Aleatorização da amplitude de aquecimento num modelo acoplado do oceano-atmosféra e mecanismo de criticalidade auto-organizada no fenômeno ENSO

Abstract

The El Nifio Southern Oscilation (ENSO) is an oceanographic and atmospheric complex phenomena, that has been a subject of many studies for the last years. Besides its importance as a large climatic modifier, ENSO events has very deep social and economics consequences. After the 1982-83 catastrophic ENSO, many researchers have been working to understand the phenomena, with the expectation to forecast it. With this if objective a large quantity of numerical models were and have been developed to described it. However its previsibility is still, untill now, an open question. Observational data of SST, for the equatorial Pacific Ocean, were used by Andrade et al. (1995), to show the absence of a caracteristic time scale for the ENSO, being evident that, the only possible and significant way to forecast ENSO events, essentialy is probalistic. According to Andrade et al, the time fluctuations of SST can be considered self correlated and fractais statistics can be applied. These results motivated to evaluated the problem of previsibility of ENSO events, using a simple coupled oceanatmosphere model, whose coupling between the total SST and the surface wind is able to produce a proper seasonal cycle. The model is presented in chapter 2 and 3. ln the chapter 4 the importance of the randomic treatment of the heating function and its importance to generate the SST fluctuation time series like a self affine fractal is discussed. ln chapter 5 the results are presented. Finally, concluding remarks are addressed in chapter 6.