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Registros recuperados: 48 | |
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Pinazo, Christel; Fraysse, Marion; Doglioli, Andrea; Faure, Vincent Martin; Pairaud, Ivane; Petrenko, Anne; Thouvenin, Benedicte; Tronczynski, Jacek; Verney, Romaric; Yohia, Christophe. |
In the framework of sustainable development, the anthropogenic impact of large coastal cities on the marine ecosystem is a key issue. This project aimed to improve our knowledge in marine ecosystem response to the anthropogenic supplies (from rivers, sewage outflows and atmosphere) from large cities. In particular, the goal is to underline how the physical forcing decreases or increases the anthropogenic impact on the coastal ecosystem and the assessment of the chemical contaminant (PCB) inputs (from city to sea) and exports (from mid-sea to open sea). |
Tipo: Text |
Palavras-chave: Apports anthropiques; Baie de Marseille; Méditerranée nord-occidentale; Modélisation 3D; MARS3D; ECO3M; Couplage physique et biogéochimique; Anthropogenic supply; Bay of Marseille; North-Western Mediterranean Sea; 3D modelling; MARS3D; ECO3M; Physical-biogeochemical coupling. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00145/25592/23739.pdf |
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Grasso, Florent; Bismuth, Eliott; Verney, Romaric. |
En se basant sur les travaux des programmes de recherche Seine-Aval 4 & 5, et plus particulièrement le modèle numérique hydro-sédimentaire MARS3D « CurviSeine » (HYMOSED-SA5), le projet ARES (« Analyse de Rejeux hydro-sédimentaires en Estuaire de Seine ») du programme de recherche Seine-Aval 6 avait pour objectifs de produire un référentiel de données validées de la dynamique hydro-sédimentaire de l’estuaire pour deux périodes de 11 ans (1990-2000 et 2005-2015). Le présent document décrit : (i) le modèle ainsi que les paramètres de modélisation (forçages, grille bathymétrique, etc…) utilisés ; (ii) la comparaison des sorties hydrologiques (température, salinité, sédiments en suspension) du modèle avec les données du réseau PHRESQUES (bouée SCENES et... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00664/77610/79628.pdf |
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Verney, Romaric; Jany, Cassandre; Thouvenin, Benedicte; Pairaud, Ivane; Vousdoukas, Michalis I.; Pinazo, Christel; Ardhuin, Fabrice; Cann, Philippe. |
Human pressures on ecosystems have increased significantly over the last decades, and especially Mediterranean coasts are strongly impacted by the development of big cities and industrialized area, such as the Bay of Marseille. Prior to any investigations on ecological or contamination impacts, it was necessary to understand sediment dynamics and its response to natural extreme events such as storm or heavy rainfall events. In situ observations were dedicated to understand the behavior of bed sediments, and their spatial distribution. A benthic station was deployed for three months to observe the impact of extreme events on hydrodynamics and sediment dynamics in a critical zone of the study area. These measurementswere used to calibrate and validate the... |
Tipo: Text |
Palavras-chave: Sediment dynamics; Large coastal cities; Urban pressure; Extreme events; Wave; Rainfall; Marseille. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00204/31515/29929.pdf |
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Maerz, Joeran; Verney, Romaric; Wirtz, Kai; Feudel, Ulrike. |
Modeling suspended particulate matter (SPM) dynamics is essential to calculate sediment transport budgets and to provide relevant knowledge for the understanding of biogeochemical cycles in coastal waters. Natural flocs are characterized by their size, shape, structure and density that determine their settling velocity and therefore their vertical as well as horizontal transport. During transport, several processes, in particular aggregation and fragmentation, alter these particle properties. In the present study, we compare two different 0D modeling approaches for flocculation processes, a size class-based (SCB) model and a distribution-based (DB) model that follows the first moment of the particle distribution function. The study leads to an improved... |
Tipo: Text |
Palavras-chave: Suspended particulate matter (SPM); Flocculation/aggregation; Size class-based model; Distribution-based model; Tidal dynamics; Model comparison. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00027/13870/11064.pdf |
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Grasso, Florent; Carlier, Antoine; Cugier, Philippe; Verney, Romaric; Marzloff, Martin. |
In coastal environments, strong feedback can exist between benthic fauna and sediment dynamics. Benthic populations can modify sediment dynamics through biofiltration and bioturbation, while hydro- and sediment dynamics directly determine local environmental conditions for benthic organisms. However, these complex feedbacks are difficult to study in situ. Here, we carried out mesocosm experiments to characterize the effects of a benthic species (the gastropod Crepidula fornicata) on mud dynamics under hydrodynamic conditions representative of their natural habitat. Different experimental tests related to the inclusion (or not) of dead or live crepidula reveal that biofiltration can increase particle settling up to 40%. Flocculation, which is strengthened... |
