A surface current flowing in the opposite direction from an adjacent surface current.

A surface current flowing in the opposite direction from an adjacent surface current.

• A. Current
• B. Downwelling
• C. Eddy
• D. Countercurrent

Answer: (D)

Opposing surface flows along a boundary are described as a countercurrent. When one surface current moves in the opposite direction to an adjacent surface current, the term countercurrent captures that reversal of flow between neighboring water masses. This happens where different forcing forces—such as winds, coastline shapes, or density differences—drive nearby ribbons of water in opposite directions, creating a shear zone at their boundary. It differs from an eddy, which is a rotating flow; downwelling, which is a vertical movement of water, not horizontal opposition; and a general current, which doesn’t specify opposition to another current. So the best description is countercurrent.

Opposing surface flows along a boundary are described as a countercurrent. When one surface current moves in the opposite direction to an adjacent surface current, the term countercurrent captures that reversal of flow between neighboring water masses. This happens where different forcing forces—such as winds, coastline shapes, or density differences—drive nearby ribbons of water in opposite directions, creating a shear zone at their boundary. It differs from an eddy, which is a rotating flow; downwelling, which is a vertical movement of water, not horizontal opposition; and a general current, which doesn’t specify opposition to another current. So the best description is countercurrent.