RAS question
The retreating monsoon (NE monsoon) is the main source of rainfall for:
Correct answer: (B) Tamil Nadu coast (Coromandel coast).
The retreating or northeast monsoon is the main source of rainfall for the Tamil Nadu coast, especially the Coromandel coast.
Explanation
Tamil Nadu coast is the answer because its rainfall rhythm is different from most of India. NCERT notes that most of India receives rain in June-September, while the coastal areas of Tamil Nadu receive rain at the beginning of winter. The southwest monsoon runs nearly parallel to the Coromandel coast, and the Western Ghats place Tamil Nadu in a rain-shadow position. During October and November, the northeast monsoon crosses the Bay of Bengal, picks up moisture, and brings rain to the Tamil Nadu coast, southern Andhra Pradesh, southeast Karnataka and southeast Kerala. This is why Chennai and the Coromandel coast depend heavily on the retreating monsoon.
Why the other options are wrong
- (A) Rajasthan gets only scanty southwest-monsoon rainfall and is not identified as a main recipient of northeast-monsoon rain.
- (C) Punjab and Haryana receive their main monsoon rain from the southwest monsoon branches, while their winter rain is meagre and linked to temperate cyclones, not the retreating monsoon.
- (D) Assam is primarily affected by the Bay of Bengal branch of the southwest monsoon, which brings widespread rains up the Brahmaputra valley.
Concept
This tests the Indian climatology distinction between the southwest monsoon and the retreating or northeast monsoon. It recurs in RAS because Tamil Nadu is the standard exception to the all-India June-September rainfall pattern.