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| Registros recuperados: 35 | |
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| Pous, Stephane; Lazure, Pascal; Carton, Xavier. |
| Previous studies modeling the circulation and thermohaline structure in the Persian Gulf have suggested that interannual variability and vertical mixing processes could explain the model biases when compared to the few observations available. Here, a realistic, interannual, high-resolution model of the Persian Gulf is presented, validated against observations and then used to describe the intraseasonal to interannual variability in the circulation, water mass formation and exchange through the Strait of Hormuz. Sensitivity experiments to model settings, in particular vertical mixing parameterizations, have been performed in order to have the best comparison with all available observations. Main circulation and water mass characteristics correspond well to... |
| Tipo: Text |
Palavras-chave: Persian Gulf; Strait of Hormuz; Numerical model; Hydrology; Currents; Interannual variability. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00244/35563/35324.pdf |
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| Cai, Sq; Long, Xm; Gan, Zj. |
| A new composite model, which consists of a generation model of the internal tides and a regularized long wave propagation model, is presented to study the generation and evolution of internal solitary waves in the sill strait. Internal bores in the sill strait are first simulated by the generation model. and then the internal tidal field outside of the sill region is given as input for the propagation model. Numerical experiments are carried out to Study the imposing tide, depth profile. channel width and shoaling effect, etc., on the generation and evolution of internal solitary waves. It is shown that only when the amplitude of internal tide at the forcing boundary of the propagation model is large enough that a train of internal solitary waves would be... |
| Tipo: Text |
Palavras-chave: Marée interne; Modèle numérique de soliton; Mer de Chine; Internal wave; Soliton; Numerical model; South China Sea. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00322/43319/42935.pdf |
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| Treguier, Anne-marie; Boebel, O; Barnier, B; Madec, G. |
| A 1/6degrees resolution primitive equation model of the Atlantic circulation is analyzed in the Agulhas region. The model has a realistic level of eddy kinetic energy, and produces anticyclonic Agulhas rings as well as cyclonic structures. In the model as well as in the data, ring trajectories undergo a transition between a turbulent character in the Cape Basin and a steady propagation in the rest of the South Atlantic. The topography of the Walvis Ridge does not seem to play a part in generating this contrast in the model. The model shows that cyclones are primarily generated from the negative shear vorticity side of the Agulhas Current as it leaves the coast, and they are most of the time paired with anticyclones in dipolar or tripolar structures.... |
| Tipo: Text |
Palavras-chave: South Africa; South Atlantic Ocean; Numerical model; Ocean currents; Oceanic eddies; Eddy flux. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-453.pdf |
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| Gaasland, Ivar. |
| Agriculture at high latitudes is expected to be a main beneficiary of a man-made climate change. A numerical model, using Norway as a case, is employed to analyze the impacts of a warmer climate on northern agriculture. The computations indicate that the current degree of self-sufficiency can be achieved with less budget support and higher economic welfare. However, it may be argued that environmental goods, such as landscape and biodiversity preservation, and rural settlement, are more important than self-sufficiency for northern agriculture. It is demonstrated that, in that case, welfare gains are substantially lower, and can even be negative. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Climate change; Northern agriculture; Environmental goods; Numerical model; Environmental Economics and Policy; Resource /Energy Economics and Policy; L52; Q18; Q24. |
| Ano: 2005 |
URL: http://purl.umn.edu/24551 |
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| Lique, Camille. |
| While perhaps the most obvious, ice retreat is just one aspect of a changing Arctic system. The Arctic Ocean is also undergoing unprecedented modifications, that mostly affect its heat and freshwater budgets. As the signal of Arctic change is expected to have its major climatic impact by reaching south the subarctic seas, on either side of Greenland, to modulate the Atlantic thermohaline circulation, the objective of this thesis is to investigate the variability of the exports of volume, heat, freshwater and sea-ice from the Arctic Ocean to the North Atlantic. First, a realistic simulation from 1958 to 2002 run with a global ocean/sea-ice model is used to investigate some aspects of the variability of the Arctic freshwater budget, trying to understand... |
| Tipo: Text |
Palavras-chave: Océan Arctique; Bilan d'eau douce; Flux d'eau douce; Glace de mer; Modèle numérique - Analyse Lagrangienne - Forçages atmosphériques; Arctic Ocean; Freshwater budget; Freshwater flux; Sea ice; Numerical model; Lagrangian analysis; Atmospheric forcing. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12597/9474.pdf |
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| Morvan, Barthelemy; Priour, Daniel; Guede, Zakoua; Bles, G.. |
| The evaluation of the mesh resistance to opening of fishing nets is an important issue in assessing the selectivity of trawls by numerical methods. Sala et al. (2007) proposed a method using a relatively expensive experimental device ensuring the 2D deformation of net sample. De la Prada and Gonzales (2015) proposed a simple uni-axial experimental set-up, which stretches a sample in the transverse direction of the meshes while leaving free its deformation in the normal direction. Both authors (Sala and De la Prada) assumed that the deformation is uniform in the sample. The present study aims at developing a finite element model taking into account the mesh resistance to opening of nets, allowing the simulation of non-uniform deformation. Mechanical... |
| Tipo: Text |
Palavras-chave: Netting; Mesh resistance to opening; Bending stiffness; Experiment; Numerical model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45813/49043.pdf |
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| Ardhuin, Fabrice; Gualtieri, Lucia; Stutzmann, Eleonore. |
