Tropospheric forcing of the boreal polar vortex splitting in January 2003

Abstract

Embedded in a winter with high wave activity, we found two subtropical Rossby wave trains in the troposphere before the major sudden stratospheric warming event in January 2003. These Rossby waves propagated north-eastwards and maintained two upper tropospheric anticyclones. At the same time, the amplification of an upward propagating planetary wave 2 in the upper troposphere and lower stratosphere was observed, which could be caused primarily by those two wave trains. Furthermore, two extratropical Rossby wave trains over the North Pacific Ocean and North America were identified a couple of days later, which contribute mainly to the vertical planetary wave activity flux just before and during the major warming event. It is shown that these different tropospheric forcing processes caused the major warming event and contributed to the splitting of the polar vortex.

Stratosphere-troposphere interactions

“…Such clouds play a key role in the spring destruction of ozone in the polar stratosphere [15,16]. In addition, CAO, having analyzed observation data, revealed the effect of Rossby wave trains in the troposphere on the amplified propagation of wave activity from the troposphere and on the split of the stratospheric polar vortex in the Arctic and Antarctic during the SSW event [17,18]. The conducted model calculations of SSW in the Antarctic in September 2002 confirmed the possibility of such a mechanism.…”

Temperature and dynamical regimes of the northern hemisphere extratropical atmosphere during sudden stratospheric warming in winter 2012–2013

“…Propagating in the middle latitudes of the upper troposphere, wave trains may strengthen anticyclones in the troposphere and intensify the expansion of wave activity flow from the troposphere to the stratosphere. In its order, the strengthening of these anticyclones during the SSW may lead to the split of the polar vortex into two parts, in particular, in a way that was shown for the SSW in Antarctica in September 2002 [25,30] and in the Arctic in January 2003 [24] and in the beginning of December 2009, a month before the SSW in January 2010 [31]. The wave trains might contribute to the formation and strengthen ing of the blocking anticyclone above the European part of Russia in 2010 [32].…”

“…(3) three dimensional Plumb flux vectors [23] that characterize the propagation of wave activity, with three day averaging, analogous to [24,25].…”

“…Thus, the major SSW was preceded by an intensifi cation of wave activity flux from the troposphere to the stratosphere in the end of November 2012; on Decem ber [21][22][23][24][25]2012; and in the beginning of January 2013 (with the maximal flux above NE Eurasia and the NE Pacific Ocean).…”

Influence of subtropical Rossby wave trains on planetary wave activity over Antarctica in September 2002

“…Furthermore, for SSW events with strong tropospheric Rossby wave forcing like in January 2003 (Peters et al, 2010) and December 2009 (Vargin, 2013) on the Northern Hemisphere, a similar model study could give a better understanding of the role of tropospheric forcing processes.…”