Development of an optical model for cirrus clouds

An optical model for cirrus clouds consisting of ice crystal particles is considered for random particle orientations. In this model, two points and four intervals of the scattering zenith angle are introduced. They are the points of forward and backward scattering and the intervals of 0°-22°, 22°-46°, 46°-60°, and 60°-180. It is argued that light scattering into these intervals are caused by different physical reasons. Therefore, the behavior of the phase functions in these intervals can be modeled independently. It is assumed that these behaviors of the phase functions are scarcely determined by the exact particle shapes but they are mainly determined by certain weight coefficients for wedges that are inherent to the particle shapes. So, the optical model is based on the weight coefficients for the wedges.