Explain any five mechanisms of Indian Monsoon.
Answers
Answer:
Due to Sun, there is differential heating of land and water. The Intertropical Convergence Zone or ITCZ shifts over Ganga plains during the Summer. Due to strong vertical air currents and formation of high pressure over Tibetan plateau, the plateau gets intensely heated during the summer.
Explanation:
The monsoons strangely affect the climate of India. To understand the mechanism of the Indian monsoon, it is first important to understand the few facts. These are
i. Differences in heating and cooling of land and sea (land gets heated rapidly and sea takes time in absorbing and releasing heat) creates low pressure area on land and high pressure area over the sea.
ii. The shift of ITCZ zone over the Ganga Plains during summers
iii. The presence of high pressure area to the east of Madagascar
iv. Intense heating of the Tibetan Plateau
v. Movement of jet streams
Due to the high pressure areas over the seas, the warm winds blowing over the Indian Ocean pick up enough moisture and strike the Indian sub-continent in the first week of June.
The monsoon winds then get divided into two branches- the Arabian Sea branch and the Bay of Bengal branch.
While the rains of the Arabian Sea branch reache Mumbai by the last week of June, the rains of Bay of Bengal rapidly approach the north eastern part of the country by the first week of June.
The rainfall in India is largely affected by the relief features. For example, the places lying in the windward side of the mountains get adequate rainfall while those lying in the leeward side get scanty rainfall.
By the first week of July, rainfall reaches the northern parts of the country.
The monsoon begins to retreat by early September from the north western parts of the country. By early December, monsoon completely retreats from the entire country.
Indian Monsoons
●The term monsoon has been derived from the Arabic word mausin or from the Malayan word monsin meaning ‘season’.
●Monsoons are seasonal winds (Rhythmic wind movements)(Periodic Winds) which reverse their direction with the change of season.
●The monsoon is a double system of seasonal winds – They flow from sea to land during the summer and from land to sea during winter.
●Some scholars tend to treat the monsoon winds as land and sea breeze on a large scale.
●Monsoons are peculiar to Indian Subcontinent, South East Asia, parts of Central Western Africa etc..
●They are more pronounced in the Indian Subcontinent compared to any other region.
●Indian Monsoons are Convection cells on a very large scale.
●They are periodic or secondary winds which seasonal reversal in wind direction.
●India receives south-west monsoon winds in summer and north-east monsoon winds in winter.
●South-west monsoons are formed due to intense low pressure system formed over the Tibetan plateau.
●North-east monsoons are associated with high pressure cells over Tibetan and Siberian plateaus.
●South-west monsoons bring intense rainfall to most of the regions in India and north-east monsoons bring rainfall to mainly south-eastern coast of India (Southern coast of Seemandhra and the coast of Tamil Nadu.).
●Countries like India, Indonesia, Bangladesh, Myanmar etc. receive most of the annual rainfall during south-west monsoon season where as South East China, Japan etc., during north-east rainfall season.
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