AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Photochemical Processing of Secondary Organic Aerosol Precursors in Biomass Burning Smoke Measured by Comprehensive Two-Dimensional Gas Chromatography
LINDSAY E. HATCH, Wentai Luo, James F. Pankow, Daniel S. Tkacik, Adam Ahern, Rawad Saleh, Ellis Shipley Robinson, Allen Robinson, Ryan Sullivan, Neil Donahue, Robert J. Yokelson, Anton Rusanen, Ditte Mogensen, Sampo Smolander, Michael Boy, Kelley C. Barsanti, Portland State University
Abstract Number: 230 Working Group: Biomass Burning Aerosol: From Emissions to Impacts
Abstract Biomass burning (BB) is the second largest source of volatile organic compounds (VOCs) worldwide; such VOCs may undergo photochemical processing leading to secondary organic aerosol (SOA) formation. Previous studies have demonstrated wide variability in the extent of SOA production in aged BB plumes, likely due to differences in SOA precursors and burn/plume conditions. In this work, we are coupling detailed laboratory measurements and process-level modeling to probe the key variables impacting BB SOA formation. As part of the fourth Fire Lab at Missoula Experiment (FLAME-4) in 2012, smog chamber experiments were conducted on fresh BB smoke from a variety of vegetative fuels. In these experiments, comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOFMS) was applied for the first time to characterize the identities and reactivities of BB VOCs. Our highly speciated measurements of gas-phase species using GCxGC/TOFMS, in conjunction with co-located real-time gas- and particle-phase instrumentation, can better assess the role of specific isomers (e.g., monoterpenes) and non-conventional precursors in leading to SOA formation in BB plumes. Further advancements can be achieved by coupling these measurements with process-level modeling. Thus, we are applying a detailed aerosol box model, which includes a near explicit description of gas-phase chemistry (using the Master Chemical Mechanism) and iterative gas-particle partitioning, to further investigate the critical reaction pathways and atmospheric conditions that influence BB SOA production. Here we present a synthesis of measurement and modeling results for the aging of black spruce smoke.