Exploiting satellite earth observation to quantify current global oceanic DMS flux and its future climate sensitivity

摘要: We used coincident Envisat RA2 and AATSR temperature wind speed data from 2008/2009 to calculate the global net sea-air flux of dimethyl sulfide (DMS), which we estimate be 19.6 Tg S a−1. Our monthly calculations are compared open ocean eddy correlation measurements DMS 10 recent cruises, with a root mean square difference 3.1 μmol m−2 day−1. In sensitivity analysis, varied temperature, salinity, surface speed, aqueous concentration, using fixed changes as well CMIP5 model output. The range in future climate scenarios is discussed. predicts reduction that this will decrease annual by 22% over 25 years. Concurrent concentration increase much smaller amounts. effect all modelled year predictions was 19% flux. had significant regional effects, some positive (Southern Ocean, North Atlantic, Northwest Pacific) negative (isolated regions along Equator Indian Ocean). Using satellite-detected coverage coccolithophore blooms, our their contribution Atlantic emissions suggests coccolithophores contribute only small percentage estimate, but may more important summertime northeast Atlantic.