United States
               Environmental Protection
               Agency
                   Office of Air Quality
                   Planning and Standards
                   Research Triangle Park, NC 27711
EPA-454/B-96-001
October 1996
               Air
&  EPA
PCRAMMET User's Guide

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                                      EPA-454/B-96-001
                  PCRAMMET

                USER'S GUIDE
    U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Emissions, Monitoring, and Analysis Division
      Research Triangle Park, NC 27711

                October 1996

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                             NOTICE

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

     The following trademarks appear in this guide:

Microsoft is a registered trademark of Microsoft Corp.
Pentium and 80486 are registered trademarks of Intel, Inc.

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                         ACKNOWLEDGEMENTS

     Many individuals have assisted with time and energy, not
only in the preparation of this User's Guide, but also in the
long-term evolution of the PCRAMMET program.  Special thanks
should go to Russ Lee, Desmond Bailey, Jerry Moss, Jerry Mersch,
Joe Tikvart, and the original developer of the code, Joan Novak.
     Modifications to the source code and preparation of this
user's guide were performed by Jayant Hardikar and James Paumier
of the Modeling Section, Systems Development Group  (Roger Erode,
Manager) of Pacific Environmental Services, Inc., Research
Triangle Park, North Carolina.  The source code to process
precipitation data was developed by Earth Tech (formerly Sigma
Research, Inc.) of Concord, Massachusetts.  This effort was
funded by the U.S. Environmental Protection Agency under Contract
No. 68D30032, with Donna B. Schwede as Work Assignment Manager.
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                        TABLE OF CONTENTS

NOTICE  	   i

ACKNOWLEDGEMENTS	ii

TABLE OF CONTENTS	iii

TABLES  	   V

1    INTRODUCTION 	 1-1
     1.1  OVERVIEW	1-1
     1.2  DIFFERENCES FROM PREVIOUS VERSIONS  	 1-3
          1.2.1     User Interface	1-4
          1.2.2     Additional File Types	1-4
          1.2.3     Output Options	1-5

2    INPUT/OUTPUT DATA	2-1
     2.1. INPUT DATA	2-1
          2.1.1     Mixing Height Data	2-2
          2.1.2     Hourly Surface Observations 	 2-5
               2.1.2.1   CD-144 and SCRAM Formats 	 2-5
               2.1.2.2   SAMSON Format  	 2-6
          2.1.3     Precipitation Data - TD-3240 Format . .  . 2-9
     2.2  OUTPUT FILE	2-10

3    RUNNING PCRAMMET AND THE PROGRAM INTERFACE 	 3-1
     3.1. INTERACTIVE MODE	3-1
     3.2  BATCH MODE	3-15

4    TECHNICAL DISCUSSION 	 4-1
     4.1  TIME OF DAY	4-1
     4.2  HOURLY VALUES OF MIXING HEIGHT  	 4-1
     4.3  PASQUILL-GIFFORD STABILITY CLASSES  	 4-3
     4.4  WINDS	4-6
     4.5  TEMPERATURE	4-6
     4.6  QUALITY ASSURANCE 	 4-7
     4.7  DEPOSITION PARAMETER ESTIMATES  	 4-9
          4.7.1     Unstable Atmosphere 	 4-9
          4.7.2     Stable Atmosphere 	  4-13
          4.7.3     Parameters at the Application Site  . .  4-16

5    PCRAMMET PROGRAM NOTES 	 5-1
     5.1  COMPILING AND LINKING PCRAMMET  	 5-1
     5.2  PCRAMMET AND SCRAM	5-2

6    ERROR AND WARNING MESSAGES 	 6-1
     6.1  WARNING MESSAGES  	 6-1
     6.2  ERROR MESSAGES	6-3

7    REFERENCES	7-1
                                IV

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APPENDIX A     FILE FORMATS	A-1




APPENDIX B     TABLES OF SITE PROPERTIES	B-l

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                             TABLES

Table                                                        Page

2-1  Conversion of Reported Precipitation Type/Intensity to
     Precipitation Codes (Liquid)                            2-12

4-1  Insolation Classes as a Function of Solar Altitude for
     Cloud Cover <. 5/10                                       4-4

4-2  Stability Classification Criteria                        4-5

B-l  Surface Roughness Length,  in Meters, for Land-Use Types
     and Seasons                                              B-l

B-2  Albedo of Natural Ground Covers for Land-Use Types and
     Seasons                                                  B-2

B-3a Daytime Bowen Ratio by Land Use and Season - Dry
     Conditions                                               B-3

B-3b Daytime Bowen Ratio by Land-Use and Season - Average
     Conditions                                               B-3

B-3c Daytime Bowen Ratio by Land-Use and Season - Wet
     Conditions                                               B-4

B-4  Average Anthropogenic Heat Flux (Qf)  and Net  Radiation
     (Q*)  for Several Urban Areas                             B-5
                               VI

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                            SECTION   1

                           INTRODUCTION

     This Users Guide contains instructions for executing the
U. S. Environmental Protection Agency's PCRAMMET program on a
personal computer (PC).  PCRAMMET is a meteorological
preprocessor used for preparing National Weather Service (NWS)
data for use in the Agency's short term air quality dispersion
models such as ISCST3, RAM, BLP, SHORTZ, and COMPLEX1.  PCRAMMET
is not restricted for use only on a PC.   It is written in
standard FORTRAN-77 code which can be compiled and run on most
platforms.

     This section provides an overview of PCRAMMET and a
description of the differences between this version and previous
versions.  In Section 2, the input and output files are discussed
in detail and Section 3 presents the user interface and
instructions on running PCRAMMET.  Section 4 discusses the
technical aspects of the processing, while Section 5 presents
instructions on how to retrieve the program and hourly surface
observations and mixing heights from the SCRAM BBS.

1.1  OVERVIEW

     The user can provide the necessary information for
processing the meteorological input data in one of two ways:
1) as an interactive prompt/response session at the PC keyboard,
or 2) with a file of responses.  The response file is accessed by
including the filename as an argument on the command line.

     The operations performed by PCRAMMET include:
          •    Calculate hourly values for atmospheric stability
               from meteorological surface observations;
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          •    Interpolate twice daily mixing heights to hourly
               values;
          •    Optionally, calculate the parameters for dry and
               wet deposition processes; and
          •    Output data in the standard (PCRAMMET unformatted)
               or ASCII format required by regulatory air quality
               dispersion models.

     The input data requirements for PCRAMMET depend on the
dispersion model and the model options for which the data are
being prepared.  The minimum input data requirements to PCRAMMET
are the twice-daily mixing heights and hourly surface
observations of wind speed, wind direction, dry bulb temperature,
opaque (or total) cloud cover and ceiling height.  For dry
deposition estimates, station pressure is recommended, and for
wet deposition estimates, the precipitation type and the amount
are required for those periods during which precipitation was
observed.

     The surface and upper air stations should be selected for
their meteorological representativeness of the general area being
modeled.  Generally this criterion corresponds to the stations
closest to the source(s) being modeled and in the same
climatological regime (e.g., coastal, mountainous, plains).

     The hourly surface data can be obtained by request from the
National Climatic Data Center (NCDC) in Asheville, North
Carolina.  Observations in CD-144 format on diskette for a
specific year and station should be requested.  Precipitation
data can be obtained from NCDC by requesting data in TD-3240
format.  An alternative to the CD-144 and TD-3240 data is the
data available on the Solar and Meteorological Surface
Observation Network  (SAMSON) CD-ROMs.

     The mixing height data also can be obtained by request from
the NCDC  (TD-9689) in either diskette or tabular form by
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specifying 'twice daily mixing heights'  for specific year(s) and
station(s).

     The mixing height data and a compressed subset of the CD-144
data, with fewer weather elements, are available from the Support
Center for Regulatory Air Models  (SCRAM)  section on EPA's Office
of Air Quality Planning and Standards (OAQPS)  Technology Transfer
Network (TTN) bulletin board system (BBS).   The hourly weather
observations from SCRAM are not sufficient for use in wet
deposition or depletion calculations in ISCST3 because the SCRAM
data do not contain the present weather fields required to
determine the type of precipitation.

     The output data file format depends on the final processing
option specified by the user.  If the meteorological output are
to be used in an air quality model for concentration estimates
without deposition effects, then an unformatted file can be
written.  However, the user has the option to write an ASCII file
directly,  allowing the user to view the results without first
translating the unformatted file to an ASCII file.  The formatted
ASCII file has the advantage that it is independent of the
compiler and computing platform on which it is created.  If an
unformatted file is created, a formatted ASCII file can be
obtained from the unformatted file by using BINTOASC.EXE, a
program found with the ISCST3 and PCRAMMET files on the SCRAM
BBS.

     For dry and wet deposition processing in ISCST3, several
additional parameters must be written to the standard PCRAMMET
output file.  Due to this additional processing in ISCST3, there
is no option to write an unformatted PCRAMMET output file; the
output will always be an ASCII file.
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1.2  DIFFERENCES FROM PREVIOUS VERSIONS

     Several enhancements have been incorporated into PCRAMMET
that affect the operation of the preprocessor.   These
enhancements include: 1) the way the user supplies processing
information to the preprocessor (the interface), 2)  an increase
in the number and type of files that can be processed, and 3)
additional options for the type of processing.

1.2.1     User Interface

     In the previous version of PCRAMMET, only one type of
processing was performed and all the necessary information to
process the data was contained in the files.  With the expanded
capabilities, a new user interface was necessary.   With this
version of PCRAMMET, the user supplies the preprocessor with the
necessary information in one of two ways: interactive or batch.
In the interactive mode, the user responds to on-screen prompts,
with particular responses to some prompts determining subsequent
prompts, i.e., the type of data and the output requirements
determines which prompts are displayed.  Once the responses are
entered, PCRAMMET begins execution.  The responses to the prompts
are saved in a file for later use.  A complete discussion of this
mode is provided in Section 3.1.

     In the second mode, the batch mode, the user runs PCRAMMET
using command line arguments.  There are two arguments on the
command line following the program name: (I) the name of the file
containing the responses to the prompts that would appear in an
interactive mode, and (2) the name of the output file.  A
discussion of this mode is provided in Section 3.2.
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1.2.2     Additional File Types

     In addition to the hourly surface weather observations in
the CD-144 format and the twice-daily mixing heights, several
additional file types can now be processed by PCRAMMET.  Hourly
surface observations (with precipitation data, if needed)
retrieved from SAMSON CD-ROM can be used in PCRAMMET.  The SAMSON
data are on a three CD-ROM set and contain radiation
measurements, weather observations and precipitation data from
the first order stations in the United States for the period
1961-1990.

     PCRAMMET can now process the CD-144 hourly surface
observations that are on OAQPS' SCRAM bulletin board in the
compressed format (i.e., shorter records).  Previously, the user
had to use a program to expand the SCRAM  (28-character) format
to the CD-144 (80-character) format.  Now, the user can use the
SCRAM files directly in PCRAMMET.  This format is referred to as
the SCRAM format in the remainder of this user's guide.

     The ISCST3 model can estimate, at the option of the user,
wet deposition.  To make this estimate, precipitation data are
required.  This version of PCRAMMET can process precipitation
data in the TD-3240 format  (NCDC) or from the SAMSON CD-ROM.
Both the variable length and fixed length formats can be
processed.  Generally, the data are ordered (from NCDC) in the
variable length format.

     These formats are discussed in more detail in Section 2.

1.2.3     Output Options

     Previous versions of PCRAMMET output an unformatted (binary)
file with hourly values of winds, temperature, stability and
mixing heights.  If the user required an ASCII file, a separate
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program had to be run on the unformatted data.   With this version
of PCRAMMET, the user has the option to write an ASCII output
file.

     The user has the option to estimate the parameters required
for dry or wet deposition estimates in ISCST3.   If the user
selects one of these options, then an ASCII output file is
created (an unformatted file is not an option)  with additional
parameters for dry deposition and wet deposition estimates.
Section 3.1, item(11) describes the additional parameters need
for deposition modeling.
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                            SECTION  2

                        INPUT/OUTPUT DATA

     PCRAMMET processes five input data formats: 1) CD-144 hourly
surface observations, 2) twice-daily mixing height data,
3) hourly surface observations retrieved from SCRAM, 4) hourly
surface observations, including precipitation data, archived on
CD-ROM, and 5) precipitation data  (TD-3240 format).

     If meteorological data are to be used as input to an air
quality model only to estimate concentration, the user has the
option of creating an unformatted  (binary) or ASCII output file.
If deposition estimates are required, the output file is created
as an ASCII file.

     In this section, the input data and output files are
discussed.  The file structures are provided in Appendix A.

2.1. INPUT DATA

     The input data requirements for PCRAMMET depend on the
dispersion model and the model options for which the data are
being prepared.  For concentration estimates for which the effect
of settling and removal processes of dry and wet deposition are
not required, the necessary data are:
          •    Wind direction
          •    Wind speed
          •    Dry bulb temperature
          •    Opaque (or total) cloud cover
          •    Cloud ceiling height
          •    Morning mixing height
          •    Afternoon mixing height.
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The mixing heights are based on NWS upper air soundings at 1200
GMT and 0000 GMT, respectively.

     For dry deposition estimates in ISCST3, one additional
variable is needed:
          •    Station pressure.

Station pressure is used only to compute the density of dry air.
If station pressure is missing, then a value of 1000 mb is
automatically substituted.

     For wet deposition estimates in ISCST3, additional data
requirements are:
          •    precipitation amount
          •    present weather  (for use in determining
               precipitation type).
The precipitation type is determined from the present weather
codes in the hourly surface observations, which indicates whether
the type of precipitation is liquid or frozen.  The hourly
precipitation amount is obtained from a separate file.

