The washing out of fine dust particles over mid-latitudes. For Europe, the major sources of dust are the Sahara and the fringes of the Sahel. This dust is picked up by air streams which rise into the upper troposphere, and carried north and west until it is washed out by precipitation. McCafferty (2008) Int. J. Astrobiol. 7 examines historical and mythical accounts of red rain.
Subjects: Earth Sciences and Geography.