The relationship between ENSO and Paraná River flow

摘要

Several studies indicate that there is a relationship between the climaticvariability in the South American continent and alterations of the positionand intensity of the heat sources in the equatorial region. The El Niñophenomenon can influence the precipitation over some regions of SouthAmerica such as the Brazilian Northeast, Amazonia, South of Brazil andUruguay. Over 80% of Brazil's energy comes from hydropower, and decisionsconcerning future availability and pricing require forecasts of river flow,ideally several months in advance. In this work the relationship betweenthe Paraná River flow and the ENSO (El Niño/Southern Oscillation)mode is investigated and statistical forecasts of river flow are tested. Anevaluation of the relationship between the Pacific sea surface temperatureand the Paraná River flow indicates an ENSO pattern over the equatorialPacific. The time series of the ENSO mode obtained by applying principalcomponents analysis on the sea surface temperature (SST) were used aspredictors for the Paraná River flow forecast. Improvement in the modelforecast skill is also obtained by considering the lagged river flow timeseries as a predictor.