CMAQ: The Community Multiscale Air Quality Modeling System

CMAQ Impact Statement
- Read a brief summary of CMAQ's mission and how its integrity and complexity contribute to air quality management decision-making.
New CMAQv5.5 Release!
- Learn about new features in our latest release
Cloud-based data sharing and CMAQ modeling
Impact of Aerosol Nitrate Photolysis on air quality
- Photolysis of aerosol nitrate creates tropospheric ozone.
- Learn more about a chemical pathway that prolongs the lifetime of nitrogen oxide s.

CMAQ (see-mak): an active open-source development project of the U.S. EPA that consists of a suite of programs for conducting air quality model simulations. CMAQ combines current knowledge in atmospheric science and air quality modeling, multi-processor computing techniques, and an open-source framework to deliver fast, technically sound estimates of ozone, particulates, toxics and deposition of acids, nutrients, and other pollutants.