The original technique, developed by Sallée et al. (2008), assumes that iso-contours of satellite absolute dynamic topography (ADT) can be proxies for the traditional sub-surface hydrographic definition of the main Southern Ocean fronts. A recent version includes updates with the following definitions : - Polar Front (PF) is associated with the -0.30 m ADT contour - Southern (main) branch of the Subantarctic Front (SAF) with the -0.10 m ADT contour - Northern branch of the Subantarctic Front (SAF-N) with the 0 m ADT contour.