2.1.1     Mixing Height Data

      Previous versions of PCRAMMET required a header record,
which is no longer needed.  This record is no longer required.
However, PCRAMMET can read mixing height files that contain this
record - the record will simply be ignored.  The header record,
if present, contains the following information:
          •    NWS meteorological surface station number,
          •    Year of surface data,
          •    Latitude of the surface station,
          •    Longitude of the surface station, and
          •    Time zone of the surface station.
                               2-2

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     The structure of the mixing height file for this version of

PCRAMMET is as follows:

     •    Mixing height record for December 31 of the year
          preceding the year of record;

     •    Mixing height record for January 1 of the year of
          record;

     •    Mixing height record for January 2 of the year of
          record;
     •    Mixing height record for December 30 of the year of
          record;

     •    Mixing height record for December 31 of the year of
          record;

     •    Mixing height record for January 1 of the year
          following the year of record (or duplicate of the
          December 31 record with year, month, day changed).


     The format of the mixing height data corresponds to the

format of the data that are available on the SCRAM BBS, which is

described in Appendix A.  Each record contains the following

information:


     •    Upper Air Station Number - the Weather Bureau Army Navy
          (WBAN) station identification number identifying the
          NWS upper air observation station used to calculate
          mixing heights.  The List of Upper Air Stations
          available from NCDC tabulates such WBAN numbers.  The
          station must be representative of the site to be
          modeled.

     •    Year - the last two digits of the year of record for
          the mixing height data.

     •    Month - the month number corresponding to a given set
          of mixing heights.

     •    Day - the calendar day number corresponding to a given
          set of mixing heights.


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     •    Nocturnal Urban Mixing Height - the minimum mixing
          height for a given day calculated from the 1200 GMT
          upper air sounding on that day, using morning surface
          temperature augmented by 5°C to account for urban
          heating.
     •    Afternoon Mixing Height - the maximum mixing height for
          a given day calculated from the afternoon surface
          temperatures and the 1200 GMT upper air sounding for
          that day.

Each record also contains additional information on wind speed
and general weather conditions that are not processed by
PCRAMMET.
     The method for calculating hourly mixing heights from the
twice daily mixing heights uses the methods suggested by
Holzworth (1972).  This method interpolates the mixing heights
using the afternoon mixing height from the preceding day and both
mixing heights from the following day.  For this reason, the
mixing heights for the last day of the year preceding the year of
record must be included as the first mixing height record and the
mixing heights for the first day of the year following the year
of record must be included as the last mixing height record.  If
these data are not available, the data for the first and last
days of the year of record can be substituted, respectively.  A
discussion of the interpolation method can be found in Section 4.

     The mixing height records input to PCRAMMET must contain the
morning and afternoon mixing heights for the day being processed.
Quality checks are not performed on mixing height data input to
PCRAMMET, and so it is recommended that the user review these
data for completeness.   A blank in a mixing height field is
interpreted as a zero, i.e., the mixing height is assumed to be
at the surface.

     The twice daily mixing height values can be purchased from
the National Climatic Data Center  (TD-9689 format) or downloaded

                               2-4

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from the SCRAM BBS.  Note that the field position of the
afternoon mixing height in the NCDC file is not the same as the
position in the files from the SCRAM BBS (See Appendix A).  The
NCDC format has the afternoon mixing height in columns 25-28 and
the PCRAMMET format has the afternoon mixing height in columns
32-35.  Therefore, the user should reformat the NCDC file to
conform to the data format available on SCRAM.

2.1.2     Hourly Surface Observations

     Hourly observations of surface weather can be obtained from
three sources: CD-144, SCRAM and SAMSON CD-ROM.  The CD-144
format is the traditional format processed by PCRAMMET.  SCRAM is
a reduced version  (fewer weather variables) of the CD-144 data
and is available on the OAQPS1 TTN bulletin board.  The SAMSON
data take advantage of the expanding technologies of personal
computers in the area of CD-ROM.  Only one of these formats can
be processed in a single PCRAMMET run.

2.1.2.1   CD-144 and SCRAM Formats

     The CD-144 format refers to the "Card Deck 144 format"
available from the NCDC.  The file is composed of one record per
hour, with all weather elements reported in an 80-column card
image.  The format of these records is described in the Card Deck
144 WBAN Hourly Surface Observations Reference Manual  (NOAA,
1970), also available from the NCDC.  Data in this file that are
checked or used by PCRAMMET includes the station number, year,
month, day, hour, cloud ceiling height, wind direction, wind
speed, dry bulb temperature, and opaque cloud cover, or total sky
cover if opaque is missing  (Appendix A).  The surface data files
downloaded from the SCRAM BBS contain these five weather elements
in a compressed format.  The weather variables not required in
the computations are omitted and the blank fields removed to
create a 28-character record.  The SCRAM format can be processed
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directly by PCRAMMET or the data may be expanded to the 80-

character records for input into PCRAMMET (See Program Notes in
Section 5).


     The variables used by PCRAMMET from the CD-144 record
include the following:


     •    Surface Station Number - the WBAN number identifying
          the NWS surface observation station for which hourly
          meteorological data are input to the PCRAMMET program.

     •    Year, Month and Day of Record - identifies the year,
          month and day during which the meteorological data were
          observed.  Only the last two digits of the year are
          reported.

     •    Hour - identifies the hour of the meteorological data
          observation.  Hour is based on the 24-hour clock and is
          recorded as 00 through 23.  Times are Local Standard
          Time (LST) and are adjusted in PCRAMMET to the 01 - 24
          clock in which hour 24 is the same as hour 00 of the
          next day.

     •    Ceiling Height - the height of the cloud base above
          local terrain and is coded in hundreds of feet.

     •    Wind Direction - the direction from which the wind is
          blowing, based on the 36 point compass, e.g. 09=East,
          18=South, 27=West, 36=North, 00=Calm.

     •    Wind Speed - the wind speed measured in knots
          (00=Calm).

     •    Dry Bulb Temperature - the ambient temperature measured
          in whole degrees Fahrenheit.

     •    Cloud Cover - There are two cloud cover parameters,
          opaque cloud cover and total cloud cover in the CD-144
          and SCRAM meteorological data files.  Both parameters
          identify the amount of cloud cover measured in tens of
          percent, e.g., 0 = clear or less than 10%, 4 = 40-49%,
          •-' = overcast or 100%.  PCRAMMET reads the field for
          opaque cloud cover.
                               2-6

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2.1.2.2   SAMSON Format

     With the advent of CD-ROM for the personal computer, large
amounts of data can be stored in small amounts of space.  NCDC
has made available solar and meteorological data for the first
order stations in the United States for the period 1961-1990 on a
set of three CD-ROMs, referred to as the SAMSON data.  PCRAMMET
processes the data retrieved from these CD-ROMs.

     PCRAMMET cannot access the data directly from a SAMSON CD-
ROM.  Rather, the user must run the software provided with the
data to retrieve the station(s), period(s)  of time and variables
for the site and period to be modeled.  The software is a DOS-
based, interactive graphical interface and is user-friendly.  The
output files are written in an ASCII file on the user's local
drive.

     The software used to extract data from the CD-ROMs can
retrieve multiple years of data for a single station and save it
in the same file.  However, PCRAMMET expects a maximum of one
year of data in a data file retrieved from a SAMSON CD-ROM.  The
reason for this restriction is explained below.

     Retrieving data from the CD-ROM is completely under the
control of the user.  When data are retrieved from the CD-ROMs,
the user has the option to specify which variables to retrieve
from a list of 21 variables stored for each station.  At a
minimum, the ceiling height, wind direction and speed, dry bulb
temperature and opaque cloud cover should be retrieved  (to be
compatible with the data in the files on SCRAM).  These variables
are sufficient for most of the models listed in Section 1, and
results in an ASCII file of about 400 Kb for one year of data.
However, if dry deposition and/or wet deposition estimates are to
be made with ISCST3, then several additional variables should be
retrieved.  These are: station pressure for dry deposition
                               2-7

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(resulting in a file size of about 445 Kb),  and present weather
and hourly precipitation amount for wet deposition (resulting in
a file size of about 537 Kb).   If all of the variables are
retrieved, then a file size of about 1.2 Mb is created.  When
precipitation data are retrieved, the size will vary because
precipitation amount is the last field and is filled only if
there was precipitation for the hour, making some records longer
than others.

     When the data are retrieved from the CD-ROM, two records are
written at the beginning of the file that identify the station
(first record) and the variables retrieved (second record).
PCRAMMET processes both of these records to obtain information
about the station  (e.g., latitude and longitude) and to determine
how to process the data that follow.  It is imperative that the
user not alter or delete these records.  These two records begin
with the tilde character (~) .  If more than one year of data are
retrieved from the CD-ROMs, these two records appear before each
year in the file.  If more than one year of data are in the file,
the program will terminate with a compiler-issued error when
PCRAMMET encounters the second set of header records.  The
program expects an integer value  (the year), but encounters a
character value  (the tilde).  However, the output for  the
previous year will be complete and intact.  It  is recommended
that the user restrict data retrieved from CD-ROM to one  station
and one year per file.

     PCRAMMET examines the  second record to determine  if  the
variables retrieved from the CD-ROM  are sufficient to  process  the
entire  file according to the user's  responses on how the  output
is expected to be  used.  If there are insufficient data,  then
PCRAMMET  writes  an error message  and stops processing.  The user
must either select a different processing option, or return to
the CD-ROMs and  retrieve the data once  again, making sure to
                                2-8

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retrieve all of the necessary variables to generate the
meteorological data output file.

     The header records are followed by the data records.  There
is one record for each hour of the time period the user
retrieved.  Unlike the CD-144 format which reports the hour on
the 00-23 clock, the hour is reported on the 01 - 24 clock.
Hour 24 of a day retrieved from SAMSON corresponds to hour 00 of
the next day for CD-144 data, i.e., the time adjustment that
PCRAMMET must go through for CD-144 data is not necessary with
SAMSON.

     Data stored in the SAMSON format are in different units than
found in the CD-144 data.  For the output to be identical from
both input formats, PCRAMMET converts the SAMSON data to the
units that are in the CD-144 data.

2.1.3     Precipitation Data - TD-3240 Format

     For wet deposition estimates from ISCST3, the dispersion
model requires the amount of precipitation as well as the
precipitation type (liquid or frozen).  The precipitation type is
obtained from the present weather fields in the hourly surface
observation files (CD-144 or SAMSON) and converted to a
precipitation code that the dispersion model interprets.  The
precipitation amount is not reported with the standard CD-144
data.  Therefore, another file of precipitation amount is
required for wet deposition processes when CD-144 data is used.

     The TD-3240 data format from NCDC contains the necessary
precipitation amount.  In addition to supplying the precipitation
data when CD-144 data are processed, these data can be used to
supplement the SAMSON precipitation data in the event there are
little or no precipitation data for a station (there are about 20
                               2-9

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such stations which are noted in the SAMSON online help),  or if
precipitation was not retrieved from the CD-ROMs.

     The TD-3240 data as received from NCDC are usually in a
variable-length format.  In this format, precipitation data for
the entire day is stored on one record, and only for those hours
during which precipitation was reported.  A fixed-length format
is also available in which one record contains the precipitation
amount for one hour.  As with variable-length files, data are
stored only for those days and hours for which precipitation was
reported. PCRAMMET can process both formats.  For variable-length
formats, the preprocessor converts the data to a fixed-length
format, writes the results to a scratch file and uses the scratch
file for processing.  The scratch file is deleted at the end of
the run.

     Precipitation is reported in inches and hundredths of an
inch in the TD-3240 format.  These units are converted to
millimeters for use in the ISCST3 dispersion model.

2.2  OUTPUT FILE

     The first record in the output file from PCRAMMET contains a
file identification record followed by one record for each day in
the year.  The file identification record contains the year of
record for the surface meteorological data, the surface station
identification number, the year of record for the mixing height
data, and the upper air station identification number.

     If the user specifies that no (dry or wet) deposition
estimates are to be performed with the output data set, then the
user has the option of creating an unformatted (binary) or ASCII
output file.  The binary output from PCRAMMET consists of one
record with the year, month, and the Julian day followed by 24
values of stability class, wind speed, temperature, flow vector,
                               2-10

-------
randomized flow vector, and rural and urban mixing heights.  The
ASCII file contains the same information except that each hour is
written as a separate record.

     The four values on the file identification record and the
year, month, Julian day and stability class record are written as
FORTRAN integer variables.  All other values on the daily records
are FORTRAN real number variables.  See Appendix A for a
description of the arrangement of the variables on each of the
daily records.

     If an unformatted file is written, all records on the output
file are written with an unformatted FORTRAN write statement.
Thus, the resulting output file structure will be dependent upon
the FORTRAN compiler used to create the PCRAMMET executable.  As
a result, to maintain compatibility with the unformatted file,
the models requiring its use must also have been created using
the same compiler.  Most executables on the SCRAM BBS requiring
the use of the PCRAMMET unformatted output file have been created
using the Microsoft™ or  Lahey™ FORTRAN compiler.

     For dry deposition estimates, three additional fields are
written to the output file: surface friction velocity (u,) ,
Monin-Obukhov length  (L), and surface roughness length (z0) .
Stull  (1988) provides a good discussion of these parameters.  The
output file is in ASCII only.

