Potential density

The potential density is the density of sea water under standard conditions in comparison to the density of pure water. It is a state variable and makes a comparison of water masses possible.

Definition and Basics

In oceanography, the density of water is an important parameter, since horizontal density differences lead to currents. Analogously to the potential temperature leads to a density, therefore the potential which represents the density at atmospheric pressure and as a deviation from the true density of water ( 1000 kg/m3 )

With

• : Density at atmospheric pressure ( 1013 mbar), in dependence on the salinity and
• The potential temperature.