The air and the ocean transport heat from the lower surface to the areas of higher surfaces and hence the cool and warm current makes a trip back to the globe i.e there is a redistribution of heat across the latitudes.
Thus the formation of currents takes place where the distribution of water takes place under the effects of the sun's gravity and air and thus moves rapidly in the surroundings. Like the wrong gulf stream and the Kuroshio current that transports water from the north pacific ocean.
As these are produced by the rotation of the earth and the axial tilt of the planet, and the impact that they derive from the Coriolis force. The deep oceanic currents also are affected by the Thermohaline belts.
The shorter duration of surface current is thus a product of the swirling motion of the particles from side to side and effected by the can be aided by the tremors felt by volcanic activity.
