Cloud Maker

Sunlight penetrating into the upper layers of the ocean may actually cause more cloudy days, according to a new study.

Sunlight feeds the tiny phytoplankton that drift in the ocean's top layer. These miniscule creatures in turn produce a sulfur compound called dimethylsulfide, or DMS, that is released into the atmosphere as a gas.

DMS, the largest natural source of sulfur in the atmosphere, is thought to contribute to cloud formation because it is a precursor to many of the particles that collect water to form clouds.

The findings of the new study, published in the January 26 issue of the journal Science, point to the likelihood that DMS concentrations might be regulating the sunny-cloudy cycle over the open ocean.

Scientists at the Institut de Ciences del Mar found that DMS concentrations over the ocean were higher when more solar radiation was hitting the ocean, but eventually the concentrations became high enough that clouds formed. Cloud formation in turn reduced the amount of sunlight striking the water, which reduced DMS concentrations.

--LiveScience Staff

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Credit: J.M. Gili, ICM-CSIC