Introduction

The specific and regular flow of ocean water is called ocean current. Are named after the direction in which they flow or the country they pass by. Below is a discussion of the types of ocean currents and their importance.

About 71.4% of the total surface area is covered with water and the remaining 28.6% is land. The geographical name of this part is hydrosphere. Oceans, seas, rivers, canals, etc. all types of water belong to the hydrosphere.

Ocean currents are usually unidirectional with a very low velocity of about 5 to 10 km per hour, as they are driven by the wind. When ocean water flows over the surface of the ocean, it is called surface current or outflow. And when it travels through a depth of 400 meters, it is called inflow. Only 10% of the total seawater flows as surface current and 90% as inflow. Ocean currents and their types are described below (1) & (2).

Definition

When the water of the oceans flows regularly from one place to another due to the effect of rotation of the earth, wind currents, differences in the salinity, density, and temperature of the seawater, and the position and shape of the continents, it is called ocean currents (4).

Types of ocean currents

When the water of the oceans flows regularly from one place to another due to the influence of the rotation speed of the earth, wind currents, difference in salinity, density, and temperature of the seawater, and the position and shape of the continents. Ocean currents are divided into two categories according to the temperature of ocean water

1. Warm ocean current

The warm and light water of the tropics flows through the surface of the water towards the polar region in the form of surface flow.

2. Cool Ocean Current

Cold and heavy water in the polar region flows through the lower part of the water to the tropics as an inflow (4).

Characteristics of ocean current

Warm ocean currents flow outward from the equatorial region to the polar region.
Cold ocean currents flow from the polar region to the equatorial region.
They do not flow straight. According to Ferrell’s law, the ocean currents turn right in the northern hemisphere and left in the southern hemisphere.
Ocean currents flow from east to west in the region where trade winds flow and from west to east in the region where westerly winds flow.
They are having a slow speed.
It flows faster in shallow seas than in deep seas. The speed of ocean currents in the deep sea is 1- 1.25 m and in the shallow sea is 2- 2.5 meters per second.
They are named after the direction in which they flow.
When warm and cool currents flow side by side, there are fog and storms. Creation of submergence at the meeting place of warm and cool ocean currents (2) & (4).

Types of Ocean currents

1. Pacific Ocean currents

The Pacific Ocean is the largest ocean in the world. Its total area is more than the combined land area of the earth. There are two different types flowing in the Pacific Ocean, namely warm currents and cold currents. The following major ocean currents have been created in the Pacific Ocean are

North and south equatorial currents (warm current)
Counter equatorial current (warm current)
Kuroshio system (warm current)
Oyashio Current (Cold current)
California Current (Cold current)
Peru Current (Cold current)
El Nino or Counter current (warm current)
East Australia current (warm current)
West wind drift (Cold current)

2. Atlantic Ocean currents

The Atlantic Ocean is the second-largest ocean in the world. Its shape is a lot like the English letter S. The Atlantic Ocean is bordered by Europe, Africa to the east, North and South America to the west, the Arctic Ocean to the north, and the Antarctic Ocean to the south. A clear pattern can be observed in the conduction of ocean currents in the Atlantic Ocean. In this vast Atlantic Ocean, two different types of currents flow namely warm currents and cold currents. The Atlantic Ocean currents are

North Equatorial current (warm current)
South Equatorial current (warm current)
Gulf Stream (warm current)
Canary current (cold current)
Labrador current (cold current)
Brazil current (warm current)
Falkland current (cold current)
South Atlantic Drift (cold current)
Benguela current (cold current)
Counter Equatorial current (warm current)

3. Indian Ocean currents

The Indian Ocean is shaped like a triangle. It is the third-largest ocean in the world. The Indian Ocean is surrounded by land in the northern part. So with these changes in seasons, the speed of ocean currents also changes a lot. This ocean is bounded on the north by Asia, on the west by Africa, and on the east by Oceania. The ocean covers an area of 7.25 million square km and has an average depth of 3.5 km. Indian Ocean currents are divided into south Indian Ocean currents and north Indian Ocean currents. The currents are described below

a. South Indian Ocean currents

West wind current
Australia current
South equatorial current
Mozambique and Madagascar’s current
Agulhas current

b. North Indian ocean currents

Somali current
Summer Monsoon current
Winter Monsoon current
Counter Equatorial current (4).