Tipo: Text |
Palavras-chave: Laboratory experiments; Coastal processes; Physical-biological interactions; Benthic engineer species; Mud settling; Flocculation; Biofiltration; Organic matter. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77403/79043.pdf |
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Druine, Flavie; Verney, Romaric; Deloffre, Julien; Lemoine, Jean-philippe; Chapalain, Marion; Landemaine, Valentin; Lafite, Robert. |
The aim of this study is to investigate the complex response of optical turbidity sensors (side- and back-scattering sensors) to Suspended Particle Matter (SPM) characteristics and the consequences when investigating SPM dynamics from long-term high frequency monitoring networks. Our investigation is based on the analysis of a unique dataset of monthly 12 h cycle measurements of SPM characteristics such as turbidity, concentration, floc size distribution, floc density and organic matter content in the macrotidal Seine Estuary (France) between February 2015 and June 2016. Results reveal that despite calibration to a Formazin standard, turbidity sensor response to SPM concentrations (in the range of 7–7000 mg L−1) are strongly variable, from the tidal scale... |
Tipo: Text |
Palavras-chave: Turbidity; Suspended sediment concentration; Optical sensor; Flocs; Long term monitoring. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00431/54227/55550.pdf |
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Charria, Guillaume; Schmitt, François; Artigas, Felipe; Berthebaud, Eric; Bonnat, Armel; Bourrin, François; Bozec, Yann; Cariou, Thierry; Claquin, Pascal; Conan, Pascal; Coppola, Laurent; Delalée, Franck; Facq, Jean-valery; Farcy, Patrick; Ferreira, Sophie; Garcia, Fabrice; Grisoni, Jean-michel; Jacqueline, Franck; Jacquet, Matthias; Lefebvre, Alain; Leredde, Yann; Le Roux, Jean-francois; Mas, Sébastien; Mostajir, Behzad; Mousseau, Laure; Pairaud, Ivane; Petton, Sebastien; Pouvreau, Stephane; Quemener, Loic; Ravel, Christophe; Raimbault, Patrick; Repecaud, Michel; Retho, Michael; Rimmelin-maury, Peggy; Riou, Philippe; Savoye, Nicolas; Souchu, Philippe; Verney, Romaric; Vuillemin, Renaud. |
COAST-HF (Coastal OceAn observing SysTem – High Frequency) is a French national observation network of the physical and biogeochemical dynamics of the coastal ocean, at high frequency. COAST-HF aims at understanding and analysing changes of contrasted coastal ecosystems at different temporal scales from extreme or intermittent high frequency (hour, day) events to multi-year trends. Since several years (from 2000 for the longest time series in Bay of Brest), the network extends along the English Channel, Atlantic and Mediterranean French coasts through 14 fixed platforms instrumented for the in situ high-frequency (≤ 1h) observations. Several French research institutes (IFREMER, CNRS, Marine Universities) are operating these systems. The organization of... |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00635/74723/74708.pdf |
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Grasso, Florent; Mengual, Baptiste; Le Hir, Pierre; Walther, Régis; Verney, Romaric. |
L'embouchure de l’estuaire de la Seine a subi de fortes altérations morphosédimentaires au cours du dernier siècle et son évolution se poursuit encore actuellement. La question du devenir du système et des habitats associés est donc posée, en tenant compte d'éventuels changements environnementaux ou climatiques. La modélisation morphosédimentaire a pour ambition de simuler le devenir de la morpho-bathymétrie, en rendant compte des couplages entre processus hydrodynamiques, transports de sédiment et évolution de la morphologie. Le projet MORPHOSEINE vise à exploiter l'outil de modélisation MARS3D CurviSeine mis en place par l’Ifremer dans le cadre des programmes Seine-Aval (SA) 4 et 5, afin de répondre à l'attente concernant l'évolution possible de... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79630/82353.pdf |
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Pinazo, Christel; Doglioli, Andrea; Faure, Vincent; Fraysse, Marion; Ross, Oliver; Pairaud, Ivane; Petrenko, Anne; Thouvenin, Benedicte; Tronczynski, Jacek; Verney, Romaric; Yohia, Christophe. |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00292/40337/38857.pdf |
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Gangloff, Aurelien; Verney, Romaric; Doxaran, David; Ody, Anouck; Estournel, Claude. |
In coastal environments, river plumes are major transport mechanisms for particulate matter, nutriments and pollutants. Ocean colour satellite imagery is a valuable tool to explore river turbid plume characteristics, providing observations at high temporal and spatial resolutions of suspended particulate matter (SPM) concentration over a long time period, covering a wide range of hydro-meteorological conditions. We propose here to use the MERIS-FR (300 m) Ocean Colour archive (2002–2012) in order to investigate Rhône River turbid plume patterns generated by the two main forcings acting on the north-eastern part of the Gulf of Lions (France): wind and river freshwater discharge. Results are exposed considering plume metrics (area of extension,... |
