Ocean Currents: Causes and types

Ocean currents are the directional movement of sea currents that are produced by wind, gravity, and water density. Currents are also foremost in marine ecosystems because they reallocate heat, water, nutrients, and oxygen from the ocean. Ocean water flows in two directions: horizontally & vertically. The horizontal current is produced by the friction between water and wind. The causes and types depend on other factors that affect the horizontal currents are rotation of the earth, differences in water level, and Coriolis force. Ocean currents play a crucial role in the firmness of the weather of coastal areas. 

Interesting facts about ocean currents: causes and types

• The intensity of the ocean currents generally declines with the maximum depth 
• The magnitude of the ocean currents ranges to 4 meters per second
• North Equatorial Currents originate from Mexico and flow in the west direction
• South Equatorial Currents divides near New Guinea into Northern & Southern Branch

Movement of Ocean Water:

The movement of ocean water is uninterrupted. This circulation of water is substantially divided into three types: Tides, Waves & Currents. The flow of water that directs the ocean surface into infinite directions is called ocean currents. Ocean currents are one of the factors that influence the temperature of ocean water. The movement of ocean currents is divided into warm ocean current & cold ocean current. 

• Warm ocean currents increase the temperature in cold regions
• Cold ocean currents reduce the temperature in warmer regions

Causes and types of Ocean Currents:

Coriolis forces, horizontal pressure-inclined forces, & frictional forces affect the ocean currents. The ocean currents UPSC causes and types notes give a brief about all the above forces further in the article. 

• Tidal currents:

Near the seashore, the tidal currents are most dominant. Thus, the alteration in tidal currents can be predicted in the future because they are periodic in nature. The pace of tidal currents at some regions is 8 knots or more.

• Wind:

The ocean currents near or at the ocean surface are affected by wind forces.

• Thermohaline:

‘Thermo’ means temperature and ‘Haline’ means salinity. The alteration in temperature & salinity at different areas of the ocean produces differences in density that in return, influence the ocean currents.

What is a Frictional Force?

The motion of water is slowed down by friction due to the neighboring fluid moving at a different speed. A slower-pace layer of water and a faster-pace layer of water affect each other. This will also affect the momentum that is transferred between both layers that produce the frictional forces.

What is Antarctic Circumpolar Current?

The ocean current that flows clockwise around the Antarctic is called the Antarctic Circumpolar Current. It is also called West Wind Drift. Antarctic Circumpolar Current is a facet in the movement of ocean water of the Southern Ocean.

• Lack of well-defined axis
• It has a sequence of individual currents that are divided by frontal zones

What is a Global Conveyor Belt?

A process of ocean currents that streamlines the flow of water around the world is termed a global conveyor belt. Along the conveyor belt, nutrients and heat also circulate the ocean currents.

What are Geostrophic currents?

When the pressure-inclined force on the sea current is stabilized by the Coriolis forces, the result is geostrophic currents.

• The pressure is high to the right of the flow in the Northern Hemisphere
• The pressure is high on the left in the Southern Hemisphere
• The track of geostrophic movement is parallel to an isobar

North and South Equatorial Currents:

South Equatorial Current:

• It directs in the Pacific, Indian oceans & Atlantic
• The south equatorial current flows from east to west
• The current flows between the latitude of the equator & 20 degrees south
• It flows 5 degrees north latitudes across the equator in the Pacific & Atlantic Oceans

North Equatorial Current:

• The direction of the North Equatorial Current is east to west in the Pacific & Atlantic Oceans
• It flows between the latitudes of 10 degrees & 20 degrees north
• North Equatorial Current is not linked to the equator
• Equatorial circulation divides the current between the Pacific & Atlantic Oceans

What is the Equatorial Counter Current?

Equatorial Counter Current is discovered in the three oceans. It originates between south and north equatorial currents at around 3-10 degrees of north latitude.

What is Humboldt Current?

This current is a prolongation of west wind from the Antarctic that flows from the north along with the west coast of South America. It is linked with the El-Nino effect in South America. It also affects the arrival of the Indian monsoon. 

What are Labrador and Benguela Currents?

Labrador currents start in the Davis Strait and the Baffin Bay. It moves eastwards and merges with the stream of gulf near Newfoundland. Labrador currents join with the Gulf Stream that makes heavy fog along the coast of Newfoundland. 

Benguela current streams from south to north along the west coast of South Africa and joins with the South Equatorial current. It results in foggy conditions at the coast of Namibia. The Benguela current helps in the development of the Kalahari and Namibian Desert.

Causes and Types of Ocean Currents

The movements of ocean currents are divided across five oceans that are given below: 

Conclusion

The causes and types of the ocean current contain many aspects like the rotation of the earth producing the ocean water that flows outwards. The ocean currents move clockwise in the northern hemisphere, whereas the ocean currents move counterclockwise in the southern hemisphere.