Dissipation due to ageostrophic turbulence in the upper-ocean mixed layer

In our study, we diagnose dissipation by ageostrophic turbulence in the upper ocean. To this end, we use the Max Planck Institute's ocean model ICON-O with a telescoping grid configuration, where the resolution is enhanced up to values smaller than 600m over large areas of the North Atlantic. This allows to represent parts of the ageostrophic turbulence spectrum associated with submesoscale instabilities and eddies. We diagnose the dissipation associated with the ageostrophic eddies and investigate to what end ageostrophic turbulence is providing an efficient energy transfer towards smaller scales. We find that such an energy transfer and the associated dissipation is strongly enhanced within the upper-ocean and within and south of the Gulf Stream front. Attempts are made to develop parameterizations for the ageostrophic downscale energy flux to couple this energy dissipation with other ocean energy reservoirs. Therewith, we aim to obtain a more realistic view on the ocean energy cycle.