Including dynamic ocean surface waves in NorESM climate simulations

Results from a suite of simulations with a version of the Norwegian Earth-System Model which includes an ocean surface-waves (OSW) component, WW3, are presented.
OSW are forced by surface winds in the control integration and may be additionally coupled to atmosphere, ocean and sea-ice components through several parametrisations dependent on wave-supported stress, wave significant height, Stokes drift, and wave radiant stress.
Significant effects on the simulated model climatology are found for each of such additional couplings.
However, for the processes considered, the effects of two-way coupling between atmosphere and OSWs, or between sea-ice and OSWs, are highly dependent on the model background climatology -- and therefore also on model systematic biases.
By contrast, additional mixing caused by Langmuir turbulence systematically causes the ocean mixed layer to deepen, with a robust impact on sea-surface temperatures (SSTs), viz mid-latitude cooling in the summer hemisphere, and mid-latitude warming in the winter hemisphere.
Replacing the dynamic OSW model, WW3, with an analytical scheme predicated on a local equilibrium sea-state (Li et al., 2017) to drive Langmuir mixing gives similar results, with a slight exaggeration of the deepening especially in the tropics likely due to missing wind-wave misalignment in the analytical formulation.