SCALED SCALED SCALED SCALED
1-HOUR 3-HOUR 8-HOUR 24-HOUR ANNUAL
CALCULATION CONG CONG CONG CONG CONG
PROCEDURE (ug/m3) (ug/m3) (ug/m3) (ug/m3) (ug/m3)
ELEVATED TERRAIN 215.6 215.6 194.0 129.3 21.56
DISTANCE FROM SOURCE 171.00 meters directed toward 160 degrees
RECEPTOR HEIGHT -6.12 meters
IMPACT AT THE
AMBIENT BOUNDARY 149.4 149.4 134.5 89.65 14.94
DISTANCE FROM SOURCE 30.00 meters directed toward 360 degrees
RECEPTOR HEIGHT -7.87 meters
********************** AERSCREEN FUMIGATION SUMMARY *********************
MAXIMUM SCALED SCALED SCALED SCALED
1-HOUR 3-HOUR 8-HOUR 24-HOUR ANNUAL
FUMIGATION CONG CONG CONG CONG CONG
PROCEDURE (ug/m3) (ug/m3) (ug/m3) (ug/m3) (ug/m3)
INVERSION BREAK-UP 759.5 759.5 683.6 455.7 75.95
DISTANCE FROM SOURCE 100.00 meters
Figure 71. Maximum concentration impact, ambient boundary, and inversion break-up
fumigation concentration summaries in AERSCREEN EXAMPLE.OUT.
Figure 72 shows partial output for aerscreen_example_max_conc_distances.txt. Note that the
overall maximum concentration 215.6 |j,g/m3 is denoted by the asterisk. See Table 2 for format.
Figure 73 shows partial output for the debug file, aerscreen_example_concentrations.txt. This
file has a similar format as aerscreen_example_max_conc_distances.txt, but lists the intermediate
outputs from FLOWSECTOR.
89
-------
Concentration
0.14942E+03
0.16692E+03
0.16713E+03
0.17382E+03
0.18151E+03
0.18070E+03
0.19976E+03
0.19948E+03
* 0.21555E+03
0.20123E+03
0.19380E+03
0.19380E+03
0.12648E+03
0.11743E+03
0.11541E+03
0.11313E+03
0.11075E+03
0.10857E+03
0.11220E+03
0.11611E+03
0.12050E+03
0.12498E+03
0.13014E+03
0.13197E+03
0.13213E+03
0.13175E+03
0.13025E+03
0.12848E+03
0.12741E+03
0.12347E+03
0.12298E+03
0.12457E+03
0.12637E+03
0 . 12624E+03
0 . 12479E+03
0 . 12125E+03
0.11656E+03
0.11257E+03
0.10888E+03
0 . 10522E+03
0 . 10171E+03
0 . 97014E+02
0.92219E+02
0.88779E+02
0.86548E+02
0.84328E+02
Distance Elevation Flow Season/Month
30
50
53
75
100
105
125
150
171
175
200
201
225
250
275
300
325
350
375
400
425
450
475
500
503
525
550
575
600
625
650
675
700
702
725
750
775
800
825
850
875
900
925
950
975
1000
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
-7
-4
-4
-4
_5
-5
-5
-5
-6
_5
-6
-6
-6
-5
_5
-6
-6
-13
-15
-14
-11
-9
_7
-6
-6
-7
-7
-8
-8
-10
-10
-8
-7
_7
-8
-9
-9
-10
-11
-11
-13
-16
-17
-17
-16
87
82
78
63
30
43
69
73
12
95
47
47
50
87
92
01
13
95
03
10
78
54
34
94
9 1
24
94
66
91
77
40
89
54
55
63
42
28
90
43
04
64
40
03
60
23
96
360
80
80
120
160
160
210
210
160
160
220
220
220
210
210
210
210
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
360
Spring
Spring
Spring
Spring
Winter
Winter
Surroner
Summer
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Summer
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
Spring
^o sector
180-210
240-270
240-270
300-330
330-0
330-0
30-60
30-60
330-0
330-0
30-60
30-60
30-60
30-60
30-60
30-60
30-60
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
