LATEST U.S. EPA UPDATES
The United States Environmental Protection Agency (U.S. EPA) is constantly updating the AERMOD Modeling System and its associated components: AERMAP, AERMET, AERSCREEN, and AERSURFACE. AERMOD, AERMAP, and AERMET make up the preferred/recommended models to be used for near-field air dispersion modeling analyses as promulgated in Appendix W of the United States Code of Federal Regulations (40 CFR Part 51).
Whenever changes are made to these models, we will update this page with the latest information regarding each of these programs. Bookmark this page and check it often for updates!
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AERMOD
A new version of AERMOD (11353) was released on December 21, 2011. A full list of changes is below in the Model Change Bulletin. Enhancements include bug fixes to subroutines involving:
- Urban sources
- Background ozone concentrations
- Elimination of erroneous warning messages and runtime errors
Current EPA AERMOD User's Guide Revision (version 11059)
Previous EPA AERMOD User's Guide Revision (version 11059)
Previous EPA AERMOD User's Guide Revision (version 09292)
Previous EPA AERMOD User's Guide
Model Change Bulletin #6 (Release of AERMOD 11353)
Model Change Bulletin #5 (Release of AERMOD 11103)
Model Change Bulletin #4 (Release of AERMOD 11059)
Model Change Bulletin #3 (Release of AERMOD 09292)
Model Change Bulletin #2 (Release of AERMOD 07026)
Model Change Bulletin #1 (Release of AERMOD 06341)
AERMOD Implementation Guide (Released on March 19, 2009)
AERSCREEN
AERSCREEN is the screening model for the AERMOD modeling system designed to produce estimates of "worst-case" 1-hour concentrations for a single source without the need for hourly meteorological data. The official AERSCREEN release (version 11126) was made on May 6, 2011. BREEZE AERSCREEN Version 1.2 incorporates the 11126 executable.
AERSCREEN officially replaced SCREEN3 as the recommended screening model in the United States. See the "Memos and Other Guidance" section below for more details.
EPA AERSCREEN User's Guide
Model Change Bulletin #3 (Release of AERSCREEN 11126)
AERMAP
A new version of AERMAP (11103) was released on April 14, 2011.
On March 19, 2009, a new AERMOD Implementation Guide was released by the U.S. EPA providing information on the new AERMAP executable dated 09040. Click here to read the full document.
Current EPA AERMAP User's Guide (version 11103)
Previous EPA AERMAP User's Guide (includes Addendums from 06341 & 09040)
Model Change Bulletin #3 (Release of AERMAP 11103)
Model Change Bulletin #2 (Release of AERMAP 09040)
Model Change Bulletin #1 (Release of AERMAP 06341)
AERMET
A new version of AERMET (11059) was released on April 7, 2011. The release included the new AERMINUTE executable, a companion to AERMET which processes 1-minute ASOS wind data to supplement data quality. On December 21, 2011, a new version of AERMINUTE (11325) was released; a full list of changes is below in the Model Change Bulletin.
Current EPA AERMET User's Guide (version 11059)
Previous EPA AERMET User's Guide (includes Addendum from 06341)
Model Change Bulletin #2 (Release of AERMET 11059)
EPA AERMINUTE User's Guide (version 11059)
Model Change Bulletin #1 (Release of AERMINUTE 11325)
AERSURFACE
AERSURFACE is a tool that processes land cover data to determine surface characteristics necessary to run AERMET. While the program is not an Appendix W model, the methodology used in AERSURFACE is required to be used in AERMOD modeling analyses.
AERMOD Implementation Guide - January 9, 2008 (Release of AERSURFACE 08009)
Memos and Other Guidance
The Support Center for Regulatory Atmospheric Modeling (SCRAM) at the U.S. EPA periodically posts memorandums which provide guidance or clarify existing policies and procedures for atmospheric modeling. Below is a list of recently released memos from SCRAM.