9. Because the sun heats sections of the Earth more or less, and hot and cold air wants to move in certain directions, this causes
air currents, or

This shows the interaction between the earth and sun.

Explanation:

There is a variation in the amount of heat that reaches the different latitudes as the interaction between the sun and earth which firms different angles of incidence on the surface.  The rays of the sun are more concentrated in mid latitudes that is the tropics and are slanting towards the poles this due the tilt in axis of earth.  This variation lads the warm air to rise and reach the poles and similar the cold polar air reaches the tropics and develops a cycle of convective cells.  This leads to a latitudinal balance in temperatures.