The EPA webinar will provide an overview of the new features in CMAQ that include: more detailed representation of the characteristics of particulate matter (PM), expanded chemistry for ozone and PM formation from global-to-local scales, more complex land and atmosphere interactions to support both air quality and ecosystems applications, increased emphasis on pollutants originating outside the US, increased scientific consistency between meteorology and chemistry models, and greater flexibility to support increasingly diverse uses of CMAQ.