Analysis of supercritical stratified tidal flow in a Scottish Fjord
Analysis of supercritical stratified tidal flow in a Scottish Fjord
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苏格兰峡湾超临界分层潮汐流分析
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发表时间：
2007
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通讯作者：
V. Vlasenko
中科院分区：
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作者：
N. Stashchuk;M. Inall;V. Vlasenko
摘要 研究了埃蒂夫湖（苏格兰）峡湾的斜压潮汐情况。分析是在现场数据和数值模拟的基础上进行的，并使用完全非线性非静水压精细分辨率模型。研究发现，将埃蒂夫湖分为内部和外部的基台顶部受到超临界流态的影响，最大弗劳德数超过 5。强烈的超临界条件导致在基台顶部上方形成流动分离。正如喷射型峡湾系统所固有的那样，这反过来会导致弱的非线性斜压波响应。另一方面，观测和数值结果还揭示了距离收缩处数公里处存在传播的内部潮汐波，其振幅高达 10 m。结果表明，这些斜压潮汐波在落潮期间在基台内侧面的一部分（深度低于 30 m）上被激发，其中局部弗劳德数要小得多......
Abstract The baroclinic tidal regime of the fjord Loch Etive (Scotland) is studied. Analysis is performed on the basis of both in situ data and numerical simulations, with the use of a fully nonlinear nonhydrostatic fine-resolution model. It was found that the crest of the sill that separates Loch Etive into inner and outer parts is subjected to a supercritical flow regime with maximum Froude numbers in excess of 5. Strong supercritical conditions lead to the formation of flow separation just above the sill’s crest. As is inherent to jet-type fjordic systems, this, in turn, leads to a weak nonlinear baroclinic wave response. On the other hand, observations and numerical results also revealed the presence of propagating internal tidal waves with amplitudes up to 10 m, several kilometers from the constriction. It is shown that these baroclinic tidal waves are excited during the ebb phase over a section of the inner flank of the sill, at a depth below 30 m, where the local Froude number is substantially less...