AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Characterization of Organic Carbon Sources in Pasadena and Bakersfield, CA During CalNex 2010
PUNITH NALLATHAMBY, Rebecca Sheesley, John Offenberg, Michael Lewandowski, Tadeusz Kleindienst, Mohammed Jaoui, Baylor University
Abstract Number: 672 Working Group: Source Apportionment
Abstract The California Nexus (CalNex) field study in 2010 focused on the nexus of air quality and climate change in Southern California; field sites in Bakersfield, CA and in Pasadena, CA were operated synoptically in May-June 2010. The Pasadena site will be used as a proxy for the greater Los Angeles urban signal, while the Bakersfield site likely represents a mix of urban and agricultural sources. Source apportionment of particulate organic and elemental carbon (OCEC) is of high interest in characterizing the air quality during the campaign. Correlations between OC and EC at the two sites show R$^2 values of 0.65, 0.49 and 0.39 for OC, EC and OC:EC respectively. Back trajectory analysis will be applied to further assess whether Bakersfield is impacted by the greater Los Angeles urban plume during the field study. Organic tracer analysis by accelerated solvent extraction and gas chromatography/mass spectrometry will be presented for PAHs, alkanes, hopanes, steranes, levoglucosan and aromatic acids. Preliminary hopane measurements indicate similar levels as reported for Riverside, CA during the SOAR campaign in 2005 (approximately 0.2 ng m$^(-3)). Source apportionment of primary emissions (motor vehicles, biomass burning etc.) using organic molecular marker Chemical Mass Balance (CMB) for OC and EC at both sites will be used to discuss regional differences in Southern California emission contributions. In addition, concentration of aromatic acids will be used to estimate potential contribution of motor-vehicle associated secondary organic aerosol.