The interactions between barotropic tides and mesoscale processes were studied using the results of a numerical model in which tidal forcing was turned on and off. The research area covered part of the East Atlantic Ocean, a steep continental slope, and the European Northwest Shelf. Tides affected the baroclinic fields at much smaller spatial scales than the barotropic tidal scales. Changes in the horizontal patterns of the M₂ and M₄ tidal constituents provided information about the two-way interactions between barotropic tides and mesoscale processes. The interaction between the atmosphere and ocean measured by the work done by wind was also affected by the barotropic tidal forcing. Tidal forcing intensified the transient processes and resulted in a substantial transformation of the wave number spectra in the transition areas from the deep ocean to the shelf. Tides flattened the sea-surface height spectra down to ~ k^−2.5 power law, thus reflecting the large contribution of the processes in the high-frequency range compared to quasi-geostrophic motion. The spectra along sections parallel or normal to the continental slope differ from each other, which indicates that mesoscale turbulence was not isotropic. An analysis of the vorticity spectra showed that the flattening was mostly due to internal tides. Compared with the deep ocean, no substantial scale selectivity was observed on the shelf area. Particle tracking showed that the lengths of the Lagrangian trajectories increased by approximately 40% if the barotropic tidal forcing was activated, which contributed to changed mixing properties. The ratio between the horizontal and vertical scales of motion varied regionally depending on whether barotropic tidal forcing was included. The overall conclusion is that the barotropic tides affect substantially the diapycnal mixing.

中文翻译：

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深海和陆架区域正压潮与中尺度过程之间的相互作用

利用打开和关闭潮汐强迫的数值模型结果研究了正压潮和中尺度过程之间的相互作用。研究区域覆盖了东大西洋的一部分，陡峭的大陆坡和欧洲西北大陆架。潮汐影响斜压场的空间尺度远小于正压潮汐尺度。M ₂和M ₄的水平方向变化潮汐成分提供了有关正压潮和中尺度过程之间双向相互作用的信息。正风潮强迫也影响了通过风做功测量的大气与海洋之间的相互作用。潮汐强迫加剧了瞬变过程，并导致了从深海到陆架过渡区域中波谱的大幅变化。潮汐将海平面高度谱展平至^{〜k -2.5}幂律，因此反映了与准地转运动相比，高频过程的巨大贡献。平行于或垂直于大陆坡的剖面的光谱互不相同，这表明中尺度湍流不是各向同性的。对涡旋谱的分析表明，平坦化主要是由于内部潮汐引起的。与深海相比，在架子区域没有观察到明显的规模选择性。粒子跟踪显示，如果正压潮汐强迫被激活，拉格朗日轨迹的长度将增加约40％，这有助于改变混合特性。水平和垂直运动比例之间的比例根据是否包括正压潮汐强迫而区域变化。