基于二维海浪谱的风涌浪分离方法研究

Separation methods of wind-wave and swell based on two-dimensional ocean wave spectrum

海浪通常以风浪和涌浪混合的形式存在。二者的成长、消衰、传播和破坏机制各不相同,实现风涌浪分离对海洋研究和工程应用具有重要意义。基于斯里兰卡汉班托塔海域的实测数据,讨论了传统波龄法中波龄阈值的选取问题,并对汉班托塔海域的海浪特征进行分析,最后利用波龄法对新提出的不依赖风速风向信息的超射法进行了研究。结果表明,波龄阈值取1.7时最为合理。汉班托塔海域为外海涌浪主导。超射法对外海涌浪的识别结果与波龄法一致,而对高频位置的风浪和局地涌浪给出了不同的结果,这主要是由海浪物理特性的改变慢于风速风向的变化引起。

Ocean waves are generally a mixture of wind-wave and swell.Due to the significant differences in their growth,decay,propagation,and destruction mechanisms,the separation of wind-wave and swell is of great significance for marine research and engineering application.Based on the measured data in the offshore of Hambantota,Sri Lanka,this paper discusses the selection of the wave age threshold in the traditional methods and analyzes the wave characteristics of the offshore of Hambantota.Finally,the method based on wave age is used to verify the newly proposed method based on the overshoot phenomenon that does not rely on meteorology information.The results show that the optimal threshold of wave age is 1.7.The offshore of Hambantota is dominated by the swell propagating from distant storms.The method based on the overshoot phenomenon is consistent with the method based on wave age in the identification of the swell propagating from distant storms but gives different results for the wind-wave and local swell at the high frequency,which can be explained by the fact that the change of physical wave characteristics is slower than that of wind.