Shelf Water Export at the Brazil-Malvinas Confluence Evidenced From Combined in situ and Satellite Observations

The Brazil-Malvinas Confluence (BMC) is the region where opposing and intense western boundary currents meet along Southwestern Atlantic slope at about 38°S, generating one of most energetic mesoscale regions global ocean. Based on shipborne observations acquired within Uruguayan Economic Exclusive Zone (EEZ), combined with satellite data an eddy tracking algorithm, we analyze cross-shelf exchanges during May 2016, when BMC was in anomalous northern position. Two types shelf water export were observed triggered by dynamics: shallow Rio de la Plata Plume waters driven off-shelf retroflection Brazil Current. This formed a 70 km wide, 20 m deep filament that propagated offshore 0.3 s –1 , transport 0.42 Sv. It lasted 10 days before being mixed ambient strong winds. An additional type consisted subsurface layer Subantarctic Shelf Waters (SASW) 60 thick subducted reaching 130 transporting 0.91 ± We show geostrophic derived from altimetry over can be useful to track this as they are significantly correlated absolute velocity measurements depth. Argo temperature salinity profiles evidence these two occurring between front separation Current shelf-break, suggesting relatively frequent phenomenon, agreement previous observations.