Some interactions of a vortex with a seamount
Some interactions of a vortex with a seamount
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涡旋与海山的一些相互作用
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
D. Dunn
中科院分区：
文献类型：
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作者：
N. R. McDonald;D. Dunn
用等值线动力学的方法，在准等转框架下研究了等高圆形海山附近初圆等位涡的等效正压涡运动的初值问题。假设漩涡的半径等于变形半径，则相互作用的性质取决于四个参数：i)相对于变形半径的漩涡与海山的距离，ii)相对于变形半径的海山半径，iii)海山的无因次高度相对于漩涡的罗斯比数（或等价于漩涡强度）的比率，iv)漩涡环流的感觉。轮廓手术实验用于研究漩涡-海山系统在这些参数变化时行为的定性变化。特别值得注意的是，当原始涡从海底山扫过流体时，它产生了额外的涡特征。此外，当原始涡旋是一个反气旋时，偶极子经常在很大的参数值范围内形成，随后从海山传播出去。
The initial value problem for the motion of an equivalent-barotropic vortex which is initially circular and of uniform potential vorticity near a circular seamount of constant height is studied within a quasigeostrophic framework using the method of contour dynamics. Given that the radius of the vortex is equal to the deformation radius, the nature of the interaction depends on four parameters: i) the distance of the vortex from the seamount relative to the deformation radius, ii) the radius of the seamount relative to the deformation radius, iii) the ratio of the non-dimensional height of the seamount relative to the Rossby number of the vortex (or, equivalently, the vortex intensity) and iv) the sense of the vortex circulation. Contour surgery experiments are used to investigate qualitative changes in behaviour of the vortex-seamount system as these parameters are varied. Of particular note is the generation of additional vortex features by the original vortex as it sweeps fluid from the seamount. Moreover, when the original vortex is an anticyclone, dipoles are frequently formed over a wide range of parameter values, which subsequently propagate away from the seamount.