Impact of varying sea-ice cover on imput of wind energy, internal waves, and mixing.
Internal waves redistribute energy in the ocean, provide the link between energy input by wind and tides, and maintain the stratification by vertical mixing. In the past, the sea ice covered areas of the Arctic Ocean had a quiescent internal wave climate, with a strong stratification and weak diapycnal mixing mainly maintained by tidal forcing. A changing climate implies a changed forcing for the internal wave field. For instance, with a retreating ice cover, there will be seasonally more open water for the wind stress to act on, and the frequency and intensity of storms might increase. In the Canada Basin, those factors have been shown to increase internal wave energy as the sea-ice coverage declines, with a local enhancement of nearinertial wave energy and mixing linked to storm activity in open water conditions. On the other hand, in the Eastern Arctic, near-inertial wave and local storm activity have been associated even with vertical heat fluxes, mostly when they are close to steep topography and near-surface Atlantic Water. However, the strong stratification, today still suppresses wind-driven mixing.
Therefore, using data from MOSAiC campaign and carrying out idealized numerical experiments, the aim of this project is to study the future response of the internal wave field to changes in the ice coverage as well as its effect on vertical mixing.
