Application of data assimilation for spectral wave model in coastal regions of South Korea

Abstract

The most important factor on the accuracy of the wave simulation is the accuracy of the wind data, which is a major force to wave generation. And it also depends on the performance of the parameterization for the development and dissipation of wave energy and on the nonlinear energy transmission between wave components. Wave model has limitations due to errors of wind fields and lack of understanding of wave dynamics like white capping dissipation, wave-bottom interaction processes and long-term wave propagation. To compensate and improve for this uncertainty of wave estimates, this paper investigates the performance of a wave model based on WAVEWATCH III version 5.16 with spectral wave data assimilation using the OI (optimal interpolation) method. The spectral wave energy computed by wave model was modified by OI as the observed significant wave height considering spatial distribution. Data assimilation was applied for the coastal region of Korea using near real-time global satellite wave observation data provided by CMEMS (Copernicus Marine environment monitoring service) and the buoy data of KMA (Korea Meteorological Administration). It was verified by calculating the bias and Root Mean Square Error (RMSE) between simulation results and observational buoys of KMA and it was shown to contribute to improving the accuracy of numerical model