     For wet deposition,  the three parameters for dry deposition
plus two additional parameters are written: precipitation type
(which is based on the present weather codes in the hourly
surface observation file) and the precipitation amount.  The
output is in ASCII only.   Table 2-1 below shows how the reported
precipitation type and intensity are converted to the
precipitation codes that are written to the output file.
                               2-11

-------
                       TABLE  2-1

Conversion of Reported Precipitation Type/Intensity to
             Precipitation Codes (Liquid)
Precipitation Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Type
Rain
Rain
Rain
Rain Showers
Rain Showers
Rain Showers
Freezing Rain
Freezing Rain
Freezing Rain
(not used)
(not used)
(not used)
Drizzle
Drizzle
Drizzle
Freezing Drizzle
Freezing Drizzle
Freezing Drizzle
Intensity
Light
Moderate
Heavy
Light
Moderate
Heavy
Light
Moderate
Heavy
.
.
-
Light
Moderate
Heavy
Light
Moderate
Heavy
                          2-12

-------
                   TABLE  2-1,  continued

Conversion of Reported  Precipitation Type/Intensity  to
              Precipitation Codes  (Liquid)
Precipitation Code
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Type
Snow
Snow
Snou
Snow Pellets
Snow Pellets
Snow Pellets
(not used)
Ice Crystals
(not used)
Snow Showers
Snow Showers
Snow Showers
(not used)
(not used)
(not used)
Snow Grains
Snow Grains
Snow Grains
Ice Pellets
Ice Pellets
Ice Pellets
(not used)
Hail
(not used)
(not used)
Small Hail
(not used)
Intensity
Light
Moderate
Heavy
Light
Moderate
Heavy
.
*
.
Light
Moderate
Heavy
.
.
_
Light
Moderate
Heavy
Light
Moderate
Heavy
.
*
.
.
*
-
     *  Intensity not reported for ice crystals, hail and small hail.
                           2-13

-------
                            SECTION  3

            RUNNING PCRAMMET AND THE  PROGRAM  INTERFACE

     The user supplies the necessary processing information to
PCRAMMET in one of two ways: 1) interactively, responding to
program prompts, or 2) in a batch mode using a file that contains
the responses to the prompts that would appear during an
interactive session (referred to as a response file).  In this
section, these two methods of providing information to PCRAMMET
are presented.  It is recommended that PCRAMMET be run in the
interactive mode until the user gains familiarity with the
various prompts and is comfortable constructing or modifying
response files.

3.1. INTERACTIVE MODE

     The user can enter the information needed by PCRAMMET by
responding to a series of screen prompts from PCRAMMET.
Particular responses will affect subsequent prompts.  In other
words, not every PCRAMMET run will have the same set of prompts.
PCRAMMET records the users responses in an annotated file named
INPUTS, which can be used to run PCRAMMET with command line
arguments, as discussed in Section 3.2.

     To start the interactive mode, the user types PCRAMMET at
the DOS prompt followed by pressing ENTER.  The following is the
sequence of prompts that appear on screen and a description of
the expected responses.  Note that not all prompts will be
displayed for every run of PCRAMMET.   The prompts depend on what
the output will be used for and the data formats to be used.
Some of the prompts discussed below have been grouped together
because either (1)  all will appear or (2)  none will appear
(again, depending on previous responses).   The responses can be
entered in upper or lower case - PCRAMMET converts many of the
                               3-1

-------
character responses to upper case for correct processing.  When a
filename is entered, it must conform to the computer platform's
file naming conventions.  On a DOS platform, this is an optional
path followed by an 8-character file plus 3-character extension.
The maximum length for a path\filename.extension is 40
characters.  PCRAMMET attempts to catch any errors the user makes
when entering responses.  A message is displayed and the program
prompts for a new response.  If a valid, but incorrect, response
is entered, simultaneously pressing the 'control1 and  'C' or
'control' and 'break' keys simultaneously will return the user to
the DOS prompt.

     The prompts and possible or expected responses are:

1)   Will you be making any dry or wet deposition calculations?
     None / Dry / Wet :
          The user can respond with NONE (N), DRY (D) or WET  (W) ,
          corresponding to no deposition, dry deposition, or wet
          and dry deposition, depending on the dispersion model
          application.  The first letter of the response also can
          be used here.

2)   Enter the OUTPUT filename:
          The name of the file where the output is to be written
          is entered at this prompt.

3)   Enter the output file type:
      Unform / Ascii  :
          This prompt is seen only  if NONE  (or N) is the response
          to the type of calculation  (in (1) above).  Valid
          responses are UNFORM  (or  U) and ASCII  (or A).  UNFORM
          will produce the unformatted  file generated  by previous
          versions  of PCRAMMET.
                                3-2

-------
4)   Enter MIXING HEIGHT data filename:
          The name of the file containing the twice-daily mixing
          heights is entered at this prompt.   If the file does
          not exist (e.g., the user misspells the name), PCRAMMET
          immediately displays an error message and prompts for
          the filename again.

5)   Enter the HOURLY SURFACE DATA filename:
          The name of the file containing the hourly weather
          observations is entered at this prompt.  If the file
          does not exist  (e.g., the user misspells the name),
          PCRAMMET immediately displays an error message and
          prompts for the filename again.

6)   Enter surface data format:
     GDI44 or SAMSON or SCRAM :

          Valid responses are CD144, SCRAM and SAMSON.  These
          formats are explained in detail in Section 2.  CD144
          corresponds to the format that previous versions of
          PCRAMMET have used, SCRAM refers to the format
          available on OAQPS1 TTN bulletin board, and SAMSON
          refers to data the user has retrieved from CD-ROM.

7)   Enter the latitude of the surface station in decimal degrees
     - positive for stations north of the equator:

     Enter the longitude of the surface station in decimal degrees
     - positive for stations *WEST* of Greenwich:

     Enter the time zone of the surface station
     - positive for stations WEST of Greenwich:

          These three prompts are seen only if the surface data
          format is CD144 (in  (6) above) or SCRAM.  The user
                               3-3

-------
          enters the latitude and longitude,  in decimal degrees,
          that correspond to the location where the hourly
          surface observations were taken.   For the output using
          CD-144 and SCRAM input data to agree with the output
          using SAMSON input data,  the latitude and longitude
          should be specified with four or more digits after the
          decimal.

          If the user is unsure about the correct values to enter
          here, the latitude, longitude, and time zone for all
          sites on the SCRAM BBS are available from the
          Meteorological Data Main Menu.  Select  Station
          Lat/Long Values Search from this menu and enter the
          station number or station name when asked to enter a
          search key.  Alternatively, NCDC has available a manual
          of latitude and longitude by station name and WBAN
          number.  SAMSON data contain this information within
          the file, so PCRAMMET does not request it.  Note: These
          prompts/responses and the station and date information
          in SAMSON data files replace the initialization record
          that appeared in the mixing height file for previous
          versions of PCRAMMET.

8)    SAMSON data may already contain hrly precip
      Do you want to supplement with TD-3240 data?
      Yes / No :
          This prompt is seen only if the response to the type of
          calculation (in (1) above) is WET and the surface data
          format is SAMSON (in (6)  above).  Valid responses are
          YES  (or Y) and NO  (or N).  If the user answers with
          YES, the user specifies the filename of TD-3240
          precipitation data to use  (in  (9) below) in the event
          the SAMSON data retrieved from CD-ROM lacks
          precipitation data.
                               3-4

-------
9)    Enter HOURLY PRECIP DATA filename:
          This prompt is seen only if the response to the type of
          calculation (in (1) above)  is WET and the surface data
          format (in (6) above) is CD144, oj: if the SAMSON data
          are to be supplemented (in (8) above).   The name of the
          file containing the precipitation data in NCDC's TD-
          3240 format is entered at this prompt.   If the file
          does not exist (e.g., the user misspells the name),
          PCRAMMET immediately displays an error message and
          prompts for the filename again.

10)  Enter precipitation file format
     Variable or Fixed:
          This prompt is seen only if the response to the type of
          calculation (in (1) above ) is WET.  Valid responses
          are VARIABLE  (or V) and FIXED  (or F).  These terms are
          explained in Section 2.1.3.

11)  For deposition, site characteristics are needed
          If the response to the type of calculation (in (1)
          above) is DRY or WET, then PCRAMMET prompts the user
          for properties representative of the measurement and
          application sites.  These properties are required for
          dry and wet deposition calculations that are performed
          with the ISCST3 model.  For many of these site
          characteristics, if the user enters an invalid value
          (e.g., a roughness length less than zero), a message is
          shown on the screen and the prompt is redisplayed.

          The following are more detailed explanations of the
          information required to respond to the prompts.

     Minimum Monin-Obukhov Length - Stable Conditions fmeters)
     The Monin-Obukhov length is a measure of atmospheric
     stability.  It is negative during the day when surface
                               3-5

-------
heating results in an unstable atmosphere and positive at
night when the surface cools (stable atmosphere).   Values
near zero indicate very unstable or stable conditions
(depending on the sign).  In urban areas during stable
conditions, the estimated value of L may not adequately
reflect the less stable boundary layer.  Hanna and Chang
(1991) point out that mechanical turbulence generated by
obstacles (buildings) in urban areas will tend to produce a
"more neutral" surface layer than that over an unobstructed
site.  They suggest that a minimum value of L be set for
stable hours in order to simulate this effect.  Using an
approximate relation between obstacle height and the zone of
flow affected by an obstacle, they suggest the following
minimum values for several urban land use classifications:
     agriculture (open)                 2m
     residential                        25m
     compact residential/industrial     50m
     commercial (19-40 story buildings) 100m
                (> 40 story buildings)  150m

Anemometer Height (meters)
The height at which the winds were measured.  For data
observed at airports, this value can range from about 6
meters (20 feet) to 9 meters (30 feet).  The user must
determine the anemometer height.  A good source is the set
of Local Climatological Data Annual Summaries, available
from NCDC.  These summaries contain information about the
instrumentation at the end of each station's data entry for
the entire period of record.

Surface Roughness Length - Measurement Site (meters)
The surface roughness length is a measure of the height of
obstacles to the wind flow.  It is not equal to the physical
dimensions of the obstacles, but is generally proportional
to them.  Typical values for a range of land-use types as a
function of season are listed in Table B-l.  At this prompt,
                          3-6

-------
the user enters a value representative of the site where the
winds were measured, e.g., an airport.

Surface Roughness Length - Application Site (meters)
At this prompt, the user enters a roughness length
representative of the site where the meteorological output
are to be applied.  The discussion above for the roughness
length at the measurement site also applies here.

Noon-time Albedo
Noon-time albedo is defined as the fraction of the incoming
solar radiation that is reflected from the ground when the
sun is directly overhead.  Adjustments are made
automatically within PCRAMMET for the variation in the
albedo with solar elevation angle.  A range of values is
given in Table B-2 as a function of several land-use types
and season.

Bowen Ratio
The Bowen ratio is a measure of the amount of moisture at
the surface.  The presence of moisture at the earth's
surface alters the energy balance, which in turn alters the
sensible heat flux and Monin-Obukhov length.  A range of
values is given in Tables B-3a, 3b and 3c as a function of
land-use types, seasons and moisture conditions.

Anthropogenic heat flux (W/ro2)
The anthropogenic heat flux can usually be neglected (set
equal to zero) in areas outside highly urbanized locations.
However, in areas with high population densities or high
energy use, this flux may not always be negligible.  Oke
(1978) presents estimates of population density and per
capita energy use for 10 cities and obtains a heat flux for
each.  Summertime values are typically 50% of the mean,
while wintertime values are about 150% of the mean in the
                          3-7

-------
colder climates.  Table B-4 provides guidance for several
urban areas.

