AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Chamber Studies Investigating Secondary Organic Aerosol Formation and Properties from Daytime and Nighttime Oxidation of Oxygenated Aromatics Emitted by Wildfires
CARLEY D. FREDRICKSON, Brett Palm, Amy P. Sullivan, Yingjie Shen, Shane Murphy, Ben H. Lee, Xuan Zhang, Joel A. Thornton, University of Washington
Abstract Number: 864 Working Group: Biomass Combustion: Emissions, Chemistry, Air Quality, Climate, and Human Health
Abstract We investigated the OH- and NO3-initiated oxidation of oxygenated aromatics, which included the phenolic compounds phenol, catechol, guaiacol, and cresol in the National Center for Atmospheric Research’s 10 m3 Atmospheric Simulation Chamber as part of the Monoterpene and Oxygenated aromatics Oxidation at Night and under LIGHTs (MOONLIGHT) campaign. Using a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) coupled with the Filter Inlet for Gases and Aerosols (FIGAERO), we measured the evolution of the molecular composition (O/C, organic nitrogen content, mean molecular weight, etc) in both the gas and particle phase, together with the corresponding effective volatility of the secondary organic aerosol (SOA) produced in each experiment. We use these observations together with measurements made during the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption and Nitrogen (WE-CAN) to constrain the importance of phenolic compounds in the formation of light-absorbing SOA in biomass burning plumes. We also compare the observations to predictions using the F0AM-WAM box model, which uses explicit chemical mechanisms coupled to an equilibrium gas-particle partitioning module, to evaluate the overall skill of known mechanisms and vapor pressure parameterizations at describing SOA from these precursors.