Heterogeneous sulfur conversion in sea-salt aerosol particles: the role of aerosol water content and size distribution
| Autor: | J. Ray, James N. Galloway, William C. Keene, M. Luria, Young Ho Kim, H. Sievering, Joe F. Boatman |
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| Rok vydání: | 1991 |
| Předmět: |
Mineralogy
chemistry.chemical_element Particulates complex mixtures Sulfur respiratory tract diseases Aerosol chemistry.chemical_compound chemistry Environmental chemistry Mass transfer Particle-size distribution General Earth and Planetary Sciences Environmental science Sulfate Sea salt aerosol Water content General Environmental Science |
| Zdroj: | Atmospheric Environment. Part A. General Topics. 25:1479-1487 |
| ISSN: | 0960-1686 |
| DOI: | 10.1016/0960-1686(91)90007-t |
| Popis: | Meteorological and chemical conditions during the July 1988 Bermuda-area sampling appear to have been favorable for conversion of sulfur gases to particulate excess sulfate (XSO4). Observed average XSO4 and SO4 concentrations of 11 and 2.1 nmol m−3, respectively, at 15 m a.s.l. in the marine boundary layer (MBL) upwind of Bermuda, indicate that conversion of SO2 to XSO4, over and above homogeneous conversion, may be necessary to explain the > 5.0 average molar ratio of XSO4 to SO2. Given an observed cloud cover of Aerosol water content, estimated as a function of particle size distribution plus consideration of SO2 mass transfer for the observed particle size distribution, shows that SO2 was rapidly transferred to the sea-salt aerosol particles. Assuming that aqueous-phase SO2 reaction kinetics within the high pH sea-salt aerosol water are controlled by O3 oxidation, and considering mass-transfer limitations, SO2 conversion to XSO4 in the sea-salt aerosol water occurred at rates of approximately 5% h−1 under the low SO2 concentration, Bermuda-area sampling conditions. All of the 2 nmol XSO4 m−3 associated with sea-salt aerosol particles during low-wind-speed, Bermuda-area sampling can be explained by this conversion mechanism. Higher wind speed, greater aerosol water content and higher SO2 concentration conditions over the North Atlantic are estimated to generate more than 4 nmol XSO4 m−3 by heterogeneous conversion of SO2 in sea-salt aerosol particles. |
| Databáze: | OpenAIRE |
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