Abstract

A new configuration of the Community Earth System Model version 2 (CESM2) with variable resolution allows for simulation of air quality over the continental U.S. at regional model scales within the global model. This framework is the first version of the Multi-Scale Infrastructure for Chemistry a... Show moreA new configuration of the Community Earth System Model version 2 (CESM2) with variable resolution allows for simulation of air quality over the continental U.S. at regional model scales within the global model. This framework is the first version of the Multi-Scale Infrastructure for Chemistry and Aerosols (MUSICA), with a regionally refined (RR) grid of 14km resolution over the contiguous United States (CONUS). Simulations have been run with a recently updated mechanism with more complex isoprene and terpene chemistry than the default mechanism. Comparisons of these simulations show improvements over the uniform, approximately 1-degree resolution simulation, in the prediction of surface ozone and its precursors, as well as PM2.5, throughout CONUS. The model is evaluated for the suite of measurements made during several field experiments in 2013, including the experiments part of the Southeast Atmosphere Study (SOAS, NOMADSS, SENEX) and the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS). The evaluation of NOx, reactive nitrogen reservoirs and a variety of volatile organic compounds, allows evaluation of ozone and secondary aerosol production. Evaluation with surface monitors of ozone and satellite observations of CO and NO2 will also be performed to assess the model performance over a full seasonal cycle. Show less