DYNAMICAL EVOLUTION OF THE NORTHERN STRATOSPHERE IN EARLY WINTER 1991/92, AS OBSERVED BY THE IMPROVED STRATOSPHERIC AND MESOSPHERIC SOUNDER

Dynamical fields based on temperature measurements from the Improved Stratospheric and Mesospheric Sounder on the Upper Atmosphere Research Satellite are presented for the Northern Hemisphere stratosphere for the period 28 October 1991 through 18 January 1992. Interpretation of these fields gives a picture of the dynamical evolution of this period in terms of the zonal-mean fields and the synoptic structures. Among the features of interest are the movements of the zonal-mean jets and several periods of stratospheric warming, culminating in a near-major warming in January.