In northern oceans, the water spins clockwise. In the southern oceans, it spins counterclockwise.
The marine currents caused by different influencing factors:
- The circulation of trade winds above the surface pushes the water into their direction.
- Different densities between the water masses cause Thermohaline Circulation. Density depends on the temperature and salinity of the water. In the cold Polar Regions the highest surface water densities are reached, this causes convective mixing and sinking of deep water, which drives the circulation.
- The Coriolis force is generated by the rotation of the earth. North of the equator, the ocean currents are deflected to the right. They combine to form a large circle, which runs toward the pole in the west and toward the equator in the east. In the southern hemisphere, the currents are deflected to the left, where they rotate in the opposite direction.
There are a total of 5 large circuits on the planet that are driven by these powerful forces.