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Abstract

A geodetic estimation of the 3D-Geostrophic Currents (GC) and Volume Transport (VT) for the Southern Ocean is provided from satellite data by combining the SSH from altimetry missions, the geoid from satellite gravity missions, and temperature and salinity profiles based on ARGO and other in-situ measurements . The estimated 3D GC is provided near full-depth in 41 layers, with a 1º spatial resolution and monthly temporal resolution, covering the 12 years period from 2004 to 2015. We analyze the obtained 3D GC over the Southern Ocean region, where the Antarctic Circumpolar Current (ACC) and its several fronts are clearly depicted, as well as other major currents such as the Agulhas current, the Malvinas current or the East Australian Current. From the 3D GC, we estimate the associated water VT and present the results for the ACC and the Drake Passage in the context of existing literature. The spatial resolution of our space data-based approach allows us to provide VT estimates for the different paths followed in the different in-situ campaigns at the Drake Passage. The results not only validate our study but also reconciles the different estimates, showing a general good agreement for the different campaigns and how the existing estimates differences depend on the epoch and exact location where the in-situ measurements were taken.