AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Detailed Analysis of Brown Carbon Constituents in Biomass Burning Emissions
ANDREY KHLYSTOV, Vera Samburova, Madhu Gyawali, Laxmi Narasimha Yatavelli, Rajan Chakrabarty, Adam Watts, Joseph Knue, Anna Cunningham, Jessica Connolly, Hans Moosmuller, Barbara Zielinska, Desert Research Institute
Abstract Number: 571 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Recent evidence indicates that some organic compounds (the so-called brown carbon, BrC) can efficiently absorb solar radiation and thus contribute significantly to the positive aerosol radiative forcing. Very little is known about this important aerosol fraction, with most research being concentrated either on searching for individual chemical compounds responsible for light absorption or characterizing bulk light absorption properties of different ambient and laboratory-generated aerosols. Water-soluble aerosol fraction has received most attention, with only a few studies investigating BrC in the non-water soluble fraction. To our knowledge, no attempt has been made so far to quantify the relative contribution of different compounds to light absorption by atmospherically relevant aerosols. We will present an attempt of closing optical properties of biomass burning aerosols using detailed chemical composition data. Five peat fuels collected in different regions of the world (Russia, USA) were burned under controlled conditions (e.g., relative humidity, combustion efficiency, fuel-moisture content) at the Desert Research Institute Biomass Burning facility (Reno, NV, USA). The collected aerosol samples were extracted separately with (a) water and (b) dichloromethane followed by acetone and analyzed using gas chromatography mass spectrometry (GC-MS; Varian 4000 Ion Trap and Scion Triple Quad MS/MS) and Total Organic Carbon analyzer (TOC; Shimadzu TOC-VCSH). Absorption spectra of the extracts and the most prominent compounds were recorded between 190 and 900 nm with a UV/VIS spectrophotometer (PerkinElmer, Lambda 650). Spectra and concentrations of individual compounds were then combined to estimate the total light absorption by the extracts.