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Q 81- Describe the reasons that cause ocean currents to form? What are the causes of the Sargasso Sea's formation? (250 words)

  • Paper & Topic: GS I à Indian Culture

 

  • Model Answer:

 

  • Introduction:

 

  • An ocean current is a continuous, directed movement of sea water caused by a variety of forces operating on the water, such as wind, the Coriolis effect, breaking waves, cabbeling, and changes in temperature and salinity.
  • The direction and strength of a current are influenced by depth contours, shoreline geometries, and interactions with other currents.
  • The majority of ocean currents are horizontal water motions.

 

  • Body:

 

  • Factors that influence the formation and modification of ocean currents include:

 

  • There are a number of elements that influence how ocean currents (moving water) are formed, including a combination of two or more.
  • Wind, water density, the geology of the ocean floor, and the coriolis effect all contribute to the distinct types of currents (referred to as surface or thermohaline, depending on their depth).

 

  • Currents are primarily influenced by the following factors:

 

  • Insolation:

 

  • The water expands when heated by sun radiation.
  • As a result, the ocean water level at the equator is around 8 cm higher than in the middle latitudes.
  • As a result, there is a very minor gradient, and water flows down the slope. Normally, the flow flows from east to west.
  •  
  • The wind (atmospheric circulation):
  • The wind blowing on the ocean's surface causes the water to move.
  • The movement of the water body throughout its route is affected by friction between the wind and the water surface.
  • The size and direction of ocean currents are determined by winds [the Coriolis force also influences direction].
  • Example: The seasonal reversal of ocean currents in the Indian Ocean is caused by monsoon winds.
  • The oceanic circulation pattern is similar to the atmospheric circulation pattern on Earth.
  • In the middle latitudes, air circulation over the oceans is primarily anticyclonic [Sub-tropical High Pressure Belt] (more pronounced in the southern hemisphere than in the northern hemisphere due to differences in the extent of landmass).
  • The same may be said for the oceanic circulation pattern.
  • The oceanic circulation follows this pattern in higher latitudes, where the wind is mostly cyclonic [Sub-polar Low Pressure Belt].
  • The monsoon winds influence current movements in locations with considerable monsoonal flow [Northern Indian Ocean], which shift directions according to seasons.
  • Gravity tends to drag water down into a pile, resulting in gradient variation.

 

  • Force of Coriolis:
  • Gyres are massive accumulations of water and the flow around them caused by the Coriolis force, which causes the water to move to the right in the northern hemisphere and to the left in the southern hemisphere. Large circular currents form in all ocean basins as a result of this. The Sargasso Sea is one such circular circulation.

 

  • Ocean Currents are caused by secondary forces such as:

 

  • The secondary forces are temperature and salinity differences.
  • Ocean currents' vertical motion is affected by differences in water density (vertical currents).
  • High-salinity water is denser than low-salinity water, and similarly, cold water is denser than warm water.
  • Water that is denser sinks, and water that is lighter rises.
  • When cold water at the poles dips and slowly travels towards the equator, cold-water ocean currents form.
  • Warm-water currents flow out from the equator along the surface, replacing sinking cold water until it reaches the poles.
  • The Sargasso Sea is a stationary sea that is contained within the subtropical north Atlantic gyre.
  • The hump stretching northward of BERMUDA is located between 20 degrees N and 35 degrees N latitude and 30 degrees W and 75 degrees W longitude.
  • There are no coasts in the North Atlantic sea area, which is 700 miles broad and 2000 miles long.
  • Ocean currents surround it on all sides.
  • It is the only sea without a land border that is totally within the Atlantic Ocean.

 

  • Features:

 

  • The Gulf Stream Current runs west, the Canary Current runs east, the North Atlantic Current runs north, and the North Atlantic Equatorial Current runs south.
  • Bermuda is located on the island's western outskirts.
  • With such strong ocean currents on all sides, this marine area, in contrast to the brutal cold of the North Atlantic, is unusually mild, with consistent weather and weak winds.
  • Another unique phenomena that has never been seen anywhere else on the planet is that this large body of water is covered in dense seaweed that creates a thick mat on the surface.
  • Sargassum is the term given to this free-floating golden-brown seaweed, and thus to the sea.

 

  • The following are the reasons for its formation:

 

  • The anti-cyclonic circulation of the North Equatorial current, the Gulf Stream, and the Canary current forms a gyral structure that isolates the water from the rest of the ocean.
  • Due to its location in the transition zone between the trade winds and the westerlies, which is typified by anti-cyclonic conditions, it has a high level of atmospheric stability. As a result, the winds remain weak, allowing little mixing with waters outside the gyre.
  • The North Atlantic Ocean is less extensive between 20°N and 40°N than other oceans at similar latitudes.
  • The North Equatorial Current and the Gulf Stream have a higher velocity, resulting in calm waters in the limited area.

 

  • Sargasso Sea's Importance:

 

  • Sargassum is home to an incredible number of marine creatures.
  • Sargassum mats serve as nurseries for turtle hatchlings, providing food and protection.
  • Sargassum is also an important habitat for shrimp, crab, fish, and other marine creatures that have evolved to live in this type of floating algae.
  • Threatened and endangered eels, as well as white marlin, porbeagle sharks, and dolphinfish, reproduce in the Sargasso Sea.
  • Every year, humpback whales travel across the Sargasso Sea.
  • Birds and commercial fish such as tuna migrate through the Sargasso Sea and rely on it for food.

 

  • Conclusion:

 

  • A long-distance ocean current joins with others to form the global conveyor belt, which plays a major role in shaping the climate of many of the world's areas.
  • Ocean currents, in particular, have an impact on the temperature of the areas through which they pass. Understanding surface ocean currents is critical for lowering shipping costs because traveling with them saves fuel.
  • Ocean currents can also be exploited for marine power generation, with test sites being investigated off the coasts of Japan, Florida, and Hawaii.
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