Investigating the connection between complexity of isolated trajectories and Lagrangian coherent structures
Investigating the connection between complexity of isolated trajectories and Lagrangian coherent structures
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研究孤立轨迹的复杂性与拉格朗日相干结构之间的联系
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Michael G. Brown
中科院分区：
文献类型：
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作者：
I. Rypina;S. E. Scott;L. Pratt;Michael G. Brown
抽象的。有人认为，流体粒子轨迹的复杂性为一种新方法（称为复杂性方法（CM））提供了基础，用于估计在有限时间间隔内测量的非周期流中的拉格朗日相干结构。解释了 CM 的基本原理，并在各种示例（理想化的和现实的）以及不同的参考系中对 CM 进行了测试。详细探讨了两种复杂性度量：轨迹的相关维数和一种新度量——遍历性缺陷。在所有考虑的例子中，这两种测量都产生与拉格朗日相干结构非常相似的结构。由于 CM 使用各个轨迹的属性，而不是紧密间隔的轨迹之间的分离率，因此它对于分析海洋漂浮物和漂流物数据集（其中轨迹通常间隔较宽且不均匀）可能具有优势。
Abstract. It is argued that the complexity of fluid particle trajectories provides the basis for a new method, referred to as the Complexity Method (CM), for estimation of Lagrangian coherent structures in aperiodic flows that are measured over finite time intervals. The basic principles of the CM are explained and the CM is tested in a variety of examples, both idealized and realistic, and in different reference frames. Two measures of complexity are explored in detail: the correlation dimension of trajectory, and a new measure – the ergodicity defect. Both measures yield structures that strongly resemble Lagrangian coherent structures in all of the examples considered. Since the CM uses properties of individual trajectories, and not separation rates between closely spaced trajectories, it may have advantages for the analysis of ocean float and drifter data sets in which trajectories are typically widely and non-uniformly spaced.