Sharp-Crested Breaking Surface Waves Observed from a Ship-Based Stereo Video System
Sharp-Crested Breaking Surface Waves Observed from a Ship-Based Stereo Video System
复制标题
从船基立体视频系统观察到的尖顶破碎表面波
DOI：
10.1175/jpo-d-16-0187.1
复制
发表时间：
2017
影响因子：
3.5
通讯作者：
J. Thomson
中科院分区：
文献类型：
--
作者：
M. Schwendeman;J. Thomson
摘要一种新的船基立体视频系统用于观察破碎的海浪（即，白浪）作为随时间演变的三维表面。首先，立体视频测量的所有波（打破和nonbreaking）比较以及从传统的浮标测量的统计参数。接下来，破碎波的检测基于白顶泡沫的存在，并研究这些波的几何形状。立体测量表明，白浪的特点是局部极端的表面坡度，虽然大规模的，波峰到波谷的陡度，这些波是不显着的。103破碎波剖面的检查进一步表明，在破碎波峰附近的局部波陡度的显着增加，估计使用希尔伯特变换。这些波峰被发现非常类似于理论斯托克斯极限波的尖角。结果表明，非线性波群动力学是一个关键的机制，作为相速度的破碎。
AbstractA new ship-based stereo video system is used to observe breaking ocean waves (i.e., whitecaps) as three-dimensional surfaces evolving in time. First, the stereo video measurements of all waves (breaking and nonbreaking) are shown to compare well with statistical parameters from traditional buoy measurements. Next, the breaking waves are detected based on the presence of whitecap foam, and the geometry of these waves is investigated. The stereo measurements show that the whitecaps are characterized by local extremes of surface slope, though the larger-scale, crest-to-trough steepness of these waves is unremarkable. Examination of 103 breaking wave profiles further demonstrates the pronounced increase in the local wave steepness near the breaking crest, as estimated using a Hilbert transform. These crests are found to closely resemble the sharp corner of the theoretical Stokes limiting wave. Results suggest that nonlinear wave group dynamics are a key mechanism for breaking, as the phase speed of th...