The Southern Ocean and its main component, the Antarctic Circumpolar Current (ACC), have a key role in the heat and carbon uptake and transport, with hotspots occurring where the current interacts with topographic features. In recent times, more and more studies have pointed out the key role of small-scale ocean processes in driving vertical exchanges, heat and carbon uptakes in the ACC.
Launched in December 2022, the new SWOT satellite provides high-resolution Sea Surface Height (SSH) observations, offering an unprecedented view of the small-scale ocean eddies and fronts that are associated with significant vertical velocities. However, these observations are limited to the ocean surface, necessitating efforts to link the surface signal to vertical dynamics.
This study presents the assimilation of SWOT SSH observations into a regional high-resolution circulation model (SHOC) and examines the impact on ocean interior dynamics within an ACC meander south of Tasmania. The model dynamics (horizontal and vertical) is assessed over a range of spatial scales using wavenumber spectral analysis and validated against an array of in-situ datasets acquired during the RVI SWOT voyage in November/December 2023. Then, we quantify the effects of assimilating novel SWOT observations on ocean interior circulation and vertical fluxes within the meander.