A Comparison of Finite-Time and Finite-Size Lyapunov Exponents
Finite-time and finite-size Lyapunov exponents are related concepts that have been used for the purpose of identifying transport structures in time-dependent flow. The preference for one or the other concept seems to be based more on a tradition within a scientific community than on proven advantages. In this study, we demonstrate that with the two concepts highly similar visualizations can be produced, by maximizing a simple similarity measure. Furthermore, we show that results depend crucially on the numerical implementation of the two concepts.
We wish to thank Tomas Torsvik, Uni Research, Uni Computing (Bergen, Norway), for the tidal flow data. This work was funded in part by the Seventh Framework Programme for Research of the European Commission, under FET-Open grant number 226042 (project SemSeg) and the Swiss National Science Foundation, under grant number 200020_140556.
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