Jump to main content.

Recent Additions

SCRAM RSS Feed & Archive

7/29/14 A webinar session with respect to the mid-May revisions to the AERMOD Modeling System and with respect to the release of a supplemental 1-hour NO2 clarification memorandum will be held on Tuesday, August 12th, 2014 at 2:30pm EDT.

6/3/14 The presentations from the 2014 EPA Regional, State, and Local Modelers' Workshop in Salt Lake City, UT are now available (Clickable links on the referenced agenda).

5/28/14 An updated version of AERSCREEN, dated 14147, has been posted on the screening models webpage. Model Change Bulletin #4 (MCB#4) provides a summary of the changes incorporated into AERSCREEN since version 11126.

5/21/14 The Guidance for PM2.5 Permit Modeling is now available.

5/16/14 An updated version of AERMOD, dated 14134, has been posted on the AERMOD webpage. Model Change Bulletin #10 (MCB#10) provides a summary of the changes incorporated into version 14134 of AERMOD, and an update to the AERMOD User's Guide Addendum is also provided.

5/16/14 An updated version of AERMET, dated 14134, has been posted on the AERMET webpage. Model Change Bulletin #5 (MCB#5) provides a summary of the changes incorporated into version 14134 of AERMET, and an update to the AERMET User's Guide Addendum is also provided.

4/8/14 Interim guidance for the treatment of condensable particulate matter test results in the PSD and NSR permitting programs is now available.

1/23/14 Important statements concerning the recent AERMET and AERMOD (dated 13350) releases.

1/15/14 The January 2014 AERMOD Modeling System Update Webinar presentation slides and hour-long recording are now available.

1/14/14 The draft SO2 Monitoring and Modeling Technical Assistance Documents have been updated based on public comments and are available on the Sulfur Dioxide Implementation web page.

12/04/13 Updated regulatory versions of CALPUFF and CALMET (version 5.8.4, dated 130731) are now available. The links to the updated CALPUFF Modeling System files, the associated Model Change Bulletins (MCBs E, F, and G) and a Modification of CALPUFF and CALMET Memorandum can be found on the CALPUFF webpage.

11/7/13 An updated release of the beta MMIF utility has been posted. Version 3.0 includes significant efficientcy improvements and the ability to extract multipe data parameters from multiple grid cells in a single run. Please reference the MMIF Change Log and the User's Manual for more information on these and other changes from the previous version.

9/19/13 An updated version of LEADPOST (13262) has been posted. A summary of changes can be found in MCB_4.txt of the leadpost.zip file.

8/26/13 The NO2/NOx In-Stack Ratio (ISR) Database has been updated based on the first database submission from the State of Oklahoma and the second database submission from the State of Alaska.

8/15/13 An updated or refreshed version of VISCREEN, dated 13190, has been posted. A summary of changes can be found in MCB#2.

7/19/13 An updated version of CAL3QHCR, dated 13196, has been posted. A summary of changes can be found in MCB#8.

5/21/13 A beta version of AERCOARE is now available on the Related Programs portion of SCRAM. AERCOARE is a meteorological data preprocessor that incorporates the Coupled Ocean Atmosphere Response Experiment (COARE) air-sea flux procedure.

3/8/13 A clarification memo regarding the "Use of ASOS Meteorological Data in AERMOD Dispersion Modeling." is now available. This clarification memo also discusses the development of the AERMINUTE meteorological data preprocessor.

3/6/13 An updated version of SCREEN3, dated 13043, has been posted on the Dispersion Modeling - Screening Models webpage. Model Change Bulletin #3 (MCB#3) summarizes the minor changes in SCREEN3, primarily to allow the program to execute correctly in newer computer operating systems.

1/18/13 An updated version of AERSURFACE, dated 13016, has been posted on the Dispersion Modeling - Related Programs webpage. Model Change Bulletin #1 (MCB#1) provides a summary of the changes incorporated into version 13016 of AERSURFACE, and a minor update to the AERSURFACE User's Guide is also provided.

12/28/12 The Modeled Attainment Test Software (MATS) has been updated to version 2.5.1.

10/5/12 The Summary of Comments documentation package for the 10th Conference on Air Quality Modeling is now available.


This website is maintained by EPA's Air Quality Modeling Group (AQMG). The AQMG conducts modeling analyses to support policy and regulatory decisions in the Office of Air and Radiation (OAR) and provides leadership and direction on the full range of air quality models and other mathematical simulation techniques used in assessing control strategies and source impacts. Documentation and guidance for these air quality models can be found on this website, including downloadable computer code, input data, and model processors.

You will need Adobe Acrobat Reader to view the Adobe PDF files on this site. See EPA's PDF page for more information about getting and using the free Acrobat Reader.

This site contains the following sections.

Air Quality Models - Provides descriptions and documentation for three types of air quality models: dispersion, photochemical, and receptor models. Also provided with the dispersion modeling section are source code and associated user's guides and documentation for preferred/recommended models, screening models, and alternative models.

Modeling Applications and Tools - Provides more detailed information on modeling analyses AQMG has conducted to support policy and regulatory decisions in OAR including assessment of control strategies and source culpability. In addition, this site provides access to EPA developed tools for use in State Implementation Plan (SIP) demonstrations and other air quality modeling assessments.

Modeling Guidance & Support - Provides current guidance for applying air quality models for regulatory applications for both State Implementation Plans (SIP) demonstrations and revisions, as well as permit applications for new source reviews including Prevention of Significant Deterioration (PSD) regulations.  Included is the Model Clearinghouse which is designed to help record the interpretation of modeling guidance for specific regulatory applications.  Also included in this area are links to modeling contacts within the EPA Regional Offices and State environmental agencies. 

Meteorological Data & Processors  - Provides information on Meteorological data used in air quality models as derived from both ambient measurements and meteorological models. Processors based on these two main sources of meteorological data are also provided.

Conferences & Workshops - Provides announcements and related information for upcoming meetings, conferences, and workshops including agendas, review materials, and links.

Reports & Journal Articles
- Provides access to reports developed by AQMG staff as well as a bibliographic listing of journal articles they have authored or co-authored.

Related Links --- Provides website links of interest to air quality modelers and policy analysts.

Employment Opportunities:  AQMG currently has no open positions to fill. As positions become open, AQMG will update this website with details. In addition, job announcements can be found on the internet at the Office of Personnel Management website. The easiest way to find the announcement is to look for openings located in Research Triangle Park, North Carolina.

If you would like to be notified when we have a position for which you may be interested in applying, you may send a resume to Tyler Fox, Group Leader at: Fox.Tyler@epa.gov.


Office of Air and Radiation | Office of Air Quality Planning and Standards

Local Navigation

Jump to main content.