Flow, water mass changes, and hydraulics in the Bosphorus
Flow, water mass changes, and hydraulics in the Bosphorus
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博斯普鲁斯海峡的流量、水量变化和水力学
DOI：
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发表时间：
2002
期刊：
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通讯作者：
E. Özsoy
中科院分区：
文献类型：
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作者：
M. Gregg;E. Özsoy
[1]Gregg等人[1999年]利用1994年9月用一个松散系留的剖面仪和声学多普勒海流剖面仪沿博斯普鲁斯海峡沿着的平均剖面，发现马尔马拉海和黑海之间的交换流是准稳定的，但远不满足两层流的水力控制条件。在这里，我们检查天气部分，并使用从声学后向散射系统的图像，以提供第一个详细的流量和水的质量变化在博斯普鲁斯海峡，并评估如何以及流量满足水力假设。30公里长，28-100米深，0.75-3公里宽，博斯普鲁斯海峡的水深测量比交换流的分析或数值模型中使用的水深测量更复杂。细节在重要方面影响着动态。例如，由于通道形状的变化，被称为收缩的最西端部分也不是横截面积的最小值。相反，它是海峡较宽的北方半部和较窄的南半部之间的过渡，收缩区以南的一些地方面积略小。急弯出现在整个海峡，并经常产生流动分离，以及引导上下流到海峡的相对两侧。由于收缩区下游的强烈混合，在海峡的南半部，界面厚度从未低于水柱的28%，达到75%。由于强烈的混合和大量的流动分离，我们得出结论，交换流可能至少部分地由摩擦控制，而不是简单的液压流。
[1] Using average sections along the Bosphorus taken in September 1994 with a loosely tethered profiler and an acoustic Doppler current profiler, Gregg et al. [1999] found the exchange flow between the Sea of Marmara and the Black Sea to be quasi-steady but far from satisfying the hydraulic control conditions for two-layered flows. Here we examine synoptic sections and use images from an acoustic backscatter system to provide the first detailed look at the flow and water mass changes in the Bosphorus and to assess how well the flow satisfies the hydraulic assumptions. Thirty kilometers long, 28–100 m deep, and 0.75–3 km wide, the Bosphorus has bathymetry for more complex than that used in analytic or numerical models of exchange flows. The particulars affect dynamics in important ways. For instance, owing to changes in channel shape, the narrowest section, known as the contraction, is not also the minimum in cross-sectional area. Rather, it is a transition between the wider northern half and the narrower southern half of the strait, and some places south of the contraction have slightly smaller areas. Sharp bends occur throughout the strait and often produce flow separations as well as directing upper and lower flows to opposite sides of the channel. Never <28% of the water column, the interface thickens to 75% in the southern half of the strait as a result of intense mixing downstream of the contraction. As a consequence of the strong mixing and numerous flow separations, we conclude that the exchange flow may be at least partly controlled by friction instead of being a simple hydraulic flow.