One-Dimensional Cloud Microphysical Models for Central Europe and Their Optical Properties

摘要

One-dimensional microphysical models for six different cloud types are proposed. These models were formulated by making use of Khrgian-Mazin's one-parameter modified gamma distribution to judiciously mate the Russian measurements of cloud liquid water content and mean radius profiles to the German observations of various cloud types. With the drop-size spectra of the clouds thus determined as a function of height, calculation of their optical properties became straightforward. Separate regression relationships were established for the six model clouds, giving liquid water content and mean radius as a function of height above the cloudbase by the method of least-squares fit. It is from these relationships that the drop-size distribution may be derived for any level in a cloud of interest, and hence its spectral extinction coefficients at any wavelengths, in turn, from the distribution. A close examination of these coefficients in the visible and infrared window regions for each of the cloud types revealed that as a function of height they were well represented by polynomial relationships of 3 to 6 degrees. Regression coefficients for these relationships are presented in three separate tables. The six one-dimensional model cloud types proposed herein may fill the gap which has long been felt in the modeling community and which is also found in our present electro-optical systems atmospheric effects library. (Author)