Meaning of Ocean Currents
Ocean currents are the directional movement of saltwater that is continuous and predictable. It is a large flow of ocean water created and affected by a number of factors. They resemble oceanic river flows. There are various forces and factors are responsible for directing an ocean current, such as-
- Wind
- Insulation or Sun Light
- Water Salinity
- The Coriolis Effect
- Gravitational Force
Importance of Ocean Currents
The ocean current is the horizontal movement of the stream of an ocean on a very large scale. The ocean currents are a continuous flow of water covering a large distance.
- The wind, Coriolis effect, gravity, temperature, etc. play a deciding role in the direction of the flow of ocean currents.
- These ocean currents are responsible for multiple climatic conditions across the world.
- The ocean currents mainly carry hot water or cold water. The current flowing from the equator carries warm water while the current flowing from the equator carries cold water.
- The ocean currents play a very significant role in heat distribution from the poles to the equator.
Types of Ocean Currents
Ocean currents can be differentiated on the basis of their depth. Therefore there are two types of ocean currents-
- Surface Currents: Surface currents are created by the global wind that gets energy from the Sun. As they trap the heat of the Sun, they transfer this heat to the polar region.
- Deep-Water Currents: Deepwater ocean currents are caused by changes in the water density which is further due to the variations in temperature and salinity of the water. This phenomenon is also called thermohaline circulation
Warm and Cold Ocean Currents
Ocean Currents can also be categorized based on temperature - Warm and Cold. Questions are often asked pertaining to this topic. The complete details of the warm and cold ocean currents.
- Warm Ocean Current: The warm currents usually carry water from the equatorial region to the polar region as the cold water present at the poles sinks.
- Cold Ocean Current: Cold currents mostly flow from the polar regions to the equatorial regions and give a chilling effect to the surrounding land where they pass by.
List of Important Ocean Currents
The details pertaining to the warm and cold water currents have been listed here. You can check here, the regions from where it is originating. Below mentioned is the list of Cold Ocean currents.
Cold Ocean Currents List | Region | Features of Ocean Currents |
Kurile or Oya shio Current | North Pacific Ocean | It is rich in nutrients |
Humboldt or Peruvian Current | South Pacific Ocean | Characterized by low salinity. |
Falkland Current | South Atlantic Ocean | The segment of the Antarctic Circumpolar Current. Also renowned as Malvinas current. |
Canary Current | North Atlantic Ocean | Characterized by low salinity. It forms the major sink of the freshwater. |
Western Australian Current | Southern Ocean & South Indian Ocean | Renowned as west wind drift |
South Indian Ocean Current | South Indian Ocean | The cold current originating from the South Indian ocean |
Eastern Greenland Current | Arctic Ocean & North Atlantic Ocean | It is characterized by low salinity |
Labrador Current | North Atlantic Ocean | The amalgamation of the cold currents originating from the Labrador and warm from the Gulf stream forms an effective fishing ground. |
Northeast Monsoon Current | North Indian Ocean | The route of the Northeast current is through the equator. |
Benguela Current | South Atlantic Ocean | Characterized by low salinity possesses a fishing zone. |
California Current | Pacific Ocean | The segment of the Pacific Gyre |
Somali Current | West Indian Ocean | Monsoon is a major influencer of the Somali current |
Antarctic Circumpolar Current | Southern Ocean | Also renowned as West Wind drift |
Here is the list of the warm ocean currents, and the regions from where they are originating.
Warm Ocean Currents List | Region | Features of Ocean Currents |
Florida Current | South Atlantic Ocean & Caribbean Sea | Its route is Florida Peninsula |
Agulhas Current | South-West Indian Ocean | It flows towards southern direction |
Gulf Stream | North Atlantic Ocean | Current motivated by wind stress |
South Equatorial Current | Atlantic Ocean, Pacific Ocean, and the Indian Ocean | The route of the South equatorial current is from east to west |
Southwest Monsoon Current | Indian Ocean | It occurs during the monsoon period in the Indian Ocean during June- October |
El Nino Current | Central & East-Central Equatorial Pacific | The direction of the flow is eastern |
Mozambique Current | Indian Ocean | The route of the flow is towards Mozambique and to the island of Madagascar |
Brazilian Current | South Atlantic Ocean | It flows to the coast of Brazil |
Norwegian Current | North Sea (Atlantic Ocean) & Barents Sea (Arctic Ocean) | It comprises two Arctic inflows of water |
East Australian Current | South-Western Pacific Ocean | This transfers the tropical fauna of the habitats to sub-tropical regions |
North Pacific Current | Pacific Ocean | The collide of Kuroshio and Oyashio resulted in the formation of the North Pacific current |
Equatorial Counter Current | Atlantic Ocean, Pacific Ocean, and the Indian Ocean | The location and the route of the Equatoria counter current are in between North and South equatorial currents, the flow of the equatorial current is from west to east. |
North Equatorial Current | Pacific Ocean & Atlantic Ocean | The route of the North equatorial current is from East to West |
Tsushima Current | Sea of Japan | It flows through the north-eastward segment |
Kuroshio Current | Pacific Ocean | Also renowned as Japan current and Black current |
Irminger Current | North Atlantic Ocean | Combination of warm and saline waters |
Antilles Current | North Atlantic Ocean | The route is northeasterly through the island that segregates the Caribbean sea from the Atlantic ocean |
Alaskan Current | North Pacific Ocean | It is a consequence of the Northward part of the Pacific Ocean |
Factors Responsible for Ocean Currents
There are certain factors that are responsible for the occurrence and movement of ocean currents, let us explore them all. The factors that influence ocean currents comprise wind, sunlight, and other factors such as salinity.