Fraction of Net Radiation Absorbed at the Ground
The flux of heat into the ground during the daytime is
parameterized as a fraction of the net radiation.  Values
suggested by Oke (1982) are:
     rural          0.15
     suburban       0.22
     urban          0.27

The three types of calculation (NONE, DRY and WET) and two
hourly surface observation formats (CD-144 and SAMSON) yield
six combinations of prompts (others are possible, depending
on responses, but these are the main categories that have an
affect on subsequent prompts).  The following tables can be
referred to by the user to assist in which prompts to expect
for the six combinations.  The prompts and responses when
using SCRAM data would be the same as for CD-144 data except
for the response to the "Surface Data Format" prompt.
                           3-8

-------
                             NO  DEPOSITION,  CD-144  DATA
         Program Prompt
          User Response
                                                                                Comments
Calculation Type

Output Filename
Output File Type
Mixing Height Filename
Hourly Surface Obs. Filename
Surface Data Format

Station Latitude
Station Longitude
Station Time Zone
NONE (or N)

output_filename
UNFORM (or U)  or  ASCII  (or A)
mi x i ng_he i gh t_fiIename
surface_data_fiIename
CD 144

station latitude
station longitude
time zone (5=Eastern, 6=Central,
7=Mountain, 8=Pacific)	
Output cannot be used for
deposition estimates in ISCST3
Does not  appear in response file
Data from SCRAM can be used -
respond with SCRAM
decimal degrees
decimal degrees
integer
                             NO  DEPOSITION,  SAMSON  DATA
         Program Prompt
                                           User Response
                                              Comments
Calculation Type

Output Filename
Output File Type
Mixing Height Filename
Hourly Surface Obs. Filename
Surface Data Format
NONE (or  N)

output_filename
UNFORM (or U)  or  ASCII  (or A)
mixing_height_filename
surface_data_fiIename
SAMSON
Output cannot be used for
deposition estimates in ISCST3
Does not  appear in response file
                                                                    latitude,  longitude and time  zone
                                                                    are in  the data file
                                               3-9

-------
                             DRY DEPOSITION,   CD-144  DATA
         Program Prompt
          User  Response
            Comments
Calculation Type

Output Filename

Mixing Height Filename
Hourly Surface Obs.  Filename
Surface Data Format

Station Latitude
Station Longitude
Station Time Zone

Minimum Monin-Obukhov Length
Anemometer Height
Surface Roughness Length -
Measurement Site
Surface Roughness Length -
Application Site
Noontime Albedo
Bowen Ratio
Anthropogenic Heat Flux
Fraction of Net Radiation
Absorbed at the Ground
DRY (or D)

output_filename

mixing_height_filename
surface_data_filename
CD 144

station latitude
station longitude
time zone (5=Eastern, 6=Central,
7=Mountain, 8=Pacific)
Output cannot  be  used  for wet
deposition estimates in  ISCST3
ASCII is only  output file type;
does not appear in  response file
SCRAM data lack  station pressure;
a default of  1000 mb  is used if
SCRAM data are used
decimal  degrees
decimal  degrees
integer

meters
meters
meters

meters

between  0.0 and  1.0
0.5 = very moist,  10.0 = very dry
0 for rural,  100 for  large urban
0.15 for rural,  0.27  for urban
                                                3-10

-------
                             DRY  DEPOSITION,  SAMSON  DATA
         Program Prompt
          User Response
            Comments
Calculation Type

Output Filename

Mixing Height  Filename
Hourly Surface Obs. Filename
Surface Data Format
Minimum Monin-obukhov Length
Anemometer Height
Surface Roughness Length -
Measurement Site
Surface Roughness Length -
Application Site
Noontime Albedo
Bowen Ratio
Anthropogenic  Heat Flux
Fraction of Net Radiation
Absorbed at the Ground
DRY (or D)

output_filename

mixing_height_filename
surface_data_filename
SAMSON
Output cannot be used for wet
deposition estimates in ISCST3
ASCII  is only output file type;
does not appear in response file
                                  meters
                                  meters
                                  meters

                                  meters

                                  between 0.0 and 1.0
                                  0.5 = very moist,  10.0  = very dry
                                  0 for rural, 100 for  large urban
                                  0.15 for rural,  0.27  for urban
                                               3-11

-------
                             WET  DEPOSITION,   CD-144  DATA
         Program Prompt
          User Response
                                                                                  Comments
Calculation Type
Output Filename

Mixing Height Filename
Hourly Surface Obs.  Filename
Surface Data Format

Station Latitude
Station Longitude
Station Time Zone

Hourly Precipitation Filename
Precipitation File Format
Minimum Monin-Obukhov Length
Anemometer Height
Surface Roughness Length  -
Measurement Site
Surface Roughness Length  -
Application Site
Noontime Albedo
Bowen Ratio
Anthropogenic Heat Flux
Fraction of Net Radiation
Absorbed at the Ground
WET (or W)
output_filename

mi x i ng_he i gh t_fiIename
surface_data_fiIename
CD 144

station latitude
station longitude
time zone (5=Eastern, 6=Central,
7=Mountain, 8=Pacific)
prec i p_data_f i I ename
VARIABLE (or V)  or FIXED (or F)
ASCII is only output  file type;
does not appear  in  response file
SCRAM data lack present weather;
do not use the SCRAM  format for
wet deposition in ISCST3
decimal degrees
decimal degrees
integer
                                   meters
                                   meters
                                   meters

                                   meters

                                   between 0.0 and 1.0
                                   0.5 = very moist,  10.0 =  very dry
                                   0 for rural, 100 for large urban
                                   0.15 for rural, 0.27 for  urban
                                                3-12

-------
                             WET DEPOSITION,   SAMSON  DATA
         Program Prompt
          User Response
                                                                                 Comments
Calculation Type
Output File Name

Mixing Height Filename
Hourly Surface Obs.  Filename
Surface Data Format
Supplement SAMSON  Precipitation
Data with TD-3240?
Hourly Precipitation Filename

Precipitation File Format

Minimum Monin-Obukhov Length
Anemometer Height
Surface Roughness  Length -
Measurement Site
Surface Roughness  Length -
Application Site
Noontime Albedo
80wen Ratio
Anthropogenic Heat Flux
Fraction of Net Radiation
Absorbed at the Ground
WET (or V)
output_filename

mi x i ng_hei ght_f iIename
surface_data_filename
SAMSON
YES (or Y)  or  NO (or N)

prec i p_data_f iIename

VARIABLE (or V)  or FIXED (or F)
ASCII is only output file type;
does not appear in  response file
prompted only if  using TD-3240 as
supplemental  data
prompted only if  using TD-3240 as
supplemental  data
meters
meters
meters

meters

between 0.0 and 1.0
0.5 = very moist,  10.0 = very dry
0 for rural,  100  for  large urban
0.15 for rural, 0.27  for urban
                                               3-13

-------
     When the user responds to  the  final  prompt,  PCRAMMET begins
processing the data.  The  current year/month/day are displayed as
each day is processed.   Depending on the  system used, the runtime
for PCRAMMET is from  35  seconds on  a 80486 33  MHz system to 10
seconds on a 90 MHz Pentium.  On completion, the following
message is displayed:

     Your responses to the program prompts have  been written to the file
"INPUTS."
        See the  file PCRAM.LOG for a review this run

The message indicates that the  responses  provided during the
interactive input (excluding  the output filename) can be found in
the file "INPUTS."  This file can be used for  subsequent runs of
PCRAMMET (as described  below).   The second line indicates that a
summary of the run is located in the file PCRAM.LOG.  This file
is an ASCII file  that can be  viewed with  any text editor or typed
to the  screen.

     In addition, if  PCRAMMET wrote any warning messages to the
log file, then the following  message appears:

        *** Warning messages were generated by PCRAMMET and are in PCRAM.LOG

     The message  indicates that nonfatal messages generated by
PCRAMMET are  located  in PCRAM.LOG.   Messages such as rural mixing
heights less than 10  meters and warnings about multiple  forms of
precipitation  are written to  this  file.

     If a  fatal  error occurs, PCRAMMET writes one message in
PCRAM.LOG  that identifies the source of the error.   The  following
message is  displayed  on the screen, and PCRAMMET stops
processing:
                                3-14

-------
                       ****** FATAL ERROR ******
                         PROGRAM TERMINATED
                See  the Output File PCRAM.LOG for  Details

The message should  provide  sufficient  information for  the  user to
identify and correct the problem and restart PCRAMMET.   Examples
of fatal errors are: 1) a file not found, and 2) incorrect
specification of a  file format  (e.g.,  indicating the surface data
are CD144 when the  file is  the SAMSON  format).  A listing  of
error messages is located in Section 6.2.

     Whether PCRAMMET successfully or  unsuccessfully completes
processing the data, the user should review PCRAM.LOG  to insure
the data were processed correctly and  as expected.

3.2  BATCH MODE

     PCRAMMET records the users responses during the interactive
session in an annotated file named INPUTS.  This file  is referred
to as a response file.  The only response that  is not  written to
this file is the output filename.  If  the user  expects to  rerun
PCRAMMET with these or similar responses, then  the user should
save INPUTS, e.g. by renaming the response file.  If the file is
not saved in some manner, then the next run of  PCRAMMET
overwrites the file without any opportunity to  save or rename the
file.

     PCRAMMET can use this  file, or a  modified  version of  it,  as
one of the command  line arguments to run the preprocessor  in
batch mode.  In addition to the program name, the user supplies
two filenames:  the file with the responses to  the prompts that
the program would display during an interactive session
(response_file) and the file to which  the output is written
(output_file).  To  start PCRAMMET in this manner, type:

          PCRAMMET  response_file  output_file
                               3-15

-------
followed by pressing ENTER.   If the user only supplies  one
filename or more  than two,  then the following message appears on
the screen and  PCRAMMET stops:

          COMMAND  ERROR:  PCRAMMET [input_control  output_for_model]
                                	 optional  	

     If the command line doesn't have an error, PCRAMMET
processes the records in the response file as if they were
entered interactively, and assuming no errors are  encountered,
processes the meteorological data.  The current year/month/day
are displayed as  each day is processed.  On successful  completion
of the processing,  PCRAMMET displays the following message:

         See the  file PCRAM.LOG  for a review this run

If any warning  messages were issued, the following message  will
also appear,  indicating that nonfatal messages  generated by
PCRAMMET  are  located in the log file:

        *** Warning messages were generated by PCRAMMET and are in PCRAM.LOG

     Any  errors in the response file will  prevent  PCRAMMET from
processing  the  remainder of the response file as well as the
input meteorological data.  PCRAMMET displays the  following
message  and stops:
                        ****** FATAL ERROR ******
                          PROGRAM TERMINATED
                 See  the Output File PCRAM.LOG for Details

Whether  PCRAMMET successfully  or  unsuccessfully completes
processing the data,  the user  should  review PCRAM.LOG to  insure
the data were processed correctly and as  expected.
                                3-16

-------
                            SECTION  4

                       TECHNICAL DISCUSSION

     In this section the technical issues regarding the data
processing are discussed.  These issues include simple data
manipulation (e.g., converting data to the correct units) and
simple quality assurance procedures, methods for computing the
hourly mixing heights and atmospheric stability, and the
theoretical basis for estimating the deposition parameters.

4.1  TIME OF DAY

     When reading the CD-144 format, PCRAMMET skips the first
hourly record of data in the year because the 24-hour period for
the regulatory models starts with the l-hour period ending 0100
LST and the observations in CD-144 files begin with the
observation reported at 0000 LST (equivalent to 2400 LST of the
previous day).   Sequential reading of the remaining data
automatically makes this adjustment for each succeeding day.
Meteorological data for the last hour in the year are assumed
equal to that for the next to the last hour because the data for
a day always ends with hour 23.  Data on the SAMSON CD-ROM begin
with hour 1 and end with hour 24,  eliminating the need to skip a
record.  However, the last hour of the year may contain missing
data and are processed similarly to the CD-144 formatted data.

4.2  HOURLY VALUES OF MIXING HEIGHT

     The processing of hourly mixing heights requires:  1)
morning and afternoon estimates of mixing heights; 2) the local
standard time of sunrise and sunset; and 3)  hourly estimates of
stability.  Morning and afternoon mixing height estimates are
based on the method of Holzworth (1972).  Two interpolation
schemes are used to estimate hourly mixing heights, one for rural
                               4-1

-------
sites and the other for urban sites.  Both estimates are included
in the PCRAMMET output file.  The time of sunrise and sunset are
calculated within PCRAMMET based on the date, latitude,
longitude, and time zone, using known earth-sun relationships
(e.g., Sellers (1965)).  The values for latitude, longitude, and
time zone for a particular station are required input to PCRAMMET
when using the CD-144 formatted data.  SAMSON data contain this
information in the first record of the file, making it
unnecessary to enter this information.  Estimates of hourly
stability class are based on Turner's (1964) method using time of
day, surface wind speed, and observations of cloud cover and
ceiling.

     To calculate an hourly mixing height, the procedure uses the
maximum mixing height  (MAX) from the previous day  (i-1) , the
computation day  (i) and the following day  (i+1) and the minimum
mixing height  (MIN) for days  (i) and  (i+1) .  For urban sites
between midnight and sunrise, under neutral  stability  (i.e.,
Class D) , the  interpolation is between MAX^a at sunset on the
previous day,  and MAXA at 1400 LST on the current day.  For
stable conditions  (i.e., Class E or F) , the  value  for the minimum
mixing height  (MIN) is used.  Between sunrise and  1400 LST,  if
the  stability  was classified as neutral in the hour before
sunrise, the earlier interpolation between MAX^ and MAXX is
continued;  if  the hour before sunrise was  classified  as  stable,
the  interpolation  is between MINi and MAX^   For  the period 1400
LST  to sunset, the value for MAXi is used.  During the hours
between sunset and midnight under neutral  stability,  the
interpolation  is between MAXi at sunset and MAXi+1 at 1400 LST the
next day;  if the stability  is stable, the  interpolation  is
between MAXi at sunset and MINi+1 at midnight.
      For rural sites between midnight  and sunrise,  the
 interpolation is between MAXi-!  at sunset  on the previous  day and
     at  1400  LST  on  the  current day.  During the hours between
                                4-2

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sunrise and 1400 LST, if stability was classified as neutral in
the hour before sunrise, the earlier interpolation between MAX^
and MAXi is continued;  if the hour before sunrise was classified
as stable, the interpolation is between 0 and MAXi.   For the
period 1400 LST to sunset, the value for MAXi is used.   During
sunset to midnight, the interpolation is between MAXi at sunset
and MAXi+: at 1400 LST the next day.

4.3  PASQUILL-GIFFORD STABILITY CLASSES

     PCRAMMET recognizes seven stability classes.  The first six
categories correspond to Pasquill's (1974) classifications  (A-F).
The seventh category corresponds to the  'dashes' in the original
classification by Pasquill and indicates a strong, ground-based
nocturnal temperature inversion with non-definable wind flow
conditions.  Standard EPA practice in regulatory dispersion
modeling is to restrict temporal changes in stability class to no
more than one per hour.  The stability smoothing procedure in
PCRAMMET implements this.

