The Inter Tropical Convergence Zone (ITCZ)

The ITCZ is present only in the northern hemisphere and the southern hemisphere over the tropics which extend from the Tropic of Cancer in the north to the Tropic of Capricorn in the south.

It is one of the five recognized tropical revolving storms (or low-pressure centers); it is also called a monsoon trough.

These low-pressure zones within this belt are caused due to thermal instability when there is a large mass of warm moist air.

The Indian monsoon surges northwards when it moves up and enters into contact with this zone and gets trapped, and then it moves up again with some translation eastwards.

Due to the shift of ITCZ, the trade winds of the southern hemisphere cross the equator between 40° and 60°E longitudes and start blowing from southwest to northeast due to the Coriolis force. It becomes southwest monsoon.