The Dynamics of ENSO Anomaly as Revealed in Ensemble Climate Simulations-Impact of Mean Stationary Wave

A series of climate ensemble experiments using the climate model from National Centers for Environmental Pre-diction (NCEP) were performed to exam impact of sea surface temperature (SST) on dynamics of El-Nino / South-ern Oscillation (ENSO). A specific question addressed in this paper is how important the mean stationary wave influ-ences anomalous Rossby wave trains or teleconnection patterns as often observed during ENSO events Evidences from those ensemble simulations argue that ENSO anomalies, especially over Pacific-North America (PNA) region, appear to be a result of modification for climatological mean stationary wave forced by persistent trop?ical SST anomalies. Therefore, the role of SST forcing in maintaining climate basic state is emphasized. In this argu?ment, the interaction between atmospheric internal dynamics and external forcing, such as SST is a key element to understand and ultimately predict ENSO.