     In the urban mode, stability categories 5, 6, and 7  (E, F,
and G) are treated as category 4  (i.e., D or neutral).  Also, it
should be noted that most regulatory models treat rural stability
class G  (7) as F (6).  For daytime cases, the appropriate
insolation class is selected by means of the Turner  (1964)
objective method using cloud cover, ceiling height, and solar
elevation as indicators.  This method assigns net radiation
indices, using the criteria shown in Table 4-1, for cases where
the total cloud cover is less than or equal to 5/10.  If the
cloud cover is greater than 5/10, but less than 10/10 (overcast),
the insolation class is reduced by one category when the ceiling
height is between 7000 and 16000 feet and by two categories for
ceilings less than 7000 feet.  For a cloud cover of 10/10 (i.e.,
overcast), the insolation class is reduced by one category when
the ceiling height is greater than 16000 feet and by two
                               4-3

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categories for ceilings between 7000 and 16000 feet.   For
ceilings below 7000 feet and 10/10 cloud cover, a net radiation
of 0 is defined and neutral stability is specified.  With the
exception of the 10/10 low cloud cases, the net radiation index
is never reduced below 1, or 'weak1.  The final stability
classification criteria is selected from Table 4-2 and Turner's
insolation classes from Table 4-1.
                            TABLE 4-1
            Insolation Classes as a Function of Solar
                Altitude for Cloud Cover < 5/10 *
     Solar elevation          Insolation          Net Radiation
        angle  (a)               class                 Index
0°
15°
35°
60°
5/10  cloud  cover,  see text
                                4-4

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            TABLE 4-2
Stability Classification Criteria
Daytime Insolation
Surface
Wind
Speed
(knots)
< 1
2
3
4
5
6
7
8
9
10
11
i!2
Strong
1
1
1
1
1
2
2
2
2
3
3
3
Moderate
1
2
2
2
2
2
2
3
3
3
3
4
Slight
2
2
2
3
3
3
3
3
3
4
4
4
Weak
3
3
3
4
4
4
4
4
4
4
4
4
Overcast
4
4
4
4
4
4
4
4
4
4
4
4
Nighttime
2:5/10
Cl oud
6
6
6
5
5
5
4
4
4
4
4
4
< 5/10
Cloud
7
7
7
6
6
6
5
5
5
5
4
4
               4-5

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4.4  WINDS

     Hourly wind direction data input to PCRAMMET are tested for
calms (coded as 0° by the NWS; note that a north wind is coded as
360°),  and if present, the wind direction from the previous hour
is substituted.  PCRAMMET converts all wind directions to flow
vectors (in the range of 0-360°) by adding or subtracting 180°.
These flow vectors are then randomized by adding a random integer
number of azimuth degrees between -4° and +5°.   This procedure is
applied to remove the directional bias introduced into the NWS
data because they are reported to only the nearest 10°.  The
randomization gives the flow vector an equal probability of
occurring anywhere within the 10° sector and so incorporates the
natural fluctuations of this parameter.  A standard set of 8784
random numbers is used.

     Hourly wind speed data in the CD-144 format are converted
from the NWS units of knots to meters per second  (ms"1) .  Wind
speeds in the SAMSON data are already in meters per second  (to
the nearest 1/10 m s"1) , but are  converted back to knots then to
meters per second to insure that the results in the output files
from the two input data formats are identical.  Wind speeds below
1.0 ms"1  (calms included) are  set to  1.0 m s"1 before computations
are made in PCRAMMET.

4.5  TEMPERATURE

     For the CD-144 data, hourly ambient temperature data are
converted from the NWS reporting units of degrees Fahrenheit  (°F)
to Kelvin  (K).  For SAMSON data, the reporting units are degrees
Celsius  (°C) and are converted to Kelvin.
                                4-6

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4.6  QUALITY ASSURANCE

     Data may be missing from any of the sources for certain
hours, days, or even months.  PCRAMMET performs a limited check
on the data, depending on the source and type.

     Quality assurance of the CD-144 surface data file beginning
with the year, month, day and hour are checked for consistency
and completeness.  If one or more hourly records are missing, or
are out of order, then the program terminates after printing
appropriate error messages.  PCRAMMET does not verify the station
identification number.

     For the CD-144 format, blanks in the data fields indicate
missing data.  In PCRAMMET, the data are read as character
strings and then checked for blanks.  If a blank is encountered,
then a message is written to the log file indicating which
variable is missing and the date and time it is missing.  A
missing data code is entered for that variable for that hour.

     Next, the year, month, and day of the hourly surface
observations are compared to the corresponding date from the
mixing height file.  If these two files are not synchronized,
then PCRAMMET stops after writing an error message (with the
month and day of the mismatch) to the log file.  PCRAMMET reads
24-hour blocks of data and performs only one check on the month
and day.

     Hourly surface observations obtained from the SCRAM BBS are
in a compressed format, i.e., only selected variables are
reported and the record length is shortened.  The SCRAM data can
be used directly in PCRAMMET or it can be expanded using a
program such as MET144, which is provided on the SCRAM BBS.  The
MET144 program provides an option to expand the SCRAM format to
the CD-144 format.  The program also provides an option to list
                               4-7

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all the missing data, with the date and time of occurrence, that
appear in the SCRAM formatted surface data file.

     Prior to processing the SAMSON data,  PCRAMMET checks to
verify that the necessary meteorological variables were retrieved
from CD-ROM for the intended modeling option (no/dry/wet
deposition).  If there are insufficient data, a message is
written to the log file and PCRAMMET stops.  If the necessary
meteorological variables are present, the SAMSON data are checked
for missing data as each record is processed.  If a missing value
is encountered, a message is written to the log file indicating
which variable and the date and time of occurrence.

     There are no data quality checks on the mixing height data.
If a data field is blank, then the preprocessor assumes a value
of zero for the field.  It is the user's responsibility to ensure
that the information in this file is complete and properly
ordered.

     The structure and contents of the precipitation file do not
allow for the data to be checked for missing records - only hours
during which precipitation occurred are reported.  A date and
time are passed to the routine that retrieves the hourly
precipitation.  This date and time is either the values from the
CD-144 or SAMSON data file.  One quality check that is performed
is to insure that special groupings of data are terminated
properly  (special flags identify these groupings).  Another check
on the data identifies when both liquid and solid forms of
precipitation are reported for an hour.  A message indicating
such an occurrence is written to the log file, and the code used
in the data processing corresponds to liquid precipitation.
                                4-8

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4.7  DEPOSITION PARAMETER ESTIMATES

     Additional meteorological parameters are required to make
estimates of dry and/or wet deposition in ISCST3.   The
computation of the friction velocity and Monin-Obukhov length in
PCRAMMET is presented in this section.  Stull (1988) provides a
good introduction to the theoretical basis for estimating these
parameters.

     The day is divided into two regimes: stable and unstable.
The atmosphere is considered stable if the time of day is between
sunset and sunrise (of the next day) and the transfer of heat is
toward the earth's surface.  The atmosphere is unstable if the
time of day is between sunrise and sunset and the transfer of
heat is away from the surface.  The parameters of interest in the
deposition process are surface roughness length (z0) ,  the  surface
friction velocity (u*)  and the Monin-Obukhov length  (L).

     The surface roughness length has been discussed in previous
sections.  The surface friction velocity is a characteristic
velocity based on (wind) shear stresses at the earth's surface.
The Monin-Obukhov length is a stability parameter that relates
this velocity to the transport of heat.  In the next two
sections, the estimates of these values are discussed for the
site where the preprocessor input data were measured.   In the
final section, these results then are used to estimate the
parameters at the site where the output from PCRAMMET are to be
applied.

4.7.1     Unstable Atmosphere

     During daytime convective conditions (L < 0),  the surface of
the earth is heated,  resulting in an upward transfer of heat.
Hourly estimates of this heat flux are required to estimate u*
and L.  The estimates for the heat flux here follow the
                               4-9

-------
development of Holtslag and van Ulden (1983).  The heat flux is
estimated from cloud cover, surface temperature, Bowen ratio and
albedo, as described below.

     Once the heat flux is computed, u*  and L are determined
through an iterative procedure using surface layer similarity.
While u. and L change with each iteration,  the hourly heat flux
remains fixed.

     A simple equation that expresses the energy balance at the
earth's surface is:

              RN+Qf = H + XE + G                          (4.1)
where RN is the net radiation,  Qf  is the anthropogenic  heat flux,
H is the sensible heat flux, AB is the latent heat flux, and G  is
the flux of heat into the ground.  Each term is expressed  as
W m"2.   The value of  G is assumed  to be proportional  to the left
side of Eq. 4-1, i.e., G = cg (RN  + Qf) ,  where cg is  the fraction
of the net radiation absorbed at  the ground, and is  specified by
the user.  Using this estimate for G and the definition of the
Bowen ratio, B0 = H / AB,  which was specified by the user,  the
following  expression for the sensible heat flux, H,  is obtained

                   (i.o-Cg)*;
                                                        (4-2>
                        B
                         o
where RN*  = RN + Qf.

     The  net radiation, RN, is estimated from total incoming
solar radiation, R,  as

               RN= (l-r)R-IN                           (4.3)
                               4-10

-------
where r is the user-specified surface albedo  (dimensionless),  and
IN is the net long-wave radiation at the earth's surface as given
by Holtslag and van Ulden  (1983).  The anthropogenic heat  flux,
Qf,  specified by the user is then added to the net radiation to
obtain J?w*.

     In the general case in which clouds are present, R  is
computed using the following formula proposed by Kasten  and
Czeplak  (1980)

              R = R0 ( I +blNt'2)                            (4.4)

where R0 (W m"2)  is the incoming solar radiation at ground  level
for clear skies, and N is the fractional opaque cloud cover.   The
empirical coefficients b1 and b2  are assigned  the values  of -0.75
and 3.4, respectively.  If cloud cover is missing for a
particular hour, then PCRAMMET assumes complete overcast (i.e.,
10/10 cloud cover) and proceeds with the calculations.   A  warning
message is written to the log file to indicate such an
occurrence.

     The incoming solar radiation for clear skies R0 is given by
              R0 = a^incj) + a2                            (4.5)

where 4> is the elevation of the sun above the horizon  (degrees) ,
a; = 990 W m"2 and az =  -30  W m"2.   The  constants a: and az account
for attenuation of the short wave radiation by water vapor and
dust in the atmosphere.  The values used in PCRAMMET are
appropriate for mid-latitudes (Holtslag and van Ulden, 1983) .

     Substituting Eqs. 4.4 and 4.5 into Eq. 4.3 and
parameterizing the net long-wave radiation as a function of
temperature and cloud cover, Holtslag and van Ulden (1983)
estimate the net radiation as
                               4-11

-------
           (1 - r) R + c. T6 - o-  T4 + c,N
                          -^	                   (4'6>
where OSB  =  5.67  x  io"8 W m"2 K"4 is the Stefan-Boltzmann constant,
and the other empirical  constants are as follows:
     c:  = 5.31 x 10"13 W m"2 K"6,
     c2  = 60 W m"2,
     C3  = 0.12.

     An empirical  expression  for the albedo as a function of
solar elevation  angle is given by
             r = r' +  (1 - r') eav+b                         (4.7)

where r' is the surface  albedo (dimensionless)  for the sun on the
meridian  specified by the user,  v is the solar elevation angle  in
degrees,  a  =  -0.1, and Jb = -0.5  (1  - r')2.

     PCRAMMET next computes the  surface friction velocity u. and
the Monin-Obukhov  length L for the  unstable atmosphere through  an
iterative procedure.   (This technique  is similar to that used in
the METPRO  processor (Paine,  1987).  The two equations for u* and
L used  in the iteration algorithm are:

             "' = 	z	~	
                 1 ^ /  ref \ _ IT; j. m                          (4.8)
                       o
and
                      p c Tu3
                L = --—£	1                             (4.9)
                       kgH
where
     H  is  the sensible  heat flux at the surface (W m"2) ,
     k  is  the von Karman constant,
     U  is  the wind speed (m s"1) ,
                                4-12

-------
     zref is the anemometer height  (m) ,
     z0 is the surface roughness at the measurement  site (m)
        specified by the user,
     p is the density of dry  air  (kg  m"3) ,
     cp is the specific heat capacity of air  (1004 J kg"1 deg"1) ,
     T is temperature  (K) , and
     g is the acceleration due  to  gravity  (9.81 m s'2) .

The values for W and ₯0 (Lumley and Panofsky,  1964 and  Businger,
1973) are:
— £)  +ln(-^H-)  - 2 tan"1
                                                       (4.10)
             1 +u         1 +u
      = 2 In (	—}  + In (	-}  -2 tan'1                 (4.11)
              2           2
where
           U = (  1 - 16z . / L )1/4                       (4.12)
            u = ( 1 -  16z  / L )1/4                        (4.13)
     This procedure  requires an initial guess for u.,  which is
found by initially setting *P and W0 to  zero.   The iteration
continues until  consecutive values of L differ by 1% or less.
                               4-13

-------
4.7.2     Stable Atmosphere

     The calculations of u* and L for the stable atmosphere
(L > 0) are based on an approach outlined by Venkatram  (1980).
The approach does not require an iterative procedure as used  for
the unstable atmosphere.  Estimates of u. and 6*  (a  temperature
scale) are made from cloud cover, wind speed and temperature.
This, in turn, provides an estimate of the heat flux, and L is
computed directly from Eq. 4.9.

     The method begins with the following estimate  for 0*:

             6. = 0.09 (1 - 0.5AT2)                        (4.14)


where N is the fraction of opaque cloud cover.  The neutral drag
coefficient, CD (dimensionless) ,  is calculated as
  The friction velocity is determined from

      = CDU/2  ( l+( 1- (  2uo / (CDU))2                  (4.16)
where
                                                        (4.17)
and 3m = 4.7 is a dimensionless constant.

