Full context:   The flow of air around the planet is divided into three main convection cells by latitude. Around the equator, the Hadley cell is driven by the rising flow of air along the equator. In the upper atmosphere, this air flows toward the poles. At mid latitudes, this circulation is reversed, with ground air flowing toward the poles with the Ferrel cell. Finally, in the high latitudes is the Polar cell, where air again rises and flows toward the poles.