Analytic functions for modeling vertical profiles of extinction in and beneath very low stratus clouds

摘要

A theoretically based microphysics model developed by the authors was used to simulate a large number of vertical drop size distribution profiles in very low stratus clouds and subcloud regions. These drop size distributions were used with Mie calculations to simulate vertical profiles of extinction coefficients at wavelengths of 0.55, 1.06, 4.0, and 10.6 $mu@m. These profiles were then fit with smooth analytic functions in order to develop a model that can be used quickly and easily to simulate gross behavior of vertical profiles of extinction coefficients. Values of parameters that appear in two selected analytic functions were determined from fitting simulated data and are presented for a few cases in this work. It is proposed that one of these analytic functions with associated parameter values be considered for possible worldwide application in modeling very low stratus clouds.