Dimethyl sulfide is the major form of volatile reduced sulfur which is emitted form the oceans to the atmosphere. The flux of DMS has an important impact on atmospheric chemistry and possibly global climate. The biogeochemical processes which control DMS concentrations in seawater are complex and poorly understood. DMS is produced from the degradation of B-dimethylsulfoniopropionate (DMSP), a natural product of certain marine phytoplankton. However, recent investigations, suggest that only a small fraction. of the total DMSP-sulfur in seawater is likely to escape to the atmosphere. This research will investigate several key aspects of the seawater DMS cycle; 1) The mechanisms and rates of DMS degradation in seawater, concentrating mainly upon biological processes, and to a lesser extent photochemical processes; and 2) The production of DMS from DMSP and testing whether two different pathways are involved in DMSP degradation.
