AN EQUATION OF STATE FOR USE IN OCEAN MODELS - ECKART FORMULA REVISITED

Approximate formulas for in situ density as a function of potential te mperature, salinity, and pressure are determined for use in numerical models. The approach taken is similar to that of Mellor, but use of th e Tumlirz equation of state results in formulas that are somewhat simp ler and more computationally efficient. Comparison is made with result s obtained from the full United Nations Educational, Scientific and Cu ltural Organization equation of state and with the results obtained fr om the sound speed equation of Del Grosso. The corresponding formulas relating in situ density to the in situ temperature are also given.