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| Titel |
Intermittent particle dynamics in marine coastal waters |
| VerfasserIn |
P. R. Renosh, F. G. Schmitt, H. Loisel |
| 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. 5 ; Nr. 22, no. 5 (2015-10-22), S.633-643 |
| Datensatznummer |
250121006
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| Publikation (Nr.) |
 copernicus.org/npg-22-633-2015.pdf |
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| Zusammenfassung |
| Marine coastal processes are highly variable over different space scales and
timescales. In this paper we analyse the intermittency properties of particle
size distribution (PSD) recorded every second using a LISST instrument (Laser
In-Situ Scattering and Transmissometry). The particle concentrations have
been recorded over 32 size classes from 2.5 to 500 μm, at 1 Hz
resolution. Such information is used to estimate at each time step the
hyperbolic slope of the particle size distribution, and to consider its
dynamics. Shannon entropy, as an indicator of the randomness, is estimated at
each time step and its dynamics is analysed. Furthermore, particles are
separated into four classes according to their size, and the intermittent
properties of these classes are considered. The empirical mode decomposition
(EMD) is used, associated with arbitrary-order Hilbert spectral analysis
(AHSA), in order to retrieve scaling multifractal moment functions, for
scales from 10 s to 8 min. The intermittent properties of two other
indicators of particle concentration are also considered in the same range of
scales: the total volume concentration Cvol-total and the
particulate beam attenuation coefficient cp(670). Both show quite
similar intermittent dynamics and are characterised by the same exponents.
Globally we find here negative Hurst exponents (meaning the small scales show
larger fluctuation than large scales) for each time series considered, and
nonlinear moment functions. |
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