Importance

Cool and warm ocean currents flowing over the oceans and seas of the world have a significant impact on the local ecosystem of seawater and human life on the land around the oceans.

1. Ice-free ports

Due to the effect of warm ocean currents, the coastal ports are ice-free in winter. As a result of the warm North Atlantic Ocean currents, most of the ports in the British Isles can be used all year round.

2. Convenience of navigation

It is easier to navigate in favor of ocean currents which saves fuel.

3. Climate control

When warm currents flow through a region, the climate there becomes warmer. When cold currents flow in the opposite way, the climate there gets colder. Cold Labrador currents, for example, reduce the warming of the Newfoundland coast, and warmer Kuroshio currents increase the west coast of Japan.

4. Rainfall and Snowfall

Due to the presence of water vapor in the air flowing over the warm currents, rain falls when the air flows over the land surface. But the air flowing over the cold currents does not rain because it is dry. However, there is occasional snowfall.

5. Creation of catastrophic weather

Normally in areas where warm and cold currents meet, there is dense fog and strong storms due to the difference in temperature. If there is difficulty in the movement of ships and aircraft. Such as the coast adjacent to Newfoundland.

6. Creation of fisheries

At the confluence of warm and cold currents, fish food plankton grows in large quantities, resulting in the creation of fisheries. Such as Newfoundland and the coast of Japan.

7. Grand bank creation

The iceberg floating with the cold current melts in contact with the warm current. As a result, rocks, pebbles, sand, etc. in the iceberg accumulate in the sea for a long time and create submerged climbs. For example, the Grand Bank on the Newfoundland coast.

8. Dangers caused by icebergs

Large icebergs or ice caps that float with the cold currents obstruct the movement of ships. Many times ships have to face big accidents (4).

How do ocean currents form?

1. Planetary winds

Planetary wind flow is the main cause. As the planetary wind flows over the ocean, it moves the water above the ocean towards its own flow. In this way, air currents create ocean currents.

2. Earth rotation speed

Ocean water cannot flow in a straight line due to the speed of rotation of the earth. According to Ferrell’s law, the northern hemisphere bends to the right and the southern hemisphere to the left, thus, creating ocean currents. For example, the currents of the Gulf Atlantics bend to the right and cause the origin of the North Atlantic Ocean currents.

3. Varies of warming in seawater

In equatorial and tropical regions, seawater is warmer due to higher altitudes. The warm water of the tropics is called light and it flows through the upper part of the water towards the cool polar region in the form of surface current or external current. To make up for this tropical water deficit, cold heavy water flows from the polar region to the tropics in the form of inflows or tributaries. Thus warm and cool ocean currents are created.

4. Variation of salinity in seawater

Less saline water is said to be lighter as it flows through the upper part towards the surface salinity or more saline heavy water in the form of external currents.

To fill this void in the water, more saline flows towards the less salty light water in the form of inflows through the lower part of the heavy sea. This is how the ocean currents originate. For example, the waters of the Atlantic Ocean are less saline than the waters of the Mediterranean Sea, so water flows from there to the Mediterranean Sea.

5. Location and shape of continents

Flowing ocean currents are more restricted at the edges or islands than on continents. This is how they originate. For example, the South Equatorial current of the Atlantic Ocean is blocked at Cape de Sao Ro in Brazil, giving rise to a new current called the Brazilian current.

6. Melting of ice

Wherever there is ice in the water, the amount of water increases, and that increased amount of water flows towards the area with less water, and ocean currents are formed. Such East Greenland currents are caused by ice melt water supply.

7. Seasonal factors

With the change of seasons, different elements of the weather change. As a result, the tides change. For example, in winter and summer in the Indian Ocean, due to the change of seasons, the ocean currents flow in opposite directions due to the influence of monsoon winds (3) & (4).

Q&A

1. What are the 3 types of ocean currents?

The three types are Atlantic, Indian, and Pacific Ocean currents.

2. What are the 5 major ocean currents?

North Atlantic
South Atlantic
Indian
North Pacific &
South Pacific.

3. What are the main types of ocean currents?

The main types are-

North Atlantic
South Atlantic
Indian
North Pacific &
South Pacific.

4. What are the ocean currents called?

Due to the rotation of the earth, constant winds, and differences in salinity, density, and temperature of seawater, seawater flows regularly from one place to another in a certain direction throughout the year.