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| Titel |
Local finite-time Lyapunov exponent, local sampling and probabilistic source and destination regions |
| VerfasserIn |
A. E. Bozorgmagham, S. D. Ross, D. G. Schmale |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 22, no. 6 ; Nr. 22, no. 6 (2015-11-11), S.663-677 |
| Datensatznummer |
250121008
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| Publikation (Nr.) |
 copernicus.org/npg-22-663-2015.pdf |
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| Zusammenfassung |
| The finite-time Lyapunov exponent (FTLE) is a powerful Lagrangian concept widely
used for describing large-scale flow patterns and transport phenomena.
However, field experiments usually have modest scales. Therefore, it is
necessary to bridge the gap between the concept of FTLE and field
experiments. In this paper, two independent observations are discussed:
(i) approximation of the local FTLE time series at a fixed location as a
function of known distances between the destination (or source) points of
released (or collected) particles and local velocity, and (ii) estimation of
the distances between the destination (or source) points of the released (or
collected) particles when consecutive release (or sampling) events are
performed at a fixed location. These two observations lay the groundwork for
an ansatz methodology that can practically assist in field experiments where
consecutive samples are collected at a fixed location, and it is desirable to
attribute source locations to the collected particles, and also in planning
of optimal local sampling of passive particles for maximal diversity
monitoring of atmospheric assemblages of microorganisms. In addition to
deterministic flows, the more realistic case of unresolved turbulence and
low-resolution flow data that yield probabilistic source (or destination)
regions are studied. It is shown that, similar to deterministic flows,
Lagrangian coherent structures (LCS) and local FTLE can describe the
separation of probabilistic source (or destination) regions corresponding to
consecutively collected (or released) particles. |
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