AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Simulation of Evolving Gas- and Aerosol-Phase Air Quality over Los Angeles
ELYSE PENNINGTON, Melissa Venecek, Yuan Wang, John Seinfeld, California Institute of Technology
Abstract Number: 200 Working Group: Urban Aerosols
Abstract Secondary organic aerosol (SOA) is an important component of urban aerosol, but modeling its mass and speciation remains a challenge. The Community Multiscale Air Quality (CMAQ) model developed by EPA has been widely used to simulate atmospheric chemistry, SOA formation, and responses to changes in emissions. Emissions inventories, a crucial input to CMAQ, for Los Angeles and other regions, are continuing to evolve. For example, McDonald et al. (2018) showed that urban mobile source emissions are declining, while those of volatile chemical products (VCPs) are becoming increasingly important. The 2018 emissions inventory of McDonald et al. over the Los Angeles Basin is incorporated into CMAQ version 5.2. The impact of these changes on CMAQ predictions of gas-phase species and SOA mass and speciation are examined in light of observational data. Prediction of gas-phase and SOA levels and speciation corresponding to the estimated 2018 emissions inventory for Los Angeles is presented. The influence of meteorological fields on the simulated SOA is explored.