The flow and descent of dense water masses formed in shallow regions of the ocean is an important leg in the global overturning circulation. The dense overflow waters tend to flow along the continental slopes as geostrophically balanced gravity plumes, but may be steered downslope by canyons and ridges cross-cutting the slopes. In that process, entrainment and mixing will be greatly enhanced. Ilicak et al. (Ocean Model 38:71–84, 2011) propose a parameterization to include the effects of corrugations in large scale models by increasing the vertical mixing locally. We re-visit the problem using the terrain-following Bergen Ocean Model and a DOME-inspired idealized topography. It is shown that the applied corrugations can move the core of the plume 800 m down the slope, while enhanced mixing raises the center of gravity by only 1–200 m. The overall effect of a corrugation is hence to lower the center of gravity, suggesting that the parameterization proposed by Ilicak et al. (Ocean Model 38:71–84) will act in the wrong vertical direction, if used on its own. A comparison of two bottom drag parameterizations, show that a parameterization consistent with a no-slip boundary condition is needed to correctly represent Ekman drainage, and that the Ekman drainage contribution to plume descent is comparable to that of the corrugation. Ridges are more effective in steering dense water downward than canyons, and we compare the dynamics between the two settings to explain the difference.

海洋浅层区域形成的稠密水团的流动和下降是全球倾覆环流的重要环节。稠密的溢流水倾向于作为地转平衡的重力羽流沿着大陆斜坡流动，但可能会被横切斜坡的峡谷和山脊引导下坡。在这个过程中，夹带和混合将大大增强。伊利卡克等人。(Ocean Model 38:71–84, 2011) 提出了一种参数化方法，通过增加局部垂直混合来将波纹的影响包括在大型模型中。我们使用跟随地形的卑尔根海洋模型和受 DOME 启发的理想化地形重新审视了这个问题。结果表明，施加的波纹可以将羽流的核心向下移动 800 m，而增强的混合仅将重心提高 1-200 m。因此，波纹的整体效果是降低重心，这表明 Ilicak 等人提出的参数化。（海洋模型 38:71-84）如果单独使用，则会在错误的垂直方向上发挥作用。两个底部阻力参数化的比较表明，需要与无滑移边界条件一致的参数化才能正确表示 Ekman 排水，并且 Ekman 排水对羽流下降的贡献与波纹的贡献相当。与峡谷相比，山脊在将稠密的水向下引导方面更有效，我们比较了两种设置之间的动态来解释差异。如果单独使用。两个底部阻力参数化的比较表明，需要与无滑移边界条件一致的参数化才能正确表示 Ekman 排水，并且 Ekman 排水对羽流下降的贡献与波纹的贡献相当。与峡谷相比，山脊在将稠密的水向下引导方面更有效，我们比较了两种设置之间的动态来解释差异。如果单独使用。两个底部阻力参数化的比较表明，需要与无滑移边界条件一致的参数化才能正确表示 Ekman 排水，并且 Ekman 排水对羽流下降的贡献与波纹的贡献相当。与峡谷相比，山脊在将稠密的水向下引导方面更有效，我们比较了两种设置之间的动态来解释差异。