180-210
Date
10061012
10020712
10020712
10012112
10011412
10011412
10012812
10012812
10011412
10011412
10011412
10011412
10012301
10012301
10012301
10012301
10012301
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
10012501
HO
34
170
170
17
4
4
11
11
4
4
4
4
-0
-0
-0
-0
-0
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
-2
_2
_2
-2
-2
-2
_2
_2
-2
-2
-2
2
75
58
58
55
75
75
90
90
72
75
75
75
43
43
43
43
43
31
31
31
31
31
31
31
31
31
31
31
31
31
31
21
21
21
21
21
21
21
21
21
21
21
21
21
21
'1
U*
0.239
0.209
0.209
0.222
0.185
0.185
0.117
0.117
0.200
0.185
0.100
0.100
0.082
0.082
0.082
0.082
0.082
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.056
0.054
0.054
0 054
0 054
0 054
0.054
0.054
0.054
0 054
0 054
0 054
0.054
0.054
0.054
0.054
W*
1.200
1.200
1.200
0.600
0.600
0.600
0.600
0.600
0.600
0.600
0.600
0.600
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9.000
-9 000
-9 000
-9 000
-9.000
-9.000
-9.000
-9 000
-9 000
-9 000
-9.000
-9.000
-9.000
-9.000
DT/DZ
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0 020
0 020
0 020
0.020
0.020
0.020
0 020
0 020
0 020
0.020
0.020
0.020
0.020
ICNV
1913.
390.
390 .
473.
1604.
1604.
698.
698.
1615.
1604.
1604.
1604.
-999.
-999.
999.
999.
999.
-999.
-999.
-999.
999.
999.
999.
-999.
-999.
-999.
-999.
999.
999.
999.
-999.
-999.
-999.
999
999
999
-999.
-999.
-999.
999
999
999
-999.
-999.
-999.
999
IMCH
268.
219.
219.
241.
183.
183.
92.
92.
205.
183.
73.
73.
54.
54.
54.
54.
54.
30 .
30 .
30 .
30.
30.
30.
30.
30.
30.
30.
30.
30.
30.
30 .
29.
29.
29
29
2 9
2 9
2 9
29
29
29.
29.
29.
29 .
M-0 LEN
-37.7
-5.1
-5.1
-59.9
-117.1
-117.1
-12 . 9
-12.9
-148.4
-117.1
-18.6
-18.6
102.6
102.6
102.6
102.6
102.6
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
6.8
6.8
6. 8
6. 8
6. 8
6.8
6.8
6.8
6. 8
6. 8
6. 8
6.8
6.8
6.8
6.8
ZO BOWEN ALBEDO REE WS
0.038
0.141
0.141
0.458
0.305
0.305
0.022
0.022
0.405
0.305
0.011
0.011
0.011
0.011
0.011
0.011
0.011
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.045
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.038
0.63
0.63
0.63
0.63
0.85
0.85
0.36
0.36
0.84
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.85
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.63
0.63
0 . 63
0 . 63
0 . 63
0.63
0.63
0.63
0 . 63
0 . 63
0 . 63
0.63
0.63
0.63
0.63
0.14
0.14
0.14
0.14
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.14
0.14
0 . 14
0 . 14
0 . 14
0.14
0.14
0.14
0 . 14
0 . 14
0 . 14
0.14
0.14
0.14
0.14
3.00
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
HT REE TA
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
313.1
313.1
313.1
313.1
287.2
287.2
313.1
313.1
287.2
287.2
287.2
287.2
261.4
261.4
261.4
261.4
261.4
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
HT
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2 . 0
2 . 0
2 . 0
2.0
2.0
2.0
2 . 0
2 . 0
2 . 0
2.0
2.0
2.0
2.0
Figure 72. Output of aerscreen_example_max_conc_distance.txt.
