Abstract: This paper proposes the hypothesis that the low-frequency variability of the North Atlantic Oscillation (NAO) arises as a result of variations in the occurrence of upper-level Rossby wave?breaking events over the North ...

Abstract: The polar vortex of the Southern Hemisphere (SH) split dramatically during September 2002. The large-scale dynamical effects were manifest throughout the stratosphere and upper troposphere, corresponding to two distinct ...

Abstract: nergy fluxes for polar regions are examined for two 30-yr periods, representing the end of the twentieth and twenty-first centuries, using data from high-resolution simulations with the ECHAM5 climate model. The net radiation ...

Abstract: No abstract available.

Abstract: he ECMWF twentieth century reanalysis (ERA-20C; 1900?2010) assimilates surface pressure and marine wind observations. The reanalysis is single-member, and the background errors are spatiotemporally varying, derived from ...