ocean current

An ocean current is any more or less continuous, directed movement of ocean water that flows in one of the Earth's oceans. Ocean Currents are rivers of hot or cold water within the ocean. The currents are generated from the forces acting upon the water like the earth's rotation, the wind, the temperature and salinity differences and the gravitation of the moon. The depth contours, the shoreline and other currents influence the current's direction and strength.
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Noun
1. the steady flow of surface ocean water in a prevailing direction
(hypernym) current, stream
(hyponym) El Nino