HR: 16:52h
AN: A14A-04    [Abstracts]
TI: Distributions Of Halogenated Succinic Acids In Aerosols Over The Sea Of Japan And The Northern North Pacific
AU: * Kawamura, K
EM: kawamura@lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, N19 N8, Kita-ku, Sapporo, 060-0819 Japan
AU: Imanishi, K
EM: imanishi@scas.co.jp
AF: Institute of Low Temperature Science, Hokkaido University, N19 N8, Kita-ku, Sapporo, 060-0819 Japan
AU: Nojiri, Y
EM: nojiri@nies.go.jp
AF: National Institute of Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506 Japan
AB: Halogens are reactive species in the atmosphere and participate in the oxidative degradation of gaseous hydrocarbons. A sudden ozone depletion found in the Arctic sunrise is associated with an enhanced concentration of filterable bromine. Filterable bromine is also suggested to involve with the formation of water-soluble organic acids in aerosols. Recently, bromine- and chlorine-containing dicarboxylic acids were detected in the arctic aerosols in spring but not in winter, suggesting that halogenated diacids are produced by photochemical-induced oxidation of biological organic precursors. Here, we report spatial and seasonal distributions of halogenated succinic acids in the marine aerosol samples collected over the western to eastern North Pacific (between Japan and Canada). Concentration ranges of bromosuccinic and chlorosuccinic acids detected are from less than 0.1 to 12.7 ngm-3 and less than 0.1 to 5.8 ngm-3, respectively. The highest concentration of bromosuccinic acid was obtained over the Sea of Japan whereas that of chlorosuccinic acid was over the western North Pacific. In general, bromosuccinic acid showed higher concentrations in the western North Pacific and a longitudinal decrease toward the east. Bromosuccinic/succinic acid concentration ratios decreased from the west to the east with higher values in the Bering Sea, where the primary productivity increase in spring and summer. This suggests that the production of bromosuccinic acid is associated with an enhanced primary productivity of the ocean. In contrast, chlorosuccinic/succinic acid concentration ratios showed an increase from the western to the eastern North Pacific, probably due to the substitution of bromine by chlorine in marine aerosols during the long-range transport. This study may provide a new insight to halogen chemistry, which may lead to the heterogeneous production of water-soluble organic aerosols in the marine atmosphere. We will discuss a potential source and formation mechanism of the halogenated organic compounds in the marine atmosphere.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0365 Troposphere: composition and chemistry
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005