Radial spreading of buoyant, surface plumes in coastal waters
Radial spreading of buoyant, surface plumes in coastal waters
复制标题
DOI：
10.1029/jc089ic02p01989
复制
发表时间：
1984-03
影响因子：
--
通讯作者：
R. Garvine
中科院分区：
文献类型：
--
作者：
R. Garvine
沿海水域浅层浮力的表面羽流有时从一个连续源（如河口）几乎呈放射状扩散而形成。这种羽流通常呈现环状结构，其中浮力水集中在膨胀环的前缘和后缘之间。这些环通常以多个同心的形式出现。建立了一个浅浮力层在静止的深环境层上径向、随时间扩展的模型。它将锋面视为不连续面，并将羽流的其余部分视为由非线性内波控制的无粘性重力传播。用特征法进行了计算，显示了一个清晰的环形结构的演变过程。径向几何结构中的快速扩散与羽流前缘锋面边界外的内波反射的结合是形成环的必要条件。提出了一种通过径向扩散固有的剪切流动不稳定性形成多环的机制。
Shallow buoyant, surface plumes in coastal waters sometimes develop by nearly radial spreading from a continuous source, such as at a river mouth. Such plumes often display a ring structure where buoyant water is concentrated between fronts at both the leading and trailing edges of the expanding ring. These rings often occur in multiple, concentric forms. A model of the radial, time dependent spreading of a shallow buoyant layer over a motionless, deep ambient layer is developed. It includes fronts as discontinuities and treats the remainder of the plume flow as inviscid, gravitational spreading controlled by nonlinear, internal waves. Calculations by the method of characteristics are presented that show the evolution of a clear ring structure. The combination of rapid spreading in the radial geometry together with reflection of internal waves off the frontal boundary at the plume leading edge is shown to be necessary for ring formation. A mechanism is suggested for the formation of multiple rings through the shear flow instability inherent in radial spreading.