Since the late 1990s, a climate shift has occurred over the tropical Pacific that is characterized with a La Nifia-like mean state. Coincident with this climate shift, climate models＇ skills in predicting the El Nifio Southern Oscillation （ENSO） events in the 2000s are sig- nificantly lower than in the 1980s-1990s, A common bias is likely to exist in contemporary ENSO models that got amplified after the climate shift. In this study, we identify this model bias to be the wind-sea surface temperature coupling processes over the tropical Pacific. Evidence is presented to show that this coupling process experienced an obvious shift around year 2000 in its coupling strength and coupling center. A simple ENSO coupled model is used to demonstrate that the changing properties of the post-2000 ENSO events can be more realistically simulated if this model bias is alleviated.
A coupled system of the interdecadal sea-air oscillator model is studied. The E1 Nifio-southem oscillation （ENSO） atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The oscillator model is involved with the variations of both the eastern and western Pacific anomaly pat- terns. This paper proposes an ENSO atmospheric physics model using a method of the perturbation theory. The aim is to create an asymptotic solving method for the ENSO model. Employing the perturbed method, the asymptotic solution of corresponding problem is obtained, and the asymptotic behaviour of the solution is studied. Thus we can obtain the prognoses of the sea surface temperature anomaly and related physical quantities.
