As the sun warms up the surface of the earth at the equator, warm air becomes lighter and rises to the atmosphere where it then flows towards the poles, causing the air to cool down and increase in density. Cooler, heavy air sinks into the surface of the planet and thence flows towards the Equator, creating an atmospheric cell circulation pattern on the surface of the Earth. Complex global wind patterns result mainly from the rotation of the Earth and from the uneven distribution of solar heat on it's surface. Free moving objects traveling on the surface of the planet experience a deflection in their trajectories, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, due to the rotation of the Earth. This deflection, which increases towards the poles, is called the Coriolis effect.
Winds pushing on the surface of the ocean make the water move.
This pattern repeats itself over and over creating a spiraling current whose speed decreases with depth, called the Ekman spiral . Circulation gyres are gigantic ocean currents flowing in circular trajectories from East to West along the Equator, towards the poles at the western ends of the ocean basins, to the east in the polar regions, and towards the Equator along the eastern boundaries of the ocean basins, where the cycle repeats again.