Dimethyl sulfide concentrations atmospheric

Many of these naturally produced gases play important roles in atmospheric chemistry. For example, OCS may maintain the stratospheric sulfate layer 10,11). Changes in the concentration of this aerosol layer could alter the global temperature. Dimethyl sulfide is produced in the ocean and is released to the atmosphere where it probably is rapidly oxidized to SO2, which contributes substantially to the background acidity of rainwater 12). Methyl chloride, which is produced in the ocean, is the dominant... 

Dimethyl sulfide (DMS), CH SCH, is the largest natural contributor to the global sulfur flux (see Section 2.2.1). The DMS-OH rate constant, approximately 5 X 10 cm molecule s at 298 K, exceeds that of DMS-NO, by a factor of 4. (In contrast, the reactions of H2S and CH,SH with NO, are, respectively, 6000 and 40 times slower than that with OH.) The DMS lifetime in the marine atmosphere as a result of both OH and NO, reactions is on the order of one to several days, with the majority of the path occurring by OH at low latitudes and by NO, in colder, darker regions. Because of the photochemical source of OH, DMS removal by OH occurs only during daytime, leading to a pronounced diel cycle in DMS concentration. 

Dimethyl sulfide (DMS), through its oxidation to sulfate in the troposphere, acts as a source of cloud condensation nuclei, thus potentially influencing the radiative balance of the atmosphere. DMS is formed in sea water through the microbial decomposition of dimethyl sulfonioproprionate (DMSP), a compound believed to act as an osmolyte in certain species of marine phytoplankton. The flux of DMS to the atmosphere is controlled by its concentration in surface sea waters, which is controlled in turn by the rate of its decomposition. Estimates indicate that 7-40% of the total turnover of DMS in the surface waters of the Pacific Ocean is due to the photosensitized destruction of this compound, illustrating the potential importance of this pathway in controlling the flux of DMS to the atmosphere. 

Analysis of samples showed that concentrations of methanethiol and dimethyl disulfide were lower in caraway- and TBHQ-treated broccoli florets than in control samples (Table V). Dimethyl tiisulfide was not detected in the refrigerated samples which indicated that its contribution to the objectionable odors of modified atmosphere stored broccoli florets was minimal. Dimethyl sulfide which has a precursor (Sr methyl methionine sulfonium salt 34) different from that for methanethiol-related compounds was present in all samples. 

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