On the Approximation of Saturation Vapor Pressure

The saturation vapor pressure of water vapor in the atmosphere is an important variable in many meteorological processes. Numerical approximation of the dependence of this variable on temperature is necessary in the modeling of these processes. Given here are the coefficients of eight approximating functions, five polynomials and three rational functions, for the saturation pressure with respect to a liquid water surface for the temperature intervals [−50°C, + 50°C] and [0°C, + 50°C], and with respect to an ice surface for the interval [−50°C, 0°C]. Considering both the required computation time and the resulting error, these functions compare favorably with others published recently.