Distribution of Dissolved Oxygen and Nutrients in Abyssal Waters Flowing into the Brazil Basin, Southwest Atlantic

The Vema Channel is a deep narrow passage in the South Atlantic and a main path for bottom water which flows northward from the Argentine Basin to the Brazil Basin and after all into the North Atlantic. The thermohaline structure and dynamics in it have been studied for many years. In this study we report our new data on dissolved oxygen and nutrients measurements performed in 2022 at the exit of the Vema Channel. This is the first time that such measurements have been made with high spatial resolution. Data from standard oceanographic sections located near the study area are also analyzed. A significant dependence in the distribution of dissolved oxygen and nutrients on the hydrological structure is shown. Local dissolved oxygen minimum indicates the lower boundary of Circumpolar waters. It was also revealed insignificant temporal variability of nutrients concentration.