Question

Discuss the mechanism of monsoon.

Answer 1

Hint: Monsoon is a little known climatic phenomenon and it still continues to puzzle the scientists. Numerous attempts have been made to discover the exact nature and causation of monsoon but so far there is no single theory which is capable of explaining monsoon fully.

Complete Answer: The mechanism of monsoon are as follows:
-The heating of land and sea during the summer months is the mechanism which sets the stage for the monsoon winds to drift towards the Indian subcontinent.
- The sun shines vertically over the Tropic of Cancer during the months of April and May and the large landmass to the north of the Indian Ocean gets intensely heated.
-This causes the formation of intense low pressure in the north-western part of the Indian subcontinent. Since the pressure in the Indian Ocean to the south of the landmass is high as the water gets heated slowly, the low-pressure cell attracts the South-east trade winds across the Equator.
-These conditions help in the northward shift of the Inter-Tropical Convergence Zone (ITCZ). The continuation of the south-east trade winds deflected towards the Indian sub-continent after crossing the Equator is actually the South-west Monsoon. These winds cross the Equator between 40 degrees East and 60 degrees East longitude.
-The phenomenon of the withdrawal of the westerly jet stream from its position over the North Indian plain, south of the Himalayas is related to the shift in the position of the Inter-Tropical Convergence Zone.
-Only after the western jet stream has withdrawn itself from the region the easterly jet stream sets in on 15 degrees North parallel. This easterly jet stream is responsible for the burst of the monsoon in India.

Note: Monsoon has been derived from the Arabic term ‘Mausem” which implies seasonal reversal in the wind pattern over the year. These alterations are a distinguishing feature of the Monsoon type of climate.