90
-------
Concentration
0.12767E+03
0.11768E+03
0 . 83517E+02
0.42414E+02
0.39925E+02
0.49116E+02
0.46231E+02
0.11514E+03
0.77764E+01
0.77789E+01
0.77802E+01
0.68684E+02
0.69684E+02
0.69040E+02
0.69988E+02
0.61306E+02
0.33467E+02
0.19780E+00
0.10403E+02
0.18922E+02
0.33730E+02
0.42504E+02
0 . 48038E+02
0.47331E+02
0.47690E+02
0.47666E+02
0.49551E+01
0.49548E+01
0.49547E+01
0.69511E+02
0.65020E+02
0.77417E+02
0.61248E+02
0.36388E+02
0.10606E+03
0.13881E+03
0.12608E+03
0.11738E+03
0.83710E+02
0.42338E+02
0.39489E+02
0.48878E+02
Distance Elevation Flow Season/Month
30
30
30
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
30
30
30
30
30
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
_7
-6
_5
-5
-5
-5
_5
_5
_5
-5
-4
-4
-5
_5
_5
_5
-5
-5
-5
_5
_5
_5
_5
-6
-7
-8
-8
-9
-10
-10
-10
-9
-9
-9
-8
-7
-7
-6
_5
_5
_5
-5
06
27
90
65
43
25
17
10
05
01
99
98
00
02
05
10
19
29
40
51
64
79
92
31
11
02
91
64
10
18
00
74
42
11
58
87
06
27
90
65
43
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
10
20
30
40
50
60
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Spring
Spring
Spring
Spring
Spring
Spring
^o sector
180-210
180-210
210-240
210-240
210-240
240-270
240-270
240-270
270-300
270-300
270-300
300-330
300-330
300-330
330-0
330-0
330-0
330-0
0-30
0-30
30-60
30-60
30-60
60-90
60-90
60-90
90-120
90-120
90-120
120-150
120-150
120-150
150-180
150-180
150-180
180-210
180-210
180-210
210-240
210-240
210-240
240-270
Date
10080512
10080512
10032501
10110912
10011001
10011812
10010812
10021712
10011612
10011612
10011612
10020312
10020612
10011412
10011412
10011412
10020612
10010812
10010419
10011412
10011412
10011412
1001031'
10010312
10011412
10011412
10011612
10011612
10011612
10020612
10012412
10012412
10010812
10011001
10080512
10030901
10082512
10082512
10032401
10121312
10011001
10012212
HO U*
80
80
-21
286
-2
40
45
286
54
54
54
24
40
4
4
4
40
45
4
4
4
4
1
1
4
4
54
54
54
40
126
126
45
-3
80
-7
92
92
-23
244
-2
34
98
98
38
89
39
89
67
89
56
56
56
98
89
75
75
75
89
67
75
75
75
75
05
95
75
75
56
56
56
89
56
56
67
03
98
46
36
36
02
32
61
.75
0.308
0.308
0 198
0.632
0.045
0.172
0.174
0.212
0.210
0.210
0.210
0.220
0.228
0.198
0.185
0.185
0.214
0.216
0.140
0.140
0.100
0.100
0.096
0.108
0.113
0.113
0.140
0.140
0.140
0.137
0.153
0.153
0.140
0.053
0.312
0.138
0.320
0.320
0.213
0.665
0.048
0.177
W*
1.800
1.800
-9 000
1.800
-9.000
0.600
0.600
1.800
0.600
0.600
0.600
1.200
1.200
0.600
0.600
0.600
1.200
0.600
0.300
0.600
0.600
0.600
0.300
0.300
0.600
0.600
0.600
0.600
0.600
1.200
1.200
1.200
0.600
-9.000
1.800
-9.000
1.800
1.800
-9.000
1.800
-9.000
0.600
DT/DZ
0.020
0.020
0 020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
0.020
ICNV
2770.
2770.
999
782.
-999.
203.
182.
782.
140.
140.
140.
2441.
1626.
1604.
1604.
1604.
1626.
182.
201.
1604.
1604.
1604.
445.
445.
1604.
1604.
140.
140.
140.
1626.
525.
525 .
182.
999.
2770.
-999.
2429.
2429 .
999.
918.
999.
239 .
ZIMCH
393 .
393 .
203
1157.
110.
165.
167 .
225.
222.
222.
222.
237.
250.
202.
183.
183.
227.
231.
