AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Instrument Intercomparison of Black Carbon Measurements and Correlations with Gas and Aerosol Composition during an Urban Field Study
MICHAEL WALKER, Brent Williams, Raul Martinez, Yaping Zhang, Dhruv Mitroo, David Hagan, Steven Dhawan, Li Du, Jay Turner, Hongyu Guo, Laura King, Rodney Weber, Lu Hu, Munkhbayar Baasandorj, Dylan Millet, Gavin McMeeking, Washington University in St. Louis
Abstract Number: 283 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Efforts to quantify the global climate impacts and epidemiological effects of black carbon (BC) aerosols have historically been hampered by inconsistent measurements. A multitude of instruments exist that are capable of measuring BC mass concentrations, each doing so by different methods of detection. Recent attempts have been made to more accurately define BC in terms of what each instrument specifically measures (e.g., equivalent black carbon (EBC), refractory black carbon (rBC), elemental carbon (EC)). BC concentrations were measured by four instruments during a recent field campaign, the St. Louis Air Quality Regional Study (SLAQRS). More specifically, EBC was measured by an Aethalometer (Magee Scientific) and Multiangle Absorption Photometer (MAAP, Thermo Scientific), rBC by a Single Particle Soot Photometer (SP2, Droplet Measurement Technologies), and EC with a semi-continuous OC-EC analyzer (Sunset Laboratory) during a ten day period in August 2013, allowing for an intercomparison of various measurement techniques. Observed differences will be discussed. Additionally, BC measurements have been correlated to measurements of volatile organic species measured by proton transfer reaction – mass spectrometry (PTR-MS), total organic aerosol mass and major inorganic aerosol species measured by a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and aerosol chemical speciation monitor (ACSM), and organic aerosol species measured by thermal desorption gas chromatography (TAG) and a volatility and polarity separator (VAPS). The suite of chemical information provided by these instruments is used along with meteorological data to help explain the observed variations in the BC measurements.