The Paraná River Response to El Niño 1982–83 and 1997–98 Events

Abstract

Abstract The most severe flooding of the twentieth century in the Argentine section of the Parana River occurred during the strong El Nino (EN) event of 1983. During the 1997–98 EN episode, discharge anomalies in the Parana basin, although of the same sign as those of the 1982–83 event, were much smaller. The main differences were observed during January–March and June–July of the year following the starting date of the event, when the 1982–83 discharge anomalies were considerably larger. This study explores this issue as well as the relationship between convection anomalies in the Parana basin and tropical Pacific and South Atlantic sea surface temperature (SST) anomalies. The correlation between convection in the upper and middle Parana and Iguazu basins, as measured by outgoing longwave radiation, and SST in both the Nino-1+2 and Nino-3 regions is statistically significant for most of the period November–July, reaching the maximum value in the three basins during May. However, the analysis of the highe...