121.
121.
73.
73.
68.
82.
87.
87.
120.
120.
120.
116.
137.
137.
120.
139.
401.
117.
417.
417.
227.
1248.
120.
171.
M-0 LEN
-34.6
-34.6
35 0
-84.8
3.7
-12.0
-11.2
-3.2
-15.1
-15.1
-15.1
-37.7
-27.8
-143.2
-117.1
-117.1
-23.0
-21.2
-51.3
-51.3
-18.6
-18.6
-36.5
-52.3
-26.6
-26.6
-4.4
-4.4
-4.4
-6.0
-2.7
-2.7
-5.8
4.7
-36.2
33.6
-34.2
-34.2
40.6
-115.9
4.0
-15.3
ZO BOWEN ALBEDO REF WS
0.031
0.031
0.013
0.013
0.013
0.115
0.115
0.115
0.244
0.244
0.244
0.391
0.391
0.391
0.305
0.305
0.305
0.305
0.089
0.089
0.011
0.011
0.011
0.025
0.025
0.025
0.029
0.029
0.029
0.032
0.032
0.032
0.034
0.034
0.034
0.031
0.038
0.038
0.019
0.019
0.019
0.141
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.85 0.15
0.63 0.14
0.63 0.14
0.63 0.14
0.63 0.14
0.63 0.14
0.63 0.14
4.00
4.00
4.00
10.00
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
4.00
2.50
4.00
4.00
4.00
10.00
1.50
1.50
HT REF TA
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
287.2
287.2
287.2
287.2
313.1
287.2
287.2
287.2
313.1
313.1
287.2
287.2
287.2
287.2
261.4
261.4
287.2
287.2
287.2
287.2
287.2
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
313.1
HT
2.0
2.0
2 . 0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2 . 0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
Figure 73. Partial output of aerscreen_example_concentrations.txt.
91
-------
With the debug option turned on, the fumigation debug file,
aerscreen_example_fumigate_debug.txt was created. This file lists the iterative process used to
calculate the effective plume height for each hour of meteorology that is used in the fumigation
calculations (Figure 74). The file also lists the iterative process of calculating the distance Xmax
for inversion break-up fumigation and subsequent concentration, Xf (Figure 75).
Calculating effective plume height for: 10010401
Stack height (adjusted): 20.00 m
Initial plume rise: 11.93 m
Iteration: 1
Plume height: 25.97 m
Plume rise: 13.20 m
Iteration: 2
Plume height: 26.60 m
Plume rise: 13.18 m
Final plume rise
Iteration: 2
Effective Plume height: 33.18 m
Plume rise: 13.18 m
Calculating effective plume height for: 10010501
Stack height (adjusted): 20.00 m
Initial plume rise: 11.93 m
Iteration: 1
Plume height: 25.97 m
Plume rise: 13.20 m
Iteration: 2
Plume height: 26.60 m
Plume rise: 13.18 m
Final plume rise
Iteration: 2
Effective Plume height: 33.18 m
Plume rise: 13.18 m
Figure 74. Partial output of aerscreen_example_fumigate_debug.txt showing effective
plume height calculations.
92
-------
INVERSION BREAK-UP FUMIGATION CALCULATIONS FOR 10010401
Stack height: 20.00 m
Stack height wind speed 2.5 m
Stack-tip downwash adjusted stack height: 20.00 m
Effective stack height: 33.18 m
Initial distance: 5.000 km
temporal period: 1
spatial sector: 1
BASE METEOROLOGICAL VARIABLES
HO U* W* DT/DZ ZICNV ZIMCH M-0 LEN ZO BOWEN ALBEDO REF WS
10.0 261.4 2.0
OTHER VARIABLES
UMIX UEFF SIG-V SIG-W THETA DT/DZ_2 BV SIG-YB SIGZ-B
3.2 3.1 0.20 0.06 266.3 0.0921 0.0582 3.7 3.7
Iteration 1
Iteration 3
NEW MAX CONCENTRATION OF 0.205E+03 AT 0.247 KM FOR DATE 10010401
temporal period: 1
spatial sector: 1
FINAL MAX CONCENTRATION OF 0.760E+03 AT 0.100 KM FOR DATE 10010901
temporal period: 3
spatial sector: 7
Figure 75. Partial output of aerscreen_example_fumigate_debug.txt showing
concentration calculations.
