AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Aerosol Emissions from Western U.S. Wildfires and Correlation with Combustion Efficiency
SONYA COLLIER, Shan Zhou, Timothy Onasch, Dan Jaffe, Lawrence Kleinman, Arthur J. Sedlacek, Nicole Briggs, Jon Hee, Edward Fortner, John Shilling, Douglas Worsnop, Robert J. Yokelson, Caroline Parworth, Xinlei Ge, Jianzhong Xu, Zachary Butterfield, Duli Chand, Manvendra Dubey, Mikhail Pekour, Stephen Springston, Qi Zhang, University of California, Davis
Abstract Number: 119 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, wildfire emissions in the Pacific Northwest region of the United States were characterized using real-time measurements near their sources using an aircraft, and farther downwind from a fixed ground site located at the Mt. Bachelor Observatory (~ 2700 m a.s.l.). The characteristics of aerosol emissions were found to depend strongly on the modified combustion efficiency (MCE), a qualitative index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the carbon oxidation state of organic aerosol increased with MCE. The relationships between the aerosol properties and MCE were consistent between fresher emissions (~1 hour old) and emissions sampled after atmospheric transport (6 - 45 hours), suggesting that organic aerosol mass loading and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. These results suggest that MCE can be a useful metric for describing aerosol properties of regionally transported wildfire emissions and their impacts on regional air quality and global climate.