Tipo: Text |
Palavras-chave: River plume metrics; Sediment dynamics; MERIS; Ocean color data; Suspended particulate matter; Gulf of Lions. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00391/50258/50885.pdf |
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Deloffre, J; Verney, Romaric; Lafite, R; Lesueur, P; Lesourd, S; Cundy, A. |
The objective of this study is to propose an original approach to the analysis of the formation of intertidal rhythmites, their preservation, and the evaluation of sedimentation rates on estuarine mudflats. Three mudflats, one from each of three estuaries, were analysed using a combination of long-term (>a year), high-frequency (1 burst/10 or 20 min), and high-resolution (0.2 cm) altimeter datasets and X-ray images of sediment cores collected during topographic surveys. The results highlight the roles played by sediment supply, hydrodynamics, and morphology of the lower estuaries on the sedimentation rhythms. While the sediment-starved Medway estuary (Kent, UK) remains stable at different time-scales, the annual sedimentation rates on the sheltered... |
Tipo: Text |
Palavras-chave: Macrotidal estuary; X ray imagery; Altimeter; Rhythmites; Mud; Morphology. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3517.pdf |
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Fettweis, M; Toorman, E; Verney, Romaric; Chapalain, Marion; Legrand, S; Lurton, Xavier; Montereale-gavazzi, G; Roche, M; Shen, X; Van Den Eynde, Dries; Van Lancker, Vera. |
Context To protect the marine environment more effectively, the European Union adopted the Marine Strategy Framework Directive (MSFD) in 2008, aiming to achieve the Good Environmental Status (GES) of the EU's marine waters by 2020 and to protect the resource base upon which marine-related economic and social activities depend. A major challenge in the implementation of the MSFD is to achieve the necessary scientific knowledge on the marine environment, its processes and the methods to monitor them. The focus of INDI67 is on the evaluation and development of indicators to monitor GES of descriptor 6 and 7. Seafloor integrity (descriptor 6) refers to the structure and functions of the benthic ecosystems. It relates to the comprises physical, chemical and... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74632/74526.pdf |
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Jourdin, Frederic; Tessier, Caroline; Le Hir, Pierre; Verney, Romaric; Lunven, Michel; Loyer, Sophie; Lusven, Andre; Filipot, Jean-francois; Lepesqueur, Jeremy. |
A pair of self-contained acoustic Doppler current profilers (SC-ADCPs) operating with different frequencies were moored on a muddy sea bottom at about 20 m depth in the Bay of Vilaine off the French Atlantic coast. With their acoustic beams oriented upwards, the SC-ADCPs ensonified most of the water column. The results of several months of in situ recorded echo intensity data spanning 2 years (2003 to 2004) from the dual-frequency ADCPs are presented in this paper. The aim was to estimate suspended particle mass concentration and mean size. A concentration index CI is proposed for the estimation of particle concentration. Based on theory the CI-unlike the volume backscatter strength-does not depend on particle size. Compared with in situ optical data, the... |
Tipo: Text |
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Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00213/32427/30896.pdf |
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Ody, Anouck; Doxaran, David; Vanhellemont, Quinten; Nechad, Bouchra; Novoa, Stefani; Many, Gael; Bourrin, Francois; Verney, Romaric; Pairaud, Ivane; Gentili, Bernard. |
Ocean color satellite sensors are powerful tools to study and monitor the dynamics of suspended particulate matter (SPM) discharged by rivers in coastal waters. In this study, we test the capabilities of Landsat-8/Operational Land Imager (OLI), AQUA&TERRA/Moderate Resolution Imaging Spectroradiometer (MODIS) and MSG-3/Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensors in terms of spectral, spatial and temporal resolutions to (i) estimate the seawater reflectance signal and then SPM concentrations and (ii) monitor the dynamics of SPM in the Rhone River plume characterized by moderately turbid surface waters in a micro-tidal sea. Consistent remote-sensing reflectance (Rrs) values are retrieved in the red spectral bands of these four satellite... |
Tipo: Text |
Palavras-chave: River plumes; Coastal waters; High resolution; Suspended particulate matter; Remote sensing. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00333/44408/44066.pdf |
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Jaud, Marion; Grasso, Florent; Le Dantec, Nicolas; Verney, Romaric; Delacourt, Christophe; Ammann, Jerome; Deloffre, Julien; Grandjean, Philippe. |
