(MSA) This may be a significant component of atmospheric aerosol particles that form from the atmospheric oxidation of dimethylsulfide (DMS), when this DMS is produced by phytoplankton. These aerosol particles can lead to the formation of cloud condensation nuclei, water droplet formation, and hence clouds and storm formation. This therefore may contribute to the turbulent mixing of oceanic surface waters and subsequent upwelling of nutrients that feed those microorganisms (a positive feedback cycle). It is thought that increased emissions of dimethylsulfide, and subsequent methanesulfonic acid over the oceans from an increase in sea water temperature may have a negative feedback on global warming by increasing cloud formation; although the net effect of clouds on global warming is very unclear at this point.
[Baird, Colin. Environmental Chemistry, p. 179, W.H. Freeman and Company, 1995.]
Source: Atmospheric Chemistry Glossary