Internal waves shoaling on the continental slope can break and form materially coherent vortices called boluses. These boluses are able to trap and transport material up the continental slope, yet the global extent of bolus transport is unknown. Previous studies of bolus formation primarily focused on systems consisting of two layers of uniform density, which do not account for the presence of ocean pycnoclines of finite thickness. We use hyperbolic tangent profiles to model the density stratification in our simulations and demonstrate the impact of the pycnocline on the bolus. A spectral clustering method is used to objectively identify the bolus as a Lagrangian coherent structure that contains the material advected upslope. The bolus size and displacement upslope are examined as a function of the pycnocline thickness, incoming wave energy, density change across the pycnocline, and topographic slope. The dependence of bolus transport on the pycnocline thickness demonstrates that boluses in continuous stratifications tend to be larger and transport material further than in corresponding two-layer stratifications.

中文翻译：

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内部波团作为连续分层流体中的相干结构

大陆坡上的内波会破裂并形成物质连贯的涡流，称为团块。这些团块能够将物质捕获并运输到大陆坡上，但团块运输的全球范围尚不清楚。先前对团块形成的研究主要集中在由两层均匀密度组成的系统上，这并没有说明有限厚度的海洋火山灰层的存在。我们在我们的模拟中使用双曲正切曲线来模拟密度分层，并证明了pycnocline 对推注的影响。使用光谱聚类方法客观地将团块识别为包含向上平流物质的拉格朗日相干结构。团块大小和位移上坡被检查为pycnocline 厚度、入射波能量、斜斜和地形坡度的密度变化。团块传输对pycnocline 厚度的依赖性表明连续分层中的团块往往比相应的两层分层中的团块更大并且传输材料更远。