Dimethylsulfide production variations over the past 200 k.y. in the equatorial Atlantic: A first estimate

Dimethylsulfide (DMS) released from phytoplankton produces cloud condensati on nuclei in the marine troposphere, thereby providing a climate-regulating mechanism by increasing cloud albedo. A 200-k.y.-long sedimentary record f rom the equatorial Atlantic of DMS-producing phytoplankton suggests that DM S production increased during the glacial stages, thus potentially working to further cool the glacial world. Important factors limiting the operation of this possible feedback mechanism for planetary cooling may be the stren gth of trade winds and the availability of fine, iron-rich dust needed to f ertilize growth of DMS producers.