A polar cloud analysis based on Micro-pulse Lidar measurements at Ny-Alesund, Svalbard and Syowa, Antarctica

in order to acquire long-term data sets of backscatter profiles of clouds and aerosols in the polar regions, we started Micro-pulse Lidar (MPL) measurements at Ny-Alesund, Svalbard in March 1998 and at Syowa Station, Antarctica in January 2001. The MPL data have been acquired and analyzed for 11 months from the Arctic measurement and for 12 months from the Antarctic measurement. Fine structures of clouds and their temporal change were observed by MPLs with a 30-m range resolution and a 1-min time average. Statistical features of the polar clouds were investigated from the Arctic and Antarctic measurements. Results from the preliminary analysis indicated some differences of seasonal cloud appearance and cloud base heights at the two polar sites. Some features obtained in this study are as follows: over Syowa Station, Antarctica, high altitude clouds tended to appear in (austral) summer, and low altitude appeared more often in (austral) spring and autumn. On the other hand, low altitude clouds in the Arctic were observed particularly in summer and early autumn. Clear sky days were not expected in this season. In both polar regions, the winter clouds were relatively thin compared to the summer clouds. (C) 2003 Elsevier Ltd. All rights reserved.