Ocean-atmosphere interactions in the tropics: a review of recent theories and models

The Southern Oscillation, an irregular interannual fluctuation between warm El Nino and cold La Nina conditions that has its largest amplitude in the tropical Pacific, is attributable to interactions between the ocean and atmosphere and corresponds to a natural model of the coupled ocean-atmosphere system (somewhat analogous to the way in which weather corresponds to an unstable mode of the atmosphere). Stability analyses reveal that a variety of unstable modes are possible. Coupled ocean-atmosphere models that march forward in time (and can be used for predictions) capture some of these modes. The differences between the various models and their relevance to the observed phenomenon are discussed. -Author