Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

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Read Full Article (file size: 2729996 bytes) Cited by JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D16305, doi:10.1029/2004JD005623, 2005 Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002 J. A. de Gouw Aeronomy Laboratory, NOAA, Boulder, Colorado, USA A. M. Middlebrook Aeronomy Laboratory, NOAA, Boulder, Colorado, USA C. Warneke Aeronomy Laboratory, NOAA, Boulder, Colorado, USA P. D. Goldan Aeronomy Laboratory, NOAA, Boulder, Colorado, USA W. C. Kuster Aeronomy Laboratory, NOAA, Boulder, Colorado, USA J. M. Roberts Aeronomy Laboratory, NOAA, Boulder, Colorado, USA F. C. Fehsenfeld Aeronomy Laboratory, NOAA, Boulder, Colorado, USA D. R. Worsnop Aerodyne Research Inc., Billerica, Massachusetts, USA M. R. Canagaratna Aerodyne Research Inc., Billerica, Massachusetts, USA A. A. P. Pszenny Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USA W. C. Keene Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA M. Marchewka Department of Chemistry, Western Michigan University, Kalamazoo, Michigan, USA S. B. Bertman Department of Chemistry, Western Michigan University, Kalamazoo, Michigan, USA T. S. Bates Pacific Marine Environmental Laboratory, NOAA, Seattle, Washington, USA Abstract An extensive set of volatile organic compounds (VOCs) and particulate organic matter (POM) was measured in polluted air during the New England Air Quality Study in 2002. Using VOC ratios, the photochemical age of the sampled air masses was estimated. This approach was validated (1) by comparing the observed rates at which VOCs were removed from the atmosphere with the rates expected from OH oxidation, (2) by comparing the VOC emission ratios inferred from the data with the average composition of urban air, and (3) by the ability to describe the increase of an alkyl nitrate with time in terms of the chemical kinetics. A large part of the variability observed for oxygenated VOCs (OVOCs) and POM could be explained by a description that includes the removal of the primary anthropogenic emissions, the formation and removal of secondary anthropogenic species, and a biogenic contribution parameterized by the emissions of isoprene. The OVOC sources determined from the data are compared with the available literature, and a satisfactory agreement is obtained. The observed sub-μm POM was highly correlated with secondary anthropogenic gas-phase species, strongly suggesting that the POM was from secondary anthropogenic sources. The results are used to describe the speciation and total mass of gas- and particle-phase organic carbon as a function of the photochemical age of an urban air mass. Shortly after emission the organic carbon mass is dominated by primary VOCs, while after two days the dominant contribution is from OVOCs and sub-μm POM. The total measured organic carbon mass decreased by about 40% over the course of two days. The increase in sub-μm POM could not be explained by the removal of aromatic precursors alone, suggesting that other species must have contributed and/or that the mechanism for POM formation is more efficient than previously assumed. Received 22 November 2004; accepted 14 June 2005; published 30 August 2005. Keywords: volatile organic compounds; particulate organic matter; polluted atmosphere. Index Terms: 0345 Atmospheric Composition and Structure: Pollution: urban and regional (0305, 0478, 4251); 0355 Atmospheric Composition and Structure: Thermosphere: composition and chemistry; 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions (0426, 1610); 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906). Read Full Article (file size: 2729996 bytes) Cited by Citation: de Gouw, J. A., et al. (2005), Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002, J. Geophys. Res., 110, D16305, doi:10.1029/2004JD005623. Copyright 2005 by the American Geophysical Union.

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