Interseasonal and interbasins hydrological coupling in South America

Abstract

The interseasonal and interbasins hydrological coupling between the Amazon and the La Plata watersheds is obtained with the help of ERA-5 atmospheric reanalysis, MERGE/CPTEC precipitation, GLEAM evapotranspiration, and the GLDAS/Noah soil moisture datasets. The hypotheses formulated in a previous work by Zanin and Satyamurty about the hydrological processes interconnecting the Amazon Basin and the La Plata Basin are tested. A new method for finding the source–sink relationships among the boxes (regions) is presented. The precipitation recycling, frequency of source–sink behaviors, the soil moisture memory, and the continental moisture transport between remote regions are evaluated. The main result of this study is that the amount of water precipitated over the southeastern region of the Amazon Basin at the end of the South American monsoon during the autumn season influences the amount of precipitation during the winter season over the central-western region of the La Plata Basin. © 2021 American Meteorological Society.