Internal wave spectra and mixing in the warming Arctic

The generation of internal wave generation might increase in the warming Arctic, especially at the sea surface, where wind power input into the upper ocean is substantially stronger as sea ice disappears. More internal wave energy implies stronger mixing that might lead to larger upward heat fluxes from the warm Atlantic Water, contributing to the ongoing sea-ice melt. To comprehensively test this hypothesis, a physics-based mixing parameterization building on an internal wave model that accounts for internal wave generation, propagation, and breaking, is required. To develop such a model, however, knowledge of the internal wave spectral characteristics and their spatio-temporal variability is indispensable. This study therefore investigates the vertical wavenumber spectra of internal wave energy and how their shape varies across the Arctic Ocean based on finescale hydrographic profiles collected by a variety of instrument platforms. It focuses on internal wave energy levels, vertical wavenumber spectral slope and bandwidth, and wave-driven mixing to elucidate their geographic and temporal variation and shed light on the environmental factors determining their variability.