Odd Observation in High Altitude Clouds with Depolarization Lidar

Observations of high altitude clouds with a depolarization measurement lidar led to very interesting episodes. The high altitude clouds are supposed to be mostly composed of ice crystals and exhibit strong depolarization. But in the course of observation, cloud layers with very low depolarization ratio appeared in the field of view of the depolarization measurement lidar. The clouds had very highly localized concentration and they did not disperse even in the middle of the cirrus cloud. The constituents of the clouds seem to be anomalously spherical for the cloud at such a high altitude at such a low temperature. The observed clouds may need an extensive study for the mechanism of formation, for the identification of their composition, and for the influence on climate and environment.