Which seasonal change marks the withdrawal of monsoon in India?

Correct option is B

The correct answer is (b) Southward shift of ITCZ

Explanation:

• The withdrawal of the monsoon in India begins when the Inter-Tropical Convergence Zone (ITCZ) starts shifting southward.
• This occurs during the post-monsoon (retreating monsoon) season, typically from mid-September to November.
• As the ITCZ moves south, low pressure weakens over the Indian subcontinent, leading to a reversal of wind direction.
• The monsoon winds retreat from northwest India first, gradually withdrawing from other parts.
• This shift results in clear skies, decrease in humidity, and rise in daytime temperatures—especially in northwestern India.

Information Booster:

• The ITCZ is a low-pressure zone where the northeast and southeast trade winds converge.
• The southward retreat of the ITCZ is influenced by the apparent movement of the sun toward the southern hemisphere.
• During this period, cyclonic storms often form in the Bay of Bengal, affecting eastern India.
• Withdrawal starts from Rajasthan and Punjab and moves southeastward.
• This marks the transition to the winter monsoon phase.

Additional Knowledge:
Certainly! Here are concise true facts about the incorrect options:

Rise in daytime temperature (Option a)

• Occurs after monsoon withdrawal due to clear skies and dry air.
• Most noticeable in northwestern India during October.

Onset of monsoon (Option c)

• Begins in early June, marked by southwest monsoon winds.
• First hits the Kerala coast, then advances northward.

Return of polar jet (Option d)

• Happens in winter, influencing western disturbances.
• Brings rain and snow to northwest India, not related to monsoon cycle.