Troposphere-stratosphere dynamic coupling under strong and weak polar vortex conditions

The relationship between Northern Hemisphere (NH) tropospheric and stratosp heric wave-like anomalies of spherical zonal wave number (ZWN) 1 is studied by applying Canonical Correlation Analysis (CCA). A lag-correlation techni que is used with 10-day lowpass altered daily time series of 50- and 500-hP a geopotential heights. Generally stratospheric circulation is determined b y ultralong tropospheric planetary waves. During winter seasons characteriz ed either by an anomalously strong or weak polar winter vortex different pr opagation characteristics for waves of ZWN 1 are observed. The non-linear p erspective of the results have implications for medium range weather foreca st and climate sensitivity experiments.