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Support Center for Regulatory Atmospheric Modeling (SCRAM)

Screening Models

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The models listed here are screening models that are usually applied before the refined air quality model to determine if refined modeling is needed. The models in this section include AERSCREENCOMPLEX1, CTSCREEN, RTDM3.2, SCREEN3, TSCREEN, VALLEY, and VISCREEN.

Screening Models
AERSCREEN is the recommended screening model based on AERMOD. The model will produce estimates of "worst-case" 1-hour concentrations for a single source, without the need for hourly meteorological data, and also includes conversion factors to estimate "worst-case" 3-hour, 8-hour, 24-hour, and annual concentrations. AERSCREEN is intended to produce concentration estimates that are equal to or greater than the estimates produced by AERMOD with a fully developed set of meteorological and terrain data, but the degree of conservatism will vary depending on the application.

AERSCREEN (Version 15181) code including the latest MAKEMET code (Version 15181) is provided below along with documentation and test cases. The MAKEMET program interfaces with AERSCREEN to generate a site-specific matrix of screening meteorological conditions based on user inputs for input into AERMOD.

Please note that before using AERSCREEN, users must have the latest AERMOD executable (09292 or later) as well as the AERMAP terrain preprocessor and BPIPPRIME executables. These programs can be downloaded from the AERMOD Modeling System section.

Model Code
AERSCREEN code and executables (v15181) (ZIP, 766KB)
MAKEMET code and executables (v15181) (ZIP, 355KB)

Model Documentation
User's Guide (PDF, 2.5MB)
Clarification memorandum on AERSCREEN as the recommended screening model (PDF, 323KB)
Model change bulletin #5 (TXT, 3KB)
Model change bulletin #4 (TXT, 1KB)
Model change bulletin #3 (TXT, 1KB)
Model change bulletin #2 (TXT, 1KB)
Model change bulletin #1 (TXT, 15KB)
Key changes since Beta release (PDF, 127KB)
Test Case (ZIP, 44.2MB)

COMPLEX1 is a multiple point source screening technique with terrain adjustment that incorporates the plume impaction algorithm of the VALLEY model.

Model Code
Executable (ZIP, 129KB)

Model Documentation
User's Guide is presently not available
Model Change Bulletin #1 (TXT, 2KB)
Model Change Bulletin #2 (TXT, 5KB)
Model Change Bulletin #3 (TXT, 3KB)
CTSCREEN is a Gaussian plume dispersion model designed as a screening technique for regulatory application to plume impaction assessments in complex terrain. CTSCREEN is a screening version of the CTDMPLUS model.

Model Code
Readme/Executable/Test Case and Source Code (ZIP, 710KB) with Extended Memory Executable

Model Documentation
User's Guide (PDF, 344KB)
Supplement to User's Guide (PDF, 80KB)
Report on Modifications to CTSCREEN and CTDMPLUS (PDF, 170KB)
Notes on Terrain Input to CTDMPLUS and CTSCREEN (TXT, 10KB)
Model Change Bulletin #1 (TXT, 2KB)
Model Change Bulletin #2 (TXT, 5KB)
Model Change Bulletin #3 (TXT, 8KB)
Model Change Bulletin #4 (TXT, 6KB)
Model Change Bulletin #5 (TXT, 2KB)

Model Tutorial
Tutorial Documentation (WP5.1, 155KB)
Instructions for CTSCREEN Tutorial (TXT, 3KB)
CTSCREEN Demonstration (ZIP, 320KB)
CTSCREEN Model, File 1 (ZIP, 305KB)
CTSCREEN Model, File 2 (ZIP, 329KB)
Text editor file (ZIP, 48KB)
Terrain data file (ZIP, 77KB)
BUCKBERG Terrain data file (TXT, 3KB)
ORIG Terrain data file (TXT, 3KB)
CTDM Batch file (TXT, 23KB)
Rough Terrain Diffusion Model (RTDM3.2) is a sequential Gaussian plume model designed to estimate ground-level concentrations in rough (or flat) terrain in the vicinity of one or more co-located point sources.

Model Code
Executable (ZIP, 106KB)

Model Documentation
User's Guide (PDF, 3MB)
Model Change Bulletin #1 (TXT, 2KB)
Model Change Bulletin #2 (TXT, 2KB)
SCREEN3 is a single source Gaussian plume model which provides maximum ground-level concentrations for point, area, flare, and volume sources, as well as concentrations in the cavity zone, and concentrations due to inversion break-up and shoreline fumigation.  SCREEN3 is a screening version of the ISC3 model.

Model Code
Readme/Code/Executable (ZIP, 669KB)

Model Documentation
User's Guide (PDF, 715KB)
Model Change Bulletin #1 (TXT, 1KB)
Model Change Bulletin #2 (TXT, 46KB)
Model Change Bulletin #3 (TXT, 4KB)
Toxics Screening Model (TSCREEN) is a Gaussian model that implements the procedures to correctly analyze toxic emissions and their subsequent dispersion from one of many different types of possible releases for superfund sites. It contains 3 models: SCREEN3, PUFF, and RVD (Relief Valve Discharge).

Model Code
Code/Executable/Test Case (ZIP, 1.6MB)

Model Documentation
User's Guide (PDF, 161KB)
TSCREEN Workbooks (PDF, 5.5MB)
Model Change Bulletin #1 (TXT, 3KB)
Model Change Bulletin #2 (TXT, 3KB)
Model Change Bulletin #3 (TXT, 7KB)
Model Change Bulletin #4 (TXT, 1KB)
Model Change Bulletin #5 (TXT, 1KB)
Model Change Bulletin #6 (TXT, 7KB)
Model Change Bulletin #7 (TXT, 2KB)

Model Tutorial
Tutorial Documentation (WP5.1, 86KB)
Instructions for TSCREEN Tutorial (TXT, 2KB)
TSCREEN Demonstration (ZIP, 579KB)
TSCREEN Model, File 1 (ZIP, 253KB)
TSCREEN Model, File 2 (ZIP, 382KB)
TSCREEN Model, File 3 (ZIP, 586KB)
VALLEY is a steady-state, complex terrain, univariate Gaussian plume dispersion algorithm designed for estimating either 24-hour or annual concentrations resulting from emissions from up to 50 (total) point and area sources.

Model Code
Code (ZIP, 76KB)

Model Documentation
User's Guide is available from NTIS (TXT, 18KB)
Model Change Bulletin #1 (TXT, 2KB)
VISCREEN calculates the potential impact of a plume of specified emissions for specific transport and dispersion conditions.

Model Code
Executable (ZIP, 211KB)

Model Documentation
VISCREEN Readme File (TXT, 3KB)
Users Guide (PDF, 4.3MB)
User's Guide Update Pages (PDF, 98KB)
Model Change Bulletin #1 (TXT, 1KB)
Model Change Bulletin #2 (TXT, 2KB)

All VISCREEN Model Documentation Listed Above (ZIP, 4.2MB)

Model Tutorial
Tutorial Documentation (ZIP, 2.9MB)

VISCREEN Excel Spreadsheet
VISCREEN Excel Spreadsheet (ZIP, 193KB)

VISCREEN Testcase (ZIP, 17KB)


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