Development of the Atmosphere-Ocean-Wave Coupled Model in the Korean Integrated Model (KIM)

The Korea Institute of Atmospheric Prediction Systems (KIAPS) has been developing an integrated model with predictive performance in an extended range (14 to 30 days) since 2020. To enhanced the performance of coupled model, it is necessary to examine the interaction and feedback among the components of the Earth system. This study introduces the current status and future plan of a KIAPS-developing coupled modeling system with a focus on atmosphere-ocean-wave coupling. 
The Korea Integrated Model (KIM), the operational atmospheric model of the Korea Meteorological Administration, was coupled with the Nucleus for European Modeling of the Ocean (NEMO) and the WAVEWATCH III (WW3) through a Model Coupling Toolkit, and the predicted variables are exchanged between the model components. The WW3 model receives the wind component from the first layer of the atmospheric model, and the surface currents and sea surface height are obtained from the ocean model. The Charnock coefficient and wave energy flux calculated by WW3 are sent to the ocean model. The Charnock coefficient impacts the air-side through a roughness length that is calculated using the bulk formula at the sea surface. Meanwhile, the wave energy flux into the ocean is applied as a surface boundary condition in the turbulent kinetic energy (TKE) model, which results in determining the ocean deepening. The presentation will focus on explaining the effects of the surface energy flux obtained from the wave model on the wave breaking in the TKE scheme of the coupled KIM in the medium-range forecasts and seasonal simulations. Furthermore, we plan to discuss strategies for improving the Coupled KIM based on preliminary results.

Acknowledgements. This work was carried out through the R&D project “Development of a Next-Generation Numerical Weather Prediction Model by the Korea Institute of Atmospheric Prediction Systems (KIAPS)”, funded by the Korea Meteorological Administration (KMA2020-02212).