A. Water density is a function of temperature, salinity, and water pressure.
Water density is most sensitive to temperature and salinity changes.
Pressure does not effect water density very much because water is relatively incompressible. Because of this, oceanographers have defined a term called sigma T, sT, which is the water density due to temperature and salinity changes alone. Most seawater is like this. B. Distribution of water density 1. The oceans are somewhat stratified having warmer water on top and colder water at depth.