Which one of the following factors is responsible for the change in the regular direction of the ocean currents in the Indian Ocean?

1. Indian Ocean is ‘half an ocean’
2. Indian Ocean has monsoon drift
3. Indian Ocean is a land-locked ocean
4. Indian Ocean has greater variation in salinity

Explanation

Option (b) is correct

• The seasonal reversal of monsoon winds is the main reason for the changing direction of Indian Ocean currents. In the North Indian Ocean, surface currents completely reverse between summer and winter in response to the monsoon. During the Southwest Monsoon (June–October), currents flow as the South-West Monsoon Drift, while the pattern reverses in winter. Thus, wind stress from the monsoon controls both the direction and strength of currents in the Indian Ocean.

Answer: (b) Indian Ocean has monsoon drift