what is the primary cause of surface currents
What causes ocean currents? Ocean currents result from two processes-the action of wind on the surface of the water, and from variation in water temperature that causes movement-a process known as convection. Convection occurs because the oceanic waters heat up becoming less dense. This water moves above the cooler water, and give off its heat to the surrounding environment. As it cools, it begins to sink, and the process begins again. Convection results in the continual circulation of ocean water on a global scale.