Abstract Reversing Falls is a large sill in a narrow section of the Saint John River on the northern coast of the Bay of Fundy, Canada. Reversing Falls limits tides from propagating farther up the river and impedes river water flowing seaward. This work aims to describe the physical processes that control flow over Reversing Falls by using output from a regional numerical model. We find form drag is more important than frictional drag for limiting the M2 tide propagation over Reversing Falls. Despite large tides and strong stratification suggestive of estuarine processes, the dynamics at Reversing Falls are dominated by a steady balance between drag and the surface pressure gradient, with the distinction that all terms in this river-like dynamical balance change sign on a semi-diurnal tidal cycle.

中文翻译：

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由于在狭窄的通道中形成阻力，潮汐幅度迅速减小

摘要 Reversing Falls 是加拿大芬迪湾北部海岸圣约翰河狭窄部分的一个大窗台。Reversing Falls 限制了潮汐在河流上游的传播，并阻止河水流向大海。这项工作旨在通过使用区域数值模型的输出来描述控制倒流瀑布上的水流的物理过程。我们发现形状阻力比摩擦阻力更重要，可限制 M2 潮汐在 Reversing Falls 上的传播。尽管大潮汐和强烈分层暗示了河口过程，但 Reversing Falls 的动态主要由阻力和表面压力梯度之间的稳定平衡主导，区别在于这个类似河流的动态平衡中的所有术语都在半昼夜变化潮汐周期。