93
-------
After processing, AERSCREEN creates a new AERSCREEN.INP file, with any user input
changes added (Figure 76). Note that any options are that are alphabetic have been set to
uppercase. AERSCREEN sets all flags to uppercase internally for program efficiency.
AERSCREEN will also output the surface characteristics for the maximum concentration as the
user-entered values in the MAKEMET DATA section and lists the time, flow vector, and surface
roughness sector of the overall maximum concentration. AERSCREEN also copies the new
AERSCREEN.INP file to AERSCREEN_EXAMPLE.INP and AERSCREEN.LOG to
AERSCREEN EXAMPLE.LOG.
94
-------
** Coordinates switched from geographic to UTM
** STACK DATA Rate Height Temp. Velocity Diam. Flow
** 0.1000E+01 20.0000 300.0000 15.0000 0.5000 6241.
** BUILDING DATA BPIP
** Y
Height Max dim. Min dim. Orient. Direct. Offset
34.0000 120.0000 60.0000 90.0000 26.6000 67.0000
** MAKEMET DATA MinT MaxT Speed AnemHt Surf Clim Albedo Bowen Length SC FILE
** 261.40 313.10 1.5 10.000 9 0 0.1500 0.8500 0.3050 "aersurface 12.out'
** TERRAIN DATA Terrain
**
UTM East UTM North Zone Nada
700198.2 3974175.5 17 4
Probe PROFBASE Use AERMAP elev
1000.0 126.80 N
** DISCRETE RECEPTORS Discflag Receptor file
** Y "discrete_receptors.txt"
** UNITS/POPULATION Units R/U Population
** M U 2400000.
Amb. dist. Flagpole Flagpole height
30.000 N 0.00
** FUMIGATION
**
** DEBUG OPTION
* *
Inversion Break-up Shoreline Distance
Y N 0.00
Debug
Y
Direct Run AERSCREEN
0.0 Y
** OUTPUT FILE "aerscreen_example.out"
** Temporal sector: Winter, flow vector: 160 degrees, spatial sector: 12
Figure 76. Header portion of new AERSCREEN.INP file.
95
-------
5. References
Hanrahan, P.L., 1999a. "The plume volume molar ratio method for determining NCh/NOx ratios
in modeling. Part I: Methodology," Journal of the Air & Waste
Management Association, 49, 1324-1331.
Hanrahan, P.L., 1999b. "The plume volume molar ratio method for determining NCh/NOx ratios
in modeling. Part II: Evaluation Studies," Journal of the Air & Waste
Management Association, 49, 1332-1338.
Leahey, D.M., and M. J. E. Davies, 1984: Observations of Plume Rise From Sour Gas Flares.
Atmospheric Environment, Vol. 18, pp. 917-922.
Schulman, L.L., D.G. Strimaitis, and J.S. Scire, 2000: Development and Evaluation of the
PRIME Plume Rise and Building Downwash Model. Journal of the Air & Waste
Management Association, Vol. 50, pp 378-390.
Turner, D.B., 1970: Workbook of Atmospheric Dispersion Estimates. Revised, Sixth Printing,
January 1973. Office of Air Programs Publication No. AP-26.
U.S. EPA, 1992: Screening Procedures for Estimating the Air Quality Impact of Stationary
Sources. EPA-454/R-92-019. U.S. Environmental Protection Agency, Research Triangle
Park, NC 27711.
U.S. EPA, 1995: SCREENS Model User's Guide. EPA-454/B-95-004. U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711.
U.S. EPA, 2004a: User's Guide for the AMS/EPA Regulatory Model - AERMOD. EPA-454/B-
03-001. U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
U.S. EPA, 2004b: User's Guide for the AERMOD Terrain Preprocessor
(AERMAP). EPA-454/B-03-003. U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina 27711.
