Coastal Deserts

Coastal deserts are found on the western edges of continents between 15° and 30° latitudes near the Tropics of Cancer and Capricorn. These are also the largest of the climatic zones, covering nearly half of the Earth's area. They are located on both sides of the equator.

The latitudes directly north and south of the equator are known as the Tropic of Cancer and Tropic of Capricorn respectively.

Coastal deserts are affected by cold ocean currents that follow the coastline. Since regional winds impact trade winds, these deserts are more changeable than others. Winter fogs created by rising cold currents often cover coastal deserts and block solar radiation.

Coastal deserts are complex because they exist where land, ocean, and atmospheric systems all mix. South America's coastal Atacama Desert is the driest desert on Earth. The Atacama Desert gets rainfall only once every 5 to 20 years.

Coastal deserts are found along the coasts of Chile and Australia. The chilly winters of coastal deserts are followed by long, warm summers. The average summer temperature ranges from 10 to 25°C; winter temperatures are 5°C or less. The greatest annual temperature is about 35°C and the least is about -4°C. In Chile, the temperature ranges from -2 to 5°C in July and 21 to 25°C in January. Remember, when it's summer in the Northern Hemisphere, it's winter in the Southern Hemisphere.

The average rainfall of these deserts is around 10 to 14 cm in most areas. The highest yearly rainfall over several years has been around 35 cm, with the lowest being around 5 cm.

The soil, fine with a medium salt content, is permeable and has good drainage. Plants have broad, shallow root systems so they can take advantage of any rain that comes their way. All coastal plants have thick, fleshy leaves that grab available water and store it for future use. In some plants, the surfaces are tightly ridged and grooved. When it rains, the stem bulges and grooves flatten to store water. As the water is used, the stem shrinks slowly back to its tight form. Coastal desert plants include the salt bush, buckwheat bush, rice grass, and black sage.

Dry climates force some types of toads to seal themselves in burrows and remain inactive for up to nine months. When a heavy rain comes along, soaking the earth, they get moving again. Some insects lay eggs that stay dormant for long periods, until the environment is suitable for hatching. Other coastal desert animals include, insects, coyotes, rabbits, toads, owls, eagles, lizards, and snakes.

Rain Shadow Deserts

Rain shadow deserts are formed when tall mountain ranges stop moisture-rich clouds from reaching areas on the far protected side of the mountains. These deserts are often found near coastal regions, but can be near other bodies of water. As moist air rises over a mountain range, water is dropped as rain or snow and the air loses its moisture. A desert is created on the far (dry) side of the range.

In the western United States, northern Nevada sits in a rain shadow of the Sierra Nevada Mountains. Snowfall on the western mountain slopes (California

Mountains Desert One Side
Fig. 10-2 Rainfall is much higher on one side of the mountain in a rain shadow desert.

side) is greater than that on the eastern slopes (Nevada side). Additionally, Nevada is nearly all located in the Great Basin area, which is fairly arid overall.

In the Turpan Depression of China, a rain shadow desert stretches for many kilometers of sand. There are a few oases and some mountain vegetation, but snow separates the Tian Shan vegetation from the rain shadow desert. Fig. 10-2 shows how rainfall drops on the ocean side of a mountain due to temperature, pressure, and topography changes.

Monsoon Deserts

When there is a large temperature difference between a continent and a nearby ocean, a monsoon results. This is a seasonal happening. In fact, monsoon comes from the Arabic word mausim, meaning "season."

Monsoons originally described the winds of the Arabian Sea, which blow for six months from the northeast and six months from the southwest. Now, monsoon generally describes winds with specific seasonal turnarounds. The southeast trade winds of the Indian Ocean dump heavy rains on the coast of India, losing their moisture on the eastern slopes of the Aravalli Range. Deserts of interior India and Pakistan are part of a monsoon rain shadow desert on the west side of the Aravalli Range.

It's odd that the wettest places in the world get no water in the winter at all. This is typical monsoon weather. When seasonal monsoon winds blow from one direction for six months, they bring torrential rains. Then, when they switch and blow from the opposite direction for the next six months, little to no rain falls. During the wet season moist air is cooled as it blows over rising land, letting lots of rain fall on the windward side of mountain ranges. Unfortunately, because of widespread conifer forest destruction (land clearing) that once protected the soil, the ground can't absorb the heavy rainfall during the monsoon season, resulting in erosion and mudslides. Monsoon conditions are also found in northern Australia, western, southern, and eastern Africa and Chile.

Continue reading here: Polar Deserts

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  • tewolde
    How can there be a desert on a coast?
    4 months ago
  • Zemzem
    How does coastal cooling cause deserts?
    1 year ago
  • mario ostermann
    Do you want results only for what contnents are coastal deserts found?
    2 years ago
  • NICOLAS KERR
    Where are the places that have coastal deserts?
    2 years ago
  • ranugad bolger-baggins
    How are deserts by the coast created?
    2 years ago
  • Bladud
    What is a coastal dessert?
    2 years ago
  • ralph
    Where are coastal desrets found?
    2 years ago
  • Estella
    Do coastal desert have good soil?
    2 years ago
  • j dreher
    How long do coastal desert winters last?
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  • zac
    Why do coastal deserts exist?
    3 years ago
  • maximilian maier
    How does ocean circulation cause coastal deserts?
    3 years ago
  • robel
    What are some environmental concerns of the coastal desert?
    3 years ago
  • Markus
    What is the cause of low precipitation in a coastal desert?
    3 years ago
  • Grazia Moretti
    Why do coastal deserts have little precipitation?
    3 years ago
  • colin wilson
    Where is coastal deserts found in australia?
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  • sophia
    Where are the coastal deserts of australia?
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  • LIDYA
    Are deserts caused by global warming?
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  • elide
    Why do coastal deserts form?
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  • bianca
    What can harm the coastal deserts water?
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  • Uberto Lombardi
    Where are coastal deserts usually found?
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  • habte
    How does coastal desert forms?
    3 years ago
  • Semere
    Why are costal deserts so arid?
    4 years ago
  • Leah
    How coastal desert formed?
    5 years ago
  • fredrik
    How coastal deser formed?
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  • Fioretta
    How coastal desert form?
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  • oskar crawford
    What part of the world is costal deserts in?
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  • susanna
    What causes the rainshadow to occassionaly form on the westward side?
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  • vivaldo
    How many coastal deserts are in the world?
    6 years ago
  • adelfina
    What is the climate and environment coastal desert?
    8 years ago
  • Miranda Dellucci
    Which side of a mountain has deserts?
    10 years ago
  • Roman
    How desert are created?
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  • aziza
    How are deserts formed by rain?
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    How long are summers in coastal deserts?
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  • Marja Hautam
    What is the climate on the ocean side of mountains?
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    What is the difference between a coastal desert and a rain shadow desert?
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