Atmospheric Chemistry Gas Phase of Sulfur Compounds

ATMOSPHERIC CHEMISTRY (GAS PHASE) OF SULFUR COMPOUNDS 6.13.1 Sulfur Oxides... 

Sulfur compounds comprise only a small fraction of earth s atmospheric composition however, these minor constituents have a significant impact on the atmosphere, hydrosphere, and biosphere. Since the late 1970s, tremendous effort has been expended to illuminate the atmospheric oxidation mechanisms of a variety of sulfur compounds. Section 2 focuses on the atmospheric oxidation mechanisms of two important organic sulfur compounds carbon disulfide and dimethyl sulfide. Because sulfur-centered radicals are key intermediates in the atmospheric oxidation of carbon disulfide and dimethyl sulfide, the oxidation mechanisms of these compounds provide valuable insight into the chemistry of organic sulfur-centered radicals in the gas phase. 

Gas-phase, solution-phase, and heterogeneous reactions all play important roles in atmospheric chemistry. The mean atmospheric composition is given in Table 1. N2, O2, and Ar comprise 99.9% of the atmosphere and, for all practical purposes, the relative proportion of these gases is constant in the lower 100 km of the atmosphere. We are concerned here with the fate of pollutants such as CO, volatile organic compounds, halocarbons, sulfur compounds, and nitrogen oxides, which are present in trace amounts and whose concentrations vary significantly both spatially and temporally. 

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