Abstract
A new treatment of absorption in the window region depending on water vapor pressure is incorporated into the IR cooling rate model of Rodgers [for review see Rodgers and Walshaw (1966). The appropriate mean diffuse transmission gradient is derived. The results are presented in the form of hemispheric cross sections and indicate that for tropical climates, the new absorption has a considerable effect on radiative transfer in the lower troposphere. The results obtained are very encouraging, showing a reduction in the differences between the measured cooling rates of Cox (1969) and the calculated cooling rates in the lower troposphere.