A permanent or continuous movement of ocean water which is circular in nature is called an ocean current. Ocean currents form close to the surface of the ocean and the speed of their rotation is 3.2 to 6.5 km per hour. These currents affect the temperature of the air near its surface and this, in turn, affects the nearby climate of land. The currents that are formed near the surface of the ocean help in the movement of heat from tropical regions to poles. At poles, the cold currents help move the cool water towards the equator. Warm currents that flow away from the equator are cooled by the cold Arctic currents.
Japan Current: A famous warm current passes the Japanese coast and flows northwards.
