Atmospheric transport of soil dust from Africa to South America

Abstract

The arid and desert regions of North Africa are a prolific source of atmospheric dust. This dust is, for example, responsible for the ‘red snows’ reported in the Alps and Pyrenees¹ and for dust falls further north in Europe^2–6, but these phenomena are infrequent and sporadic. By contrast, the transport of mineral dust into the tropical North Atlantic is common and often produces a widespread dense haze⁷. Investigations in the past 15 yr^8–11 have shown that, in the summer months^12,13, the distribution of dust is related to macro and micro-meteorological circumstances, that the dust often reaches altitudes of 5–7 km and that it may be spread over several hundreds of kilometres in latitude and extend to the Caribbean Sea and the south-east United States. We report here the results from an aerosol sampling station at Cayenne, French Guiana, which indicate that large quantities of soil dust are being carried out of North Africa and across the Atlantic during the winter months as well but at this time of year the transport is primarily to South America.