What could be the main reason/reasons of the formation of African and Eurasian desert belt?It is loc

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Question

What could be the main reason/reasons of the formation of African and Eurasian desert belt?It is located in the sub-tropical high pressure cells.It is under the influence of warm ocean currents.Which of the statements given above is/are correct in this context?

Accepted Answer

Correct Answer: A — 1 onlyStep-by-step Solution:The African and Eurasian desert belt includes some of the world's largest and most famous deserts: Sahara (Africa), Arabian Desert, Syrian Desert, Iranian Desert (Persia), Thar Desert (India/Pakistan), Gobi Desert edges, and parts of Central Asia. Understanding why this belt exists requires knowledge of global atmospheric circulation.Statement 1 — Located in sub-tropical high pressure cells: This is correct and is the PRIMARY reason. The African and Eurasian desert belt lies approximately between 15°–35° North and South of the equator — the zone dominated by the Sub-Tropical High Pressure Belts (also called Horse Latitudes or Sub-Tropical Anticyclones — around 30°N and 30°S). Here's the mechanism: (a) Near the equator, air heats up and rises (ITCZ/equatorial trough); (b) The rising air cools, loses moisture as tropical rainfall, and reaches the upper atmosphere; (c) This dry air then moves poleward and descends at around 30°N and 30°S — creating permanent high-pressure zones; (d) Descending air is compressed and warmed — dramatically reducing relative humidity and evaporating any available moisture; (e) Result: extremely dry conditions, clear skies (sunlight evaporates any moisture), and desert formation. This is the fundamental reason for the global desert belt. ✓Statement 2 — Under influence of warm ocean currents: This is incorrect. The coastal deserts of Africa and South America (Namib, Atacama) are actually associated with cold ocean currents — not warm ones. Cold currents (Benguela Current off Namibia/Angola, Canary Current off Morocco/Western Sahara, Humboldt/Peru Current off Atacama) cool the air above them, reducing its capacity to carry moisture — creating dry, stable conditions along the coast. Warm currents do the opposite — they would bring moisture and rainfall. The interior deserts (Sahara, Arabian, Iranian) are too far from the ocean for ocean currents to matter — they are dominated by the continental effects of the sub-tropical high pressure. ✗Key Concept: Global desert distribution: Hot deserts — between 15°–35°N and 15°–35°S (Sub-tropical deserts — Sahara, Arabian, Thar, Kalahari, Australian); Cold ocean current coastal deserts — Namib (Benguela Current), Atacama (Humboldt Current); Rain shadow deserts — leeward sides of mountains (Patagonian desert, Great Basin USA); Continental interior deserts — far from ocean moisture (Gobi, Central Asian deserts). The Thar Desert (Rajasthan) is unique — despite being in the sub-tropical high pressure zone, it receives some monsoon rainfall, making it less arid than the Sahara at the same latitude.

What could be the main reason/reasons of the formation of African and Eurasian desert belt?It is located in the sub-tropical high pressure cells.It is under the influence of warm ocean currents.Which of the statements given above is/are correct in this context?

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What could be the main reason/reasons of the formation of African and Eurasian desert belt?It is located in the sub-tropical high pressure cells.It is under the influence of warm ocean currents.Which of the statements given above is/are correct in this context?

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