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The mechanism of sulfate aerosol formation: Chemical and sulfur isotopic evidence
Author(s) -
Saltzman E. S.,
Brass G. W.,
Price D. A.
Publication year - 1983
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl010i007p00513
Subject(s) - aerosol , sulfate , sulfur , homogeneous , sulfate aerosol , fractionation , environmental chemistry , stable isotope ratio , chemistry , mineralogy , atmospheric sciences , environmental science , geology , chromatography , organic chemistry , physics , thermodynamics , quantum mechanics
In order to study the mechanism of aerosol sulfate formation, weekly samples of SO 2 and aerosol SO 4 = were collected at Hubbard Brook Experimental Forest, West Thornton, New Hampshire from July to December, 1980. Samples were analyzed for concentration and sulfur isotopes (δ 34 S). Late summer‐early fall samples are characterized by high, variable SO 4 = levels and low SO 2 levels, while late fall ‐ early winter samples exhibit low SO 4 = and high SO 2 levels. These trends suggest that the oxidation rate varies seasonally, with faster oxidation during warmer months. The sulfur isotopic fractionation between aerosol SO 4 = and SO 2 is intermediate between that expected from homogeneous and heterogeneous reactions, indicating that both processes can be important. The isotopic data suggest that homogeneous oxidation reactions are more important than solution reactions, particularly during warm months.