A Case Study of a Quasi-stationary, Very Long Polar Stratospheric Cloud Layer Edge

Abstract

 A case study of occurrence of polar stratospheric clouds (PSCs) on February 13th, 2017 in northern Sweden is discussed in the present paper. For the first time a quasi-stationary edge of a bright and extended PSCs layer (∼ 600 km long) on the Eastern side of the Scandinavian Mountain Range was photographed as well as registered with lidar observations. Both lidar measurements and model simulations demonstrated that atmospheric conditions were fairly unchanged for several hours during the presence of the PSC. Strong winds across the Scandinavian Mountain Range were responsible for triggering the formation of mountain lee waves in the Kiruna area, which in turn induced the formation of the quasi-stationary long and straight edge of the PSCs.