WAVEWATCHⅢ第三代海浪数值模式在中国东海的应用和改进

Application and Improvement of WavewatchⅢThird Generation Wave Numerical Model in the East China Sea

利用东海的浮标观测数据,比较了WAVEWATCHⅢ第三代海浪数值模式的ST2、ST4和ST6三种源函数方案在东海的适用性。结果表明,三种源函数方案在波高小于3 m中低风速情形下,模拟波高与观测波高符合的很好,而在波高大于3 m的高风速情形下,模拟波高偏大。在此基础上,提出了以波龄和波陡为参数的海面粗糙度参数化公式,以此来计算拖曳系数。该方案可以自动满足拖曳系数在临界风速达到饱和的观测事实,将上述拖曳系数计算方案应用于最新的ST6源函数方案,在保持中低风速时的模拟精度的同时,可有效地改善高风速时模拟波高偏大问题,而且可使模拟周期与浮标观测结果更为一致。

Based on the buoy observation data of the East China Sea,the applicability of three source function schemes ST2,ST4 and ST6 of WAVEWATCHⅢin the East China Sea is compared.The results show that the simulated wave height agrees well with the observed wave height in the case of low and medium wind speed with wave height less than 3 m,while the simulated wave height is larger in the case of high wind speed with wave height greater than 3 m.On this basis,a parameterized formula of sea surface roughness with wave age and wave steepness as parameters is proposed to calculate the drag coefficient.The parameterization scheme can automatically meet the observation fact that the drag coefficient reaches saturation at the critical wind speed.The above drag coefficient calculation scheme is applied to the latest ST6 source function scheme,which not only maintains the simulation accuracy at medium and low wind speed,but also effectively improves the problem of large simulation wave height at high wind speed,moreover,the simulation period is more consistent with the buoy observation results.