U.S. EPA, 2004c: User's Guide for the AERMOD Meteorological
Preprocessor (AERMET). EPA-454/B-03-002. U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711.
U.S. EPA, 2004d: User's Guide to the Building Profile Input Program. EPA-454/R-93-038. U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina 27711.
U.S. EPA, 2005. Guideline on Air Quality Models. 40 CFR Part 51 Appendix W.
96
-------
U.S. EPA, 2008: AERSURFACE User's Guide. EPA-454/B-08-001. U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711.
U.S. EPA, 2009: AERMOD Implementation Guide. U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711.
97
-------
Appendix A. Input parameters and invalid responses
Below, AERSCREEN input parameters are listed with invalid responses and actions taken by
AERSCREEN when reading the data from the AERSCREEN.INP file or prompts. Some
variables are only checked if the appropriate flags are set. Building dimensions are not checked
if downwash is not included in AERSCREEN processing. Other variables such as urban
population or flagpole heights are not checked if the source is not urban or flagpole receptors are
not used.
As previously noted, when reading data from AERSCREEN.INP, if any of the data sections,
emissions, building information, terrain information, meteorological information, and other
parameters, is missing, AERSCREEN will alert the user and stop processing. If the emissions
data is listed after the building, terrain, or other parameter data sections, AERSCREEN will alert
the user and stop processing.
A-l
-------
Source parameters and invalid values.
Parameter
Units flag
Source type
Emission rate
Stack height
Stack diameter
Negative exit velocity
Flare height
Heat release rate
Heat loss fraction
Release height
Initial vertical
dimension
Initial lateral dimension
Circular radius
Rectangular area source
horizontal dimensions
Orientation angle
Number of vertices
Urban/rural flag
Urban population
Minimum ambient
distance
NO2 conversion method
NO2/NOX in-stack ratio
Ozone background
concentration
Ozone background
concentration units
Pollutant ID
Source type
All
All
All
Point, capped stack,
horizontal stack
Point, capped stack,
horizontal stack
Point, capped stack,
horizontal stack
Flare
Flare
Flare
Area, volume, circular
area
Area, volume, circular
area
Volume
Circular area
Area
Area
Circular area
All
All
All
All
All
All
All
All
Invalid response
If prompts, response is not upper or lower case E or M. If input file,
response is not upper or lowercase M.
Response is not upper or lower-case: P, F, H, A, C, S, or V
Negative or non-numeric
Negative or non-numeric
Negative or non-numeric
Non-numeric
Negative or non-numeric
Negative or non-numeric
Non-numeric
Negative or non-numeric
Negative or non-numeric
Negative or non-numeric
Negative or non-numeric
Negative or non-numeric
Non-numeric or non-zero
Non-numeric or not equal to 20
Response is not upper or lower-case Y or N
Non-numeric, negative or less than 100 people
Non-numeric, negative or if volume source, inside the volume.
"PVMRM" and "OLM" are both on MODELOPT card or
POLLUTID is NO2 and neither PVMRM or OLM is on
MODELOPT card
Non-numeric, negative, or exceeds 1 .0
Non-numeric, negative, or exceeds 1 .0
Not upper or lower-case "PPB", "PPM", or "UG/M3"
Not set to NO2 but MODELOPT includes PVMRM or OLM
AERSCREEN.INP
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and reset to 1x1 0"5 m/s
if negative
Issue message and stop
Issue message and stop
Issue message and reset to 0 if
negative
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop (if source is
urban)
Issue message and reset to minimum
distance based on source type if
negative. If non-numeric issue
message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Prompts
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Issue message and reset to
IxlO"5 m/s if negative
Re-prompt
Re-prompt
Issue message and reset to
0 if negative
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
N/A
N/A
Re-prompt
Re-prompt
Re-prompt if non-numeric
N/A
Re-prompt
Re-prompt
Re-prompt
N/A
A-2
-------
Invalid building parameter inputs.
