O centróide da piscina de água quente do pacífico como um indicador dos fen?menos El Ni?o e La Ni?a

摘要

The El Ni?o -La Ni?a oceanographic phenomena were analized making use of the zonal component of the Pacific warm pool (PAQ) which describes east-west displacements along the intertropical belt of this ocean. We manipulated an ocean surface temperature (TSO) timeseries to classify the PAQ and to estimate its centroid between 1981 and 2003. All the El Ni?o (1982-83; 1986-87; 1990-95; e 1997-98) and La Ni?a (1984-85; 1988-89; 1998-2000) episodes described in the academic literature were eminent in the timeserie of the zonal component of the Pacific warm pool (CZPAQ). The most intense El Ni?o episodes were ranked according to its furthest eastward displacement. The timeserie of the CZPAQ was in phase with both the TSO anomaly and the Southern Oscillation Index. The fluctuations associated to the CZPAQ were illustraded in the spectrum where interannual oscillations associated to the El Ni?o -La Ni?a phenomena were observed. Shorter migrations to the west during the La Ni?a years were notable in comparison to those eastward moviments during the El Ni?o events. Therefore, the zonal displacements of the PAQ, represented here by the centroid, were presented as having significant worth to indicate the El Ni?o and La Ni?a phenomena. The main advantage of this technique is that it depends on a single arbitrary parameter to represent the PAQ, the threshold of the ocean surface temperature in the Pacific Ocean.