Chemical Composition of Wildland and Agricultural Biomass Burning Particles Measured Downwind During BBOP Study

Friday, 19 December 2014: 10:35 AM
Edward Fortner1, Timothy Bruce Onasch2, John Shilling3, Mikhail Pekour3, Lawrence I Kleinman4, Arthur J Sedlacek III5 and Douglas R Worsnop6, (1)Aerodyne Research Inc., Billerica, MA, United States, (2)Aerodyne Research, Inc., Billerica, MA, United States, (3)Pacific Northwest National Laboratory, Richland, WA, United States, (4)Brookhaven National Laboratory, Upton, NY, United States, (5)Brookhaven National Lab, Upton, NY, United States, (6)Aerodyne Research Inc, Billerica, MA, United States
The Biomass Burning Observation Project (BBOP), a Department of Energy (DOE) sponsored study, measured wildland fires in the Pacific Northwest and prescribed agricultural burns in the Central Southeastern US from the DOE Gulfstream-1 (G-1) aircraft platform over a four month period in 2013. The chemical composition of the emitted particulate emissions were characterized using an Aerodyne Soot Particle Aerosol Mass Spectrometer (SP-AMS) and will be presented in the context of the fire location and source. The SP-AMS was operated with both laser and resistively heated tungsten vaporizers, alternatively turning the laser vaporizer on and off. With the laser vaporizer off, the instrument operated as a standard HR-AMS. Under these sampling conditions, the non-refractory chemical composition of the biomass burning particles will be characterized as a function of the fuel type burned and the observed modified combustion efficiency and observed changes during downwind transport. Specific attention will focus on the level of oxidation (i.e., O:C, H:C, and OM:OC ratios), anhydrosugar, and aromatic content. With the laser vaporizer on, the SP-AMS was also sensitive to the refractory black carbon content, in addition to the non-refractory components, and will be presented within the context of technique-specific collection efficiencies. Under these sampling conditions, addition information on the mass of black carbon, the OM/BC ratio, and the RBC(coat-to-core) ratio will be examined, with a focus on correlating with the simultaneous optical measurements.