What could be the main reason/reasons for the formation of African and Eurasian desert belt ?
1. It is located in the sub-tropical high pressure cells.
2. It is under the influence of warm ocean currents.
Which of the statements given above is/are correct in this context?
Correct Answer: Option A
Explanation
1. The African and Eurasian desert belt, encompassing major deserts like the Sahara, Arabian, and Thar, lies roughly between 20° and 30° latitude North.
2. Statement 1 is correct. This latitudinal zone corresponds to the location of the descending limb of the Hadley Cell, creating belts of high atmospheric pressure known as the sub-tropical high pressure cells (or Horse Latitudes).
3. In these high-pressure zones, air sinks, warms adiabatically (by compression), and becomes very dry. This inhibits cloud formation and precipitation, leading to arid conditions and the formation of large deserts.
4. Statement 2 is incorrect. Warm ocean currents, like the Gulf Stream, tend to bring moisture to adjacent landmasses, potentially increasing rainfall. They do not cause deserts.
5. Coastal deserts are often associated with cold ocean currents (e.g., the Canary Current off Northwest Africa), which cool the air above them, reducing its moisture-holding capacity and contributing to aridity. However, the primary large-scale reason for the entire belt is the atmospheric circulation pattern described in Statement 1.
6. Therefore, the location within the sub-tropical high pressure cells is the main reason for the formation of this extensive desert belt.
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