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 ...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.展开更多
The forcing of anomalous divergent wind and transient vorticity fluxes to the anomaly of stationary waves of DJF (December—January—February) 1982/1983 is studied.The results show that the anomaly of the transient vo...The forcing of anomalous divergent wind and transient vorticity fluxes to the anomaly of stationary waves of DJF (December—January—February) 1982/1983 is studied.The results show that the anomaly of the transient vorticity flux convergence tends to cancel or dissipate the anomaly of the vorticity sources generated by divergent wind.The stationary wave anomalies are maintained by both of these forcings.It is also found that,for the DJF 1982/1983 case,both of the vorticity source anomaly over the tropical and equatorial eastern Pacific and that over the midlatitude North Pacific are important to maintain the atmospheric circulation anomaly over the Pacific/North America region.展开更多
文摘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.
文摘The forcing of anomalous divergent wind and transient vorticity fluxes to the anomaly of stationary waves of DJF (December—January—February) 1982/1983 is studied.The results show that the anomaly of the transient vorticity flux convergence tends to cancel or dissipate the anomaly of the vorticity sources generated by divergent wind.The stationary wave anomalies are maintained by both of these forcings.It is also found that,for the DJF 1982/1983 case,both of the vorticity source anomaly over the tropical and equatorial eastern Pacific and that over the midlatitude North Pacific are important to maintain the atmospheric circulation anomaly over the Pacific/North America region.
