Question

Assertion (A): Tamil Nadu does not receive rainfall during the South-West Monsoon season.

Reason (R): Tamil Nadu is located in the rain shadow region of the Arabian Sea branch.

• A. Both A and R are true, and R is the correct explanation of A.
• B. Both A and R are true, but R is not the correct explanation of A.
• C. A is true, but R is false.
• D. A is false, but R is true.

Answer 1

Answer:

A. Both A and R are true, and R is the correct explanation of A.

South-West Monsoon and Tamil Nadu's Rainfall Pattern

• The South-West Monsoon, typically active from June to September, brings the majority of rainfall to most parts of India.
• However, Tamil Nadu primarily receives its rainfall from the North-East Monsoon, which occurs between October and December.
• This unique rainfall pattern for Tamil Nadu is due to its geographical location and the nature of monsoon winds.

Reason for Tamil Nadu's Rainfall Pattern

• During the South-West Monsoon season, the prevailing winds blow from the Arabian Sea towards the Indian subcontinent.
• These winds move parallel to the Eastern Ghats mountain range in peninsular India.
• The Western Ghats act as a barrier, causing the Arabian Sea branch of the South-West Monsoon to shed most of its moisture on the western side of the ghats (like Kerala, Karnataka, Maharashtra).
• Consequently, Tamil Nadu, situated on the leeward side or the rain shadow region of the Western Ghats relative to the Arabian Sea branch, receives very little rainfall during this period.
• The winds reaching Tamil Nadu from the Arabian Sea have already lost most of their moisture.
• Conversely, when the monsoon winds retreat and reverse their direction during the North-East Monsoon, they pick up moisture from the Bay of Bengal and bring heavy rainfall to the coastal areas of Tamil Nadu, Andhra Pradesh, and parts of Karnataka.