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Support Center for Regulatory Atmospheric Modeling (SCRAM)

Meteorological Processors and Accessory Programs

Surface and upper air data, provided by NWS, are important inputs for air quality models. Before these data are used in some of the EPA dispersion models, meteorological processors are used to manipulate the data. Some of these processors re-format data for input into air quality dispersion models, while other processors use the NWS observational data to calculate important inputs for the dispersion models. These processors include: AERMET, MIXHGT, MPRM, PCRAMMET, and STAR.

Other accessory programs are also provided that produce graphical or statistical outputs that can aid in the interpretation and understanding of the NWS data or dispersion model results. These accessory programs include: BINTOASC, METLIST, WINDROSE, WRPLOT.

Meteorological Processors

AERMET - Version 19191
AERMET is a meteorological data preprocessor for AERMOD. AERMET processes commercially available or custom on-site met data and creates two files: a surface data file and a profile data file. The tool AERSURFACE can be used to estimate the surface characteristics for input to AERMET.
Model Code

Executable - v19191 (ZIP)(1 MB, 08-21-2019) - 64-bit Operating Systems
Executable - v19191 (ZIP)(1 MB, 08-21-2019) - 32-bit Operating Systems
Source Code - v19191 (ZIP)(467 KB, 08-21-2019)

Model Documentation

User's Guide for the AERMOD Meteorological Preprocessor (AERMET) (PDF)(310 pp, 3 MB, 08-21-2019, 454-B-19-028)

Model Change Bulletin #9 - Version Date 19191 (PDF)(1 pg, 144 KB, 08-21-2019)
Model Change Bulletins Archive (ZIP)(632 KB, 08-21-2019)

March 8, 2013 Clarification Memorandum - Use of ASOS Meteorological Data in AERMOD Dispersion Modeling (PDF)(35 pp, 1 MB, 03-08-2013)

Test Cases
AERMET Test Cases (ZIP)(123 MB, 08-21-2019)

FIXISHD Utility Program - This is no longer needed.
AERMINUTE - Version 15272
AERMINUTE processes 1-minute ASOS wind data to generate hourly average winds for input to AERMET in Stage 2.
Model Code
AERMINUTE - v15272 (ZIP)(531 KB, 09-29-2015)
Model Documentation
README (TXT)(675 KB, 09-29-2015)
User’s Guide - v15272 (PDF)(65 pp, 1 MB, 09-29-2015, 454-B-15-006)

Model Change Bulletin #4 - Version Date 15272 (TXT)(2 KB, 09-29-2015)
Model Change Bulletins Archive (ZIP)(4 KB, 09-29-2015)
MIXHGT (Mixing Height Program)
A program which calculates twice daily mixing heights for use in PCRAMMET. This program requires surface and radiosonde files as inputs.
Model Code
Executable (ZIP)(207 KB, 12-06-1998) - Readme included
Source Code (ZIP)(19 KB, 12-06-1998)
Model Documentation

Test Case (ZIP)(827 KB, 12-06-1998)
User's Guide (PDF)(18 pp, 56 KB, 12-06-1998)

Model Change Bulletin #1 - Version Date 98340 (TXT)(1 KB, 12-06-1998)

MPRM (Meteorological Processor for Regulatory Models)
A program used to process meteorological data, both National Weather Service and on-site, for use in regulatory modeling. MPRM has 3 stages: (1) listing missing, suspect , and invalid data, (2) merging quality assured and corrected meteorological data, and (3) creating meteorological data files for input to air quality dispersion models.
Model Code
MPRM Executable (ZIP)(642 KB, 12-15-1999)
Executable for data extraction and quality assurance (ZIP)(642 KB, 12-15-1999)
Source Code (ZIP)(205 KB, 12-15-1999)
Model Documentation

README (TXT)(6 KB, 12-15-1999)
Test Case (ZIP)(341 KB, 12-15-1999)
User's Guide (PDF)(192 pp, 506 KB, 08-01-1996, 454-B-96-002)
Addendum to User's Guide Addendum (PDF)(12 pp, 43 KB, 06-04-1999)

Model Change Bulletin #6 - Version Date 99349 (TXT)(2 KB, 12-15-1999)
Model Change Bulletins Archive (ZIP)(9 KB, 12-15-1999)

