Question

Discuss the effect of differential heating of land and sea as a driving mechanism of the Indian monsoon.

Answer 1

To understand the mechanism of the monsoons, the following facts are important

• The differential heating and cooling of land and water creates create a low pressure on the landmass of India while the seas around experience comparatively hgh pressure.
• The shift of the position of Inter-Tropical Convergence Zone (ITCZ) in summer over the Ganga plain (this is the equatorial trough normally positioned arund 20⁰N of the equator- also known as monsoon trough during the monsoon season.
• The presence of the high-pressure area over Madagascar approximately at 20⁰S over the Indian Ocean. The intensity and position of this high-pressure area affect the Indian monsoon.
• The Tibetan plateau gets intensely heated during summer which results in strong vertical air currents and the formation of high pressure over the plateau of about 5 km above sea level.
• The movement of the westerly Jet-stream to the north of the Himalayas and the presence of the tropical easterly jet over the Indian peninsula during summer.
• Teleconnections, the Southern Oscillation and the El Nino