Modelling the propagation of an internal solitary wave across double ridges and a shelf-slope
Modelling the propagation of an internal solitary wave across double ridges and a shelf-slope
复制标题
DOI：
10.1007/s10652-008-9104-5
复制
发表时间：
2009-06
影响因子：
2.2
通讯作者：
M. Cheng;J. R. Hsu;Chen-Yuan Chen-Chen-Yuan-Chen-2110213282;Cheng-Wu Chen
中科院分区：
文献类型：
--
作者：
M. Cheng;J. R. Hsu;Chen-Yuan Chen-Chen-Yuan-Chen-2110213282;Cheng-Wu Chen
南海北部的内孤立波（ISW）的演化最近引起了台湾和美国许多海洋学家的关注。这些ISW被认为是由吕宋海峡上空的黑潮流的一个分支引起的，该分支向西传播，越过台湾和菲律宾之间吕宋海峡的两个海脊，并进一步到达南海陆架斜坡的大陆边缘。本文利用数值模型和实验室实验，提出了跨越两个三角形障碍物的洼地 ISW 演化的一些初步结果。实验结果证实，两个障碍物之间的间隔和相对高度是ISW与障碍物相互作用的重要因素。然而，在坳陷型ISW穿过吕宋海峡的情况下，由于相对水深的变化，两个脊对ISW特征的影响可能不如陆架斜坡的影响显着。数值实验的结果还表明，一旦波开始与陆架斜坡接触，ISW 的振幅就会增大，在实验室实验中，内部水跃和涡流运动引起的波浪破碎很明显。最终，在转折点以外的大陆架边缘，凹陷型ISW可能会变成高地型，其中上层大于底层，形成分层水柱。
Evolution of the internal solitary waves (ISWs) in the northern South China Sea (SCS) has recently attracted the attention of many oceanographers in Taiwan and the United States. These ISWs are believed to have been induced by a branch of the Kuroshio current over Luzon Strait, which propagates westward over two ridges in the Luzon Strait between Taiwan and the Philippines, and further onto the continental margin with a shelf-slope in the SCS. This paper presents some preliminary results for the evolution of a depression ISW across two triangular obstacles using numerical modelling and laboratory experiments. The experimental results confirm that the intervals and relative height between the two obstacles are important factors in the interaction of an ISW with the obstacles. However, in the case of the movement of an ISW of depression-type across the Luzon Strait, the effect of the two ridges on the characteristics of the ISW might be less significant than that from the shelf-slope, due to the variations in relative water depth. Results from numerical experiments also show that the amplitude of an ISW can be augmented once the wave commences its contact with a shelf-slope, where an internal hydraulic jump and wave breaking with vortex motion are evident in the laboratory experiments. Eventually, an ISW of depression-type could become an elevation-type at the edge of the continental shelf landwards beyond the turning point, where the upper layer is larger than the bottom layer in a stratified water column.