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Why do deserts generally exist between 15 and 30 degrees north or south of the equator?

-The Inter Tropical Convergence Zone (ITCZ) causes dry air to flow south, away from the equator at 15-30 degrees.
-Adiabatic cooling draws hot air from 15-30 degrees latitude to the tropics, causing condensation to form over the equator.
-The Sun's rays are more direct at 15-30 degrees north and south, causing air to lose water moisture more rapidly that at other latitudes.
-Warm moist air rises at the equator, and cool dry air sinks approximately 15-30 degrees latitude away from the equator, creating circular atmospheric currents of air known as Hadley Cells.

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Final answer:

Deserts are found between 15 and 30 degrees latitude north and south of the equator primarily because of the Hadley Cells, where descending dry air creates arid high-pressure areas, as well as the rain shadow effect from mountain ranges.

Step-by-step explanation:

Deserts generally exist between 15 and 30 degrees north or south of the equator due to the global wind and climate patterns known as the Hadley Cells. These cells create a cycle where warm moist air rises at the equator and cool, dry air sinks approximately 15-30 degrees latitude away from the equator. The descending dry air results in high-pressure, arid conditions, producing deserts.

Moreover, these areas are often on the leeward side of mountain ranges, leading to a rain shadow effect, where moist air releases its precipitation on the windward side, leaving the leeward side dry. Examples of this include the Mohave and Sonoran deserts. With evaporation typically exceeding precipitation, subtropical deserts can have extremely high daytime temperatures and very low annual rainfalls, such as those found in central Australia and northern Africa.

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