The cold stratospheric winters 1994/1995 and 1995/1996

Abstract
The stratospheric winters 1994/1995 and 1995/1996 were both extremely cold. The temperature (T) fell below that necessary for type 1 polar stratospheric cloud formation (195 K at 50 hPa) on many consecutive days in each winter and occasionally reached values low enough for ice cloud formation. The meteorological situation each winter was quite different. Both seasons were cold throughout Dec and Jan. In 1995 a dynamical warming event increased T in the latter part of Feb but a further cold spell occurred in early Mar. In contrast, the polar vortex remained well developed until early Mar 1996, when T increased rapidly. While both winters were extremely cold at 50 hPa, the polar vortex was deeper in Feb 1996 when extremely low T occurred over large areas at 30 hPa.