A desert is defined as an arid area that gets little precipitation, generally less than 10 inches (250 mm) per year. Deserts occur on every continent and wherever there are arid lands and include the hot, dry desert of rock and sand that is almost barren of plants, the semiarid deserts where rainfall is between 10 and 20 inches per year, coastal deserts, and the deserts on the polar ice caps of the Antarctic and Greenland.
Arid conditions and deserts result from a combination of complex factors like the general circulation of the atmosphere, the location of large landmasses, and local geography. That’s the reason why deserts occur at different latitudes, longitudes, and elevations. But most deserts are found in certain latitudes and most of the world's large deserts are found in the trade wind latitudes. The Sahara is the largest of these and other notable trade wind deserts are found in Australia.
Some deserts lie between latitudes 30° and 50° N and between latitudes 30° and 50° S. These deserts are known as midlatitude deserts. The Sonoran Desert of southwestern North America is a typical midlatitude desert.
Rain shadow deserts are formed because tall mountain ranges prevent moisture-rich clouds from reaching areas on the lee, or protected side of the range. Examples of rain shadow deserts include the Tian Shan Desert in China and Death Valley in California.
Coastal deserts generally are found on the western edges of continents near the Tropics of Cancer and Capricorn. The Atacama of South America, a coastal desert, is the Earth's driest desert.
Polar deserts are found at the Arctic and Antarctica. These are not sandy deserts but there are gravel plains and rocky mountains.
Deserts are natural laboratories where we can study the interactions of wind and sometimes water on the arid surfaces. They also contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. However deserts are also fragile environments and the misuse of deserts is a serious and growing problem in parts of our world.
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Catalog
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