     To obtain real-valued solutions for u», the following must
hold
                               4-14

-------
                                                       (4.18)
     If this condition holds, then vu is computed from Eq. 4.16;
if this condition does not hold  (under very stable conditions),
then the solution to the quadratic equation is imaginary,  and a
slightly different approach is taken.

     Equality in the above condition corresponds to  a minimum
wind speed, C7cr, at which  (and above) a  real-valued  solution to
Eq. 4.16 is
             U  =
              cr
                  \
                                    (4.19)
TC.
                         D
For this value, there  is a corresponding  friction  velocity,  u*cr,
such that

                u   = ER^L.                                (4.20)
                        2
     For wind  speeds  less  than this  critical  value,  Eq.  4.16 no
longer yields  a real-valued  solution,  and  it  is  desirable to have
u, - 0 as U - 0.  Therefore,  for U < Ucr, u.cr  is scaled by the
ratio U / Ucrl  and u.  is calculated as
                                                           (4.21)
For U < Ucr,  van Ulden and Holtslag (1985)  showed that there is a
nearly linear  variation of 6* with u,.   Therefore, 6*  is  similarly
scaled as
                               4-15

-------
                         u
                e  = e   —
                 *   »cr
                         U.cr
(4.22)
With the u. from Eq.  4.16 or 4.21 and the 6* from Eq.  4.14  or
4.22, the heat flux H is computed as
               H = -pcpu,6,  .                              (4.23)

Finally, using these estimates of u. and H,  L  is computed from
Eq. 4.9.

     In the case of strong winds, H may become unrealistically
large.  Therefore, a limit of -64 W m"2  is placed on the  heat
flux, which forces a limit on the product u»9*.  This  yields a
cubic equation in u,,  which is solved to obtain a new u..   With
this new value for u. and H = -64 W m"2,  L is recomputed from  Eqs.
4.9 and 4.23 as:
                    L = T u* / (k g 60                    (4.24)

     If the value of the Monin-Obukhov  length is less than the
minimum value specified by the user, then L is reset to this
minimum value and a new value for u* is  computed.

4.7.3     Parameters at the Application Site

     The discussion above focused on the estimates at the
measurement site.  Typically, the measurement site is not  the
location where the output meteorological data from PCRAMMET are
to be applied.  Dry deposition estimates are sensitive to  the
value of the friction velocity, therefore, the friction velocity
and Monin-Obukhov length estimated for  the measurement site are
adjusted to represent the site where the output are to be
applied.  With the surface roughness length entered by the user
for the application site and the estimates of u* and L at the
                               4-16

-------
measurement site, u* and L representative of the application site
are estimated and written to the output file.

     Walcek et al.  (1986) suggest that near the surface

                uiu.i a U2U.2                               (4.25)

for changes in the underlying surface roughness, where the
subscripts 1 and 2 represent the previous and current estimates.
PCRAMMET incorporates this approach to estimate u* and L at the
application site.

     With the roughness length representative of surface
conditions at the application site, a new estimate for u* is
obtained through an iterative process using surface layer
similarity.  The Monin-Obukhov length is obtained from

                  L2 = Lj  (u*2/un)3                       (4.26)

(on the first iteration, the subscript 1 represents the value  at
the measurement site).  When two consecutive estimates of u* are
within 1%, then the process stops.
                               4-17

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                           SECTION  5

                      PCRAMMET PROGRAM NOTES

     PCRAMMET is suited for operation on a PC.   The input files
are of reasonable size and the programs involved execute in a
moderate amount of time.  In this section, a description of the
files and steps required to compile and link PCRAMMET is
presented.  The section concludes with steps to retrieve the
program and hourly surface weather observations and twice-daily
mixing heights from the SCRAM BBS.

5.1  COMPILING AND LINKING PCRAMMET

     There are five source code files associated with PCRAMMET:

     PCRAMMET.FOR   main program - setup, initialization and
                    input/output handling;
     PCRLIB.FOR     routines that are used by several of the
                    subprograms;
     PCRDATA.FOR    routines to process the raw input data;
     PCRPARAM.FOR   routines to compute the boundary layer and
                    deposition parameters;
     PCRAM.INC      variable declarations and common blocks that
                    are used in the routines in the files above.

     The executable provided on the SCRAM BBS was created using
the Lahey F77L-32/EM  Fortran Compiler, version 5.2.  A math
coprocessor is mandatory for use of a Lahey-compiled executable.
If the source code is modified, the following commands will
compile the source code:
                               5-1

-------
     d:\suJbdir\f77l3  pcrammet.for /b /i /I /no /nw /dlLAHEY
     d:\suJbdir\f7713  pcrlib.for   /b /i /I /no /nw
     d:\suJbdir\f7713  pcrdata.for  /b /i /I /no /nw
     d:\suJbdir\f7713  pcrparam.for /b /i /I /no /nw


where d: \ suJbdir \ refers to the drive and directory where the
Lahey compiler and linker reside if the directory is not in your

path.  The switches after the filename provide the following
control:

     /b   checks array subscripts and character substring bounds;
     /i   interface checking between subprograms;
     /I   lists line numbers in the event the executable program
          terminates abnormally;
     /no  compiler options are not displayed when a file is
          compiled;
     /nw  warning messages are not displayed when a file is
          compiled.


The /dlLAHEY specifier is required because the source code uses

conditional compiler directives to properly access any command

line arguments that may be used to run PCRAMMET.


     To create the executable, the following command is used:

     d: \suJbdir\3861ink pcram, per lib, pcrdata, pcrparam
               -stub runb  -pack
                *

The switches after the filenames have the following effect:

     -stub runb     binds the Lahey/Phar Lap 386 | DOS-Extender to
                    the  (protected-mode) executable,

     -pack          performs data compression on the executable
                    file.

     The next, and final, step is optional and simply disables
the 386[DOS-Extender banner that is shown whenever the executable

program is run:


     CFIG386 PCRAMMET.EXE  -nosignon.


The resulting executable code size is 380 Kb.
                                5-2

-------
     If the user needs to create a version that does not rely on
a math coprocessor or needs to create an unformatted
meteorological file that is compatible with models compiled with
a Microsoft Fortran compiler, then PCRAMMET can be compiled and
linked using the batch file included with the PCRAMMET package.
The batch file invokes Microsoft Fortran compiler and linker and
creates an executable of about 175 Kb.

5.2  PCRAMMET AND SCRAM

     The following steps for retrieving the program and data from
the SCRAM BBS, some of which may have already been performed by
the user, are all that are needed for minimal implementation of
PCRAMMET:

 1)  Many of the programs and data files on SCRAM are available
     only in a compressed format, which includes PCRAMMET source
     and executable code and the hourly surface data.  These
     files must be decompressed with PKUNZIP (version 2.04g) or
     other program that recognizes this format.  If the user does
     not have PKUNZIP (version 2.04g), it can be downloaded from
     the OAQPS TTN.  PKUNZIP can be found in the <1> System
     Utilities section of the Main Menu.  Select 
     Archivers/Dearchivers and download PKUNZIP.EXE.  If the user
     is unfamiliar with downloading from the OAQPS TTN, the menu
     item  Help Downloading/Uploading may be useful from the
     Systems Utility menu.

 2)  Download the file(s) containing the PCRAMMET code and
     dearchive the file(s) by entering 
     at the DOS prompt.  The files with the .FOR extension
     contain the source code for the programs and the ones with
     the .EXE extension are the executable modules for the same.
     The .RME file is a file containing a very brief synopsis of
     what is contained in this User's Guide.
                               5-3

-------
3)   To download the hourly surface data file,  select 
    Meteorological Data from the SCRAM Main menu,  then select
    urface Data followed by <1> Surface Meteorological Data
    File Downloads.  This will present a list of States for
    which there are data available.  Remember the File Area
    Number of the State you wish to select as the States list
    scrolls by.  Enter the File Area Number and select the
    station/year and download that file.  The selected file
    nnnnn-yy.ZIP (nnnnn = Station Number, yy = Year) should now
    be dearchived by entering  at the DOS
    prompt.  This will produce two files: Snnnnnyy.DAT and
    Snnnnnyy.TXT.  The Snnnnnyy.TXT file contains a 'before and
    after1 listing of the missing meteorological parameters that
    were filled in by the SCRAM staff before the files were
    placed on the SCRAM BBS.  The Snnnnnyy.DAT file contains the
    surface meteorological data in a 28 byte format used by the
    SCRAM BBS to conserve disk space.  Optionally, this file may
    be converted to the NWS CD-144 format by executing the
    MET144 program.  This is accomplished by entering  and selecting the expansion
    option  (1) when the program begins execution.  The
    Snnnnnyy.EXP file will contain the surface data in CD144
    format and is now ready for input into PCRAMMET.  A note on
    the MET144 program - the edit option  (0) will function
    properly only on the SCRAM 28-byte record format file.  If
    there  is no  'I1 in the FLAG field of the station selection
    menu on the SCRAM BBS, the data in the file should be
    complete.  If an  'I1 is present in the FLAG field, the data
    are incomplete and the user may wish to consider another
    meteorological data file to use for modeling.

    Data  for all NWS surface stations were considered for
    placement  on the SCRAM BBS; however, the data for many of
    the sites  were  incomplete.  Reasons  for not placing the data
    on the SCRAM BBS  included  less than  24 observations per day
                               5-4

-------
     or several months of missing data.   If an alternate station
     is selected for model analysis,  that station should be
     representative of the site.

4)    Download the twice daily mixing height data file.   Select
      Meteorological Data from the SCRAM Main menu,  then
     select  Mixing Height Data followed by <2> Mixing Height
     Data File Downloads.  This will present a list of  States for
     which there are data available.   Remember the File Area
     Number of the State you wish to select as the list of States
     scrolls by.  Enter the File Area Number and select the
     station/year that you wish to download.  This download
     process produces the file containing mixing height data
     named nnnnn-yy.TXT.  Again,  if an 'I1 is present in the FLAG
     field of the station selection menu, the user may  wish to
     consider another site for modeling.   The step to add an
     initialization record has been removed in this version of
     PCRAMMET.
                               5-5

-------
                            SECTION   6

                    ERROR  AND WARNING MESSAGES

     There are several conditions under which PCRAMMET may write
warning and error messages.  Warning messages are written to the
log file (PCRAM.LOG) and PCRAMMET continues processing the data.
Error conditions are fatal and a single error message is written
to the log file and PCRAMMET stops processing the data.  In the
next two sections, the warning and error messages generated by
PCRAMMET, with a brief explanation of each, is presented.

6.1  WARNING MESSAGES

     In the messages below, text in italics indicates that a
value (for example, the date)  will appear in the actual message
rather than the italicized text.

Rural Mixing Height < 10 m  (  x.x) for (yy/mm/dd/hh) date/hour
     Indicates that an estimate of the rural mixing height was
     less than 10 meters.  The estimated height and the date of
     occurrence are reported.

Urban Mixing Height < 10 m  (  x.x) for (yy/mm/dd/hh) date/hour
     Indicates that an estimate of the urban mixing height was
     less than 10 meters.  The estimated height and the date of
     occurrence are reported.
                               6-1

-------
Warning — more than one type of precipitation reported on
(YYDDDHH):(date/hour)
               format TYPE = nnnnnnnn   PRECIP. CODE USED =  x

     If more than one type of precipitation is reported, then
     PCRAMMET informs the user of the date (as year and Julian
     day) and hour when the multiple precipitation types
     occurred, the surface data file format (CD144, SCRAM or
     SAMSON), the precipitation code, and the code that was
     written to the output file.  The code for liquid
     precipitation is written to the output file.

CCCODE: The character " " is not allowable.  Cloud cover defaults
     to 10.

     Indicates a blank in the cloud cover field.  Occurs many
     times when the 28-byte record surface file is used instead
     of the 80-byte record file.  MET144 must be used to expand
     the 28-byte record file to 80-bytes.

FILMET: TD-3240 precip substituted for SAMSON on (yy/mm/dd/hh):
     date/hour

     If the precipitation was missing in the data file retrieved
     from the SAMSON CD-ROM and the user responded that the
     SAMSON data are to be supplemented with TD-3240 data, then
     PCRAMMET writes this message to the log file for the data
     and time shown.

     The following messages appear if the variable referenced  is
missing  for the date and time displayed in the message.  FILCD4
refers to CD-144 format data  (and the subroutine that generated
the message)  and FILSAM refers to data retrieved from the SAMSON
CD-ROM  (and the subroutine that generated the message).
                                6-2

-------
FILCD4: Wind direction missing for (yy/mm/dd/hh) date/hour
FILCD4: Wind speed missing for (yy/mm/dd/hh)  date/hour
FILCD4: Station pressure missing for (yy/mm/dd/hh) date/hour,
     using 1000 mb (Note: this message is seen only if the run is
     for DRY or WET deposition)
FILCD4: Temperature missing for (yy/mm/dd/hh) date/hour
FILSAM: Wind direction missing for (yy/mm/dd/hh) date/hour
FILSAM: Wind speed missing for (yy/mm/dd/hh)  date/hour
FILSAM: Station pressure missing for (yy/mm/dd/hh) date/hour,
     using 1000 mb
FILSAM: Temperature missing for (yy/mm/dd/hh) date/hour
FILSAM: Cloud cover missing for (yy/mm/dd/hh) date/hour
FILSAM: Ceiling height missing for (yy/mm/dd/hh) date/hour
FILSAM: Precipitation missing for (yy/mm/dd/hh) date/hour

6.2  ERROR MESSAGES

     There are about 40 error messages that could originate from
PCRAMMET.  PCRAMMET stops processing data if any of the follwoing
conditions occurs.  The messages are:

ERROR OPENING THE INPUT FILE
     An input file could not be opened.

