MAINTENANCE MECHANISMS OF THE STATIONARY WAVE ANOMALY TELECONNECTION PATTERNS IN THE UPPER TROPOSPHERE

The spatial structure and temporal variations of the stationary wave anomalies in the upper troposphere during the Northern Hemisphere winter are studied with the ECMWF data of 1980-1988 and PCA (principal component analysis) method.The vorticity source anomalies of the main teleconnection patterns are analyzed,and their roles in the maintenance of the stationary wave anomaly teleconnection patterns are investigated with the harotropic model.The results show that the anomalies of transient vorticity flux convergences tend to cancel the anomaly of vorticity sources generated by divergent winds.The stationary wave anomaly patterns caused by divergent wind anomalies only are very different from observations.However,if the anomalous transient vorticity flux convergences are also included in the vorticity sources,the simulated patterns will be greatly improved.