The impact of wave-induced mixing on the simulation of the upper mixed layer in climate models

Abstract

The upper ocean plays a critical role in the atmosphere-ocean coupled system. Wave-induced vertical mixing significantly influences the structure of the upper ocean which is crucial for climate predictions. This study evaluates the biases in the LICOM model’s simulation of the upper ocean and incorporates the wave-induced mixing coefficient Bv, derived from the WAVEWATCHIII wave model using a parameterization scheme for non-breaking wave-induced mixing. This coefficient was integrated into the vertical mixing scheme of the LICOM model to assess the impact on upper ocean simulation. The results indicate that wave-induced mixing increases the mixed layer depth (MLD) and decreases the sea surface temperature (SST), enhances vertical mixing, and leads to a decrease in upper ocean temperature while increasing subsurface temperature. Validation with Argo observations and the EN4 data product demonstrates that considering wave-induced mixing improves the simulated MLD, SST, and upper ocean temperature climatology, aligning them more closely with observed values. Consequently, incorporating wave-induced mixing can enhance the predictive capabilities of the LICOM model.