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Registros recuperados: 53 | |
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Planque, Benjamin; Lazure, Pascal; Jegou, Anne-marie. |
Collecting hydrological observations over the whole Bay of Biscay continental shelf can require several weeks. As a result, the observations are not truly synoptic and the interpretation of hydrological structures is corrupted by the time-lags between observations at distinct locations. We evaluated the effects of non-synoptic sampling during a spring cruise (17 April to 13 May 2000), using outputs from 3D hydrodynamic models as a substitute for true synoptic sampling. We developed a method for clustering hydrological regions based on the vertical structure of the water column and temporal changes in hydrography. In parallel, outputs from the 3D model were compared with field observations. The results show that in spring 2000 the Bay of Biscay continental... |
Tipo: Text |
Palavras-chave: Typology; Spatial temporal interactions; Hydrodynamics; Clustering analysis; Bay of Biscay. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3959.pdf |
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Demory, David; Combe, Charlotte; Hartmann, Philipp; Talec, Amelle; Pruvost, Eric; Hamouda, Raouf; Souille, Fabien; Lamarea, Pierre-olivier; Bristeau, Marie-odile; Sainte-marie, Jacques; Rabouille, Sophie; Mairet, Francis; Sciandra, Antoine; Bernard, Olivier. |
Hydrodynamics in a high-rate production reactor for microalgae cultivation affects the light history perceived by cells. The interplay between cell movement and medium turbidity leads to a complex light pattern, whose forcing effects on photosynthesis and photoacclimation dynamics are nontrivial. Hydrodynamics of high density algal ponds mixed by a paddle wheel has been studied recently, although the focus has never been on describing its impact on photosynthetic growth efficiency. In this multidisciplinary downscaling study, we first reconstructed single cell trajectories in an open raceway using an original hydrodynamical model offering a powerful discretization of the Navier-Stokes equations tailored to systems with free surfaces. The trajectory of a... |
Tipo: Text |
Palavras-chave: Photosynthesis; Hydrodynamics; Modelling; Photoacclimation; Dunaliella salina; Non-photochemical quenching. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55692/57352.pdf |
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Plus, Martin; Dumas, Franck; Stanisiere, Jean-yves; Maurer, Daniele. |
A numerical model (MARS-2D) was developed, with the aim of describing the hydrodynamics that prevail in Arcachon Bay. Direct model results as well as derived mixing and transport time-scales (tidal prism, local and integrated flushing times, age of water masses), were used to understand the behaviour of water masses and exchanges between the Bay and its frontiers. Particular attention was paid to the processes that drive the hydrodynamics (tides, wind and rivers), in order to understand their respective influence. The Arcachon Bay hydrodynamic system appears primarily to be highly influenced by tides; secondarily, by winds. About two third of the lagoon total volume is flushed in and out at each tidal cycle, which represent a mean tidal prism of 384... |
Tipo: Text |
Palavras-chave: Arcachon Bay; Tracer; Age of seawater; Flushing time; Tidal prism; Residual fluxes; Hydrodynamics. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6424.pdf |
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Marion, C.; Dufois, Francois; Arnaud, Mireille; Vella, C.. |
The environment is impacted by natural and anthropogenic disturbances that occur at different spatial and temporal scales, and that lead to major changes and even disequilibria when exceeding the resiliency capacities of the ecosystem. With an annual mean flow of 1700 m(3) s(-1), the Rhone River is the largest of the western Mediterranean basin. Its annual solid discharges vary between 2 and 20 Mt, with flood events responsible for more than 70% of these amounts. In the marine coastal area, close to the mouth, both flocculation and aggregation lead to the formation of fine-grained deposits, i.e. the prodelta. This area is characterized by sediment accumulation rates up to 20-50 cm yr(-1) and high accumulations of particle reactive contaminants such as... |
Tipo: Text |
Palavras-chave: Sediment dynamics; Floods; Hydrodynamics; Radiotracers; Rhone River prodelta. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11695/8479.pdf |
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Bouhoubeiny, Elkhadim; Druault, Philippe; Germain, Gregory. |
Time-Resolved Particle Image Velocimetry (PIV) measurements are performed to investigate the hydrodynamic flow interaction with a representative piece of fishing net structure. Using the advanced post-processing mathematical tool based on Proper Orthogonal Decomposition, the phase averaged mean properties of turbulent flows are extracted from PIV database, demonstrating the existence of a Turbulent Boundary Layer (TBL) flow developing all around the sheet of net. The results also show that the mesh opening and so the turbulent flow passing through the structure are strongly influenced by the structure oscillations. This work allows us to demonstrate that the drag computation of fishing gear, commonly based on uniform velocity, needs to consider not only... |
Tipo: Text |
Palavras-chave: Fishing net structure; Hydrodynamics; PIV; Turbulent boundary layer flow. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00184/29552/27878.pdf |