ERROR OPENING FILE FOR SCREEN INPUT RESPONSES
     The file that will be used to capture the user responses
     during an interactive prompt/response run could not be
     opened.

ERROR READING THE INPUT FILE: DEPOSITION TYPE
     A runtime error was encountered while reading deposition
     type from the response file.
                               6-3

-------
INCORRECT DEPOSITION TYPE SPECIFIED:
     An error was encountered while reading the response file:
     the deposition type - NONE, DRY or WET - was not correctly
     specified.

ERROR READING THE INPUT FILE: OUTPUT FILE TYPE
     An error was encountered while reading the response file:
     the output file type (ASCII or UNFORM),  was not specified
     properly.

ERROR READING THE INPUT FILE: SURFACE FILE NAME
     An error was encountered while reading the response file:
     the input hourly surface observation filename was not
     specified properly.

ERROR READING THE INPUT FILE: SURFACE FILE TYPE
     An error was encountered while reading the response file:
     the file format type (CD144 or SAMSON),  was not specified
     properly.

ERROR READING THE INPUT FILE: MIXING HEIGHT FILE NAME
     An error was encountered while reading the response file:
     the input mixing height filename was not specified properly.

ERROR READING THE INPUT FILE: PRECIPITATION YES|NO
     An error was encountered while reading the response file:the
     response as to the use of precipitation data was invalid.

ERROR READING THE INPUT FILE: PRECIP FILE NAME
     An error was encountered while reading the response file:
     the input hourly precipitation data filename was not
     specified properly.
                               6-4

-------
ERROR READING THE INPUT FILE: PRECIP FILE TYPE
     An error was encountered while reading the response file:
     the precipitation file type (FIXED or VARIABLE) was not
     specified properly.

ERROR READING THE INPUT FILE: SITE LATITUDE
     An error was encountered while reading the response file:
     the station latitude was improperly specified - this message
     is seen only if the surface observations are CD144 or SCRAM
     format.

ERROR READING THE INPUT FILE: SITE LONGITUDE
     An error was encountered while reading the response file:
     the station longitude was improperly specified - this
     message is seen only if the surface observations are CD144
     or SCRAM format.

ERROR READING TIME ZONE FROM THE INPUT FILE
     An error was encountered while reading the response file:
     the surface station's time zone was improperly specified -
     this message is seen only if the surface observations are
     CD144 or SCRAM format.

ERROR OPENING THE SURFACE FILE
     An error occurred when attempting to open the file of hourly
     surface observations.

ERROR OPENING THE MIXING HEIGHT FILE:
     An error occurred when attempting to open the file of mixing
     height data.

ERROR OPENING THE PRECIPITATION FILE:
     An error occurred when attempting to open the file of
     precipitation data.
                               6-5

-------
PRECIP FILE NOT VARIABLE FORMAT AS SPECIFIED BY USER
     The user specified that the precipitation data are variable-
     length block data; PCRAMMET determined that the format is
     not VARIABLE-length.  The format is likely FIXED-length, or
     a format unfamiliar to PCRAMMET.

ERROR OPENING TEMPORARY PRECIPITATION FILE
     When a variable-length precipitation file is used, a
     temporary file is opened to reformat the data for internal
     use.  The attempt to open this temporary file failed.

PRECIP FILE NOT FIXED FORMAT AS SPECIFIED BY USER
     The user specified that the precipitation data are fixed-
     length block data; PCRAMMET determined that the format is
     not FIXED-length.  The format is likely VARIABLE-length, or
     a format unfamiliar to PCRAMMET.

ERROR OPENING PRECIPITATION FILE:
     The precipitation file does not exist - check the spelling
     or the path.

ERROR OPENING OUTPUT FILE (UNFORM):
     The attempt to open the output file as an unformatted file
     failed.

ERROR OPENING OUTPUT FILE (ASCII):
     The attempt to open the output file as an ASCII file failed.

SURFACE FILE NOT OF TYPE CD-144 AS SPECIFIED BY USER
     The user specified that the hourly surface observations are
     in the CD144 format; PCRAMMET has determined that the format
     is not the CD144 format.  The format is likely to be SAMSON,
     SCRAM, or possibly a format unfamiliar to PCRAMMET.
                               6-6

-------
SURFACE FILE NOT OF TYPE SAMSON AS SPECIFIED BY USER
     The user specified that the hourly surface observations are
     in the SAMSON format; PCRAMMET has determined that the
     format is not the SAMSON format.  The format is likely to be
     CD144, SCRAM, or possibly a format unfamiliar to PCRAMMET.

SURFACE FILE NOT OF TYPE SCRAM AS SPECIFIED BY USER
     The user specified that the hourly surface observations are
     in the SCRAM format; PCRAMMET has determined that the format
     is not the SCRAM format.  The format is likely to be CD144,
     SAMSON or possibly a format unfamiliar to PCRAMMET.

SCRAM DATA AND WET DEPOSITION NOT COMPATIBLE
     The user specified SCRAM data for the hourly surface
     observation file and processing for wet deposition.  These
     two options are not compatible - wet deposition requires
     information on the precipitation type (when precipitation is
     occurring) which is available from the present weather
     codes.  The present weather codes are not in the SCRAM
     meteorological data files.  The user has to choose an
     alternate format for the surface observations or not process
     the data for wet deposition.

ERROR READING HEADER RECORD OF THE SURFACE FILE:
     An error was encountered while reading one of the header
     records of a SAMSON-formatted hourly surface observation
     data file.

ILLEGAL VARIABLE ID IN HEADER RECORD:
     An error was encountered while decoding the second header
     record (the list of weather variables in the file) of a
     SAMSON-formatted hourly surface observation data file.
                               6-7

-------
INSUFFICIENT DATA IN SAMSON FILE FOR PROCESSING
     After decoding the second header record in the SAMSON data
     file, there is insufficient data to estimate the parameters
     for any dispersion model.

INSUFFICIENT DATA IN SAMSON FILE FOR WET DEPOSITION
     After decoding the second header record in the SAMSON data
     file, there is insufficient data to estimate the parameters
     for wet deposition (precipitation type and amount).

ERROR READING SAMSON SURFACE DATA:
     An error was encountered while reading the hourly surface
     data from a SAMSON-formatted data file.

ERROR READING CD144 SURFACE DATA:
     An error was encountered while reading the hourly surface
     data from a CD144-formatted data file.

ERROR READING MIXING HEIGHT DATA:
     An error was encountered while reading the twice-daily
     mixing height data.

SURFACE AND MIXING HEIGHT TIME STAMP MISMATCH:
     The date of the hourly surface observations and mixing
     height data are not synchronized.

SURFACE AND PRECIP DATA TIME STAMP MISMATCH:
     The date of the hourly surface observations and
     precipitation data are not synchronized.

STABILITY CALCULATED TO BE LESS THAN 1:
     The estimate of the Pasquill-Gifford  stability category is
     in error.
                                6-8

-------
ANEMOMETER HT < ROUGHNESS LENGTH
     The anemometer height specified in the response file (batch
     processing) is less than the surface roughness length.   This
     message will appear if either the roughness length at the
     measurement site or application site is above the anemometer
     height.

ANEMOMETER HT < 0.0
     The anemometer height specified in the response file (batch
     processing) is less than 0.0.

ALBEDO OUT OF RANGE
     The albedo specified in the response file (batch processing)
     is either less than 0.0 or greater than 1.0.

NET RADIATION ABSORBED BY GROUND OUT OF RANGE
     The fraction of the net radiation absorbed by the ground
     specified in the response file (batch processing) is less
     than 0.0 or greater than 1.0.

     These last four messages only appear when using PCRAMMET in
a batch mode.  In the interactive mode, PCRAMMET prompts the user
for another value.  In the batch mode, PCRAMMET cannot prompt for
another value, so an error message is written to the log file and
the preprocessor stops.
                               6-9

-------
                            SECTION   7
                           REFERENCES


Businger, J. A., 1973: Turbulent Transfer in the Atmospheric
     Surface Layer.  Workshop on Micrometeorology, D. Haugen
     (editor).  American Meteorological Society, Boston, MA
     02108.


Hanna,  S.R. and J.C. Chang, 1991: Modification of the Hybrid
     Plume Dispersion Model (HPDM) for Urban Conditions and Its
     Evaluation Using the Indianapolis Data Set.  Vol. I. User's
     Guide for HPDM-Urban.  Sigma Research Corporation, Concord,
     MA, 01742.

Holtslag, A. A. M. and A. P.  van Ulden, 1983: "A Simple Scheme
     for Daytime Estimates of the Surface Fluxes from Routine
     Weather Data."  J. Climate Appl. Meteorology, 22.'- 517-529.

Holzworth, G.C., 1972: Mixing Heights, Wind Speeds, and Potential
     for Urban Air Pollution Throughout the Contiguous United
     States, Environmental Protection Agency, Publication No. AP-
     101, Division of Meteorology, Research Triangle Park, NC
     27711.

Iqbal,  M. 1983:  An Introduction to Solar Radiation,.  Academic
     Press, New York, NY.

Kasten, F. and G. Czeplak, 1980: "Solar and Terrestrial Radiation
     Dependent on the Amount and Type of Cloud."  Solar Energy,
     21: 177-189.

Lumley, J. L. and H. A. Panofsky, 1964: The Structure of
     Atmospheric Turbulence.   Monographs and Texts in Physics and
     Astronomy, Vol XII.  Interscience Publ., John Wiley & Sons,
     New York, NY.

NCDC, 1990: Hourly Precipitation Data TD-3240, National Climatic
     Data Center, Asheville,  NC 28801.


NOAA, 1970: Card Deck 144 WBAN Hourly Surface Observations
     Reference Manual, available from the National Climatic Data
     Center, Asheville, NC  28801.
                               7-1

-------
Oke, T.R., 1978: Boundary Layer Climates,. John Wiley & Sons,
     New York, NY.

Oke, T.R., 1982:  "The Energetic Basis of the Urban Heat Island."
     Quart. J. Royal Meteor. Soc., 108; 1-24.

Paine, R.J., 1987:  User's Guide to the CTDM Meteorological
     Preprocessor fMETPRO) Programf  U.S. Environmental Protection
     Agency, Research Triangle Park, NC 27711.

Pasquill, F.,1974: Atmospheric Diffusion, D. Van Nostrand
     Company, Ltd., London, 2nd Edition.

Sellers, W.D., 1965: Physical Climatology, U. of Chicago Press.

Sheih, C.M., M.L. Wesley, and B.B. Hicks 1979: "Estimated Dry
     Deposition Velocities of Sulfur Over the Eastern U.S. and
     Surrounding Regions."  Atmos. Environ., 13; 361-368.

Stull, R.B., 1988: An Introduction to Boundary Layer Meteorology,.
     Kluwer Academic Publishers, Dordrecht, The Netherlands.

Turner, D.B., 1964: "A Diffusion Model for an Urban Area."  -L.
     Applied Meteorology, 3_:  83-91.

van Ulden, A. P., and A. A. M. Holtslag, 1985: "Estimation of
     Atmospheric Boundary Layer Parameters for Diffusion
     Applications."  J. Climate Appl. Meteorology, 24: 1196-1207.

Venkatram, A., 1980: "Estimating the Monin-Obukhov Length in the
     Stable Boundary Layer for Dispersion Calculations."
     Boundary Layer Meteorology, 19: 481-485.

Walcek, C. J., R. A. Brost, J. S. Chang and M. L. Wesley, 1986:
     "SO2,  Sulfate and HNO3 Deposition Velocities Computed Using
     Regional Land Use and Meteorological Data."  Atmos.
     Environ., 20, 949-964.
                               7-2

-------
                           APPENDIX  A
                           FILE FORMATS
MIXING HEIGHT DATA RECORDS  (SCRAN BBS/PCRAMMET FORMAT)
     Element.
     Mixing Station Number
     Year
     Month
     Day
     AM Mixing Value
     PM Mixing Value
Columns
1- 5
6- 7
8- 9
10-11
14-17
32-35
     Note:  NWS format has the PM Mixing Value in positions 25-28
SURFACE DATA RECORD  (28 BYTE RECORD - MET144 FORMAT)

     Element                                 Columns
     Surface Station Number                  1- 5
     Year                                    6- 7
     Month                                   8-9
     Day                                     10-11
     Hour                                    12-13
     Ceiling Height  (Hundreds of Feet)       14-16
     Wind Direction  (Tens of Degrees)        17-18
     Wind Speed (Knots)                      19-21
     Dry Bulb Temperature (° Fahrenheit)      22-24
     Total Cloud Cover                       25-26
     Opaque Cloud Cover                      27-28
SURFACE DATA RECORD (80 BYTE RECORD - CD144 FORMAT)

     Element                                 Columns
     Surface Station Number                  1- 5
     Year                                    6- 7
     Month                                   8-9
     Day                                     10-11
     Hour                                    12-13
     Ceiling Height (Hundreds of Feet)        14-16
     Wind Direction (Tens of Degrees)         39-40
     Wind Speed (Knots)                      41-42
     Dry Bulb Temperature (° Fahrenheit)      47-49
     Opaque Cloud Cover                      79
                               A-l

-------
SURFACE DATA RECORD - SAMSON FORMAT

     The first record in the file retrieved from the SAMSON CD-
ROMs contains station data.  The format of this record is:
Columns

001

002-006

008-029

031-032

033-036
039-044
039
040-041
043-044

047-053
047
048-050
052-053
Element

Indicator

WBAN Number

City

State

Time Zone



Latitude
Longitude
056-059   Elevation
Definition

  to indicate a header record

Station number identifier

City where station is located

State where station is located

The number of hours by which the local
standard time lags or leads Universal
Time.

