Air at the equator would rise until it reached the tropopause, which would deflect this air toward the poles where it would spread in all directions until it reached the equator where it would begin to rise again.
In summer, landmasses are heated and develop low-pressure cells, which permit air to flow onto the land.
These seasonal changes in wind direction are known as monsoons .
During the summer , the air over the continent becomes much warmer than the water surface, so the surface air moves from the water to the land. The humid air from the water converges with dry air from over the continent and produces precipitation over the region, over 400 inches at some locations ! During the winter the flow reverses and the dominant surface flow moves from the land to the water.
At irregular intervals of three to seven years, these warm counter-currents become unusually strong and replace normally cold offshore waters with warm equatorial waters.
These unusually strong warm undercurrents block the upwelling of colder, nutrient filled water.
As a result, anchovies starve wrecking the local fishing industry. At the same time, usually arid inland areas receive more rainfall than usual which substantially increases the yields of cotton and pastures.