Influência remota da TSM do atlântico sudoeste no posicionamento da zona de convergência do atlântico sul (ZCAS)

Abstract

In this study, the complex interaction between the Sea Surface Temperature (SST) of the Southwest Atlantic Ocean in the region of the Brazil-Malvinas (Falkland) Confluence (BMC) and the South Atlantic Convergence Zone (SACZ) was investigated. This interaction plays an important role in the dynamics of precipitation in South America, as SACZ exerts a relevant influence on the precipitation regime in Brazil. Thirty years of data from the fifth generation of the ECMWF reanalysis (ERA5) of atmospheric parameters and SST were used to construct a climatological average and analyze three selected SACZ occurrence events. SST time series were constructed, and the patterns observed in the periods of the selected SACZ events were analyzed to identify indicators of any relationship between the SST in the Southwest Atlantic and the position/intensity of the SACZ. The analyses indicated that the configuration of the SST anomalies south of the South Atlantic is related to variations in general circulation in South America. The analyzed events were divided into two patterns: the first where the ocean surface water has a temperature above normal throughout the BMC region, and the second pattern presents a significant horizontal SST gradient in the BMC region. In the first pattern, the SACZ presented a typical configuration, positioning itself on the coast of Southeast Brazil. In the second pattern, the position of the SACZ was north of the typical configuration, establishing itself with an oceanic branch between the coast of Northeast Brazil and the north of the Southeast region.