Reassessing the Role of the Antarctic Slope Current in Poleward Ocean Heat Transport

Abstract

Abstract The Antarctic Slope Current (ASC) is often considered a barrier to the poleward transport of Circumpolar Deep Water (CDW), yet its vast extent has hindered circumpolar analysis of this relationship. Here, we use a high‐resolution global ocean‐sea ice model that resolves the slope current to assess the link between variability in the ASC and poleward CDW heat transport, circumpolarly and across varying timescales. We find that the ASC velocity and CDW heat transport have weak correlations, with an average 0.3, over the continental slope. In fact, less than 25% of the continental slope has a correlation of over either seasonal or interannual timescales. Isolated regions of strong covariability occur where the isopycnal depth at the shelf break varies substantially in time. Overall, our results suggest that circumpolarly, the ASC is weakly associated with poleward CDW heat transport, cautioning against the general assumption of a consistent dynamical link between the two around Antarctica.