Convection cells- circulating system of fluid (such as air or water) in which heat is transferred through the process of convection. Convection is the movement of heat due to the flow of the fluid itself. In a convection cell, the fluid is heated at the bottom, becomes less dense, rises, and then cools as it moves toward the top, becoming denser and sinking. This creates a continuous cycle of rising and sinking fluid, which forms the "cell."
Three types- Hadley(nearest the equator), Ferrel ( Middle of the planet), Arctic cell( northern most)