The monsoon system of the Indian sub-continent differs considerably from that of the rest of Asia. The centers of action, air masses involved, and the mechanism of precipitation of the Indian monsoons are altogether different from other monsoon systems.
Although pseudo-monsoons or monsoonal tendencies develop over other parts of the world, it is only around the Indian Ocean.; that monsoonal circulation in the true sense of the term is observed. Here, the monsoons “appear as truly massive interruptions and reversal of the normal global atmospheric circulation.”
According to Byers, Indian monsoon is the ideal monsoon where differential heating of land and ocean subjected to the annual latitudinal cycle of the sun at its zenith gives rise to immense seasonal wind regimes.
However, the mechanisms of Indian monsoons are not as simple as they are thought to be. G.B. Cressey has aptly remarked, “It has been well said that although every school boy understands the Indian monsoon, the official meteorological department is still in doubt as regards its origin”.
The main reason for this very strong development of monsoons is the vast size of the Indian sub-continent and adjacent seas. The very high and extensive mountain system of the Himalayas to the extreme north of the sub-continent is another favourable factor.
The east-west alignment of this mountain chain forms a formidable physical barrier between the tropical and polar air masses, which is of great meteorological significance.