Impact of Channel Geometry and Rotation on the Trapping of Internal Tides
Impact of Channel Geometry and Rotation on the Trapping of Internal Tides
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航道几何形状和旋转对内潮汐捕获的影响
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
L. Maas
中科院分区：
文献类型：
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作者：
S. Drijfhout;L. Maas
用等密度三维海洋模型研究了内潮的产生和传播。研究了航道中均匀分层海洋在开放边界上受正压潮汐作用时的响应。潮汐进入海峡，迫使内潮越过另一端的大陆斜坡。航道长1,200公里，宽191.25公里。底部的情况有所不同。通过四次实验，给出了跨航道几何形状对内潮传播和捕获的影响，并讨论了波能在远离大陆坡处的穿透尺度。特别是发现了跨航道底坡对内潮能穿透的限制。大多数内波折射到它们被困在那里的跨海峡平面。例外情况是边缘波将部分能量从大陆斜坡带走。在大陆坡附近旋转的情况下，在没有跨海峡坡的情况下产生的庞加莱波不再具有2D理论所预测的波吸引子的特征，但几乎完全被阻止，而右边界的Kelvin波保留了在不旋转的情况下存在的跨海峡平面的2D吸引子。反射的正压右边界开尔文波起到沿跨海峡坡度的二次内波发生器的作用。
The generation and propagation of internal tides has been studied with an isopycnic three-dimensional ocean model. The response of a uniformly stratified sea in a channel, which is forced by a barotropic tide on its open boundary, is considered. The tide progresses into the channel and forces internal tides over a continental slope at the other end. The channel has a length of 1200 km and a width of 191.25 km. The bottom profile has been varied. In a series of four experiments it is shown how the cross-channel geometry affects the propagation and trapping of internal tides, and the penetration scale of wave energy, away from the continental slope, is discussed. In particular it is found that a cross-channel bottom slope constrains the penetration of the internal tidal energy. Most internal waves refract toward a cross-channel plane where they are trapped. The exception is formed by edge waves that carry part of the energy away from the continental slope. In the case of rotation near the continental slope, the Poincare waves that arise in the absence of a cross-channel slope no longer bear the characteristics of the wave attractor predicted by 2D theory, but are almost completely arrested, while the right-bound Kelvin wave preserves the 2D attractor in the cross-channel plane, which is present in the nonrotating case. The reflected, barotropic right-bound Kelvin wave acts as a secondary internal wave generator along the cross-channel slope.