Oceanic exchange across the steep slope of the Ross Sea has a critical impact not only on physical and biological processes of the Ross Sea shelf, but also on the global meridional overturning circulation. This study quantifies the volume transport of circumpolar deep water (CDW) and dense shelf water (DSW) across the Ross Sea slope and elucidates the mechanisms responsible for the exchanges using a coupled ocean-sea ice-ice shelve model at eddy-resolving resolution. Momentum balance analysis indicates that the onshore transport of CDW is geostrophically controlled by along-isobath pressure gradient force. Offshore transport of DSW is driven by the ageostrophic pressure gradient force that is contributed by advection and viscosity along the isobath. Vorticity balance analysis shows that vortex squeezing associated with upslope transport is driven by advection of relative vorticity in the CDW layer, and the vortex stretching associated with downslope transport is driven by the curl of viscosity in the bottom DSW layer.

 

CDW, DSW, momentum balance, vorticity balance, cross-slope exchange