Polar cell
The polar cell , together with the Hadley cell and the Ferrel cell, form a system of planetary circulation in the troposphere .
Schematically, the origin of the polar cell lies in the downward flow of cold, dry air masses over the polar regions , which increases the air pressure . Close to the ground, these air masses then flow towards the equator , being deflected obliquely to the west by the Coriolis force . At around 60 degrees latitude they warmed up enough to be able to ascend again and return to the polar regions along the tropopause .
The polar cell is separated from the Ferrel cell in the direction of the equator by unstable Rossby waves with polar fronts.