Consulta: subjectFacets:"ADCP"
Registros recuperados: 9
Data/hora: 07/06/2024 00:46:39

Modélisation des turbidités en Bretagne sud et validation par des mesures in situ
Provedor de dados: 5
Autores: Tessier, Caroline; Le Hir, Pierre; Dumas, Franck; Jourdin, F.
A hydrodynamic and sediment model of South Brittany is calibrated with ADCP measurements, which allow to estimate hydrodynamic forcing and concentration of suspended particulate matter. The exercise of comparison between observed and simulated concentrations reveals that turbidity is highly dependant on numerous strongly coupled sedimentary and physical processes.
Tipo: Text
Palavras-chave: Waves; ADCP; Acoustical backscattering; Modelisation; Turbidity; Vagues; ADCP; Rétrodiffusion acoustique; Modélisation; Turbidité.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6300.pdf

The influence of bottom currents on the Zambezi Valley morphology (Mozambique Channel, SW Indian Ocean): In situ current observations and hydrodynamic modelling
Provedor de dados: 5
Autores: Miramontes, Elda; Penven, Pierrick; Fierens, Ruth; Droz, Laurence; Toucanne, Samuel; Jorry, Stephan; Jouet, Gwenael; Pastor, Lucie; Silva Jacinto, Ricardo; Gaillot, Arnaud; Giraudeau, Jacques; Raisson, François.
Mixed turbidite-contourite systems can be found in oceans where bottom currents and turbidity currents interact. The Zambezi turbidite system, located in the Mozambique Channel (SW Indian Ocean), is one of the largest sedimentary systems in the world in length and area of the related catchments. The oceanic circulation in the Mozambique Channel is intense and complex, dominated by eddies flowing southwards and deep currents flowing northwards along the Mozambican margin. Current measurements obtained from moorings at 3400–4050 m water depth in the Zambezi and Tsiribihina valleys show periods of intense currents at the seafloor with peaks of 40–50 cm s−1 that last up to one month and are not related to turbidity currents. These strong bottom-current events...
Tipo: Text
Palavras-chave: Contourite; Turbidity current; Mixed system; Oceanic circulation; Mooring; ADCP; ROMS model; Bedform.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00476/58743/61269.pdf

A comprehensive assessment of turbulence at a tidal-stream energy site influenced by wind-generated ocean waves
Provedor de dados: 5
Autores: Thiébaut, Maxime; Filipot, Jean-francois; Maisondieu, Christophe; Damblans, Guillaume; Duarte, Rui; Droniou, Eloi; Chaplain, Nicolas; Guillou, Sylvain.
Velocity measurements collected by an upward-looking acoustic Doppler current profiler were used to provide the first study of ambient turbulence in Alderney Race. Turbulence metrics were estimated at mid-depth during peak flooding and ebbing tidal conditions. The dissipation rate ε and the integral lengthscale (L) were estimated using two independent methods: the spectral method and the structure function method. The spectral method provided ε and (L) estimates with standard deviations twice lower than that obtained from the structure function method. Removal of wave and Doppler noise-induced bias when estimating the dissipation rate was shown to be a crucial step in turbulence characterization. It allowed for a significant refining in (L) estimates...
Tipo: Text
Palavras-chave: Turbulence; Tidal energy; Wave; Doppler noise; ADCP; Alderney Race.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00592/70394/68478.pdf

On the modeling errors in the tidal power assessment
Provedor de dados: 5
Autores: Filipot, Jean-francois; Delafosse, Coline; Marzin, Thibault; Baston, Susana.
The present paper discusses the errors produced while estimating the tidal power with numerical circulation models. The study relies on the analysis of five model-data comparisons issued from the literature. As usually done in the tidal power assessment studies, statistics are first derived for the current velocities. The novelty of this work resides in the direct computation of power density statistics. The errors in the power density prediction are found to be significantly higher than for the current velocity, as expected since power density is a function of velocity cubed. This stresses the need to consider the uncertainties in the tidal energy estimation for the profitability assessment of potential tidal sites.
Tipo: Text
Palavras-chave: Tidal power; Numerical circulation models; ADCP; Statistics.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00230/34114/32569.pdf

The Atlantic Meridional Overturning Circulation and the subpolar gyre observed at the A25-OVIDE section in June 2002 and 2004
Provedor de dados: 5
Autores: Lherminier, Pascale; Mercier, Herle; Huck, Thierry; Gourcuff, Claire; Perez, Fiz F.; Morin, Pascal; Sarafanov, Artem; Falina, Anastasia.
The horizontal circulation of the subpolar gyre and the Meridional Overturning Circulation (MOC) are investigated here by comparing two snapshots of the North Atlantic as delivered by two hydrographic sections between Greenland and Portugal. The corresponding cruises were carried out in June–July 2002 and June–July 2004 on R/V Thalassa within the framework of the Ovide project. The absolute transports in June 2004 are described in detail, and then compared with transports in June 2002. The MOC (in density coordinates), driven by the volume balance between the northward North Atlantic Current (NAC) and the net southward export of dense water from the subpolar gyre, did not change: View the MathML source (1 Sv=106 m3 s−1). Its upper limb, above σ1=32.1, is...
Tipo: Text
Palavras-chave: North Atlantic; Subpolar gyre; Meridional Overturning Circulation; OVIDE; Hydrology; ADCP.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00011/12272/9057.pdf

