- Books Name
- Learn with me Social Science Book
- Publication
- Learn with me publication
- Course
- CBSE Class 9
- Subject
- Social Science
The Indian Monsoon
- The climate of India is strongly influenced by monsoon winds.
- The Arab traders who noticed these winds named it as monsoon.
Following facts are important to understand mechanism monsoons –
- The differential heating and cooling of land and water.
- The Inter-Tropical Convergence Zone (ITCZ) is a broad trough of low pressure in equatorial latitudes where the northeast and the southeast trade winds converge.
- The presence of the high-pressure area, east of Madagascar.
- The intense heating of Tibetan plateau during summer.
- The movement of the westerly jet stream to the north of the Himalayas and the presence of the tropical easterly jet stream over the Indian peninsula during summer.
- Apart from his changes in the pressure conditions over the southern oceans also affect monsoon.
- The periodic change in pressure conditions known as ‘Southern Oscillation’ or SO affects monsoon too.
- El Nino is a warm ocean current that flows past the Peruvian coast in place of the cold Peruvian current, every 2 to 5 years.
The Onset of the Monsoon and Withdrawal
- The monsoon are pulsating winds affected by different atmospheric conditions encountered by it, on its way over the warm tropical seas.
- Monsoon arrives at the southern tip of the Indian peninsula generally by first week of June.
- Sudden increase and continuation of the monsoon for several days is called as ‘burst’.
- The Arabian Sea and the Bay of Bengal branches of the monsoon merge over the northwestern part of the Ganga plains.
- The withdrawal or the retreat of the monsoon is a more gradual process which begins in the northwestern states of India by early September.
- The retreating monsoon or the transition season sees the change from hot rainy season to dry winter conditions.
- The low-pressure conditions over northwestern India get transferred to the Bay of Bengal by early November causing cyclonic depressions originating over the Andaman Sea.