High-latitude dust over the North Atlantic: inputs from Icelandic proglacial dust storms.

Mineral aerosols play an important role in the atmosphere-ocean climate system. Research has focused almost exclusively on sources in low-latitude arid regions, but here we show that there are substantial sources in cold, higher latitudes. A 6-year record of measurements made on Heimaey, an island south of Iceland, reveals frequent dust events with concentrations exceeding 20 micrograms per cubic meter. Much of this potentially iron-rich dust is transported southward and deposited in the North Atlantic. Emissions are highest in spring and spatially and temporally associated with active glacial outwash plains; large dust events appear to be associated with glacial outburst floods. In response to global warming, ice retreat on Iceland and in other glacierized areas is likely to increase dust emissions from these regions.