The horizontal flow of water at the ocean's surface.

• A. Surface Current
• B. Langmuir Circulation
• C. North Atlantic Deep Water
• D. Sverdrup (sv)

Answer: (A)

Surface currents are the horizontal flow of water at the ocean surface. They’re driven mainly by winds, with the Coriolis effect shaping the direction so large gyres form in the major oceans. This flow stays in the upper part of the water column, typically tens to a few hundred meters deep. Langmuir Circulation is a wind- and wave-driven vertical circulation pattern that creates streaks and counter-rotating cells near the surface, not a single broad horizontal current. North Atlantic Deep Water is a deep-water mass that sinks in polar regions and travels along the ocean depths. Sverdrup is a unit of transport used to describe large-scale flow, not the surface current itself. So the best term for the horizontal flow at the ocean’s surface is surface current.