Impact of winter storms on sediment erosion in the Rhone River prodelta and fate of sediment in the Gulf of Lions (North Western Mediterranean Sea)
Provedor de dados: 5
Autores: Dufois, Francois; Verney, Romaric; Le Hir, Pierre; Dumas, Franck; Charmasson, Sabine.
In this study a three-dimensional sediment transport model was developed. The model accounts for both current and wave forcing on the sediment and was implemented over the Gulf of Lions. A two-way nesting technique was used to focus on the Rhone River prodelta which is considered as a sink for riverine sediment. In addition, to understand the resuspension of trapped sediment over the Rhone prodelta, an in situ experiment, called SCOPE, was conducted during the winter 2007/2008. The experiment consisted of measuring hydro-sedimentary parameters using a mooring station comprising a current profiler (ADCP) and an altimeter (acoustic transducer) located in the eastern part of the Rhone prodelta. The three-dimensional transport model was validated using these...
Tipo: Text
Palavras-chave: Sediment transport; Gulf of Lions; Rhone prodelta; 3D modelling; ADCP; ALTUS.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00165/27584/25743.pdf

Circulation on the shelf and the upper slope of the Bay of Biscay
Provedor de dados: 5
Autores: Le Boyer, Arnaud; Charria, Guillaume; Le Cann, Bernard; Lazure, Pascal; Marie, Louis.
Here, we used measurements taken with an array of 10 acoustic Doppler current profilers deployed from July 2009 to August 2011 to describe the tidally filtered circulation over the shelf and upper slope on the French side off the French coasts of the Bay of Biscay. The measurements provided an overview of the shelf and slope circulation throughout the entire water column over a large range of spatial and time scales. The average circulation over the shelf and upper slope of the Bay of Biscay was poleward following the topography with a speed of the order of 3 cm s(-1). This average circulation had marked seasonal variability. In summer, the currents were equatorward on the outer shelf near surface. Deeper in the water column, the flow remained poleward. In...
Tipo: Text
Palavras-chave: Bay of Biscay; Observation; Shelf and slope circulation; Vertical profile; ADCP; Wind driven circulation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00139/24976/26395.pdf

Poleward along-shore current pulses on the inner shelf of the Bay of Biscay
Provedor de dados: 5
Autores: Kersale, M.; Marie, Louis; Le Cann, B.; Serpette, A.; Lathuiliere, C.; Le Boyer, A.; Rubio, A.; Lazure, Pascal.
We analyzed strong events of coastal poleward along-shore currents above 10 cm s−1 and up to more than 50 cm s−1 on the inner shelf (50-80 m depth) of the Bay of Biscay (BoB) from the Spanish coast to the Brittany coast. We used data from four acoustic Doppler current profilers (ADCPs) deployed from July 2009 to August 2011. The goal of this study was to analyze current variability at meso- and subinertial scales and their generation mechanisms. These currents occurred all year long and were classified into three types. Events occurring principally in the southern part of the BoB were classified as southern events. Bay-scale events were defined when strong poleward currents were detected over all the shelf, typically stronger on the Spanish and the...
Tipo: Text
Palavras-chave: Coastal jets; ADCP; Shelf circulation; Wind forcing; Coastal trapped waves; Bay of Biscay.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00299/40984/40075.pdf

THE PHYSICAL ENVIRONMENT IN CORAL REEFS OF THE TAYRONA NATIONAL NATURAL PARK (COLOMBIAN CARIBBEAN) IN RESPONSE TO SEASONAL UPWELLING*
Provedor de dados: 50
Autores: Bayraktarov,Elisa; Bastidas-Salamanca,Martha L; Wild,Christian.
Coral reefs are subjected to physical changes in their surroundings including wind velocity, water temperature, and water currents that can affect ecological processes on different spatial and temporal scales. However, the dynamics of these physical variables in coral reef ecosystems are poorly understood. In this context, Tayrona National Natural Park (TNNP) in the Colombian Caribbean is an ideal study location because it contains coral reefs and is exposed to seasonal upwelling that strongly changes all key physical factors mentioned above. This study therefore investigated wind velocity and water temperature over two years, as well as water current velocity and direction for representative months of each season at a windand wave-exposed and a sheltered...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water current velocity and direction; ADCP; Upwelling; Coral reefs; Colombian Caribbean.
Ano: 2014
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612014000100007