| Microseismic activity, recorded everywhere on Earth, is largely due to ocean waves. Recent progress has clearly identified sources of microseisms in the most energetic band, with periods from 3 to 10 s. In contrast, the generation of longer-period microseisms has been strongly debated. Two mechanisms have been proposed to explain seismic wave generation: a primary mechanism, by which ocean waves propagating over bottom slopes generate seismic waves, and a secondary mechanism which relies on the nonlinear interaction of ocean waves. Here we show that the primary mechanism explains the average power, frequency distribution, and most of the variability in signals recorded by vertical seismometers, for seismic periods ranging from 13 to 300 s. The secondary... |
| Tipo: Text |
Palavras-chave: Hum; Infragravity waves; Numerical model; Microseisms. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00251/36219/34769.pdf |
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| Morvan, Barthelemy; Bles, G; Dumergue, Nicolas; Priour, Daniel. |
| The evaluation of the mesh opening stiffness of fishing nets is an important issue in assessing the selectivity of trawls. It appeared that a larger bending rigidity of twines decreases the mesh opening and could reduce the escapement of fish. Nevertheless, netting structure is complex. A netting is made up of braided twines made of polyethylene or polyamide. These twines are tied with non-symmetrical knots. Thus, these assemblies develop contact-friction interactions. Moreover, the netting can be subject to large deformation. In this study, we investigate the responses of netting samples to different types of solicitations. Samples are loaded and unloaded with creep and relaxation stages, with different boundary conditions. Then, two models have been... |
| Tipo: Text |
Palavras-chave: Numerical model; Experiments; Braided twine; Mesh opening rigidity; Large deformation.. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00348/45899/45581.pdf |
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| Treguier, Anne-marie; Chassignet, Eric P.; Le Boyer, Arnaud; Pinardi, Nadia. |
| We present a historical perspective on ocean mesoscale variability and turbulence, from the physical basis and the first numerical models to recent simulations and forecasts. In the mesoscale range (typically, spatial scales of 100 km and time scales of a month), nonlinearity, and energy cascades were well understood in the 1970s, but the emergence of coherent vortices took place much later. New challenges have arisen with the exploration of the submesoscale regime, where frontal dynamics play a key role and the range of flow instabilities is wider than in the quasi-geostrophic regime. Special focus is placed on the interaction of mesoscale turbulence with the continental slopes. The contrast between the variability on the western and eastern boundaries of... |
| Tipo: Text |
Palavras-chave: Numerical model; Ocean forecast; Ocean mesoscale turbulence. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52106/52939.pdf |
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| Brunstad, Rolf Jens; Gaasland, Ivar; Vardal, Erling. |
| Without support, the levels of agricultural public goods will fall short of the demand in high cost countries like Norway, Finland and Iceland. However, as demonstrated in this paper using Norway as a case, the current support and agricultural activity is far out of proportions from a public goods perspective. Model simulations show that at most 40% of the current support level can be defended by the public good argument. Furthermore, the present support, stimulating high production levels, is badly targeted at the public goods in question. Since agricultural land is a major component of both food security and landscape preservation, thus giving rise to a high degree of cost complementarities between the two public goods, it would be more efficient to... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Food security; Landscape preservation; Public goods; Agricultural policy; Numerical model; Food Security and Poverty; Land Economics/Use. |
| Ano: 2005 |
URL: http://purl.umn.edu/24470 |
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| Harnois, V.; Weller, Sam D.; Johanning, L.; Thies, P. R.; Le Boulluec, Marc; Le Roux, Dominique; Soule, Veronique; Ohana, Jeremy. |
| The design of wave energy mooring systems is challenging: overdesign incurs a significant cost penalty, underdesign may lead to a premature failure and incorrect design could reduce the power production. Consequently, compliant mooring systems are being developed for wave energy applications. This paper presents tank test results for a scale model of the buoy and mooring used at the SouthWest Mooring Test Facility (SWMTF), an offshore facility developed to conduct long-term sea trials for wave energy device moorings. A compliant three leg catenary mooring system using Nylon ropes in the water column is investigated. Preliminary static, quasi-static, decay, regular and irregular wave tests were conducted on the 1:5 scale model, using the Ifremer basin in... |
| Tipo: Text |
Palavras-chave: Wave energy converter; Tank tests; Numerical model; Highly dynamic mooring system; Fibre rope. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00233/34375/35785.pdf |
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| Dubarbier, Benjamin; Castelle, Bruno; Marieu, Vincent; Michallet, Hervé; Grasso, Florent; Ruessink, Gerben. |
| The recent advances of numerical beach profile models allowed the simulation of on/offshore sandbar migrations on timescales of weeks to months with fair success. These models were systematically applied to natural, persistently evolving, beaches. In this contribution, we apply our model to small-scale laboratory experiments for which coarse and lightweight sediment is used to satisfy the laws of similitude in the flume. Such experiments can result in equilibrium beach profiles and provide detailed information on the respective role of undertow and wave nonlinearities on sediment transport and the resulting cross-shore sandbar migration. Here we first apply the coupled, wave-averaged, cross-shore waves-currents-bathymetric evolution model 1DBeach to an... |
| Tipo: Text |
Palavras-chave: Beach profile; Numerical model; Physical modelling; Equilibrium profile; Sandbar migration. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29089/27503.pdf |
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| Registros recuperados: 35 | |
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