Retrieval of the maximum horizontal current speed induced by ocean internal solitary waves from low resolution time series mooring data based on the KdV theory
Retrieval of the maximum horizontal current speed induced by ocean internal solitary waves from low resolution time series mooring data based on the KdV theory
复制标题
基于KdV理论的低分辨率时间序列系泊数据反演海洋内孤立波诱发的最大水平流速
DOI：
10.1016/j.oceaneng.2014.11.023
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发表时间：
2015
影响因子：
5
通讯作者：
He Yinghui
中科院分区：
文献类型：
--
作者：
Cai Shuqun;Xu Jiexin;Liu Junliang;Chen Zhiwu;Xie Jieshuo;Li Juan;He Yinghui
内孤立波是存在于海洋跃层中的非线性大振幅波。通常情况下，由于ISW的通过周期大多不超过30分钟，而观测采样间隔太低，因此很难获得ISW引起的最大水平流速；同时，为了避免系泊声学多普勒海流剖面仪携带的电池电量不足，只关注环流或内潮研究的海洋学家会选择不少于5分钟的采样间隔。我们能否利用这些低时间分辨率的观测数据来反演ISW引起的最大水平海流速度？本文基于KdV(KdV)方程理论(浅水理论)，提出了一种反演ISW引起的水平最大流速的方法。根据南海中国北部东沙群岛附近海流资料的计算结果表明，该方法可以很好地从低时间分辨率的海流资料序列中反演海流的最大水平流速，同时，当观测数据的采样间隔或海流特征半宽度增大时，或海面波的非线性相速减小时，反演的最大水平流速的相对误差减小。文中还讨论了该方法在有限水深中的适用性。
Internal solitary waves (ISWs) are the nonlinear large amplitude waves existing in the oceanic pycnocline. Normally, it is difficult to obtain the maximum horizontal current speed induced by ISW since most of the passage periods of ISWs are no more than 30 min while the observational sampling interval is too low; meanwhile, to avoid power shortage of the mooring Acoustic Doppler Current Profiler-carried electric battery, oceanographers who are only concerned about the study of circulation or internal tide would choose a sampling interval of no less than 5 min. Can we use these low-time-resolution observational data to retrieve the maximum horizontal current speed induced by ISW? In this article, based on Korteweg-de Vries (KdV) equation theory (shallow-water theory), we propose a method to retrieve the maximum horizontal current speed induced by ISW. According to the calculated results based on the observational current data of ISWs near the Dongsha Islands in the northern South China Sea, it is found that, our method could well retrieve the maximum horizontal current speed induced by ISW from the low-time-resolution observational current data series, meanwhile, when the sampling interval of observational data or the ISW characteristic half-width increases, or when the ISW nonlinear phase speed decreases, the relative error of the retrieved maximum horizontal current speed will reduce. The applicability of the method to ISWs in finite-depth is also discussed.