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

Explains that Earth's rotation produces the Coriolis effect which deflects moving objects, but notes a plane on the equator would not be apparently deflected (Coriolis is zero at the equator).

A student can use the fact that Coriolis is negligible at the equator to question whether rotation-driven deflection explains an eastward equatorial flow.

States directly that 'doldrums' (calm regions near equator) are the main reason behind the counter equatorial current (backward movement of equatorial waters).

Combine this with a map of trade-wind-driven sea level differences to test whether calm doldrums permit wind/pressure-driven return flow rather than Coriolis-driven flow.

Describes how easterly trade winds drive north and south equatorial currents westward, raising western ocean level and creating a west-east counter-equatorial current between them.

Use basic ocean-slope/pressure concepts (higher western sea level) to infer that gravity/pressure gradients and trade-wind piling, not rotation alone, can drive eastward counter-current.

Shows that changes in prevailing winds (strong SW monsoon replacing NE trades) can reverse/obliterate equatorial currents and eliminate the counter current.

A student can extend this by checking seasonal wind patterns on a map to see if wind changes, rather than steady Earth rotation, control the counter-current's presence and direction.

Notes that the Equatorial Counter Current compensates for westward North Equatorial Current, indicating a circulation balance between opposing flows.

One can infer that the counter-current is part of large-scale wind-driven circulation balance (compensation for piled-up western waters) rather than a direct consequence of axial rotation.