CONICET | Buscador de Institutos y Recursos Humanos

The southern portion of Malvinas Current (MC) circulationwas exanimated using satellite altimetry data and at in-situ velocity timeseries gathered at three mooring sites (from March 2015 to May 2017) along the PatagonianShelf break at 44.7°S. The in-situdata provided the first opportunity to compare altimetry-derived velocitieswith high temporal resolution near-surface current meter velocities in thistract of MC. Globally, altimetry-derivedvelocities compared rather well with the in-situvelocities at 300 m depth both in strength and direction. Correlations werehigh (>0.8) between the in-situ velocitiesand the surface velocities derived from satellite altimetric data. The qualityof the altimetric surface geostrophic velocities being assessed, altimetry wasused to further interpret the observations at the isolated mooring sites and toput them in context of the 24-year-long altimetric time series. Leading modes andtemporal scales of variability were analyzed. During the in-situ measurement period, the spatial structure of the two-dominantmodes of Mean Sea Level Anomaly that explain more than 50% of the variance wereassociated to the presence a westward meander of high ADT close to 44.7° S,which affect the MC flow beyond that latitude. The 24-year-long altimetry timeseries revealed that these patterns are robust. Moreover, we combinedaltimetric and the in-situ data tocompute a volume transport time series of the MC at 44.7°S. Finally, theorigins of these variations and the impacts in the volume transport are discussed.