Coastal deserts generally are found on the western edges of continents near the Tropics of Cancer and Capricorn. They are affected by cold ocean currents that parallel the coast. Because local wind systems dominate the trade winds, these deserts are less stable than other deserts. Winter fogs, produced by upwelling cold currents, frequently blanket coastal deserts and block solar radiation. Coastal deserts are relatively complex because they are at the juncture of terrestrial, oceanic, and atmospheric systems. A coastal desert, the Atacama of South America, is the Earth's driest desert. In the Atacama, measurable rainfall--1 millimeter or more of rain--may occur as infrequently as once every 5-20 years.
|
|
|
 High dunes of the Namib desert near Sossus Viei (photograph by Georg Gerster). |
 Morning fog moistens the dunes of the Namib coastal desert (photograph by Georg Gerster). |
Information provided by A
. S . Walker
http://pubs.usgs.gov