What explains the eastward flow of the equatorial counter-current? The Earth’s rotation on its axis? Convergence of the two equatorial currents? [2015]

What explains the eastward flow of the equatorial counter-current?

The Earth’s rotation on its axis
Convergence of the two equatorial currents
Difference in salinity of water
Occurrence of the belt of calm near the equator

Explanation

Option (b) is correct

The eastward flow of the Equatorial Counter-Current is primarily explained by the convergence of the North and South Equatorial Currents, which flow westward due to trade winds. This convergence causes a piling-up of water near the western coasts (e.g., Eastern Brazil).
The accumulated water flows back eastward toward regions of lower water levels, forming the counter-current. The Earth’s rotation and weaker winds near the equator further facilitate this eastward flow.

World map diagram illustrating major ocean currents, with warm currents marked in red and cold currents in blue, including labels for Equatorial, Subtropical, and Antarctic Circumpolar currents. The map highlights current directions and key gyres, emphasizing seasonal changes in the Indian Ocean's Equatorial Counter-Equatorial Current during monsoon periods.