Alice Della Penna (University of Auckland , New Zealand); Jeffery Early (Northwest Research Associates, United States); Evan Mason (IMEDEA, Spain)

The ocean surface is the conduit connecting the energetic ocean circulation to the overlying atmosphere. The rate at which materials and properties cross this interface, the air-sea flux, is dictated by the relative speed of the ocean surface to the overlying atmosphere and the gradient and diffusivity of the matter being fluxed.
The importance of the coupling between interior ocean currents and surface motions is investigated here in observations of SSH and ocean vector winds together with a wave-vortex model used to identify the mechanism modulating this coupling. This combined analysis highlights the regional and temporal variability of coupling between surface and deep ocean velocities in eddies and identifies the density gradient at the base of the mixed layer as one of the dominant drivers of deep-ocean surface coupling.