BASIC FEATURES OF LARGE-SCALE PROCESSES IN THE MIDDLE ATMOSPHERE DURING DYANA

Large-scale processes in the stratosphere and mesosphere were investig ated for the DYANA period, mainly on the basis of rocket sounding seri es and satellite-based maps. It was found that undisturbed circulation prevailed during the early winter period with low stratospheric tempe ratures near the Pole. Periodic warm pulses appeared in January in the upper stratosphere and an intense warming was observed at these level s in early February, the downward penetration of which (below 25-30 km ) was relatively confined. Wavenumber 1 predominated during the warmin g. In late February the cold cyclonic vortex was restored near the Pol e and this persisted into March.