Do Finite-Size Lyapunov Exponents detect coherent structures?

被引：46

作者：

Karrasch, Daniel ^{[1
]}

Haller, George ^{[1
]}

机构：

[1] ETH, Inst Mech Syst, CH-8092 Zurich, Switzerland

来源：

CHAOS | 2013年 / 23卷 / 04期

关键词：

INVARIANT-MANIFOLDS; VARIATIONAL THEORY; BARRIERS;

D O I：

10.1063/1.4837075

中图分类号：

O29 [应用数学];

学科分类号：

070104 ;

摘要：

Ridges of the Finite-Size Lyapunov Exponent (FSLE) field have been used as indicators of hyperbolic Lagrangian Coherent Structures (LCSs). A rigorous mathematical link between the FSLE and LCSs, however, has been missing. Here, we prove that an FSLE ridge satisfying certain conditions does signal a nearby ridge of some Finite-Time Lyapunov Exponent (FTLE) field, which in turn indicates a hyperbolic LCS under further conditions. Other FSLE ridges violating our conditions, however, are seen to be false positives for LCSs. We also find further limitations of the FSLE in Lagrangian coherence detection, including ill-posedness, artificial jump-discontinuities, and sensitivity with respect to the computational time step. (C) 2013 AIP Publishing LLC.

引用

页数：11

共 32 条

[1]

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