In this study, we revisit early works from the late 1980s about potential vorticity (PV) homogenization in the World Ocean using ARGO data and a hierarchy of coupled ocean-atmosphere models (MITgcm in idealised geometry and HadGEM3). Specifically, we focus on a new index of PV homogenization along isopycnals which we apply to the water column globally. The analysis indicates a striking partitioning of this index among different ocean basins, with highest PV homogenization observed in the North Pacific and the South Atlantic, and a weak degree of homogenization observed throughout the Southern Ocean. A rich behaviour is revealed in the North Atlantic and South Pacific basins.
