Effect of stratospheric sudden warming and vortex intensification on the tropospheric climate

Abstract

The effect of stratospheric sudden warming (SSW) and vortex intensification (VI) on the tropospheric climate is examined through composite analysis of the observational data. Specifically examined in the present study is the Eulerian meridional circulations associated with SSW and VI. It is found that prominent signal in the troposphere tends to appear associated with the occurrence of SSW and VI. The patterns created are very similar between SSW and VI except for the polarity. In the high latitude region, the pattern similar to the Arctic Oscillation (AO) is created before and after the occurrence of SSW and VI with changing polarities. In the tropics, convection tends to enhance in the Southern Hemisphere (Northern Hemisphere) tropics after the occurrence of SSW (VI). These signals are created through three prominent cells of the anomalous Eulerian meridional circulation that extends from polar cap to the tropical Southern Hemisphere. The mechanism for the formation of the cells associated with SSW and VI is also discussed.