Indian Monsoon: Formation, El Niño, La Niña and UPSC Notes
The Indian Monsoon is one of the world's most significant climatic systems and plays a vital role in India's agriculture, economy, and water resources. The Southwest Monsoon usually begins over Kerala in early June and gradually advances across the country, bringing nearly 75% of India's annual rainfall .
The monsoon forms due to the differential heating of land and sea . During summer, the Indian landmass heats up rapidly, creating a low-pressure area over northwestern India, while the Indian Ocean remains relatively cooler with high pressure. Moisture-laden winds from the Arabian Sea and Bay of Bengal move towards the low-pressure region, causing widespread rainfall. The Himalayas act as a natural barrier, preventing these winds from escaping into Central Asia.
El Niño is the abnormal warming of sea surface temperatures in the central and eastern Pacific Ocean. It generally weakens the Indian monsoon and may lead to drought-like conditions. In contrast, La Niña is the cooling of these waters and is often associated with stronger-than-normal monsoon rainfall, although regional variations may occur.
UPSC Prelims Facts
- Southwest Monsoon contributes about 75% of India's annual rainfall .
- Two branches: Arabian Sea Branch and Bay of Bengal Branch .
- El Niño often suppresses monsoon rainfall.
- La Niña generally strengthens monsoon activity.
Mains Relevance
GS Paper I – Indian Geography, Climatology, Agriculture, and Disaster Management.
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