INTERANNUAL VARIABILITY IN THE STRATOSPHERIC-TROPOSPHERIC CIRCULATIONIN A COUPLED OCEAN-ATMOSPHERE GCM

Relationships between the northern winter stratospheric and tropospher ic circulations and the sea surface temperature (SST) simulated by a g lobal coupled ocean-atmosphere general circulation model are investiga ted. Two modes are extracted for interannual variability of the zonal- mean zonal wind by an empirical orthogonal function analysis. The firs t mode is related with interannual variations of the stratospheric pol ar vortex. This mode has a significant correlation with the North Paci fic SST through tropospheric circulation changes. The second mode is t he variation of the tropospheric subtropical jet and is related with t he simulated El Nino. Model results imply no strong relationship betwe en El Nino and the polar vortex.