Daily and seasonal dynamics of suspended particles in the Rhone River plume based on remote sensing and field optical measurements
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Oui |
| Statut de publication | : | Publié |
| Année de publication | : | 2012 |
| Auteurs (3) | : | LORTHIOIS Thomas DOXARAN David CHAMI Malik |
| Revue scientifique | : | Geo-marine Letters |
| Volume | : | 32 |
| Fascicule | : | 2 |
| Pages | : | 89-101 |
| DOI | : | 10.1007/s00367-012-0274-2 |
| URL | : | <go to isi>://wos:000302283600002 |
| Abstract | : | Satellite ocean colour remote sensing can serve as a powerful tool to assess river plume characteristics because it provides daily mapping of surface suspended particulate matter (SPM) concentration at high spatial resolution. This study's ultimate objective was to better understand daily and seasonal particle dynamics in a coastal area strongly influenced by freshwater discharge and wind-the Rhne River (France), this being the major source of terrestrial input to the Mediterranean Sea. SPM concentrations and biogenic composition (chlorophyll a, organic carbon) were investigated during several bio-optical field campaigns conducted in spring-autumn of 2010 both from aboard a research vessel and by means of an autonomous profiling float. Freshwater discharge and wind velocities varied significantly during the year, associated with marked fluctuations in surface SPM (upper 1 m), even within hours and not restricted to any specific season. Thus, the range was ca. 12-25 g m(-3) (dry mass basis) on 9 April (spring), and ca. 3-39 g m(-3) on 4-5 November (late autumn). Short-term variations were observed also in SPM composition in terms of POC (albeit not chl a), with POC/SPM ratios ranging between ca. 3 and 11% over ca. 3 weeks in spring. Nevertheless, the particulate backscattering coefficient (b (bp)) proved to be a robust proxy of SPM concentration in the river plume (b (bp)(770) = 0.0076 Au SPM, R-2 = 0.80, N = 56). It has recently been demonstrated that 80% of the Rhne's terrestrial discharge occurs during flood events. The results of the present study revealed that, under these conditions, SPM is constrained largely within surface waters (i.e. at depths < 5 m), with only weak daily vertical variability. By implication, ocean colour satellite data are highly suitable in meaningfully estimating the overall SPM load exported by the Rhne River to the Mediterranean. These findings make a solid contribution to future improvements of three-dimensional sediment transport models for the region and similar settings. |
| Mots-clés | : | - |
| Commentaire | : | Times Cited: 3 3 |
| Tags | : | GOYA PROVPANACHE |
| Fichier attaché | : | - |
| Citation | : |
Lorthiois T, Doxaran D, Chami M (2012) Daily and seasonal dynamics of suspended particles in the Rhone River plume based on remote sensing and field optical measurements. Geo-mar Lett 32: 89-101 | doi: 10.1007/s00367-012-0274-2
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