The wind circulates in each of the two hemispheres in three distinct cells which help transport energy and heat from the equator to both of the poles. The winds are driven by the energy from the sun at the surface as warm air rises and colder air sinks. The circulation cell that is closest to the equator is called Hadley cell.
The Himalayas have a profound effect on the climate of the Indian subcontinent and the Tibetan Plateau. They prevent frigid, dry winds from blowing south into the subcontinent, which keeps South Asia much warmer than corresponding temperate regions in the other continents.
