A two-dimensional, vertical section of the Strait of Gibraltar is simulated numerically with the nonhydrostatic / non-Boussinesq three-dimensional CROCO model to investigate details of small-scale dynamics. The proposed configuration is simple, computationally efficient and incorporates the configuration of sills characteristic of this region. Despite the shortcomings of a 2D representation, this configuration provides a realistic depiction of small-scale mechanisms in the strait during a typical tidal cycle: internal solitary waves generation and propagation, occurrence of hydraulic controls and hydraulic jumps at the sills and appearance of active turbulent patches. In particular, the well-known eastward propagation of large amplitude internal waves is assessed using the Korteweg de Vries (KdV) propagation model for solitary waves. As a step towards establishing a realistic Large Eddy Simulation (LES), the sensitivity of the configuration to various choices is investigated, e.g., resolution, amplitude of tidal forcing or numerical schemes. In such conditions, our analyses indicate that the representation of the small-scale dynamics of the Strait of Gibraltar can be much improved by increasing the resolution and relaxing the hydrostatic assumption. Further studies are necessary to grasp the mechanisms of mixing and/or stirring induced by this fine scale processes.

中文翻译：

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直布罗陀海峡水力控制、孤立波和初级不稳定性的数值模拟

使用非静水力/非 Boussinesq 三维 CROCO 模型对直布罗陀海峡的二维垂直剖面进行数值模拟，以研究小尺度动力学的细节。所提出的配置简单、计算效率高并且结合了该区域特征的窗台配置。尽管 2D 表示存在缺陷，但这种配置提供了典型潮汐周期期间海峡中小型机制的真实描述：内部孤立波的产生和传播、水力控制的发生和门槛处的水跃以及活跃湍流的出现补丁。特别是，众所周知的大振幅内波向东传播是使用孤立波的 Korteweg de Vries (KdV) 传播模型进行评估的。作为建立现实大涡模拟 (LES) 的一个步骤，研究了配置对各种选择的敏感性，例如分辨率、潮汐强迫的幅度或数值方案。在这种情况下，我们的分析表明，通过提高分辨率和放宽流体静力假设，可以大大改善直布罗陀海峡小尺度动力学的表征。需要进一步研究以了解由这种精细规模过程引起的混合和/或搅拌机制。我们的分析表明，通过提高分辨率和放宽流体静力假设，可以大大改善直布罗陀海峡小尺度动力学的表征。需要进一步研究以了解由这种精细规模过程引起的混合和/或搅拌机制。我们的分析表明，通过提高分辨率和放宽流体静力假设，可以大大改善直布罗陀海峡小尺度动力学的表征。需要进一步研究以了解由这种精细规模过程引起的混合和/或搅拌机制。