AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Secondary Organic Aerosol Formation in Biomass-Burning Plumes: Theoretical Analysis of Lab Studies
Qijing Bian, Shantanu Jathar, John Kodros, Kelley Barsanti, Lindsay Hatch, Andrew May, SONIA KREIDENWEIS, Jeffrey R. Pierce, Colorado State University
Abstract Number: 10 Working Group: Combustion
Abstract Secondary organic aerosol (SOA) has been shown to form from biomass-burning emissions in laboratory and field studies. However, there is significant variability between individual studies, which could be due to differences in fuels, fire conditions, dilution, and/or conditions of laboratory studies. This talk will focus on important processes affecting SOA formation in laboratory chamber studies. In smog-chamber studies, vapor wall losses have been demonstrated to be an important factor that suppresses traditional secondary organic aerosol (SOA) formation; however, impacts of vapor wall losses on the production of biomass-burning SOA have not yet been investigated. We use an aerosol microphysics model of that accounts for size, volatility, and chemistry to estimate the influence of the vapor wall loss on the SOA formation observed during the FLAME-III chamber studies. Our simulations show that the mean OA enhancement is 1.8 throughout the experiments when considering vapor wall loss, which roughly matches the mean observed enhancement during FLAME-III. On the other hand, the mean OA enhancement increases to over 3 when wall loss is turned off, which implies that the vapor wall losses are suppressing SOA formation. These results are generally robust across the parameter uncertainties (wall-loss and mass-transfer coefficients, and chemistry assumptions).