Examkin

Question

Difficulty: MediumClimate, Weather Systems, and Monsoon of India

With reference to the climatic conditions of India during the post-monsoon (retreating monsoon) season, which of the following atmospheric mechanisms is primarily responsible for bringing precipitation to the Coromandel Coast of Tamil Nadu during October and November?

  1. A
    The offshore South-West monsoon winds blowing directly across the Western Ghats into Tamil Nadu.
  2. The North-East trade winds picking up moisture while traversing the Bay of Bengal before hitting the coast.Answer
  3. C
    The Sub-Tropical Westerly Jet Stream drawing moisture-laden winds directly from the Arabian Sea across South India.
  4. D
    Tropical depressions moving westward from the Arabian Sea onto the eastern coast of Peninsular India.

Answer

The North-East trade winds picking up moisture while traversing the Bay of Bengal before hitting the coast.
During the autumn retreat of the monsoon (October–November), the pressure gradient reverses. The North-East trade winds blow from the high-pressure zone over northern India toward the Bay of Bengal. As they traverse the Bay of Bengal, they absorb moisture and strike the Coromandel Coast of Tamil Nadu, causing major rainfall in this region.

Step-by-Step Solution

1
Analyze the pressure system and wind direction during the post-monsoon season.
During October and November, the sun moves southward, causing the Inter-Tropical Convergence Zone (ITCZ) to shift south of the equator. High pressure develops over northern India, establishing dry North-East trade winds blowing from land towards the sea.
Understanding pressure shifts explains the retreat of the South-West monsoon and the onset of North-East monsoon flow.
2
Trace the path of the North-East trade winds across the Indian subcontinent and Bay of Bengal.
While these winds originate as dry continental winds over northern landmasses, the easterly branch crosses the open waters of the Bay of Bengal, absorbing significant moisture.
Moisture acquisition over the Bay of Bengal is essential for cloud formation and precipitation on the east coast.
3
Determine the impact of these moisture-laden winds on the Coromandel Coast.
When these North-East winds hit the Coromandel Coast of Tamil Nadu, they meet land and release heavy precipitation, making October-November the chief rainy season for Tamil Nadu.
This establishes the exact atmospheric mechanism responsible for the region's winter rainfall.

Key Concept

Retreating North-East Monsoon and Coromandel Coast Rainfall
Rate this question

Topics

Climate, Weather Systems, and Monsoon of India

More questions from this topic