Ocean currents are the regular movements of water in the oceans. The main causes of Ocean Currents are
Causes of Ocean Currents
Temperature: affects the origin and nature of ocean currents. As equatorial and tropical regions are warm, the oceans lying near the Equator and the tropics are warmer than the oceans lying near the Polar Regions. Thus, the ocean currents from warm equatorial regions move towards the Polar Regions as warm currents. Similarly, the cold currents move from the Polar Regions to the equatorial regions as cold currents.
Level of Salinity: Oceans with a higher level of salinity is denser than oceans with lower levels of salinity. Generally, the ocean currents are generated from areas of less salinity to areas of high salinity. Because the Mediterranean Sea is more saline than the Atlantic Ocean, most ocean currents flow from the Atlantic Ocean to the Mediterranean Sea.
Rotation of the Earth: The Earth rotates from west to east. The speed of rotation of the Earth is maximum at the Equator. All the moving bodies move in a clockwise direction in the Northern Hemisphere and in an anti-clockwise in the Southern Hemisphere. This is also known as the Coriolis Effect.
Planetary Winds: Winds affect the ocean currents. The trade winds blow between the Equator and the Tropics. These winds thus move the equatorial water towards the poles. For example, the Southeast Trade Winds drift the equatorial current to the eastern coast of Australia as the warm East Australian Current.
Landforms: A landform may influence the ocean currents. For example, the shape of various landmasses may obstruct the flow of water and influence its movement. For example, the South Equatorial Current gets deflected towards the Northern Hemisphere.
The circulation pattern of the ocean currents is influenced by the Earth’s atmospheric circulation pattern. At higher latitudes, the wind flow is cyclonic. Thus, the oceanic currents move in a cyclonic pattern. Similarly, in middle latitudes, air circulation is mainly anti-cyclonic. The currents thus move in an anticyclonic pattern.
Also, Read Movements of Ocean Waters