Monsoon theories
Topic: Climate of India and the Monsoon · NCERT: Beyond NCERT
Meaning
Monsoon theories are the different explanations of why the monsoon happens. Each one added a new piece:
- Halley (1686), thermal theory: the monsoon is a giant sea breeze, caused by land heating faster than the sea.
- Flohn (1951), dynamic theory: the ITCZ (a low-pressure belt where winds from both hemispheres meet) and the planetary wind belts shift north and south with the sun.
- 1950s, jet stream and Tibet theories: upper-air winds and the heating of the Tibetan Plateau control the monsoon.
- Later, teleconnections: links with distant oceans, such as ENSO in the Pacific and the IOD in the Indian Ocean.
Class 11 says no single theory explains the monsoon fully. The real breakthrough was studying it at the global scale.
Example
Halley's theory explains why winds blow from the Arabian Sea onto the hot Kerala coast in June. Teleconnections explain why the same coast can get weaker rain in an El Nino year, when the Pacific Ocean off Peru is unusually warm.