Wind Cause the Ocean Currents
The wind is the most dominant force for ocean currents. It has been observed that most of the oceanic currents follow the direction of the planetary winds such as trade winds, westerlies, and polar easterlies.
Sunlight Causes the Ocean Currents
Sunlight is the other factor that affects ocean currents in an extensive manner. Sunlight mostly creates two differences: the first one is temperature difference sunlight being direct on the equatorial region heats up the water over there while the other one is salinity difference, where the water in regions away from equators has a low temperature as the sunlight is not direct and intense there.
Salinity and Ocean Currents
The presence of salt in ocean water determines the density of water as more salt content in water will make the water denser while less amount of salt results in less water density.
Coriolis Effects of Ocean Currents
Another very significant force responsible for the movement of ocean currents is the Coriolis force or Coriolis effect. Due to the movement of the earth that is from west to east direction the flow of water from the equator to the poles is never in a straight line.
- The deflective forces deflect the path of ocean currents, this deflective force is known as the Coriolis effect caused by the rotation of the earth.
- Because of the Coriolis effect, all the dynamic bodies are deflected in the clockwise direction in the northern hemisphere whereas they will be deflected in the anti-clockwise direction in the southern hemisphere.
- Similarly, the flow of ocean currents is also deflected in the northern hemisphere in the clockwise direction while in the anti-clockwise direction in the southern hemisphere
Effects of Ocean Currents
The ocean currents impact and contribute to being the major influencer of the climatic patterns, rainfall, in the formation of deserts, fogs etc. Check here the complete list of ocean currents, that has been provided here.
- Climatic patterns- The warm and cold ocean currents influence climatic conditions. The warm currents influence by surging the temperature of the region whereas the cold currents lower the temperature of the area.
- Rainfall- The winds over warm currents influence the rainfalls as well and play an instrumental role in cooling the area.
- Formation of Fog- The congregation of the warm and cold currents can influence in forming of the fog.
- Formation of Desert- The cold currents are responsible and are an influencer in the formation of deserts.
- It also influences and affects trade and commerce, by providing directions to the ships.
Ocean Currents UPSC Notes PDF
Ocean current is an essential and unavoidable concept of oceanography in world geography. To understand the oceans and the behavior of oceans it is a must for an aspirant to prepare this topic comprehensively because without understanding oceanography in detail the concepts of world geography cannot be understood. For a comprehensive preparation for the exam, all the fundamentals of world geography ought to be distinct and clear.
➩ Ocean Currents UPSC PDF
To get in touch with the core concepts of the Ocean Currents and other pertaining concepts and bring forth a methodical startegy the candidates can get access to the NCERT Books for UPSC or the UPSC Books. Ocean currents are an extremely important topic with respect to UPSC Prelims and Mains as well.
Ocean Current UPSC Question
The aspirants who are preparing and eyeing the IAS Exam can also check out the UPSC Syllabus and refer to the Geography books for UPSC. The candidates can track the level of their performance by practicing the questions that have been asked in previous years. The candidates can practice the question that has been presented here.
Q.1 Consider the following factors: [UPSC Prelims-2014]
- Rotation of the earth
- Air pressure and Wind
- Density of the Ocean Water
- Revolution of the Earth
Which of the above factors influences ocean currents?
- 1 and 2
- 1,2,3
- 1 and 4
- 2,3,4
Answer:- Option 2
Q2. Consider the following statements: [UPSC Prelims 2002]
- Ocean currents are slow to surface movement of water in ocean
- Ocean currents assist in maintaining the earth’s heat balance
- Ocean currents are set in motion primarily by prevailing winds
- Tropical currents are affected by the configuration of the ocean
Which of the statements are correct?
- 1 and 2
- 2,3 and 4
- 1,3 and 4
- 1,2,3 and 4
Answer:- Option 2
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