Numerical Experiments and Data Analysis.

For the purpose of investigating the fundamental nature of the interannual oscillation observed in the tropical Pacific in conjunction with El Nifto/Southern Oscillation (ENSO), the Comprehensive Ocean Atmosphere Data Set was analyzed. Based upon this analysis, an "intermediate " tropical atmosphere-ocean coupled model was developed. For reason of their particular importance to atmosphere-ocean interactions, moisture processes such as condensation-convergence, evaporation-sea surface temperature and evaporation- wind feedbacks were given special emphasis in both the data analysis and modeling processes. The atmospheric component of the model is based on the first baroclinic mode, which is driven by the atmospheric internal heating. The oceanic model consists of two layers with an iinbedded oceanic mixed-layer, by which SST is predicted. The present study has demonstrated that despite the structura