Fronts of the Malvinas Current System: Surface and Subsurface Expressions Revealed by Satellite Altimetry, Argo Floats, and Mercator Operational Model Outputs

We examine the surface and subsurface signature of ocean fronts closely associated with the Malvinas Current dynamics. We first evaluate the performances of the Mercator Ocean eddy permitting (1/12° spatial resolution) global operational system in the southwestern Atlantic Ocean over the last 10 years (2007–2016) using satellite, Argo float and in situ data collected near 41°S. Observations versus model comparisons show that the model correctly reproduces the general circulation and the complex hydrographic features of the study area including the vicinity of the Brazil-Malvinas Confluence. The model outputs accurately match the observations except in June 2015. The causes for the June 2015 mismatch are analyzed. We then used the model and satellite altimetry to identify isolines of absolute dynamic topography (ADT) and potential density at different depths associated with the mean front location and establish their correspondence with specific water mass boundaries. Frontal displacements as depicted in satellite ADT, model ADT, and model potential density at 450 m are in general agreement. The ADT and potential density at 450 m provide nonidentical and complementary information on eddies shed by the Polar Front (PF): while ADT depicts the surface circulation with PF eddies entrained into the energetic circulation over the deep Argentine Basin, potential density at 450 m is more effective at monitoring PF eddies feeding the Malvinas Current.

Fil: Artana, Camila Indira. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; Francia. Universite Pierre et Marie Curie; Francia

Fil: Lellouche, Jean Michel. Mercator Ocean; Francia. Centre National de la Recherche Scientifique; Francia

Fil: Park, Young Hyang. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; Francia. Universite Pierre et Marie Curie; Francia

Fil: Garric, Gilles. Centre National de la Recherche Scientifique; Francia. Mercator Ocean; Francia

Fil: Koenig, Zoé. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; Francia. Universite Pierre et Marie Curie; Francia

Fil: Sennéchael, Nathalie. Muséum National d'Histoire Naturelle; Francia. Universite Pierre et Marie Curie; Francia. Centre National de la Recherche Scientifique; Francia

Fil: Ferrari, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina

Fil: Piola, Alberto Ricardo. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Saraceno, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina

Fil: Provost, Christine. Universite Pierre et Marie Curie; Francia. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; Francia