The Influence of ENSO in the Precipitation Regime in Southern South America

Abstract

El Niño Southern Oscillation (ENSO) phenomenon has been statistically related to several hydroclimatic extremes all around the world. In this paper; several zones in the continental region of Southern South America are identified. These zones present teleconections between the extremes phases of ENSO and the precipitation phenomenon characterized through the standardized precipitation index. The methodology is based on the estimation of the first harmonic and the properties of length and phase of the resulting vector; and in the analysis of vectorial coherence between both phenomena. In order to estimate probabilities and to verify the significance levels of the relationship found, a test based on the hypergeometric distribution is used. Also, some regions in the Pacific Ocean that present the best statistical correlation between the sea surface temperature (SST) anomalies and the time series of index of precipitation in the zones of influence are presented.