The Coriolis Effect is caused by the rotation of the earth. It deflects all free moving objects to the right north of the equator and left south of the equator. It causes air moving south in the northern hemisphere to turn westward. If someone was standing at the equator, southbound air would appear to move west when Earth turns east. The flow of air is caused by the differences in heating, and the Coriolis effect creates wind patterns. Wind systems influence weather, determine when and where ships and plains can travel efficiently.