Revisions of ERA5 Reanalysis of Wind Speed and Application to Wave Simulation in the Bohai Sea

Using wind observation data from buoys, the applicability evaluation of ERA5 wind velocity in the Bohai Sea are conducted in this paper. The research results indicate that when the wind speed is greater than 10 m/s, ERA5 reanalysis wind speed is usually lower than the observed wind speed, which is 1.25 m/s lower than the observed wind speed. Based on the observation of wind speed by buoys, a correction coefficient for the wind field is given using linear regression method. Using the revised wind field as the driving force for the SWAN model, three sets of comparative experiments are designed and combined with buoy observations to evaluate the correction effect. The results show that the simulated wave heights using the revised wind field are closer to the actual observed values, the average accuracy of the simulated wave height extremes was increased from 77% to over 90%, the relative error was reduced from 20% to about 10%, and the absolute error was reduced from 0.86–0.97 m to 0.20–0.61. Through the validation analysis, the revised coefficients of the ERA5 reanalysis wind field in the Bohai Sea area given in this paper can provide reference for the safety and risk assessment of marine engineering.