Parameter
Downwash flag
Building height
Maximum building
horizontal dimension
Minimum building
horizontal dimension
Angle of maximum
horizontal dimension
relative to North
Angle of stack location
relative to North
Distance from stack to
building center
Use pre-existing
BPIPPRM input file
Invalid response
Response is not upper or
lower-case Y or N
Negative or non-numeric
Negative or non-numeric
Non-numeric, negative or
exceeds maximum
horizontal dimension
Non-numeric, less than
zero or exceeds 179
degrees
Non-numeric, less than
zero or exceeds 360
degrees
Negative or non-numeric
File does not exist
Processing flag in file
incorrectly set for
AERMOD or more than
one stack listed in file.
AERSCREEN.INP
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Prompts
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Issue message and stop
A-3
-------
Invalid meteorological data inputs.
Parameter
Minimum Temperature
Maximum Temperature
Minimum wind speed
Anemometer height
Surface code
Climatology code
User albedo
User Bowen Ratio
User surface roughness
AERSURFACE output
file
Invalid response
Non-numeric, negative (if
Kelvin), or minimum
temperature is equal to or
exceeds maximum
temperature
Negative or non-numeric
Negative or non-numeric
Non-numeric, negative or
greater than 9
Non-numeric, less than
lor exceeds 4 if surface
code between 1 and 8
inclusive
Non-numeric, negative, or
exceeds 1.0
Non-numeric
Negative or non-numeric
Does not exist (if surface
code = 9)
Surface characteristics
non-numeric, albedo is
negative or exceeds 1.0 or
surface roughness is
negative
AERSCREEN.INP
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop if
non-numeric.
Issue message and stop if
negative or exceeds 1.0
and surface code is 0
Issue message and stop if
non-numeric.
Issue message and stop if
non-numeric.
Issue message and stop if
negative and surface code
isO
Issue message and stop
Issue message and stop if
surface code is 9
Prompts
Re-prompt for
temperatures
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt for surface
characteristics type
Issue message and re-
prompt for surface
characteristics type
A-4
-------
Invalid terrain data inputs.
Parameter
Terrain flag
Latitude
Longitude
UTM Easting
UTM Northing
UTM zone
NAD code
Probe distance
Discrete receptor
flag
Discrete receptor file
Flagpole receptor
use flag
Flagpole height
Source elevation
AERMAP use flag
Demlisttxt
NADGRIDS
directory or folder
Invalid response
Response is not upper or lower-
case Y or N
Absolute value exceeds 90
degrees
Absolute value exceeds 180
degrees
N/A
N/A
Negative
Not equal to 1 or 4
Negative or less than minimum
ambient distance
Response is not upper or lower-
case Y or N
File does not exist
The number of distances exceeds
ten or negative distances found
Units line not included in file
Response is not upper or lower-
case Y or N
Negative or non-numeric
N/A
Response is not upper or lower-
case Y or N
File is not in current folder
No grid files are in directory or
folder or NADGRIDS keyword
not listed in demlist.txt
AERSCREEN.INP
Issue message and stop
N/A
N/A
N/A
N/A
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop (if
flagpole receptors used)
N/A
Issue message and stop
Issue message and stop
Issue message and stop
Prompts
Re-prompt
Re-prompt
Re-prompt
N/A
N/A
Re-prompt
Re-prompt
Re-prompt for probe
distance and minimum
ambient distance
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
N/A
Re-prompt
Issue message and stop
Issue message and stop
Invalid fumigation inputs.
Parameter
Inversion break-up
fumigation flag
Shoreline
fumigation flag
Distance to
shoreline
Direction from
source to shoreline
Run AERSCREEN
flag
Invalid response
Response is not upper or lower-
case Y or N
Response is not upper or lower-
case Y or N
Distance is greater than 3 km or
less than 0 km
Direction greater than 360 or
less than 0 but not equal to -9
Response is not upper or lower-
case Y or N; or if no fumigation
requested response is not upper
or lower-case Y
AERSCREEN.INP
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Issue message and stop
Prompts
Re-prompt
Re-prompt
Re-prompt
Re-prompt
Re-prompt
A-5
-------
-------
United States Office of Air Quality Planning and Standards Publication No. EPA-454/B-15-005
Environmental Protection Air Quality Assessment Division July 2015
Agency Research Triangle Park, NC
------- |