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

Answer: (b) Convergence of the two equatorial currents

The equatorial countercurrents are driven by a distinct surface wind pattern in the tropics.
Strong westward trade winds result in westward surface flow in most of the tropical Atlantic and Pacific Oceans.
However, several hundred mi. (km.) north of the equator, the winds are much weaker, in comparison
The stronger winds to the south pile up water where the winds are weak.
As a result, the surface of the ocean can be up to 6 in. (15 cm.) higher and the thermocline as much as 328 ft. (100 m.) deeper than it is directly to the north.
The excess water flows eastward under the influence of the Earth’s rotation, giving rise to the equatorial countercurrents.
In the Indian Ocean, the equatorial countercurrent is located several hundred mi. (km.) south of the equator.
In all three oceans, the equatorial countercurrent is concentrated in the upper 656 ft. (200 m.), above the thermocline.
The intensity of the equatorial countercurrent varies from season to season and from month to month.
The strongest seasonal changes occur in the Atlantic Ocean.
Eastward flow reaches a maximum in the summer and fall, with speeds of up to 12 in. (30 cm.) per second, and disappears in the spring.
Seasonal changes are weaker in the Pacific Ocean. Here, the equatorial countercurrent exists year-round, and is strongest in the fall and winter, with speeds slightly