A comprehensive observational data set was used to examine shoreward propagating semidiurnal internal tides as they shoal, break and run-up as turbulent boluses across the edge of the Australian North West Shelf (NWS), offshore Dampier, during late winter 2013. The measured waveforms and wavefields supported the grouping of events into two distinct categories: (1) pre-; and, (2) post- wave breaking. It was found that the transition from (1) to (2) was marked by the rise of nonlinear steepening (α) and reduction in dispersion (β), both coefficients that parameterize nonlinear wave effects on the Korteweg-de Vries (KdV) equation. We introduced a criterion for wave breaking from the dimensionless parameter (δ) that relates these two terms: wave breaking occurs when δ < 1. In the first group, dispersive effects were dominant to spread energy out of the semidiurnal wave to a dispersive wave packet of short-period internal solitary waves (ISWs). In the second, dispersion was considered small compared to the cumulative effect of nonlinear steepening. Here, the semidiurnal wave built sufficient energy at its rear face to generate wave breaking, which has been known to produce multiple turbulent boluses. Similar observations have not been described for this region during winter months and highlight that the nonlinear internal wave field is an important feature on the NWS throughout the year. Additionally, measurements obtained through autonomous ocean glider profiles revealed some of the post-breaking characteristics that included intensive vertical mixing and transport of dense water and suspended material onshore of the shelf break.

在2013年冬末期间，使用了一个综合的观测数据集来检查沿海岸传播的半日内潮，它们在澳大利亚西北大陆架（NWS）边缘，丹皮尔的边缘沿湍流团块浅滩，破裂和上升。波场支持将事件分为两个不同的类别：（1）前置；（2）波浪后破碎。发现从（1）到（2）的跃迁以非线性变陡（α）的增加和色散（β）的减少为标志，这两个系数都将非线性波效应参数化为Korteweg-de Vries（KdV）方程。我们从与这两个术语相关的无量纲参数（δ）引入了断波准则：δ<1.在第一组中，色散效应占主导地位，是将能量从半日波中散布到短周期内部孤立波（ISW）的色散包中。在第二个中，与非线性变陡的累积效应相比，色散被认为较小。在这里，半日波在其背面建立了足够的能量以产生波折，这已经众所周知会产生多个湍流团。冬季没有对该地区进行类似的观测，并且强调了非线性内波场是全年NWS的重要特征。此外，