La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Analysis of high frequency temperature time series in the Seine estuary from the Marel autonomous monitoring buoy
Auteurs :	G. Dur, Auteur ; F. G. Schmitt, Auteur ; S. Souissi, Auteur
Type de document :	Article
Dans :	Hydrobiologia (588 SEP 2007)
Article en page(s) :	59-68
Résumé :	In the marine sciences, continuous monitoring systems have been regarded as very useful tools to provide continuous high frequency measurements of many parameters. We analyse here a high frequency time series of temperature measurements recorded every 10 min between 1997 and 2004 in the macro tidal Seine estuary ( France) by a Marel buoy, an automatic monitoring network for littoral environment. We have adapted multi- scale data analysis methods to deal with the many missing values present in the time series. A power spectral density analysis is performed over time scales spanning 5 decades, from 20 min to more than 7 years. A scale invariant behaviour of the form E(f) approximate to f (-beta) with beta = 2.2 is revealed for scales below 5 h. Over this scaling range, we have performed structure functions analysis, and shown that the Seine river temperature data exhibit turbulent- like intermittent properties, with multifractal statistics. The multifractal exponents obtained possess some similarities with passive scalar turbulence results.

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