Thermodynamic properties of standard seawater: extensions to high temperatures and pressures

[摘要] Measurements of (p, ρ, T) properties of standard seawater withpractical salinity S≈35, temperature T=(273.14 to 468.06) Kand pressures, p, up to 140 MPa are reported with the reproducibility ofthe density measurements observed to be in the average percent deviationrange Δρ/ρ=±(0.01 to 0.03)%. The measurements are made with a newly constructed vibration-tubedensimeter which is calibrated using double-distilled water, methanol andaqueous NaCl solutions. Based on these and previous measurements, anempirical expression for the density of standard seawater has been developedas a function of pressure and temperature. This equation is used to calculateother volumetric properties including isothermal compressibility, isobaricthermal expansibility, differences in isobaric and isochoric heat capacities,the thermal pressure coefficient, internal pressure and the secant bulkmodulus. The results can be used to extend the present equation of state ofseawater to higher temperatures for pressure up to 140 MPa.

[学科分类] 海洋学与技术