National Aeronautics and Space Administration

The stratospheric sudden warming event in early January 2013 has unique dynamical characteristics in terms of its development and interactions with the tropospheric flow. The animation of these northern hemisphere EPV fields from the GEOS-5 atmospheric analyses shows the evolution of this major SSW of January 2013. The movie starts in mid-December 2012 and continues through the various phases of the warming event, until the end of January. The animation includes one frame from every three hours of the GEOS-5 assimilation. Read More.