Agricultural Fires in the Southeastern U.S. during SEAC4RS: Emissions of Trace Gases and Particles and Evolution of Reactive Nitrogen and Ozone

Friday, 19 December 2014: 9:00 AM
Xiaoxi Liu1, Greg Huey1, Andreas Joel Beyersdorf2, Pedro Campuzano Jost3, Jason Michael St Clair4, John Crounse4, Glenn S Diskin5, Jose L Jimenez6, Laura King1, Tomas Mikoviny7, Jeff Peischl8, Ilana B Pollack9, Thomas B Ryerson10, Glen W Sachse2, David Tanner1, Yuhang Wang1, Paul O Wennberg4, Armin Wisthaler7,11, Robert J Yokelson12 and Yuzhong Zhang1, (1)Georgia Institute of Technology, Atlanta, GA, United States, (2)NASA Langley Research Center, Hampton, VA, United States, (3)Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (4)California Institute of Technology, Pasadena, CA, United States, (5)NASA Langley Research Ctr, Hampton, VA, United States, (6)University of Colorado at Boulder, Boulder, CO, United States, (7)University of Oslo, Oslo, Norway, (8)NOAA ESRL, Boulder, CO, United States, (9)NOAA, Boulder, CO, United States, (10)NOAA Chemical Sciences Divisio, Boulder, CO, United States, (11)University of Innsbruck, Innsbruck, Austria, (12)University of Montana, Department of Chemistry, Missoula, MT, United States
Biomass burning produces significant amounts of trace gases and aerosol particles, which play important roles in atmospheric chemistry and climate. However, few measurements of biomass burning have been made in temperate regions. This study quantifies the emission factors of trace gases and fine particles from 16 agricultural fires in the southeastern U.S. sampled during the SEAC4RS campaign. The evolution of reactive nitrogen species (PANs, NOx, and nitrate) and ozone in these fire plumes was also studied. The agricultural fires emitted significant levels of sulfur and chlorine. Sulfur was mainly emitted as SO2 while chlorine was mainly found in the form of particulate chloride. The preliminary emission factors of SO2, sulfate, and chloride are larger than those for other types of biomass burning with average values of 0.92±0.50, 0.21±0.19, and 1.1±0.73 g/kg. Emission factors of other major gaseous (such as hydrogen cyanide, hydroxyacetone, acetonitrile, and monoterpenes) and particulate species (such as nitrate and ammonium) and their variations in agricultural fires will also be examined. PAN was found to form very rapidly in the sampled plumes of agricultural fires. The ratio of PAN to NOy reached up to 40% in less than 1 hour. Other peroxyacyl nitrates (APAN, PPN, and PiBN) all formed rapidly at similar speeds. O3 formation occurred in most agricultural fire plumes but O3 destruction was also observed.