Impacts of wave-induced ocean surface turbulent kinetic energy flux on typhoon characteristics

The parameterization of the sea surface turbulent kinetic energy (TKE) flux due to wave breaking was revisited using the observed data. It is found that the fraction of wave energy taken up into the ocean as sea surface TKE flux depends on the relative angle between wind and wave direction. The fraction tends to be larger under opposite wind conditions than following wind conditions. Based on the observed results, a new parameterization of TKE flux was proposed. The TKE flux parameterization was implemented into the atmosphere-ocean-wave coupled model. The experiments on typhoon hindcast using the model showed that TKE flux affects weak mixing at the ocean surface, strong mixing at the bottom of the mixed layer, and near-inertial internal waves depending on the thickness of the mixed layer depth (MLD). In the coupled atmosphere-ocean-wave model, the effects of these mixing differences are also fed back to the atmospheric side; the maximum difference in the central pressure of the typhoon depending on TKE flux parameterization is 10 hPa. The results of this study suggest the importance of considering waves in the sea surface TKE flux for typhoon simulations.

Automated summary

The study found that the fraction of wave energy taken up into the ocean as sea surface TKE flux depends on the relative angle between wind and wave direction. A new parameterization of TKE flux was proposed based on the observed results. This parameterization affects weak mixing at the ocean surface, strong mixing at the bottom of the mixed layer, and near-inertial internal waves in typhoon simulations.