Lidar Observations of Polar Stratospheric Clouds Above Spitsbergen

摘要

Lidar measurements of Polar Stratospheric Clouds (PSCs) are reported from the NDSC primary station at Ny-Alesund, Spitsbergen (79 deg N, 12 deg E). PSC layers are highly variable in time and space. Depolarization measurements characterize the PSCs with respect to their shape (spherical or aspherical). The onset of PSC events in winter 1995/96, which had the longest 'PSC season' observed so far at Spitsbergen, was detectable only in the depolarization channel. Typical altitude distributions of backscatter and depolarization ratios for early, mid and late winter periods reveal decreasing altitudes.