Wind-Wave Characteristics in the Bohai Sea, the Yellow Sea and the East China Sea: A Numerical Study of Cold Wave Event

The ocean wave is one of the main marine disasters that have great effects on the ocean engineering. The research on the ocean waves can supply data for ocean engineering and protect it. In recent years, the results of numerical study have been an important basis for wave forecasting and engineering design. The full-spectral third-generation ocean wind-wave model, WAVEWATCH-Ⅲ, has been implemented in the Bohai Sea, the Yellow Sea and the East China Sea for investigating wind-wave characteristics. The QSCAT/NCEP blended wind data (0.5° resolution) from Colorado Research Associates 4 times daily were used to simulate the wind waves in two cold wave events in 1999 and 2000. Firstly, the results from WAVEWATCH-Ⅲ were tested, and the main factors that influence simulation were analyzed. Compared with the Janson-1 altimetric data, the capability of WAVEWATCH-Ⅲ for the selected region was validated. It is also shown that, during the course of the cold wave, the east and south water boundary of the selected region have little effects on the simulation of the significant wave heights, while the islands are important influencing factors, especially when the wave height value is small. Secondly, the characteristics of ocean waves in the region were studied. The directions of wind and wave are mainly the same during the cold wave events. The center of maximum wave height corresponds to that of maximum wind speed in the south Yellow Sea and the East China Sea. However, in the Bohai Sea and the north Yellow Sea, the center of maximum wave height is in the south to that of maximum wind speed, which is probably induced by the closeness of the sea regions. Finally, the response characteristics of wave spectra to the cold wave events were analyzed. In cold wave events, frequency and direction of ocean waves at certain point are centralized mostly when its wave energy is most. At the same time, the peak frequency is lowest. The response of the wave energy lags behind the variation of the wind speed, while the factors related to the lag time are uncertain.