Answer: The density of water plays a very significant role in the movement of ocean water. This density sometimes shows variations, that are caused by the factors such as temperature as well as the salinity.
The density of a water is directly proportional to its salinity and inversely proportional to its temperature. This means that, as the temperature decreases density increases and as the salinity increases density increases.
So this two factors togetherly, are responsible for the ocean water circulation due to the affect of coriolis force and the surface wind, known as the thermohaline circulation.
This ocean water when flows, carries heat from one place to another.