10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
The Effect of Temperature on Secondary Organic Aerosol Formation from Evaporated Fuels and Aromatic Compounds under Daytime and Nighttime Conditions
JEFF BEAN, Shaokai Gao, Terry Lathem, Phillips 66
Abstract Number: 102 Working Group: Aerosol Chemistry
Abstract Secondary organic aerosol (SOA) is an important contributor to ambient concentrations of particulate matter. SOA is formed from oxidation of anthropogenic and biogenic volatile organic compounds (VOCs) in the atmosphere. Chemical transport models (CTMs), such as the Community Multi-scale Air Quality Model (CMAQ) and the Comprehensive Air Quality Model with Extensions (CAMx), provide estimates of SOA formation based on data acquired from environmental chamber experiments and ambient measurements. The model parameters used to calculate SOA must be continuously evaluated and updated to incorporate advances in SOA research. It is important to evaluate model performance for multiple VOC precursors and across a variety of environmental conditions.
The present study compares SOA formation in 7.5 m3 environmental chambers with box model predictions for evaporative emissions of commercial fuels (gasoline and diesel) and single component aromatics. Experiments were conducted across a range of temperatures as well as under both daytime and nighttime oxidative conditions. Experiments were modeled using the SAPRC box model with the SAPRC07 chemical mechanism and the AERO6 SOA parameters, similar to the SAPRC07TC_AE6_AQ mechanism used by CMAQ version 5.1. Key results from comparisons of modeled and experimental SOA formation at varying temperatures and oxidative conditions will be presented. These results highlight areas where further improvements are needed to increase model accuracy.