Azimuth orientation of crystal-cloud particles due to wind speed pulsations: mathematical model

摘要

We discuss the possibility that particles of a crystal cloud can take a preferred orientation with respect to wind direction under the action of aerodynamic forces in the atmosphere. It is shown theoretically that the preferred orientation can be caused by wind speed pulsations and by the forces applied to a particle falling due to gravity in the presence of wind speed gradient. The theoretical estimate of the parameter of the function of particle orientation distribution over azimuth angles well agrees with its experimental estimate from the backscattering phase matrices of cirrus clouds obtained from data of polarization lidar measurements.