High gradient phenomena in two‐dimensional vortex interactions
High gradient phenomena in two‐dimensional vortex interactions
复制标题
二维涡旋相互作用中的高梯度现象
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
D. Dritschel
中科院分区：
文献类型：
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作者：
H. Yao;N. Zabusky;D. Dritschel
Hyperdiffusion是一种简单的线性涡动扩散率方案，常用于大气和海洋模拟，因为它增加了给定模式分辨率下惯性行为空间尺度的范围。与分子扩散（在大气和海洋中完全可以忽略不计）相比，超扩散更严格地将耗散限制在数值模型的最小尺度上。但这就是超扩散所做的一切吗？本文研究了两个不等尺寸分布涡的非弹性相互作用。轮廓手术（CS）模拟相比，伪谱（PS）模拟采用超扩散或分子扩散。这个例子说明了被认为是二维（2-D）（和分层2-D）涡动力学的最基本特征，即极高涡度梯度的形成。在早期（即，几个漩涡旋转的漩涡
Hyperdiffusion, a simple linear eddy diffusivity scheme, is commonly used in atmospheric and oceanic simulations because it increases the range of inertially behaving spatial scales for a given model resolution. Compared with molecular diffusion (which is utterly negligible in the atmosphere and oceans), hyperdiffusion more sharply confines the dissipation to the smallest scales of the numerical model. But is this all that hyperdiffusion does? In this paper, the inelastic interaction of two distributed vortices of unequal size is examined. Contour surgery (CS) simulations are compared with pseudospectral (PS) simulations employing hyperdiffusion or molecular diffusion. The example illustrates what is believed to be the most fundamental characteristic of two‐dimensional (2‐D) (and layerwise‐2‐D) vortex dynamics, namely, the formation of exceedingly high vorticity gradients. There is an excellent agreement between the hyperdiffusive PS and CS calculations at early times (i.e., for a few vortex rotation peri...