Tidal Forcing and Internal Wave Generation in the Arctic Ocean: High-Resolution FESOM Simulations

Internal waves are a key driver of diapycnal mixing in the global ocean and play an essential role in setting the large-scale overturning circulation. In the Arctic Ocean, however, internal-wave-driven mixing is assumed to be weak due to strong stratification and the presence of sea ice, which limits wind forcing and surface wave activity. The scenario of ongoing sea-ice decline raises the possibility of enhanced internal wave activity and associated mixing, potentially increasing upward oceanic heat fluxes and further accelerating ice loss.

In this study, we investigate the role of tidal forcing as a source of internal waves in the Arctic Ocean using the ocean model FESOM. We perform simulations with tidal forcing at unprecedented horizontal resolution (around 1 km). The simulations are conducted for different seasons and sea-ice conditions to examine how variations in sea-ice modulate tidal currents and internal wave generation. By comparing simulations with and without tidal forcing, we assess the impact of tides on sea-ice dynamics, providing initial insight into coupling between tides, internal waves, and sea ice in the Arctic Ocean. The diagnosed internal tide generation will serve to force the internal wave model IDEMIX, which we will couple to FESOM to provide a consistent mixing parameterization for the simulation of the warming Arctic.