Climate feedback loop

The emission of DMS by marine algae to the atmosphere offers potential as part of a climate control feedback loop. Rapid oxidation of DMS to form a non-sea salt sulphate aerosol provides the source of nuclei needed for the formation of clouds. The extra cloud cover increases the cloud albedo effect, causing a lowering in surface temperature, and increased surface wind levels. The lowered temperature may reduce DMS output by the algae. The windiness is to their advantage, stirring surface waters to bring up more nutrients from deeper water.

Cloud condensation nuclei

Clouds are formed when water vapour in the air condenses or freezes. But in order for the water vapour to condense, cloud condensing nuclei (CCN) must be present in the atmosphere. The major source of CCN over the oceans appears to be the dimethyl sulphide produced by planktonic algae in sea water. (see variation 22)