The Effect on Simulated Ocean Climate of a Parameterization of Unbroken Wave-induced Mixing incorporated into the k-epsilon Mixing Scheme

A new parameterization of mixing processes in the upper ocean is tested in a ¼ degree resolution global ocean climate model. The parameterization represents the effect of turbulent mixing by unbroken waves as an additional turbulent shear production term in the k-epsilon mixing scheme. The results show that the inclusion of a parameterization of unbroken wave induced mixing into a high-resolution ocean climate model causes a temperature difference of more than 1 degree near the surface in regions of high wind speed. This effect is particularly pronounced over the Southern Ocean. In this region, the simulation of mixed-layer depth is also slightly improved in both July and December, compared with observations. As formulated here, the parameterization of wave-induced mixing is easily incorporated into the k-epsilon mixing scheme as an extra term in the turbulent shear production equation and could be easily included in other models that use the same mixing scheme. This process is currently omitted from many climate model simulations but may have important regional effects on the world ocean climate.