An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

About EPA

About the Atmospheric and Environmental Systems Modeling Division

On This Page:

What We Do
Main Office Location


What We Do

The Atmospheric & Environmental Systems Modeling Division (AESMD):

  • Conducts research to help EPA characterize processes that impact the transport, transformation, and fate of environmental contaminants in the air, and how they interact with the rest of the environment, in support of the Clean Air and Clean Water Acts;
  • Develops and uses modeling tools to help manage air quality at multiple scales, such as models that estimate the contributions of various air emission sources to air pollution and inform exposure and effects assessments;
  • Studies emission impacts from alternative energy pathways that can improve the cost-effectiveness of air quality management approaches and identify potential implications of energy system changes on air quality and other environmental media; and
  • Advances the science of atmospheric modeling tools to support robust air quality management policy decisions.

Relevant Research


 Alan Vette, Director

Tom Pierce, Associate Director


  • Atmospheric Chemistry and Aerosol Branch
  • Atmospheric Dynamics and Meteorology Branch
  • Emissions Systems Analysis Branch
  • Natural Systems Characterization Branch


Main Office Location

US EPA ORD Center for Environmental Measurement and Modeling 
Atmospheric and Environmental Systems Modeling Division
109 T.W. Alexander Drive
Mail Code: E243-02
Research Triangle Park, NC 27709