Thermohaline is a large scale ocean water circulation driven by density differences due to the changes in surface water temperatures and fresh water fluxes.
Explanation:
Thermohaline circulation is the ocean circulation driven by variation in ocean densities. The deep ocean currents are influenced variations in the temperature controlled water density (thermo) and the salinity (haline) of the ocean waters. This circulation happens due to the thermal and haline influences on the ocean waters.
Due to extremely cold water, the ocean waters in the Earth’s polar region gets very cold and forms sea ice leaving salt behind. This decreases sea water temperature but increases the salinity levels.
With increase in salinity, the density of the water also increases which makes the water heavy and sink and the surface water moves in to fill the sunken sea water.
Again this surface water also becomes cold and the cycle continues leading the global ocean conveyor belt and causes freshwater fluxes depending upon the latitude of the ocean.
