The Dust Busters

dust plume over oceanWood’s Hole is studying, among very many other things, the upper micron of the ocean.

Like most living things, microscopic marine plants need iron and other minerals to live and grow. On land, soil provides a ubiquitous source of minerals, but how do essential nutrients get into vast watery stretches of the open ocean?

The question has long mystified oceanographers. According to one theory, large swirling currents, called eddies, pump nutrients from the depths up toward the sunlit surface, giving phytoplankton the ingredients they need to flourish. But a larger source of iron may be dust storms, which blow huge quantities of mineral-rich soil particles (called Aeolian dust) out to sea, particularly from desert regions in Africa and Asia.

This image [click the image for larger pic] is an intense dust storm — a massive plume of dust from the Saharan Desert over the Atlantic Ocean. The plume extends more than 1,000 miles, covering a vast swath extending from the Cape Verde Islands (lower left), off the coast of Senegal, to the Canary Islands (top center) off the coast of Morocco.