The stratospheric dynamic and its variability play one of the key roles in the tasks of weather forecasting on a sub-seasonal scale in winter season in the Northern Hemisphere. The stratospheric influence on tropospheric dynamics is most pronounced during sudden stratospheric warming (SSW), when in many cases it is possible to trace the spread of dynamic disturbances from the stratosphere to the underlying troposphere, down to the Earth’s surface. Therefore, a more complete understanding of the formation of SSW events will assist to clarify the forecast of anomalies of synoptic activity with an advance time of 10 to 30 days. In this paper based on the data of idealized numerical modeling we analyze the differences in the characteristics of the stratospheric polar vortex (SPV), such as the intensity and frequency of the SSW at different phases of the El Niño – Southern Oscillation (ENSO). The results of the study allow to explain the mechanisms of formation of these differences and show that the predictability of SSW in El Niño conditions is higher than in La Niña conditions.
A. V. Panasik (Wed,) studied this question.