Arden Buck equation


The Arden Buck equations are a group of empirical correlations that relate the saturation [vapor pressure] to temperature for moist air. The curve fits have been optimized for more accuracy than the Goff–Gratch equation in the range.
A set of several equations were developed, each of which is applicable in a different situation.

Formula

The equations suggested by are:
where:
Buck also lists enhancement factors for a temperature range of −80 to 50 °C at pressures of 1,000 mb, 500 mb, and 250 mb. These coefficients are listed in the table below.