Mesoscale Eddies of the Brazil-Malvinas Confluence Zone and Their Influence on the Formation of the Sea Surface Temperature Fields

Problem Statement and Purpose. The Brazil-Malvinas Confluence zone is one of the productive zones of the World Ocean. The mixing of the warm tropical waters of the Brazilian Current with the cold subantarctic waters of the Malvina Current leads to the formation of layers of water with different thermohaline characteristics, and this alternation in combination with the action of mesoscale and submesoscale eddies leads to an increased growth of phytoplankton, which is not only one of the main suppliers of oxygen to the atmosphere and a source of food for marine inhabitants, but it can also have negative consequences with its increased growth. The processes of water dynamics in the confluence zone of the Brazilian and Malvina (Falkland) currents are of great importance because they contribute to the transfer of nutrientrich deep waters to the photic zone, and their changes can affect the state of local marine ecosystems. The emergence of cyclonic and anticyclonic mesoscale eddies is associated with the vertical movement of water masses in the center of these formations, which leads to the formation of sea surface temperature anomalies. Data & Methods. The eddies were identified based on the satellite altimetry observations of the Global Ocean Gridded L4 Sea Surface Heights and Derived Variables Nrt product. Current velocity analysis was performed based on 2021 data from the Global Ocean Physics Analysis and Forecast product of the Copernicus Marine Monitoring Service. The analysis of sea surface temperature (SST) anomalies was performed based on data from the NOAA OI SST V2 High Resolution Dataset product Optimum Daily Interpolation of Sea Surface Temperature. Temperature and salinity observations on the Argo platforms were used in this study. Results. The formation of SST anomalies is not associated with all eddies formations. A significant role in this process is played by the initial conditions under which eddies are formed (location in Brazil-Malvinas Confluence and the meanders of its extension, current speed, bottom topography, water masses structure), and the duration of the life cycle of the formation, especially in the early stages. The eddies which led to SST anomalies were associated with higher flow velocities than the eddies with which no anomalies were associated, and an asymmetric structure. The maximum current velocities in the circulations were located in the layer from 2 to 400 m.