Numerical simulation of the tropical Pacific response to equatorial wind stress anomalies

The results of the tropical Pacific response to the sudden onset of the equatorial wind stress anomalies are discussed. The ocean model is a barotropic, non-linearized one that includes reduced-gravity and an equation for the temperature of the ocean mixed-layer. The experiments are based on a state of equilibrium reached through a long running under the action of annual mean wind stress. There are two kinds of westward wind intensity regions: the whole tropical Pacific and the western tropical Pacific, which are all between latitude 6. 8°N and 6. 8°S.
In these cases, the results show that the positive sea surface temperature (SST) anomalies in the Eastern Pacific and the negative SST anomalies in the Western Pacific are produced, and the positive SST anomalies propagate eastward, just as those observed during the actual El Nino phenomena. The propagations of the Kelvin waves and Rossby waves in the ocean are discussed.
Another experiment is also carried out in simulating the process of the decay of El Nino phenomena. The propagations of the Kelvin waves and Rossby waves in the ocean are discussed. Mother experiment is also carried out in simulating the process of the decay of El Nino event after the weakened Equatorial Pacific eastern winds returned to normal. The results are similar to the observations, too.