Internal waves and mixing in the Arctic Ocean

The variability of internal wave shear levels in the eastern Arctic Ocean is explored using velocity profiler and CTD data from Fram Strait and the Nansen Basin. Shear levels are consistently low over the abyssal plains and higher over rougher topography. Applying the parameterization of GREGG (1989, Journal of Geophysical Research, 94, 9686-9698) to these data gives diapycnal diffusivities that vary from about 10^-6 to above 10^-4 m s^-2. Extrapolating these diffusivities to the entire Arctic Basin suggests that internal wave mixing could play a major role in transporting heat from the warm intermediate water to the surface. Internal wave generation by the barotropic tide on rough topography may explain the higher shear levels found there.