Station latitude
N = north of eguator
Degrees
Minutes

Station longitude
W = west, E = east
Degrees
Minutes

Elevation of the station in meters above
sea level.
The FORTRAN format of this record is:

(1X,A5,1X,A22,1X,A2,1X,I3,2X/A1,I2,1X/I2,2X,A1/I3,1X,I2/2X,I4)



     Each variable is represented by a position number.  This
position number always corresponds to that variable, no matter
how many or how few variables are retrieved.  The second record

contains the  list of variables  (by a position number) that  appear
in the data file.  There  is no particular format; the variable

number appears above the  column of data it represents with  at

least one space  (and usually many more) between the position

numbers.
                               A-2

-------
     The third and subsequent records contain the weather

elements retrieved from the SAMSON CD-ROMs.  The data are free

format, i.e., there is at least one space between each element in
the record.  The year, month, day, hour and observation indicator

always appear on each record.  These are followed by the

variables retrieved by the user.  If all the variables were

retrieved, they would appear in the following order:


Position  Description

          Year, month, day, hour  (LST), observation indicator
1         Extraterrestrial horizontal radiation
2         Extraterrestrial direct normal radiation
3         Global horizontal radiation
4         Direct normal radiation
5         Diffuse horizontal radiation
6         Total cloud cover
7         Opaque cloud cover
8         Dry bulb temperature
9         Dew point temperature
10        Relative humidity
11        Station pressure
12        Wind direction
13        Wind speed
14        Visibility
15        Ceiling height
16        Present weather
17        Precipitable water
18        Broadband aerosol optical depth
19        Snow depth
20        Days since last snowfall
21        Hourly precipitation amount and flag


The online help that accompanies the CD-ROMs contains a complete
discussion of these variables, including the units, missing value
indicators and any special considerations or comments.
                               A-3

-------
HOURLY PRECIPITATION - TD-3240 FORMAT

     Precipitation data are reported only for those hours during
which precipitation occurred.  Variable-length blocks contain a
stations's precipitation record for one day on a physical record.
The format of the precipitation data for variable-length blocks
is as follows:

Field     Columns   Description
001       001-003   Record type
002       004-011   Station identifier
003       012-015   Meteorological element type
004       016-017   Measurement units
005       018-021   Year
006       022-023   Month
007       024-027   Day  (right justified, zero filled)
008       028-030   Number of data groups to follow
009       031-034   Hour  (left justified, zero filled)
010       035-040   Value of meteorological element
Oil       041       Measurement flag #1
012       042       Quality flag #2  (not used, blank)
     Data groups  in  the  same form as fields 009-012 are repeated
as many times  as  necessary to contain one day of values on  one
record.  These data  would occupy fields 013 through 108,  the
maximum number of fields.

     Fixed-length blocks contain a stations's precipitation
record for  one hour  on a physical record.  The structure  is
identical to the  variable-length blocks, except that  only one
hour of data appears on  the record, i.e. fields 001 through 012.
                               A-4

-------
     The National Climatic Data Center publication TD-3240 Hourly
Precipitation (NCDC, 1990) contains a complete discussion of the
format, definitions and remarks for each of the fields presented
above.
                               A-5

-------
OUTPUT FILE (UNFORMATTED!
HEADER RECORD
     Data type
     Integer
     Integer
     Integer
     Integer
Number    Description
 1       Surface Station Number
 1       Surface Station Year
 1       Mixing Height Station Number
 1       Mixing Height Station Year
DATA RECORDS  TONE PER DAY)
     Data type
     Integer
     Integer
     Real
     Integer
     Real
     Real
     Real

     Real

     Real
Number Description
 1     Year
 1     Month
 1     Julian Day
24     Hourly Values of Stability Class
24     Hourly Values of Wind Speed (m/s)
24     Hourly Values of Temperature (K)
24     Hourly Values of Flow Vector
       Values (degrees)
24     Hourly Values of Randomized Flow
       Vector Values (degrees)
48     Array dimensioned 2,24 containing:
       24 rural mixing height values  (1), and
       24 urban mixing height values  (2)  (m)
                               A-6

-------
OUTPUT FILE (ASCII FORMAT)

HEADER RECORD

     The first record of the ASCII output file consists of the
following four variables:

     Field     Description
     001       Surface Station Number
     002       Surface Station Year
     003       Mixing Height Station Number
     004       Mixing Height Station Year
These variables are written with the format:
     ( 4(16, IX) )

DATA RECORDS (ONE PER HOUR)

     If the user selected the option to process the input data
for CONCENTRATION estimates (i.e., NO DEPOSITION), then the ASCII
output file consists of the following variables, one record for
each hour of the period.

     Field     Description
     001       Year (2 digits)
     002       Month
     003       Day
     004       Hour
     005       Random flow vector
     006       Wind speed (m/s)
     007       Ambient temperature (K)
     008       Stability category
     009       Rural mixing height (m)
     010       Urban mixing height (m)
These variables are written with the format:
     ( 412, 2F9.4, F6.1, 12, 2F7.1 )
                               A-7

-------
     If the user selected the option to process the input data
for DRY DEPOSITION estimates, then the following three variables
are added to the 10 above:
     Field     Description
     Oil       Friction velocity at the application site (m/s)
     012       Monin-Obukhov length at the application site  (m)
     013       Roughness length at the application site (m)
The 13 variables are written with the format:
     ( 412, 2F9.4, F6.1, 12, 2F7.1, F9.4, F10.1, F8.4 )

     If the user selected the option to process the input data
for WET DEPOSITION estimates, then the following three variables
are added to the 13 above:
     Field     Description
     014       Precipitation code  (1-18: liquid, 19 and above:
               frozen)
     015       Precipitation amount (mm)
The 15 variables are written with the format:
     ( 412, 2F9.4, F6.1, 12, 2F7.1, F9.4, F10.1, F8.4, 14, F7.2)
                               A-8

-------
                           APPENDIX B

                    TABLES OF SITE PROPERTIES

     In this appendix, guidance on specifying the site properties
required for estimating the dispersion parameters is given.
Table B-l gives representative values for the surface roughness
length, B-2 for albedo, B-3 for Bowen ratio and B-4 for
anthropogenic heat flux.
                            TABLE B-l
   Surface Roughness Length, in Meters, for Land-Use Types and
                Seasons (from Sheih et al., 1979)

1.
2.
3.
4.
5.
6.
7.
8.
Land-Use Type
Water Surface
Deciduous Forest
Coniferous Forest
Swamp
Cultivated Land
Grassland
Urban
Desert Shrubland
Spring
0.0001
1.00
1.30
0.20
0.03
0.05
1.00
0.30
Summer
0.0001
1.30
1.30
0.20
0.20
0.10
1.00
0.30
Autumn
0.0001
0.80
1.30
0.20
0.05
0.01
1.00
0.30
Winter
0.0001
0.50
1.30
0.05
0.01
0.001
1.00
0.15
                               B-l

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                          TABLE B-2
   Albedo1 of Natural Ground Covers for Land-Use Types and
                  Seasons (from Iqbal,  1983)

1.
2.
3.
4.
5.
6.
7.
8.
Land-Use Type
Water Surface
Deciduous Forest
Coniferous Forest
Swamp
Cultivated Land
Grassland
Urban
Desert Shrubland
Spring
0.12
0.12
0.12
0.12
0.14
0.18
0.14
0.30
Summer
0.10
0.12
0.12
0.14
0.20
0.18
0.16
0.28
Autumn
0.14
0.12
0.12
0.16
0.18
0.20
0.18
0.28
Winter2
0.20
0.50
0.35
0.30
0.60
0.60
0.35
0.45
     See also Iqbal (1983) for specific crops or ground
     covers.

Definitions of Seasons:

Spring:   Periods when vegetation is emerging or partially
          green.  This is a transitional situation that
          applies for 1-2 months after the last killing frost
          in spring.

Summer:   Periods when vegetation is lush and healthy,
          typical of mid-summer, but also of other seasons
          where frost is less common.

Autumn:   Periods when freezing conditions are common,
          deciduous trees are leafless, crops are not yet
          planted or are already harvested (bare soil
          exposed), grass surfaces are brown, and no snow is
          present.

Winter:   Periods when surfaces were covered by snow, and
          when temperatures are sub-freezing.
     Winter albedo depends upon whether a snow cover is
     present continuously, intermittently, or seldom.  Albedo
     ranges from about 0.30 for bare snow cover to about 0.65
     for continuous cover.
                             B-2

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                 TABLE B-3a
Daytime Bowen Ratio by Land Use and Season
      Dry  Conditions  (from  Paine,  1987)
Land-Use
Water (fresh and sea)
Deciduous Forest
Coniferous Forest
Swamp
Cultivated Land
Grassland
Urban
Desert Shrubland

Spring
0.1
1.5
1.5
0.2
1.0
1.0
2.0
5.0
TABLE
Daytime Bowen Ratio by
Average
Land-Use
Water (fresh and sea)
Deciduous Forest
Coniferous Forest
Swamp
Cultivated Land
Grassland
Urban
Desert Shrubland
Conditions
Spring
0.1
0.7
0.7
0.1
0.3
0.4
1.0
3.0
Summer
0.1
0.6
0.6
0.2
1.5
2.0
4.0
6.0
B-3b
Land-Use and
(from Paine,
Summer
0.1
0.3
0.3
0.1
0.5
0.8
2.0
4.0
Autumn
0.1
2.0
1.5
0.2
2.0
2.0
4.0
10.0

Season -
1987)
Autumn
0.1
1.0
0.8
0.1
0.7
1.0
2.0
6.0
Winter1
2.02
2.0
2.0
2.0
2.0
2.0
2.0
10.0



Winter
1.5
1.5
1.5
1.5
1.5
1.5
1.5
6.0
                     B-3

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                           TABLE B-3C
          Daytime Bowen Ratio by Land-Use and Season -
                Wet Conditions (from Paine,  1987)

	Land-Use	Spring	Summer	Autumn	Winter
 Water (fresh and sea)      0.1       0.1       0.1        0.3
 Deciduous Forest          0.3       0.2       0.4        0.5
 Coniferous Forest         0.3       0.2       0.3        0.3
 Swamp                     0.1       0.1       0.1        0.5
 Cultivated Land           0.2       0.3       0.4        0.5
 Grassland                 0.3       0.4       0.5        0.5
 Urban                     0.5       1.0       1.0        0.5
 Desert Shrubland          1.0       5.0       2.0        2.0
                               B-4

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                          TABLE  B-4
Average Anthropogenic Heat Flux (Qf) and Net Radiation  (Q*)
          for Several Urban Areas (from Oke, 1978)
Urban area/
latitude/period
Manhattan (40°N)
annual
s miner
winter
Montreal (45°N)
annual
sunner
winter
Budapest (47°N)
annual
sunner
winter
Sheffield (53°N)
annual
West Berlin (52°N)
annua I
Vancouver (49°N)
annual
summer
winter
Hong Kong (22°N)
annua I
Singapore (1°N)
annua I
Los Angeles (34°N)
annua I
Fairbanks (64°N)
annua I
Population
(x 106)

1.7



1.1



1.3



0.5

2.3

0.6



3.9

2.1

7.0

0.03
Population
density
(persons/km2)

28,810



14,102



11,500



10,420

9,830

5,360



3,730

3,700

2,000

810
Per capita
energy usage
(MJxIoVyr)

128



221



118



58

67

112



34

25

331

740
(W/m2)

117
40
198

99
57
153

43
32
51

19

21

19
15
23

4

3

21

19
0.
(W/m2)

93



52
92
13

46
100
-8

56

57

57
107
6

-110

'110

108

18
                            B-5

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TECHNICAL REPORT DATA
(Please read Instructions on reverse before completing)
1. REPORT NO. 2.
EPA-454/B-96-001
4. TITLE AND SUBTITLE
PCRAMMET User's Guide
7. AUTHOR(S)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Pacific Environmental Services, Inc.
5001 South Miami Boulevard
P.O. Box 12077
Research Triangle Park, NC 27709-2077
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emissions, Monitoring, and Analysis Division
Research Triangle Park, NC 27711
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
October 1996
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
1 1 . CONTRACT/GRANT NO.
68D30032
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This document presents user instructions on the use of the PCRAMMET meteorological preprocessor
program. PCRAMMET is a PC-driven, user interactive program which merges surface and mixing height
data into a single output file for use in refined atmospheric dispersion models, such as ISC. This revision
of the PCRAMMET program allows the user to enter options needed for use in dry and wet deposition of
the ISCST3 model. PCRAMMET allows for surface meteorological data to be in any of the following
formats: (1) SCRAM BBS, (2) SAMSON CD, or (3) CD144. The mixing height data may be in the
following formats: (1) SCRAM BBS, or (2) TD9689. A precipitation file may also be used by
PCRAMMET, in the TD3240 format.
17 . KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Air Pollution Meteorology
Air Dispersion Models
Meteorological Processor
18. DISTRIBUTION STATEMENT
Release Unlimited
b. IDENTIFIERS/OPEN ENDED TERMS
Refined Modeling
Deposition
Dispersion
19. SECURITY CLASS (Rq>on)
Unclassified
20. SECURITY CLASS (Page)
Unclassified
c. COSATI Field/Group

21. NO. OF PAGES
98
22. PRICE
,PA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION IS OBSOLETE

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