Policy relevant science: Using satellite and aircraft observations to improve the CMAQ and CAMx regulatory air quality models

Federal and state agencies rely on EPA approved models to develop strategies that will improve air quality with the ultimate goal of compliance with the National Ambient Air Quality Standards (NAAQS). We will describe modifications to the Community Multi-Scale Air Quality (CMAQ) model and Comprehensive Air Quality Model with Extensions (CAMx) frameworks motivated by analysis of NASA satellite and aircraft measurements. Observations of tropospheric column NO2 from OMI have already led to the identification of an important deficiency in the chemical mechanisms used by models; data collected during the DISCOVER-AQ field campaign has been instrumental in devising an improved representation of the chemistry of nitrogen species. Our recent work has focused on the use of: OMI observations of tropospheric O3 to assess the representation of boundary conditions used by AQ models, OMI NO2 to derive a top down NOx emission from commercial shipping vessels that affect air quality in the Eastern U.S., and OMI HCHO to assess the C5H8 emission inventories provided by MEGAN and BEIS. We will describe how these OMI-driven model improvements are affecting the State Implementation Plans (SIPs) being prepared for submission to EPA in summer 2015 and how future modeling efforts may be impacted.