DYNAMICAL EVOLUTION OF THE NORTHERN STRATOSPHERE IN EARLY WINTER 199192, AS OBSERVED BY THE IMPROVED STRATOSPHERIC AND MESOSPHERIC SOUNDER/

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