Indian Ocean Currents
Currents in the Indian Ocean include the following:
- The North East Monsoon Drift
- The South West Monsoon Drift
- North Equatorial Current (Warm)
- South Equatorial Current (Warm)
- Somali Current (Cold)
- Mozambique Current (Warm)
- Madagascar Current (Warm)
- Agulhas Current (Warm)
- West Australian Current (Cold)
Indian Ocean Current
The circulation currents of Indian Ocean is different from the Pacific and the Atlantic Ocean. The Indian Ocean is surrounded by huge landmass of Eurasia in the north and is only half the ocean. Hence the circulation in the South Indian Ocean is similar to the other two oceans while the circulation in the North Indian Ocean is completely different. The monsoon winds also play a peculiar role in the reversal of the direction of currents in the North Indian Ocean.
The North Indian Ocean Circulation
The currents in the North Indian Ocean are affected by the landmass of Eurasia and the monsoon winds. Hence there is a change in the direction of the currents from season to season in response to the seasonal rhythm of the monsoons.
- The North Equatorial current and counter equatorial current is absent in summer.
- Due to the influence of south-west monsoon and the absence of north-east tradewinds, a strong current flows from west to east in the summer season.
- The South-West monsoon Drift originates is summer and from June to September, the North Equatorial current is replaced by an easterly movement of water.
- Thus the circulation of currents is in a clockwise direction.
- Somali current is also formed in summer by the eastward movement of water caused by the South-West monsoon Drift. It flows from the 'Horn of Africa' in the north-east of Africa. It is a cold current and due to the region of upwelling, Somali and its neighbouring countries are arid.
- North Equatorial current is formed in winter under the influence of North-east tradewinds.
- It originates from the south of Indonesia and flows from east to west towards the south of Srilanka.
- The North-East Monsoon Drift is also formed in winter starting from December when the North-East monsoon causes a westwards and southwards drift along the eastern coasts of India and along the Arabian coast.
- This generates an anti-clockwise circulation in the Arabian Sea and the Bay of Bengal.
Southern Indian Ocean
The circulation in South Indian Ocean is continuous unlike North Indian Ocean and is not affected by the change of seasons.
- South Equatorial Current: The South East Tradewinds originate the South Equatorial Current. It flows from east to west and is a warm current. The flow of this current is strengthened by the South Pacific Equatorial current through Indonesia.
- Equatorial Counter Current: At the equator, there is upwelling in winter due to North and South Equatorial currents and this causes the generation of Equatorial counter current.
- The South Equatorial current splits into two branches by the Madagascar Island: The Madagascar current and the Mozambique current.
- These flow along the east of Madagascar and east of Mozambique respectively to converge at the Cape of Agulhas. Henceforth this current is known as Agulhas current.
- All the three currents are warm currents.
- The Agulhas current joined by the West Wind Drift or the Antarctic Circumpolar Current and is deviated to its justify by the landmass of Australia.
- This flows as the West Australian current along the west coast of Australia in the northern direction to finally reach the South Equatorial current, thus completing the anti-clockwise circulation in the South Indian Ocean.
- Since it is formed by West Wind Drift, West Australian current is a cold current.