A Delayed Action Oscillator for ENSO

Abstract

A simple nonlinear model is proposed for the El Niño/Southern Oscillation (ENSO) phenomenon. Its key feature is the inclusion of oceanic wave transit effects through a negative, delayed feedback. A linear stability analysis and numerical results are presented to show that the period of the oscillation is typically several times the delay. It is argued such an effect can account for the long time scale of ENSO.