Why most of the hot deserts of the world lie on the western margins of...
Tropical deserts are located between 10deg to 30deg north and south of the equator on the western margin of the continents, for example, Atacama Desert in South America. Californian desert in North America, Namib and Kalahari Desert in Southern Africa, Sahara and West Australian desert.
The deserts lie in the belt of the trade winds which blow from northeast in the northern hemisphere and southeast in the southern hemisphere. Therefore, the general direction of the trade winds is from the east to west. These winds shed their moisture on the eastern margins of the continents and by the time they reach the west they have lost their moisture.
These deserts fall on the leeward side of the mountains and hence, get less rainfall.
It is also an area of descending air; therefore, the air gets compressed and becomes warm, so the moisture-holding capacity of the air increases.
The tropical deserts have cold currents flowing on the coast therefore there is less rainfall.
Why most of the hot deserts of the world lie on the western margins of...
Geographical Overview
Hot deserts predominantly locate on the western margins of continents. This phenomenon results from a combination of climatic and geographical factors.
Subtropical High-Pressure Systems
- Western coasts are influenced by subtropical high-pressure systems, which create stable and dry conditions.
- These systems inhibit cloud formation and precipitation, leading to arid climates.
Cold Ocean Currents
- The presence of cold ocean currents along western coastlines contributes to lower humidity.
- These currents cool the air above them, reducing its capacity to hold moisture and leading to drier conditions on land.
Rain Shadow Effect
- Mountain ranges, often located inland from western coasts, trap moist air moving inland.
- As air rises over mountains, it cools and loses moisture as rain, leaving the leeward side dry and contributing to desert formation.
Trade Winds and Coriolis Effect
- Trade winds blow from east to west in the tropics, driving moisture-laden air towards the continents.
- The Coriolis effect can deflect these winds, enhancing the dry conditions on the western sides of continents.
Conclusion
In summary, the hot deserts' locations on the western margins of continents are influenced by high-pressure systems, cold ocean currents, the rain shadow effect, and wind patterns. These factors work together to create the arid environments characteristic of hot deserts. Understanding these dynamics helps explain the geographical distribution of deserts worldwide.