The Application of Infrared Flux Models to Atmospheric Data

Abstract

The infrared flux expressions, both upward and downward at an arbitrary reference level, are presented for two computational models. In one model the stipulated cloud and terrain surfaces are nontransparent, but not necessarily black, each with an emissivity given by the departure of the apparent reflectance from unity. The second model includes a semitransparent layer that is assigned an infinitesimal thickness and an emissivity given by the departure from unity of the sum of the reflectance and the transmittance. All significant simplifications that have been adopted in the application of the models are reviewed. Results from sample computations of total infrared flux, cooling rates, and simulated high-altitude views through a ?window? region of the spectrum are presented. Surface effects are noted.