The distribution of major hot deserts in the northern hemisphere, primarily situated between the latitudes of 20-30 degrees north and predominantly on the western sides of the continents, can be attributed to a confluence of geographic, atmospheric, and oceanic factors. Firstly, the positioning of these deserts within the tropics ensures prolonged exposure to the sun’s direct rays, intensifying temperatures and fostering aridity. This geographical belt falls within the subtropical high-pressure zones, where sinking air masses inhibit cloud formation and precipitation, consequently leading to desertification. Moreover, the western sides of continents often encounter rain shadows, resulting from prevailing wind patterns. As moisture-laden winds from the oceans approach landmasses, they are forced to ascend over mountain ranges, causing cooling and condensation, thus depleting their moisture content before reaching the leeward side, where deserts typically form. Examples include the Sahara Desert in Africa, the Arabian Desert in the Middle East, and the Sonoran Desert in North America. Furthermore, the influence of ocean currents, such as the cold Canary and California currents along the western coastlines, contributes to the aridity by cooling the adjacent air masses, reducing their capacity to hold moisture. Consequently, the combination of these factors delineates the characteristic distribution of major hot deserts in the northern hemisphere.
Tag: Salient features of the world’s physical geography.
Decoding the Question:
- In Introduction, try to define a hot desert with some examples.
- In Body, discuss the reasons behind the hot deserts phenomenon.
- In Conclusion, mention the impact and the significance of hot deserts.
Answer:
A desert is a barren area of landscape where little precipitation occurs and consequently living conditions are hostile to plant and animal life. In other words, it is an extremely dry area of land with sparse vegetation.
Some Popular Hot Deserts in the Northern Hemisphere:
- Sahara Desert- Africa (23° N)
- Thar Desert – Asia (India) (27° N)
- Arabian Desert: Asia (20° N)
Reasons Most of the World’s Hot Deserts are Located near 20-30 degree N and on the Western Side of the Continents:
1. Offshore areas of trade wind and falling under the rain shadow area: When the moisture laden trade wind flows from east to west shed their moisture on the eastern part and by the time they reach the western margin, they become dry. These dry winds make the soil more and this led to the formation of the desert.
2. Anticyclonic conditions: The areas between 20 ° -30 ° latitude on western margins of continents are the regions of descending air. Because of this, the air gets compressed and warm as it descends and thus the moisture keeps decreasing.
3.Formation of Rain-shadow Zone: A region in the lee of mountains that receives less rainfall than the region windward of the mountains is called rain-shadow zone.
4. Presence of cold ocean currents along the western coast of continents tends to stabilize the air over the coast. This prevents cloud formation and rainfall. Hence, it leads to arid conditions or the formation of marine deserts on the adjacent coastal lands.
Due to all these climatic and geographical factors most of the Hot Deserts in the northern hemisphere are located between 20- 30° N and on the western side of the continents.
In case you still have your doubts, contact us on 9811333901.
For UPSC Prelims Resources, Click here
For Daily Updates and Study Material:
Join our Telegram Channel – Edukemy for IAS
- 1. Learn through Videos – here
- 2. Be Exam Ready by Practicing Daily MCQs – here
- 3. Daily Newsletter – Get all your Current Affairs Covered – here
- 4. Mains Answer Writing Practice – here
