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Polsenaere, Pierre; Deborde, Jonathan; Detandt, Guillaume; Vidal, Luciana O.; Perez, Marcela A. P.; Marieu, Vincent; Abril, Gwenael. |
In November 2011, the partial pressures of carbon dioxide (pCO(2)) in water and air in a floodplain lake of the Amazon River in Brazil were 800 +/- 75 and 387 +/- 8 ppmv, respectively. Turbulent CO2 fluxes from the lake measured with eddy covariance ranged from 0.05 to 2.2 mmol m(-2) s(-1). The corresponding gas transfer velocities k(600) ranged from 1.3 to 31.6 cm h(-1), averaging 12.2 +/- 6.7 cm h(-1). At moderate to high wind speed, k(600) increased with wind speed, with values above parameterizations for other lake ecosystems. During the prevailing tropical low wind speed (below 2.7 m s(-1)) and high insolation conditions, unexpected high k(600) values (up to 20 cm h(-1)) were obtained and correlated with latent heat and sensible heat fluxes. In... |
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Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00603/71532/69950.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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Lafon, Virginie; Marieu, Vincent; Butel, Rémi; Dehouck, Aurélie; Froidefond, Jean-marie; Trut, Gilles. |
This study presents the first results of an ongoing research program that aims to derive thematic maps of the intertidal lagoon of Arcachon (SW Atlantic coast of France) from space imagery. At this stage, we present the results of the tests performed on Formosat-2 imagery. Several classification strategies have been tried with the aim to discriminate the sedimentary facies and the main species of the lagoon. The classes calculated by an optimized unsupervised clustering method, based on simulated annealing global minimization technique, were used to train a supervised classification algorithm. This approach allowed us to derive a bio-sedimentary map which overall accuracy is about 84%. Also, this method has the advantage of describing the fraction of... |
Tipo: Text |
Palavras-chave: Télédétection; Cartographie; Littoral; Classification optimisée; Recuit simulé. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00254/36572/35110.pdf |
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Lienart, Camilla; Savoye, Nicolas; David, Valerie; Ramond, Pierre; Tress, Paco Rodriguez; Hanquiez, Vincent; Marieu, Vincent; Aubert, Fabien; Aubin, Sebastien; Bichon, Sabrina; Boinet, Christophe; Bourasseau, Line; Bozec, Yann; Breret, Martine; Breton, Elsa; Caparros, Jocelyne; Cariou, Thierry; Claquin, Pascal; Conan, Pascal; Corre, Anne-marie; Costes, Laurence; Crouvoisier, Muriel; Del Amo, Yolanda; Derriennic, Herve; Dindinaud, Francois; Duran, Robert; Durozier, Maia; Devesa, Jeremy; Ferreira, Sophie; Feunteun, Eric; Garcia, Nicole; Geslin, Sandrine; Grossteffan, Emilie; Gueux, Aurore; Guillaudeau, Julien; Guillou, Gael; Jolly, Orianne; Lachaussee, Nicolas; Lafont, Michel; Lagadec, Veronique; Lamoureux, Jezabel; Lauga, Beatrice; Lebreton, Benoit; Lecuyer, Eric; Lehodey, Jean-paul; Leroux, Cedric; L'Helguen, Stephane; Mace, Eric; Maria, Eric; Mousseau, Laure; Nowaczyk, Antoine; Pineau, Philippe; Petit, Franck; Pujo-pay, Mireille; Raimbault, Patrick; Rimmelin-maury, Peggy; Rouaud, Vanessa; Sauriau, Pierre-guy; Sultan, Emmanuelle; Susperregui, Nicolas. |
In costal systems, particulate organic matter (POM) results from a multiplicity of sources having their respective dynamics in terms of production, decomposition, transport and burial. The POM pool experiences thus considerable spatial and temporal variability. In order to better understand this variability, the present study employs statistical multivariate analyses to investigate links between POM composition and environmental forcings for a panel of twelve coastal systems distributed along the three maritime regions of France and monitored weekly to monthly for 1 to 8 years. At multi-system scale, two main gradients of POC composition have been identified: a ‘Continent-Ocean’ gradient associated with hydrodynamics, sedimentary dynamics and depth of the... |
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Palavras-chave: Particulate organic matter; Coastal systems; Environmental forcing; Meta-analysis; France. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00433/54471/55848.pdf |
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Toucanne, Samuel; Zaragosi, Sebastien; Bourillet, Jean-francois; Marieu, Vincent; Cremer, Michel; Kageyama, Masa; Van Vliet-lanoe, Brigitte; Eynaud, Frederique; Turon, Jean-louis; Gibbard, Philip L.. |
The Fleuve Manche (English Channel) palaeoriver represents the largest river system that drained the European continent during Pleistocene lowstands, particularly during the Elsterian (Marine Isotope Stage 12) and Saalian Drenthe (MIS 6) glaciations when extensive ice advances into the North Sea area forced the central European rivers to flow southwards to the Bay of Biscay (NE Atlantic). Numerous long piston cores and high-resolution acoustic data from the northern Bay of Biscay have been correlated using a well-constrained chronostratigraphical framework, and for the first time allow the estimation of the discharge of the Fleuve Manche palaeoriver at the end of the last glacial period (i.e. Weichselian). Our results, discussed in the light of... |
Tipo: Text |
Palavras-chave: Fleuve Manche palaeoriver; English Channel; Sediment and meltwater discharge; European ice sheet; Deglaciation; Termination 1; North Sea area; European drainage network. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11310/7858.pdf |
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