Detecting Salinity Fronts From Satellite Observations in the Brazil-Malvinas Confluence

Small-scale variability is essential to understanding ocean circulation, air-sea interactions, and biogeochemical processes. Yet, current satellite-derived sea surface salinity (SSS) data can only resolve features larger than 40 km. This study aims to capture smaller scale variability (≤25 km) by reconstructing SSS data from satellite observations. The focus is on the Brazil-Malvinas Confluence (BMC), a biologically productive region characterized by intense mesoscale structures and associated with strong SSS gradients primarily due to the discharge of the La Plata River. A Lagrangian reconstruction method is employed to advect satellite SSS fields by altimetric geostrophic currents to capture smaller-scale details. These reconstructed fields are validated against in-situ salinity measurements from thermosalinographs. Results show that the reconstructed fields successfully capture smaller scale features observed in the region. This approach seeks to enhance the effective resolution of SSS data, overcoming the limitations of current satellite observations.