Surface currents
Ocean Currents are masses of ocean water that flow from one place to another. Surface Currents are movements of water that flow horizontally in the upper part of the ocean's surface. Surface currents develop from friction between the ocean and the wind that blows across its surface. Some currents do not last long, and they affect only small areas, and theses water movements are responses to local or seasonal influences. Other surface currents are more permanent, and they are closely related to the general circulation pattern of the atmosphere.
Gyres
Huge circular-moving current systems dominate the surface of the oceans. Gyres are large whirls of water within an ocean basin. There are five main ocean gyres: the North Pacific Gyre, the South Pacific Gyre, the North Atlantic Gyre, the South Atlantic Gyre, and the Indian Ocean Gyre. Wind and the Coriolis effect generates surface currents. Because of Earth's rotation, currents are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. As a result, gyres flow in opposite directions in the two hemispheres.