ABSTRACT

There are two types of marine currents: (a) surface currents (surface circulation) in the upper 400-m layer of the ocean, which makes up about 10% of all water in the ocean, and (b) deep-water currents (thermohaline circulation) in the other 90% of the ocean water, moving around the ocean basins by density-driven forces and gravity. Since the density difference is a function of differential temperature and salinity, water sinks into the deep ocean basins at high latitudes where the temperatures are colder, causing the density to increase. The marine currents are influenced by two types of forces:

Primary forces: These result from solar heating, wind, gravity, and coriolis and start the water moving.