module esat_m IMPLICIT NONE CONTAINS elemental real function esat(T, P) ! Saturation vapor pressure of water in Pa. Buck, 1981, ! J. Appl. Meteor. 20, 1527-1532, equation (8). REAL, INTENT(IN):: T ! temperature, in K REAL, INTENT(IN):: P ! air pressure, in Pa !-------------------------------------------------------------------- esat = (1.0007 + 3.46e-8 * P) * 6.1121e2 & * exp(17.502 * (T - 273.15) / (T - 32.18)) END FUNCTION esat END MODULE esat_m