Accurate, simple equation for saturated vapour pressure over water and ice

Ambaum, M. H. P. ORCID: https://orcid.org/0000-0002-6824-8083 (2020) Accurate, simple equation for saturated vapour pressure over water and ice. Quarterly Journal of the Royal Meteorological Society, 146 (733). pp. 4252-5258. ISSN 1477-870X doi: 10.1002/qj.3899

Abstract/Summary

We present and assess a simple equation for saturated vapour pressure over water and ice. The equation does not rely on an explicit integration of the Clausius–Clapeyron equation, but instead uses the equality of the Gibbs functions of the vapour and the liquid or ice in equilibrium. The resulting equation is simple, physically consistent with standard thermodynamic assumptions, uses only basic physical parameters, and is at least as accurate as commonly used empirical fits. It is further shown that the finite volume of liquid water has a negligible effect on the vapour pressure. The main variation from accurate tabulated data results from the variation of vapour and liquid isobaric heat capacities. Nevertheless, it is shown that, for the purpose of accurate calculation of saturated vapour pressure, this can usually be ignored.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/93718
Identification Number/DOI	10.1002/qj.3899
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Royal Meteorological Society
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