Intertidal mudflats play a critical role in estuarine exchange, connecting marine and continental supplies of nutrients and sediments. However, their complex morphodynamics, associated with a wide range of physical and biological processes, are still poorly understood and require further field investigation. In addition, mudflats are challenging areas for Structure-from-Motion (SfM) photogrammetric surveys. Indeed, the mudflats generally hold back residual tidal water, which can make stereo restitution particularly difficult because of poor correlations or sun-glint effects. This study aims to show the potential of light UAVs (Unmanned Aerial Vehicles) for monitoring sedimentary hydrodynamics at different spatial scales in a silty estuary. For each UAV... |
Tipo: Text |
Palavras-chave: Coastal monitoring; Unmanned Aerial Vehicle; Photogrammetry; Estuary; Mudflat areas; Morphological features. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00326/43721/43167.pdf |
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Bacq, Nicolas; Cugier, Philippe; Grasso, Florent; Le Gendre, Romain; Le Hir, Pierre; Lemoine, Jean-philippe; Riou, Philippe; Schulz, Elisabeth; Thouvenin, Benedicte; Verney, Romaric. |
Dans le cadre du programme de recherche Seine-Aval 5, différentes stratégies de modélisation numérique sont mises en place pour aider à répondre aux questionnements scientifiques et sociétaux associés au fonctionnement physique, biologique, chimique et écologique de l'estuaire de la Seine (ex. projets RESET et HYMOSED). Les forçages météo-marins (vent, vague, marée) et hydrologique (débit) contrôlent le fonctionnement hydro-morpho-sédimentaire et biogéochimique de l'estuaire, modifiant ainsi les paramètres environnementaux de l’estuaire amont jusqu’à la baie de Seine (ex. nature des fonds, courant, turbidité, salinité, température, oxygène dissous, chlorophylle-a). La modélisation de ces paramètres, ainsi que leur évolution face à différents scénarios... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00284/39480/37966.pdf |
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Le Fouest, Vincent; Chami, Malik; Verney, Romaric. |
The export of riverine suspended particulate matter (SPM) in the coastal ocean has major implications for the biogeochemical cycles. In the Mediterranean Sea (France), the Rhone River inputs of SPM into the Gulf of Lion (GoL) are highly variable in time, which severely impedes the assessment of SPM fluxes. The objectives of this study are (i) to investigate the prediction of the land-to-ocean flux of SPM using the complementarity (i.e., synergy) between a hydrodynamic sediment transport model and satellite observations, and (ii) to analyze the spatial distribution of the SPM export. An original approach that combines the MARS-3D model with satellite ocean color data is proposed. Satellite-derived SPM and light penetration depth are used to initialize... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00266/37728/35736.pdf |
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Gentil, Mathieu; Many, Gaël; Durrieu De Madron, Xavier; Cauchy, Pierre; Pairaud, Ivane; Testor, Pierre; Verney, Romaric; Bourrin, François. |
The recent integration of Acoustic Doppler Current Profilers (ADCPs) onto underwater gliders changes the way current and sediment dynamics in the coastal zone can be monitored. Their endurance and ability to measure in all weather conditions increases the probability of capturing sporadic meteorological events, such as storms and floods, which are key elements of sediment dynamics. We used a Slocum glider equipped with a CTD (Conductivity, Temperature, Depth), an optical payload, and an RDI 600 kHz phased array ADCP. Two deployments were carried out during two contrasting periods of the year in the Rhone River region of freshwater influence (ROFI). Coastal absolute currents were reconstructed using the shear method and bottom tracking measurements, and... |
Tipo: Text |
Palavras-chave: Glider; Optics; Acoustics; Satellite; Coastal hydrodynamics; Suspended particulate matter; Particulate fluxes; Gulf of Lions; Mediterranean. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00648/76039/76962.pdf |
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Verney, Romaric; Lafite, Robert; Brun-cottan, Jean-claude. |
Estuarine systems are complex environments where seasonal and spatial variations occur in concentrations of suspended particulate matter, in primary constituents, and in organic matter content. This study investigated in the laboratory the flocculation potential of estuarine-suspended particulate matter throughout the year in order to better identify the controlling factors and their hierarchy. Kinetic experiments were performed in the lab with a "video in lab" device, based on a jar test technique, using suspended sediments sampled every 2 months over a 14-month period at three stations in the Seine estuary (France). These sampling stations are representative of (1) the upper estuary, dominated by freshwater, and (2) the middle estuary, characterized by a... |
Tipo: Text |
Palavras-chave: Seine estuary (France); Kolmogorov microscale; Diatom bloom; Floc structure; Cohesive sediment; Flocculation. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6631.pdf |
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Registros recuperados: 48 | |
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