Problem of correct accounting the special features of cirrus microstructure in climatic models

Optical models of high-level clouds (HLCs) used for calculation of radiation fluxes in the atmosphere are analyzed briefly. Results of the experiments on polarization laser sensing of cirrus performed with the lidar developed at the National Research Tomsk State University are described. Optical and microphysical characteristics of such clouds obtained from the results of measurements of their entire backscattering phase matrices are presented. It is shown that the orientation of crystals in the cirrus significantly affects the transmission of shortwave solar radiation. This fact proves incorrectness of the representation of real crystalline particles in HLCs with spherical particles with the corresponding effective radii during calculating the Earth’s radiation budget.