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Burel, Thomas; Schaal, Gauthier; Grall, Jacques; Le Duff, Michel; Chapalain, Georges; Schmitt, Blondie; Gemin, Maxence; Boucher, Olivier; Ar Gall, Erwan. |
Wave height was used as a proxy to assess the effect of hydrodynamics on the development and structure of intertidal North-East Atlantic rocky macroalgal communities (Brittany). The characterization of hydrodynamics at small-scale (about 10 m) was performed through wave height in situ monitoring using pressure sensors. Both the diversity and the cover of the macroalgal communities were sampled in parallel. Wave heights exhibit large variations with values ranging from ca. 5 cm to 1.60 m. We show that wave height directly controls the cover of macroalgal canopies (Pearson's r between −0.62 and −0.39). In all communities, most of the fucoid covers regressed with increasing wave height values. By contrast, positive correlations were found at low shore levels... |
Tipo: Text |
Palavras-chave: Macroalgal communities; Intertidal zone; Rocky shores; Wave heights; Hydrodynamics; Mini-diver; Brittany. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00506/61769/65752.pdf |
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Plantecuny, M; Bodoy, Alain. |
In order to estimate energetic relationship, microphytic and benthic bivalve levels of a shallow (1.5 m), sandy ecosystem near Marseille (Gulf of Fos, Southern France) were sampled monthly during 1.5 year, in two sites differing by their wave exposure. In the sheltered area, the bivalve Ruditapes decussatus was the dominant species, while another bivalve, Donax trunculus , was found in the open, wave exposed site. Chlorophyll a and primary production of the phytoplankton and the microphytobenthos, as well as population dynamic, growth and biochemical composition of bivalves (lipids, proteins and carbohydrates) were monitored. |
Tipo: Text |
Palavras-chave: Ruditapes decussatus; Bivalvia; Periphyton; Phytoplankton; Biochemical composition; Growth; Marine molluscs; Hydrodynamics; Seasonal variations; Primary production; Trophic relationships. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1528.pdf |
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Pernet, Fabrice; Barret, Jean; Le Gall, Patrik; Corporeau, Charlotte; Degremont, Lionel; Lagarde, Franck; Pepin, Jean-francois; Keck, Nicolas. |
Experiments were conducted to investigate the effects of farming sites, seeding date, age of oysters, ploidy level and rearing structures on mortality, pathogens and energetic reserves of oysters Crassostrea gigas. Mortality of oysters coincided with infections involving, primarily, the ostreid herpesvirus OsHV-1 and, secondarily, bacteria of the group Vibrio splendidus, when seawater temperature was between 17 and 24°C. Mortality started in early May and lasted until late September, with an interruption in July and August when seawater temperatures rose above 24°C. Mortality varied with farming site: oysters maintained in the open Mediterranean Sea showed no mortality and OsHV-1 was occasionally detected at a low level only, while oysters maintained in... |
Tipo: Text |
Palavras-chave: Pacific oyster; Mortality; Disease; Farming practices; Hydrodynamics; Energetic. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19739/17379.pdf |
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Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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Gomez, E; Millet, B; Picot, B. |
The Mejean-Perols Lagoon is situated on the French Mediterranean coast. It is a small (747 ha) and shallow (70 cm) lagoon. Some treated effluent from Montpellier flows into this hypereutrophic lagoon. The cartography of C, N and P concentrations in the sediment was studied based on 35 bottom samples. The nitrogen and organic carbon concentrations were more or less homogeneous, the highest concentrations being found in the middle of the lagoon. The phosphate was principally bound onto the sediment in the west zone. The observed distribution was independent of grain size, the distribution of which was rather homogeneous. In this lagoon water circulation is wind induced. Four different water flow structures were observed, as functions of the prevailing winds... |
Tipo: Text |
Palavras-chave: Sédiment; Lagune côtière; Hydrodynamique; Sels nutritifs; Carbone; Sediment; Coastal lagoon; Hydrodynamics; Nutrients; Carbon. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43642/43247.pdf |
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Augris, Claude; Hamon, Dominique. |
This atlas presents in a synthetic form the hydrodynamical, geological and biological characteristics of one of the most studied region of the French littoral. Geologic and geophysical data of the Saint-Brieuc Bay show that the deep basement consists of pre-palaeozoic or palaeozoic sedimentary series in the centre of the Bay, whereas metamorphic and magmatic formations are dominant in coastal regions. The location of superficial sediments in the Bay, is mainly due to marine currents. A granulometric gradient, from very fine to coarse sediments, appears in two directions: from the coast towards the high sea, and from the west to the east. Rocky substrates disrupt the sediment distribution, with, most of the time, a concentration of coarse sediments near the... |
Tipo: Text |
Palavras-chave: Atlas; Bathymetry; Bottom topography; Commercial species; Geomorphology; Hydrodynamics; Marine resources; Sediment analysis; Sedimentary basins; Zoobenthos. |
Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00031/14246/11527.pdf |
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Registros recuperados: 53 | |
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