The Roles of Langmuir Circulations in the Dispersion of Surface Tracers
The Roles of Langmuir Circulations in the Dispersion of Surface Tracers
复制标题
朗缪尔环流在表面示踪剂扩散中的作用
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
Stephen J. Auer
中科院分区：
文献类型：
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作者：
A. Faller;Stephen J. Auer
摘要本文提出了一系列离散漂浮示踪物在湖泊和海洋中扩散的理论和数值模型。这些模型的核心是朗缪尔环流的作用，它将示踪剂集中到狭窄的料堆中，这抑制了示踪剂的分散。但是，随时间变化的朗缪尔环流会使示踪剂的行发生漂移，从而通过当地时间的依赖性和顺风平流而分裂，从而促进分散。因此，朗缪尔环流一般呈现较小规模的背景湍流无关的直接估计的表面色散。分析模型包括：1）线性平均流收敛加均匀湍流中的示踪剂理论，该理论适用于料堆宽度; 2）具有空间周期性平均流和周期性小尺度涡流扩散系数的模型，该模型允许估计稳定平行单元的朗缪尔尺度弥散度。随机飞行计算复杂的时间-d模型…
Abstract A hierarchy of theoretical and numerical models for the dispersion of discrete floating tracers on lakes and oceans is presented. Central to these models is the role of Langmuir circulations, which concentrate tracers into narrow windrows this inhibiting tracer dispersion. But time-dependent Langmuir circulations cause the rows of tracers to wander and so split, by local time dependence and by downwind advection, thus promoting dispersion. Accordingly, the Langmuir circulations generally render the smaller-scale background turbulence irrelevant for direct estimates of surface dispersion. Analytical models includes: 1) a theory of tracers in a linear mean-flow convergence plus homogeneous turbulence, this theory being applicable to the width of windrows; and 2) a model with a spatially periodic mean flow and a periodic small-scale eddy diffusion coefficient that allows an estimate of the Langmuir-scale dispersivity for steady parallel cells. Random-flight calculations for a model of complex time-d...