Climate Conditions in Tropical Monsoon Lands

The basic cause of monsoon climates is the difference in the rate of heating and cooling of land and sea. In the summer, when the sun is overhead at the tropic of Cancer, the great land masses of the northern hemisphere are heated. central Asia backed by the lofty Himalayan ranges is more than 15 degree F. hotter than its normal temperature and a region of intense low pressure is set up. The seas, which warm up much slower, remain comparatively cool. At the same time, the southern hemisphere experiences winter, and a region of high pressure is set up in the continental interior of Australia. Winds blow outwards as the South-East Monsoon, to Java, and after crossing the equator are drawn towards the continental low pressure area reaching the Indian sub-continent as the South-west Monsoon.

In the winter, conditions are reversed. The sun is overhead at the Tropic of Capricorn, central Asia is extremely cold, resulting in rapid cooling of the land. A region of high pressure is created with outblowing winds-the North-East Monsoon. On crossing the equator, the winds are attracted to the low pressure centre in Australia and arrive in northern Australia as the North-West Monsoon. In other parts of the world which experience a Tropical monsoon climate a similar seasonal reversal of wind directions occurs.