Sudden stratospheric warmings(SSWs)are extreme cases of stratospheric polar vortex weakening[1].They are termed minor when a reversal of the stratospheric meridional temperature gradient in the subpolar region at 10 h...Sudden stratospheric warmings(SSWs)are extreme cases of stratospheric polar vortex weakening[1].They are termed minor when a reversal of the stratospheric meridional temperature gradient in the subpolar region at 10 hPa and poleward of 60occurs,or major when this is accompanied by a complete reversal of the stratospheric circumpolar westerly jet[2].Although SSWs occur in both hemispheres,major SSWs are usually observed in the Northern Hemisphere,with a frequency of approximately six per decade.In contrast,only one major SSW has been recorded in the Southern Hemisphere,which occurred in 2002[3].展开更多
基金supported by the National Key Research&Development Program of China(2018YFC1506003)the National Natural Science Foundation of China(41925020,41721004)supported by the Natural Environment Research Council(NE/P006779/1,NE/N018001/1)。
文摘Sudden stratospheric warmings(SSWs)are extreme cases of stratospheric polar vortex weakening[1].They are termed minor when a reversal of the stratospheric meridional temperature gradient in the subpolar region at 10 hPa and poleward of 60occurs,or major when this is accompanied by a complete reversal of the stratospheric circumpolar westerly jet[2].Although SSWs occur in both hemispheres,major SSWs are usually observed in the Northern Hemisphere,with a frequency of approximately six per decade.In contrast,only one major SSW has been recorded in the Southern Hemisphere,which occurred in 2002[3].
