The clockwise deflection of air in the cells near the poles is called polar circulation (It also called an air circulation or an atmospheric circulation). It is a system of winds by which the necessary transport of heat from tropical to polar latitudes is accomplished. The circulation cell closest to the equator is called the Hadley cell (between 30 and 40 degrees north and south). Ferell cells are the middle cells (60 and 70 degrees north and south).Polar cells are the smallest and weakest cells (from between 60 and 70 degrees north and south, to the poles).