Camanchacas are marine stratocumulus cloud banks that form on the Chilean coast, by the Earth's driest desert, the

Atacama Desert The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...

, and move inland. In Peru, a similar fog is called garúa, and in Angola cacimbo. On the side of the

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...

s where these cloud banks form, the camanchaca is a dense fog that does not produce

rain Rain is a form of precipitation where water drop (liquid), droplets that have condensation, condensed from Water vapor#In Earth's atmosphere, atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is res ...

. The moisture that makes up the cloud measure between 1 and 40

microns The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...

across, too fine to form rain droplets.

Fog collection

In 1985, scientists devised a

fog collection upright=1.3, ''Atrapanieblas'' or fog collection in Atacama_Desert.html" ;"title="Alto Patache, Atacama Desert">Alto Patache, Atacama Desert, Chile Fog collection, also known as fog harvesting, is the harvesting of water from fog using large p ...

system of

polyolefin A polyolefin is a type of polymer with the general formula (CH2CHR)n where R is an alkyl group. They are usually derived from a small set of simple olefins (alkenes). Dominant in a commercial sense are polyethylene and polypropylene. More speciali ...

netting to capture the water droplets in the fog to produce running water for villages in these otherwise

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

areas. The Camanchacas Project installed 50 large fog-collecting nets on a mountain ridge, which capture some 2% of the water in the fog. In 2005, another installation of panels of producing per square meter per day.

References

Stratus Climate of Chile Fog {{chile-stub