The Brazil-Malvinas Confluence (BMC) is an intense frontal region between relatively cold-fresh subantarctic and warm-salty subtropical waters. Its spatial structure reflects the collision of the southward Brazil Current with the northward Malvinas Current, which results in the southward retroflection of the Malvinas Current accompanied by the overshoot of the Brazil Current as an elongated anticyclonic meander. At the locus of the along-slope initial collision, the Subantarctic and Brazil Current Fronts usually merge together and produce a very intense frontal region. Occasionally, however, the anticyclonic meander occasionally breaks as an eddy and the Subantarctic Front retreats south, so that the Malvinas Current diverts east much further south and the water transport reaching the Brazil Current Front weakens substantially; these are the conditions we encountered during the March 2017 RETRO-BMC cruise on board the BIO Hespérides. In this study we will present and analyse novel data illustrating the surface and subsurface variability of the mesoscalar structures in the BMC. Altimetry data shows that the temporal evolution of the frontal system and associated mesoscalar structures is slow, on time scales of the order of one month. In contrast, SST images show the intermittent expulsion of surface filaments of brackish water (with high Rio de La Plata contributions), which reach several hundred kilometres offshore along the frontal system and display substantial changes at time scales of the order of days. Further, subsurface SeaSoar data obtained during the RETRO-BMC cruise show that the subsurface eddy-like structures are much smaller that the surface ones and also change at time scales of the order of very few days

V Encuentro de la Oceanografía Física (EOF 2018) - V Physical Oceanography Meeting, VI Simposio Internacional de Ciencias del Mar - VI International Symposium of Marine Sciences (ISMS 2018), 20- 22 June 2018, Vigo.-- 1 page

Peer Reviewed