Tropical-extratropical interactions and effects on south america

variability. Wavetrains over Southern Pacific have been identified in many studies of teleconnections connecting the tropical region to higher latitudes. The Pacific South Atlantic Pattern (PSA) is the dominant pattern linking the tropical convection to anomalies at higher latitudes. In this study OLR anomalies are analysed to select days with strong convection at several areas in the Tropical Pacific. The atmospheric circulation anomalies related to the convection in each area are investigated analysing low frequency streamfunction anomaly fields. Averages of five days, centred on the selected days of low frequency are used to do a composite field. The main objective is to analyse the position of the wavetrains related to the tropical convection and its influence on South America. The analyses are performed for the austral winter and summer, from 1982 to 1989. The convection anomalies are analysed in the west and east parts of Indonesia and areas of Central and East Pacific which show above normal convection in El Nino years. The OLR composites show that the displacement of anomalous convection over Tropical Pacific have a connection with the position of anomalous convection over South America, affecting the intensity of the South Atlantic Convergence Zone (SACZ) in the austral summer. Different wavetrain patterns are obtained for each case, showing an influence of tropical convection on the atmospheric characteristics over South America. Precipitation anomalies over South America are also shown for the analysed periods. The same analyses are performed for the period of 1990 to 1997 and compared to the previous results to identify long term