Pacific and Indian Ocean

Introduction

Ocean currents are the continuous, directional movement of seawater which are also predictable and driven by gravity, water density, and wind. The effect of wind on ocean currents is termed as Coriolis Effect. Ocean water can move in two directions, horizontal and vertical. It is these horizontal movements that are responsible for ocean currents. While the vertical movements in the water bodies are responsible for the movements called upwellings or downwellings. Together, these form an abiotic system. This abiotic setup accounts for the transfer of heat in the oceanic bodies, variation of biodiversity in them, and also the Earth’s climatic system.

Ocean Currents: Pacific and the Indian Ocean

The Ocean Currents: Pacific and the Indian Oceans include a number and different types of ocean currents. 

• Two west-wards moving currents prevail from north to south of the equator, which are called the North Equatorial Currents and South Equatorial Currents. In between these two, an opposite equatorial current, moving from west to east also acts. 
• The Indian Ocean is obstructed by the continental masses in the northern part, therefore, there are differences in the pattern of circulation of ocean currents in the Indian Ocean.  

The ocean currents in each, the Pacific Ocean and the Indian Ocean will be discussed in detail further.

Ocean Currents: The Indian Ocean

The Indian Ocean covers about one-fifth of the total oceanic water area of the world. The Indian Ocean is surrounded by the following: Iran, Pakistan, India, and Bangladesh on its northern side; the Malay Peninsula, the Sunda Islands of Indonesia, and Australia on its eastern side; the Southern Ocean on the southern side; and lastly Africa and the Arabian Peninsula on its western side. Furthermore, in the southwest portion, it joins the Atlantic Ocean, and in the east and southeast part, it merges with the Pacific Ocean.

Ocean Currents: Currents operating in the Indian Ocean

In the southern hemisphere of the Indian Ocean, the general pattern of circulation is similar to that of other oceans, that is the anti-clockwise pattern.

In the northern hemisphere of the Indian Ocean, the ocean currents are influenced by the monsoon winds which are subjected to seasonal changes. Due to the changes in monsoon winds, there is a reversal in ocean currents during the winter and summer seasons.

Ocean Currents: Indian Ocean: Currents of the Southern Hemisphere

The South Equatorial Current flowing from east to west is powered by the Pacific Ocean’s corresponding current. Next, there is a flow of the  Mozambique Current. The confluence of these two forms the Agulhas Current. The Agulhas Current upon crossing the Indian Ocean joins the West Wind Drift. A part of this joint current flows to form the cold West Australian Current. Finally, this joins with the South Equatorial Current and completes the entire circuit. 

Ocean Currents: Indian Ocean: Currents of the Northern Hemisphere During Winters, 

In the northern part of the Indian Ocean, the Bay of Bengal and the Arabian Sea are influenced by the North East Monsoon Winds, during the winters. The North-East Monsoon winds make the waters of the Bay of Bengal and the Arabian Sea flow westward and thus create an anti-clockwise circulation. 

Ocean Currents: Indian Ocean: Currents of the Northern Hemisphere During Summer

During summers, the northern part of the Indian Ocean is influenced by the Southwest Monsoon. As a result, the water in the Bay of Bengal and the Arabian Sea move eastwards in a clockwise manner and the South West Monsoon Drift current is formed. 

Ocean Currents: the Pacific Ocean

The Pacific Ocean is the largest of all the major oceans and it occupies about one-third of the Earth’s surface. To understand how and which current prevails over the Pacific ocean, let us know about the boundaries of the Pacific Ocean. From the north to south it extends from the Arctic Ocean to Antarctica. Further, it is surrounded by the Asian and Australian continents in the west and by America in the east. 

Ocean Currents: Currents operating in the Pacific Ocean 

Two major ocean currents prevail over the Pacific Ocean, which is, currents of the northern hemisphere and currents of the southern hemisphere. 

Ocean Currents: Pacific Ocean: Currents of the Northern Hemisphere

The North Equatorial Current flows northwards and forms the warm Kuro Shio current. Later a cold Oya Shio merges with the Kuro Shio current. Under the influence of westerlies, the Kuro Shio current is transformed into the North Pacific Current. This upon reaching the west coast of North America, branches off into the warm Alaska Current and the cold California Current. California Current ultimately merges with the North Equatorial Current to complete the circuit.

Ocean Currents: Pacific Ocean: Currents of the Southern Hemisphere

In the southern part of the Pacific Ocean, the South Equatorial Current flows westwards and gets converted to the East Australian Current as it turns southward. As this passes the West Wind drifts to the Pacific, from west to east, and it transforms into the cold South Pacific Current. On reaching the south-western coast of South America, it flows as the cold Humbolt Current. Humbolt Current merges with the South Equatorial Current to complete the circuit. 

Ocean Currents: North Equatorial Current

It is a crucial ocean current prevailing over the Pacific and the Atlantic Ocean, flowing from east to west. It is not connected to the equator. it is demarcated from the equatorial circulation by an opposite eastward flowing equatorial current. 

Ocean Currents: South Equatorial Current

It is an important ocean current that flows east to west in the Pacific, Atlantic, and Indian Oceans. The flow is in between the equator and is almost 20° southward directed.

Conclusion

This article covers all the important points that are needed to understand the Ocean Currents prevailing in the Pacific Ocean and the Indian Ocean. Information on the North Equatorial Current and South Equatorial Current has also been stated. This can serve as the most helpful and brief revisionary article. It caters to all the relevant questions related to Ocean Currents: Pacific and the Indian Ocean.