Comparison between Spatially Resolved Airborne Flux Measurements and Emission Inventories of Volatile Organic Compounds in Los Angeles.
Eva Y Pfannerstill, Caleb Arata, Qindan Zhu, Benjamin C Schulze, Roy Woods, Colin Harkins, Rebecca H Schwantes, Brian C McDonald, John H Seinfeld, Anthony Bucholtz, Ronald C Cohen, Allen H Goldstein
Author Information
Eva Y Pfannerstill: Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States. ORCID
Caleb Arata: Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States.
Qindan Zhu: Department of Earth and Planetary Science, University of California at Berkeley, Berkeley 94720, California, United States. ORCID
Benjamin C Schulze: Department of Environmental Science and Engineering, California Institute of Technology, Pasadena 91125, California, United States. ORCID
Roy Woods: Department of Meteorology, Naval Postgraduate School, Monterey 93943, California, United States.
Colin Harkins: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder 80305, Colorado, United States. ORCID
Rebecca H Schwantes: NOAA Chemical Sciences Laboratory, Boulder 80305, Colorado, United States. ORCID
Brian C McDonald: NOAA Chemical Sciences Laboratory, Boulder 80305, Colorado, United States. ORCID
John H Seinfeld: Department of Environmental Science and Engineering, California Institute of Technology, Pasadena 91125, California, United States. ORCID
Anthony Bucholtz: Department of Meteorology, Naval Postgraduate School, Monterey 93943, California, United States.
Ronald C Cohen: Department of Earth and Planetary Science, University of California at Berkeley, Berkeley 94720, California, United States. ORCID
Allen H Goldstein: Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States. ORCID
Los Angeles is a major hotspot for Ozone and particulate matter air pollution in the United States. Ozone and PM in this region have not improved substantially for the past decade, despite a reduction in vehicular emissions of their precursors, NO and volatile organic compounds (VOCs). This reduction in "traditional" sources has made the current emission mixture of air pollutant precursors more uncertain. To map and quantify emissions of a wide range of VOCs in this urban area, we performed airborne eddy covariance measurements with wavelet analysis. VOC fluxes measured include tracers for source categories, such as traffic, vegetation, and volatile chemical products (VCPs). Mass fluxes were dominated by oxygenated VOCs, with ethanol contributing ∼29% of the total. In terms of OH reactivity and aerosol formation potential, terpenoids contributed more than half. Observed fluxes were compared with two commonly used emission inventories: the California Air Resources Board inventory and the combination of the Biogenic Emission Inventory System with the Fuel-based Inventory of Vehicle Emissions combined with volatile chemical products (FIVE-VCP). The comparison shows mismatches regarding the amount, spatial distribution, and weekend effects of observed VOC emissions with the inventories. The agreement was best for typical transportation related VOCs, while discrepancies were larger for biogenic and VCP-related VOCs.
