Dimethyl sulfide and its oxidation products in the atmosphere of the Atlantic and Southern Oceans

Dimethyl sulfide, methane sulfonate, non-sea-salt sulfate and sulfur dioxide concentrations in air were obtained during a cruise between the U.K. and the Antarctic during the period October 1992–January 1993. In equatorial regions (30°N to 30°S) the atmospheric DMS concentration ranged from 3 to 46 ng (S)m−3 with an average of 18 ng(S)m−3. In the polar waters and regions south of the Falkland Islands concentrations from 3 to 714ng(S)m−3 were observed with a mean concentration of 73ng(S)m−3. Methane sulfonate concentrations were also enhanced in the vicinity of the Antarctic Peninsula and in the Weddell Sea. A simple model of DMS oxidation was used to estimate the ocean to atmosphere flux rate, and this was found to be within the range of previous estimates, with a mean value of 1011 ng(S) m−2 h−1.