Indian Monsoon: Basics and Features

Basics

• The word ‘monsoon’ is believed to have originated from the Arabic word for the season ‘mawsam’.
• Monsoons are seasonal winds that reverse their direction according to the change in season, so they are periodic winds.
• The monsoon is the representative character of India and South Asia.
• Areas with monsoon climate
  • South Asia
  • Southeast Asia
  • East Africa
  • Tropical marine monsoon variant of Brazil coast.
  • North and Northeast Australia.

Features of Indian Monsoon

1. Seasonal Reversal of Wind
   • Monsoons are modified trade winds and they reverse from being southwest onshore wind and northeast offshore winds.
   • As per Halley’s model, reversal is due to differential heating of land and water across seasons.
2. Monsoon Burst
   • The onset of monsoon is sudden, and is also called “monsoon burst”.
   • Burst happens on the Malabar coast between May 28 and June 5.
3. Advance is Gradual
   • After sudden onset, the advance is gradual and covers much of the country by July 15.
   • The retreat of monsoon is also gradual
4. Variability of Monsoon
   • The variability of monsoon wind is high and rain is not dependable. It is both a temporal and spatial variable.