Estuarine Exchange Flow Is Related to Mixing through the Salinity Variance Budget
Estuarine Exchange Flow Is Related to Mixing through the Salinity Variance Budget
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DOI：
10.1175/jpo-d-17-0266.1
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发表时间：
2018-06
影响因子：
3.5
通讯作者：
P. MacCready;W. Geyer;H. Burchard
中科院分区：
文献类型：
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作者：
P. MacCready;W. Geyer;H. Burchard
净混合和河口交换流之间的关系可以用盐度方差预算来量化。在这里，“混合”被定义为体积积分盐度方差的破坏率，并且交换流量使用总交换流量来量化。这些概念进行了探讨，使用理想化的三维模型河口。结果表明，在稳态（例如，在春季-小潮周期内求平均值），体积积分混合近似由混合Sin Sout Qr给出，其中Sin和Sout是河口流入层和流出层的代表性盐度，Qr是河流体积通量。这种关系提供了熟悉的努森关系的扩展，其中交换流是基于这三个相同的量的知识来诊断的，定量地将混合与交换流联系起来。
The relationship between net mixing and the estuarine exchange flow may be quantified using a salinity variance budget. Here “mixing” is defined as the rate of destruction of volume-integrated salinity variance, and the exchange flow is quantified using the total exchange flow. These concepts are explored using an idealized 3D model estuary. It is shown that in steady state (e.g., averaging over the spring–neap cycle) the volume-integrated mixing is approximately given by Mixing ≅ SinSoutQr, where Sin and Sout are the representative salinities of in- and outflowing layers at the mouth and Qr is the river volume flux. This relationship provides an extension of the familiar Knudsen relation, in which the exchange flow is diagnosed based on knowledge of these same three quantities, quantitatively linking mixing to the exchange flow.