Monsoon Circulation

A monsoon is a seasonal reversal of wind and rainfall driven by the unequal way land and ocean heat and cool through the year and by the annual swing of the Intertropical Convergence Zone that follows. Heated land draws in moist ocean air that rises and falls as rain; the pattern reverses with the seasons. The South Asian, East Asian, West African and Australian monsoons are the world's principal systems, and in India alone the summer monsoon supplies close to eighty percent of annual rainfall for an agricultural sector employing most of the population.