Identification of Persistent Modes of Anomalies and Their Impact on Predictability in the Barotropic Atmosphere with Orographic Forcing
地形强迫正压大气异常持续类型的确定及其对可预报性的影响

A data set generated by integrating a nonlinear barotropic vorticity equation model with an orographic forcing is used to study the characteristic time scale of EOF temporal coefficients in streamfunction anomalies.Then a most persistent mode(MPM) is determined and its influence on predictability is investigated. It is found that there is a close correlation between the MPM.and the evolution of circulation anomalies, and the structure of initial fields has obvious impact on predictability.Finally the potential application of atmospheric MPM to the extended-and medium-range weather forecasts is discussed.