The Coriolis effect is caused by earth spinning in its own axis. The Coriolis effect is the way all things that are freely moving across the surface of the earth tend to curve as they move. This causes winds to blow in certain patterns that in turn affect ocean surface currents.
Due to the Coriolis effect, surface currents in the northern hemisphere oceans flow clockwise in large circular patterns called gyres, while those in the southern hemisphere oceans flow counter-clockwise
