A new high pressure equation of state for seawater

Abstract

A new high pressure equation of state for water and seawater has been derived from the experimental results of Millero and coworkers in Miami and Bradshaw and Schleicher in Woods Hole. The form of the equation of state is a second degree secant bulk modulus K = Pv 0 (v 0−v p =K 0+AP+BP 2 K = K w 0+aS+bS 3 2 A = A w+cS+dS 3 2 B = B w+eS where ν 0 and ν P are the specific volume at 0 and P applied pressure and S is the salinity (ℵ). The coefficients K W O , A W , and B W for the pure water part of the equation are polynomial functions of temperature. The standard error of the pure water equation of state is 4.3 × 10 −6 cm 3 g −1 in ν W P . The temperature dependent parameters a, b, c, d, and e have been determined from the high pressure measurements on seawater. The overall standard error of the seawater equation of state is 9.0 × 10 −6 cm 3 g −1 in ν P . Over the oceanic ranges of temperature, pressure, and salinity the standard error is 5.0 × 10 −6 cm 3 g −1 in ν P . This new high pressure equation of state has recently (1979) been recommended by the UNESCO Joint Panel on Oceanographic Tables and Standards for use by the oceanographic community.