STUDY ON THE EFFECT OF DIFFERENT WIND FORCING ON WAVE SIMULATION USING ERA5, JRA-55 AND LFM

抄録

 In recent years, highly accurate meteorological Grid Point Value (GPV) data has become easily available in Japan, and also been used in coastal engineering practices. Those mainly include the Japanese 55-year Reanalysis (JRA-55), the Meso-Scale Model (MSM), and the Local Forecast Model (LFM) data provided by Japanese Meteorological Agency (JMA). Their intended use differs on own characteristics (for instance, spatio-temporal resolution). As high-resolution data [i.e. LFM (2 km x 2 km), MSM (5 km x 5 km)] limited to the area covering Japan, in practice, global scale wind data [i.e. JRA-55, the fifth generation of ECMWF atmospheric reanalysis of global climate (ERA5)] need to be incorporated as wind forcing in sea wave simulation. Hence, it is necessary to investigate the characteristics of simulated wave depending on different input wind forcing. The objective of this study is to conclude the important points to consider when applying each meteorological GPV data for wave simulation in practice. In this study, mainly considering the applicability in overseas projects, global wave simulation was performed using JRA-55 and ERA5 as external wind forcing. Wave characteristics of the two simulations were compared. In addition, the accuracy of the simulation was examined by comparing simulated and measured wave data. Moreover, the application of JRA-55, ERA5 and LFM wind data (processed with WRF model), in the simulation of typhoon-generated wind wave is discussed in the latter part.