The absolute seawater entropy: Part I. Definition
arXiv:2410.04821 · doi:10.5802/crgeos.333
Abstract
The first improvements concern the complex non-linear dependence of entropy on pressure, temperature and salinity, with the use of the standard TEOS10 formulation based on a fit of the oceanic Gibbs function to more recent observations. On the other hand, more recent thermodynamic tables have been used to increase the accuracy of the Millero's salinity increment to this standard formulation, to deduce the absolute version of entropy with new values for the pure-water and sea-salts absolute reference entropies. The differences between the values of the seawater entropy calculated with the Millero and TEOS10 formulations (standard and absolute) are documented, before a more complete study shown in the second part of the paper of the absolute seawater entropy computed from observed vertical profiles and analysed surface datasets.
V1: First submitted on the 7th of October 2024. V2: arXiv reference for the Part-II. V3: First Revised version. V4: Accepted in the Comptes Rendus (Geoscience) Paris, France on the 23th of March, 2026 (3 Figures; 27 pages)