Equatorial Current

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What is Equatorial Current?

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An equatorial current is an oceanic current which is flowing towards the west near the equator region. It is predominantly controlled by the winds. Talking about the character of this current, equatorial-current systems consist of prior two westward-flowing currents which are approximately 600 miles (that is 1,000 km) wide (North and South equatorial currents) it is separated by an eastward-flowing counter-current which travels only 300 miles (that is 480 km) wide. 

Usually, this flows at depths of less than 1,650 feet (that is 500 m), the equatorial currents travel at the rate of 10 to 40 inches per second (which is 25 to 100 cm per second). The equatorial undercurrents are centered on the equator at depths of 160 to 500 feet (49 to 152 m), flow eastward at rates up to 5 feet/s (1.5 m/s) this is approximately 1,000 feet (305 m) deep and 640 miles (1,030 km) wide.

North Equatorial Current 

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The North Equatorial Current is a great significance of the Pacific and the Atlantic Oceans which flows east-to-west which travels between 10 degrees north to 20 degrees north. This is the southern part of the clockwise subtropical gyre. Despite this name, the North Equatorial Current is not accurately connected to the equator region. In both oceans, they are separated from the equatorial circulation done by the Equatorial Counter Current. This flows eastward. The westward area surface flow at the equator side in both the oceans is part of the South equatorial current.  The North Equatorial Current Speed is usually flowing at its depths. It is less than 1,650 feet (500 m), the equatorial currents travel at rates of 10 to 40 inches per second (this is 25 to 100 cm per second as calculated).

Equatorial Counter Current

The Equatorial Counter Current is the eastward flowing, and the wind-driven current that extends to the depths of 100 to 150m in the Atlantic, Indian, and in Pacific Oceans. Commonly the North Equatorial Countercurrent (abbreviated as NECC), here the current flows from west to east at around about 3-10°N in the Atlantic Ocean, Indian and in the Pacific basins. This current occurs between the North Equatorial Current and in the South Equatorial Current. The NECC should not be confused with the Equatorial Undercurrent (EUC). This flows towards the eastern part along the equator which counts for the depth of around 200m in the western Pacific. This rises to about 100m in the eastern Pacific.

In the Indian Ocean, the circulating current is being dominated by the impact of the reversing Asian monsoon winds. Here the current tends to reverse around the hemispheres seasonally in this basin. The NECC also has a pronounced seasonal cycle flowing in the Atlantic and in the Pacific. It reaches its maximum strength in the late boreal summer and then it falls to its minimum strength in the late boreal winter and in the springtime. Also, this NECC in the Atlantic completely stops blowing in the late winter and in the early spring. 


South Equatorial Current 

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The South Equatorial Current is the oceanic currents in the Pacific Ocean, Atlantic Ocean, and the Indian Ocean. This flows east-to-west which is between the equator and which is about 20 degrees south. While in the pacific and in the Atlantic Oceans this current extends across the equatorial region to about 5 degrees northwards.

In the southern hemisphere, the South Equatorial Current is the westward limb of the ever-large subtropical gyres. While these gyres are being driven by the combination of the trade winds occurring in the tropics and by the westerly winds. The westerly winds are found in the south of about 30 degrees towards the south, through a complicated process that includes the western boundary current intensification.  

On the equatorial side, the South Equatorial Current is being driven directly by the trade winds that blow from the east to west direction.

In the Indian Ocean, the wind that is flowing westward is the South Equatorial Current which is well-developed not only on the southern side of the equator. While directly on the equatorial side, here the winds reverse twice a year for the monsoons, and hence the surface current can be blowing either eastward or towards the west. 

Counter Equatorial Current 

The Equatorial Counter Current is another east-driven current. This current extends to the depths of approximately .100-150m in the Atlantic, Indian, and Pacific Oceans. More often called this is called the North Equatorial Counter Current (NECC), this current type flows from the west-to-east at about 3-10°N in the Atlantic, Indian, Pacific Ocean, between the NEC and the SEC (North Equatorial Current and South Equatorial Current). 

In the Indian Ocean, the circulation of the current is being dominated by the impact of reversing the Asian monsoon winds. This current tends to reverse in the hemispheres seasonally in this basin. The NECC is being pronounced as the seasonal cycle in the Atlantic and in the Pacific, after reaching the maximum strength in the late boreal summer and by the fall and minimum strength in late boreal winter and spring. 

North Equatorial Counter Current

The North Equatorial Counter Current lies between 3 degrees to 10 degrees. This current is considered to be quite rough as the northern boundary for the South Equatorial Current abbreviated as SEC.  

North and South Equatorial Current

The North Equatorial Current is a very significant part of the Pacific and the Atlantic Oceans current which flows from the east-to-west in between 10° north and 20° north. While the southern side is a clockwise subtropical gyre. The westward surface flow at the equatorial region in both the oceans which is part of the South Equatorial Current.

FAQ (Frequently Asked Questions)

1. What Causes Equatorial Current?

Ans. The current that exists for the westward trade winds, which is in addition to the driving divergent of the westward surface flow (that the upwelling is the most intense at the equatorial region), also maintain a steady eastward pressure force that is by piling up the warm surface waters which are in the western side of the ocean basin.

2. What are the Five Major Ocean Currents?

Ans. Majorly there are five gyres: The North Atlantic Ocean current, the South Atlantic Ocean current, the North Pacific Ocean current, the South Pacific Ocean current, and the Indian Ocean Gyre. The Antarctic Current is situated in the Southern Ocean and this constantly circles around Antarctica as there are no landmasses that interrupt these currents.

3. What are Gyres?

Ans. Gyres are defined as the large system of rotating ocean currents. The ocean twists into various types of currents. Thus, these larger and more permanent currents contribute to making up the systems of currents which is known as gyres. The Wind, tides, creates differences in the temperature and its salinity drive the ocean currents.