Chemical composition and optical properties of wildland and agricultural biomass burning particles measured downwind during the BBOP study
Poster PDF
Authors
Timothy B Onasch — Aerodyne Research, Inc.
John E Shilling — Pacific Northwest National Laboratory
Ed Fortner — Aerodyne Research, Inc.
Mikhail S. Pekour — Pacific Northwest National Laboratory
Larry Kleinman — Brookhaven National Laboratory
Arthur J Sedlacek — Brookhaven National Laboratory
Robert James Yokelson — University of Montana
Peter R. Buseck — Arizona State University
Kouji Adachi — Meteorological Research Institute
Douglas R Worsnop — Aerodyne Research, Inc.
Leah R Williams — Aerodyne Research Inc
Category
Absorbing aerosol
Description
The Biomass Burning Observation Project (BBOP), a Department of Energy (DOE) sponsored study, measured emissions from 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 particulate emissions was 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 high resolution AMS. Under these sampling conditions, the chemical composition of the non-refractory biomass-burning aerosol has been characterized as a function of the fuel type burned, the observed modified combustion efficiency (MCE), and observed changes during downwind transport. Specific attention focuses on the level of oxidation (i.e., O:C, H:C, and OM:OC ratios), anhydrosugar content, and aromatic content. Here we present a few burns with well-defined sampling conditions. With the laser vaporizer on the SP-AMS was sensitive to both the refractory black carbon (rBC) content and the non-refractory components. Information on the mass of black carbon, the BC/OM ratio, and the RBC (coat-to-core) ratio was examined, with a focus on correlating with the simultaneous optical measurements. Positive matrix factorization (PMF) analysis was used to identify sources and aging characteristics of the biomass burning emissions.
