In the winter months in the Northern Hemisphere, massive dust storms from the African Sahara waft southwest across the Atlantic to drop tons of vital minerals on the Amazon basin in South America. Now, scientists have pinpointed the source of many of those dust storms and estimated their dust content.
The Amazonian rainforest depends on Saharan dust for many of its nutrients, including iron and phosphorus (SN: 9/29/01, p. 200: Dust, the Thermostat). "If it weren't for those nutrients, the Amazon would be a wet desert," says Ilan Koren, an atmospheric scientist at the Weizmann Institute in Rehovot, Israel.
Using satellite measurements of dust clouds, Koren and his colleagues estimate that 40 million tons