A meteorological processor which combines hourly NWS surface and twice daily mixing heights into a single file, computes a mixing height for each hour. PCRAMMET also incorporates surface characteristic parameters (Monin-Obukhov length, surface roughness length, albedo, Bowen ratio, anthropogenic heat flux, and net radiation) for deposition modeling. Output from PCRAMMET is commonly used as input to ISCST3 and BLP. PCRAMMET is a PC version of the original RAMMET program.
Model Code
Executable (ZIP)(303 KB, 06-18-1999) - README included.
Source Code (ZIP)(53 KB, 06-18-1999)
Model Documentation

PCRAMMET User's Guide (PDF)(95 pp, 161 KB, 06-18-1999, 454-B-96-001)

Model Change Bulletin #4 - Version Date 99169 (TXT)(2 KB, 06-18-1999)
Model Change Bulletins Archive (ZIP)(4 KB, 06-18-1999)

Test Cases Using Different Input Data Formats:
PCREX1 (ZIP)(330 KB, 12-01-1999) - CD144/TD3240 fixed format example
PCREX2 (ZIP)(412 KB, 12-01-1999) - SAMSON example
PCREX3 (ZIP)(178 KB, 12-01-1999) - SCRAM example
PCREX4 (ZIP)(330 KB, 12-01-1999) - CD144/TD3240 variable format example
PCREX5 (ZIP)(260 KB, 12-01-1999) - HUSWO data
PCRAMMET Demonstration (ZIP)(362 KB, 07-01-1992)
PCRAMMET Program (ZIP)(166 KB, 07-01-1992)
Tutorial Documentation (ZIP)(27 KB, 07-01-1992)
Instructions on PCRAMMET tutorial (TXT)(2 KB, 07-01-1992)
STAR (STability ARray program)
This program calculates a frequency distribution for wind speed, wind direction and wind stability. The output is an array suitable for input to ISCLT3.

Model Code and Documentation

Executable, Source Code and Test Case (ZIP)(208 KB, 07-12-1990) - Readme included.

Model Change Bulletin #3 - Version Date 90193 (TXT)(3 KB, 07-12-1990)
Model Change Bulletins Archive (ZIP)(4 KB, 07-12-1990)

Accessory Programs

A program that converts meteorological data from binary format to ASCII format. It is used primarily to give convert meteorological data when using the deposition option in the ISCST3 model (and is located with the model).
This program creates a listing file of specified meteorological data for a specified day or range of days, for QC or other purposes of inspection of a meteorological dataset. This program is used with the ISC3 model (and is located with the model).
A program that produces wind frequency statistics for 16 directions (22.5 degree arcs) to generate a graphical wind rose for each wind sector. The program uses the TD-1440 meteorological data (raw SCRAM format) as input.
Model Code and Documentation

Executable and Test files (ZIP)(285 KB, 06-29-1990)

Model Change Bulletin #1 - Version Date 90180 (TXT)(2 KB, 06-29-1990)

A program which computes wind rose statistics based on 10 degree wind increments. Unlike WINDROSE, WRPLOT can provide a graphical plot. Windrose uses the TD-1440 SCRAM meteorological data as input.
Model Code
Executable and test data (ZIP)(1 MB, 02-10-1993)
Model Documentation

Tutorial (ZIP)(48 KB, 07-01-1992 - Documentation, test data and readme. 
Instructions for WRPLOT Tutorial (TXT)(2 KB, 07-01-1992)
WRPLOT Demonstration (ZIP)(989 KB, 02-10-1993)

Model Change Bulletin #2 - Version Date 93036 (TXT)(4 KB, 02-10-1993)
Model Change Bulletins Archive (ZIP)(3 KB, 02-10-1993)

Test Data Sets
1984 Meteorological Data for RDU, NC (ZIP)(71 KB, 08-29-1990)
1985 Meteorological Data for RDU, NC (ZIP)(70 KB, 08-29-1990)
1986 Meteorological Data for RDU, NC (ZIP)(71 KB, 08-29-1990)
1987 Meteorological Data for RDU, NC (ZIP)(70 KB, 08-29-1990)
1988 Meteorological Data for RDU, NC (ZIP)(71 KB, 08-29-1990
1989 Meteorological Data for RDU, NC (ZIP)(71 KB, 08-29-1990)

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