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This image shows a fog bank in a valley of the Atacama Desert, along the coast of northern Chile. These fog banks are called "las camanchacas."
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Image Courtesy of Darryl Scott

Extreme Weather in the Southeast Pacific

The weather in the Southeast Pacific region is thought of as extreme, because it receives very little rain and is extremely dry. For example, some places in the Atacama Desert in Chile receive less than one millimeter (0.04 inches) of rain a year.

There are several reasons why this region is so dry. The Chilean Coastal Range and the Andes mountains block this area from receiving moisture. In addition, a large wind current called the Pacific Anticyclone blows dry air into the region. Finally, an ocean current called the Humboldt Current brings cool water up the coast of Chile. The ocean current cools the air above it and forms clouds that usually don't produce precipitation.

Over the Southeast Pacific Ocean the clouds do produce drizzle, but this doesn't usually happen over the land. Instead, fog sometimes forms along the coast. People who live in this region call this fog "camanchacas." It is important to support life. Even though it doesn't actually rain, algae, lichen, and some cacti are able to capture enough moisture from the fog in order to survive. People use nets to capture water from the fog.

Last modified September 18, 2008 by Becca Hatheway.

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