Publications des scientifiques de l'IRD

Fromant G., Floc'h F., Lebourges Dhaussy Anne, Jourdin F., Perrot Yannick, Le Dantec N., Delacourt C. (2017). In Situ quantification of the suspended load of estuarine aggregates from multifrequency acoustic inversions. Journal of Atmospheric and Oceanic Technology, 34 (8), p. 1625-1643. ISSN 0739-0572.

Titre du document
In Situ quantification of the suspended load of estuarine aggregates from multifrequency acoustic inversions
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000408107300001
Auteurs
Fromant G., Floc'h F., Lebourges Dhaussy Anne, Jourdin F., Perrot Yannick, Le Dantec N., Delacourt C.
Source
Journal of Atmospheric and Oceanic Technology, 2017, 34 (8), p. 1625-1643 ISSN 0739-0572
The study of the suspended particulate matter (SPM) transport is essential to understanding oceans and rivers, for their presence can impact the environment, from marine habitats or water quality degradations to important changes of the seabed morphology. Among a large number of surrogate techniques in traditional water sampling, acoustical methods have the advantage of providing nonintrusive measurements, with high spatial and temporal resolutions. However, the ability of fine-grained sediments to aggregate under the process of flocculation complexifies the interpretation of acoustical measurements. The objective of this paper is to design a simple backscatteringmodel for flocculated sediment suspensions, in order to interpret the information provided by a multifrequency profiler and to retrieve both the concentration and the dominant size of a suspension of flocculated sediments in an estuarine context. In situ granulometry laser data, collected in the Aulne macrotidal estuary (France), showed that over the size distribution observed, a mean porosity of apparent particles in suspension can be used directly as input for model generation. The in situ acoustic signal was concurrently recorded at 0.5, 1, 2, and 4MHz, and then inverted using the nonnegative least squares algorithm after constraining the model with an optimal porosity, allowing for a discrete representation of the mass concentration distributed over several equivalent spherical radii. The inversion results are in good agreement with the in situ mass concentration obtained through in situ water samplings.
Plan de classement
Limnologie physique / Océanographie physique [032]
Description Géographique
FRANCE
Localisation
Fonds IRD [F B010070923]
Identifiant IRD
fdi:010070923
Contact