PERTURBATION CORRECTION TO THE 2-STREAM MODEL APPLIED TO THE EARTH ATMOSPHERE

In the interior of a clear, cloudless, and optically thin atmosphere ( tau(0) less than or equal to 0.8) the predictions of even the most acc urate two-stream models can significantly deviate from exact calculati ons. A perturbation correction to the differential form of a particula rly simple two-stream model (delta-function model) has been deduced in terms of error corrections to inversions for the single scattering al bedo and the asymmetry factor. This corrected differential form was de veloped and validated for the visible region of the wavelength spectru m in the case of a cloudless vertically inhomogeneous plane-parallel t errestrial atmosphere.