High frequency variability of particle ...
Document type :
Article dans une revue scientifique: Article original
Title :
High frequency variability of particle size distribution and its dependency on turbulence over the sea bottom during re-suspension processes
Author(s) :
Renosh, P.R. [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Schmitt, François G [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Loisel, Hubert [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Sentchev, Alexei [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Mériaux, Xavier [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Schmitt, François G [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Loisel, Hubert [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Sentchev, Alexei [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Mériaux, Xavier [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Journal title :
CONTINENTAL SHELF RESEARCH
Pages :
51-60
Publisher :
Elsevier
Publication date :
2014
ISSN :
0278-4343
HAL domain(s) :
Planète et Univers [physics]/Sciences de la Terre/Océanographie
English abstract : [en]
The impact of tidal current, waves, and turbulence on particles re-suspension over the sea bottom is studied through eulerian high frequency measurements of velocity and particle size distribution (PSD) during 5 tidal ...
Show more >The impact of tidal current, waves, and turbulence on particles re-suspension over the sea bottom is studied through eulerian high frequency measurements of velocity and particle size distribution (PSD) during 5 tidal cycles (65 hours) in a coastal environment of the eastern English Channel. High frequency variability of PSD is observed along with the velocity fluctuations. Power spectral analysis shows that turbulent velocity and PSD parameters have similarities in their spectral behaviour over the whole range of examined temporal scales. The low frequency variability of particles is controlled by turbulence (beta =-5/3) and the high frequency is partly driven by dynamical processes impacted by the sea bottom interactions with turbulence (wall turbulence). Stokes number (St), rarely measured in situ, exhibits very low values, emphasizing that these particles can be considered as passive tracers. The effect of tide and waves on turbidity and PSD is highlighted. During slack tide, when the current reaches its minimum value, we observe a higher proportion of small particles compared to larger ones. To a lower extent, high significant wave heights are also associated with a greater concentration of suspended sediments and the presence of larger particles (larger Sauter's diameter D_A, and lower PSD slope xi).Show less >
Show more >The impact of tidal current, waves, and turbulence on particles re-suspension over the sea bottom is studied through eulerian high frequency measurements of velocity and particle size distribution (PSD) during 5 tidal cycles (65 hours) in a coastal environment of the eastern English Channel. High frequency variability of PSD is observed along with the velocity fluctuations. Power spectral analysis shows that turbulent velocity and PSD parameters have similarities in their spectral behaviour over the whole range of examined temporal scales. The low frequency variability of particles is controlled by turbulence (beta =-5/3) and the high frequency is partly driven by dynamical processes impacted by the sea bottom interactions with turbulence (wall turbulence). Stokes number (St), rarely measured in situ, exhibits very low values, emphasizing that these particles can be considered as passive tracers. The effect of tide and waves on turbidity and PSD is highlighted. During slack tide, when the current reaches its minimum value, we observe a higher proportion of small particles compared to larger ones. To a lower extent, high significant wave heights are also associated with a greater concentration of suspended sediments and the presence of larger particles (larger Sauter's diameter D_A, and lower PSD slope xi).Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Internationale
Popular science :
Non
Source :