GLOBAL AIR CIRCULATION

GLOBAL AIR CIRCULATION
air doer not simply flow from the equator to the poles , it circulates in giant cells known as hadley and ferrel cells . As air warms it expands becoming less dense and rising this creates areas of low pressure . As the air rises it cools and condense causing heavy rainfall over the tropics and slight snowfall over the poles . This cool air then sinks forming high pressure belts . At surface level in the tropics these sinking currents are deflected poleward as the westerlies and towards the equator the equator as trade winds. At the poles they become the polar eastern .