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

Abstract

The major sudden stratospheric warming (SSW) in the beginning of January 2013 led to considerable temperature growth in the polar stratosphere (up to 60 K at ∼44 km altitude), to mean zonal wind reversal, to the split of the stratospheric polar vortex, and to a change in the temperature and dynamic regimes of the mesosphere and lower thermosphere. Using the data of reanalysis and ground-based spectrometric and satellite observations, the changes in thermodynamic parameters related to the SSW and expanding from the troposphere to the lower thermosphere are analyzed. An intensification of wave activity fluxes from the troposphere to the stratosphere is revealed a week before the SSW over East Siberia and China. It is shown that wave trains propagating eastwards in the upper troposphere could contribute to the intensification of an anticyclone over the northeast Atlantic Ocean a week before the SSW. In its order, such intensification has led to the split of the stratospheric polar vortex into two parts during the SSW.