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Registros recuperados: 76 | |
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Gohin, Francis; Saulquin, Bertrand; Oger-jeanneret, Helene; Lozac' H, L; Lampert, Luis; Lefebvre, Alain; Riou, Philippe; Bruchon, F. |
The application of the new Water Framework Directive (WFD) of the European Union will require a dense and frequent monitoring of chlorophyll-a near the coast. Not counting the transitional water bodies located in the vicinity of estuaries, not less than seventy four coastal water bodies have to be monitored along the coast of the French Atlantic continental shelf and the English Channel. All the available data have to be gathered to implement a comprehensive monitoring scheme. To this purpose, we evaluate the capacity of ocean colour imagery to complete the conventional in situ data set collected in coastal networks. Satellite-derived chlorophyll-a concentration is obtained by the application of a coastal Look-Up-Table to water-leaving radiance of the... |
Tipo: Text |
Palavras-chave: SeaWiFS; Coastal; Surveillance; Monitoring; Chlorophyll; Satellite. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4501.pdf |
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L'Heveder, Blandine; Speich, Sabrina; Ragueneau, Olivier; Gohin, Francis; Bryere, Philippe. |
Seasonal Sea Surface Temperature (SST) changes in the Western English Channel have been estimated for the previous decades from high-resolution satellite data. Coastal seas, well separated from offshore waters by intense frontal structures, show colder SST by 1 to 2°C in summer. A significant warming trend is observed in the autumn season. This positive trend is stronger offshore, with an annual mean SST increase of 0.32°C/decade, but weaker in coastal waters (0.23°C/decade), where strong vertical mixing induced by tides and winds acts to reduce surface warming. The performance of an ensemble of CMIP5 climate model in simulating recent seasonal changes of SST in the region is estimated. The median of CMIP5 models reproduces very well the observed SST mean... |
Tipo: Text |
Palavras-chave: SST; Climate change; Western English Channel; CMIP5; Regional study. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00350/46163/45861.pdf |
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Thomas, Yoann; Pouvreau, Stephane; Alunno-bruscia, Marianne; Barille, Laurent; Gohin, Francis; Bryere, Philippe; Gernez, Pierre. |
Aim The spread of non-indigenous species in marine ecosystems world-wide is one of today's most serious environmental concerns. Using mechanistic modelling, we investigated how global change relates to the invasion of European coasts by a non-native marine invertebrate, the Pacific oyster Crassostrea gigas. Location Bourgneuf Bay on the French Atlantic coast was considered as the northern boundary of C. gigas expansion at the time of its introduction to Europe in the 1970s. From this latitudinal reference, variations in the spatial distribution of the C. gigas reproductive niche were analysed along the north-western European coast from Gibraltar to Norway. Methods The effects of environmental variations on C. gigas physiology and phenology were studied... |
Tipo: Text |
Palavras-chave: Biogeographical range expansion; Crassostrea gigas; DEB model; European coasts; Functional traits; Global change; Individual-based model; Invasive species; Remote-sensing. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00287/39828/38459.pdf |
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Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002). |
Tipo: Text |
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf |
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Saulquin, Bertrand; Gohin, Francis. |
A night-time series of sea surface temperature (SST) of the advanced very high-resolution radiometer (AVHRR) sensors provided by the AVHRR/Pathfinder was analysed over the period 1986-2006 in the English Channel. The studied area is characterized by a strong influence of the bathymetry on the mixing of the water column, mostly through the action of the tide and waves, leading to regional patterns in the SST fields. Another specific aspect of the area is the relatively large number of in situ measurements available from coastal stations. The remotely sensed SST data with fine spatial resolution and high-frequency measurements made at coastal stations have been analysed using a common model. The long-term evolution of SST has been defined in this study... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12460/9881.pdf |
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Buestel, Dominique; Dao, Jean-claude; Gohin, Francis. |
The efficiency of the fishing drags in the Saint Brieuc Bay, Brittany, has been determined through the analysis of the tracks left on the seabed. The results, which focus mostly on the age class n°2 (2.5 years), show that the efficiency and the damages caused by the drags vary heavily according to the nature of the seabed. For soft bottoms, the average efficiency is 67 % and the global damage is 2 %. Concerning hard bottoms, the values are respectively 30 % and 17 %. These efficiency results combined with those of a dragging expedition in a set sector of the Saint-Brieuc Bay enable a direct assessment of the abundance. A result treatment method deriving from the geostatistical theory is used: it takes into account the spatial structure of the king scallop... |
Tipo: Text |
Palavras-chave: Coquille Saint Jacques; Plongée; Dragage; Pecten maximus L.; Estimation stocks. |
Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-6536.pdf |
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Druon, Jean-noel; Loyer, S; Gohin, Francis. |
Different scales of hydrological and biological patterns of the Bay of Biscay are assessed using space-borne and airborne optical remote sensing data, field measurements and a 3-dimensional biophysical model. If field measurements provide accurate values on the vertical dimension, ocean colour data offer frequent observations of surface biological patterns at various scales of major importance for the validation of ecosystem modelling. Although the hydrobiological model of the continental margin reproduces the main seasonal variability of surface biomass, the optical remote sensing data have helped to identify low grid resolution, input inaccuracies and neglect of swell-induced erosion mechanism as model limitations in shallow waters. Airborne remote... |
Tipo: Text |
Palavras-chave: Bay of Biscay; Models; Scaling; Remote sensing; Satellite observation; Phytoplankton. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-953.pdf |
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Menesguen, Alain; Cugier, Philippe; Loyer, Sophie; Vanhoutte Brunier, Alice; Hoch, Thierry; Guillaud, Jean-francois; Gohin, Francis. |
The general trend in ecosystem modelling is to improve the spatial resolution by shifting from rough box-models to fine 3D models. Despite the continuous speeding-up of computing, 3D models involving numerous state variables may remain intractable, especially for parameter calibration, when processes with long half-life periods (i.e, from years to decades) are introduced, such as the behaviour of organic matter in sediment and population dynamics of benthic species. In these cases, a first approach can be provided by fast-running box-models, if they take into account the most crucial hydrodynamic properties of the system. In a macrotidal shelf sea such as the English Channel, the long-term horizontal transport can be summarized by the tidal residual... |
Tipo: Text |
Palavras-chave: English Channel; Stratification; Diatom/dinoflagellate succession; 3D model; Layered box model. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2315.pdf |
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Rivier, Aurelie; Guillou, Nicolas; Chapalain, Georges; Gohin, Francis. |
Concentration of near-surface suspended particulate matter (SPM) is a key parameter for the characterization of sediment dynamics and the quantification of light in the water column for hydrological and biological modeling in coastal seas. The influences of tides and wind-generated surface-gravity waves on non-algal near-surface SPM in the English Channel have recently been identified by Rivier et al. (2012) on the basis of statistical models applied to a large satellite dataset. The present study extends this analysis by comparing satellite images and numerical model predictions of non-algal near-surface SPM. Satellite images are MODIS and MERIS remote-sensing reflectance processed by the IFREMER semi-analytical algorithm (Gohin et al., 2011). These data... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00108/21959/19553.pdf |
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Gohin, Francis; Langlois, G. |
This study proposes a method for bathythermal analysis applied to the temperature profiles collected in the Bay of Biscay since 1950 and recorded at the French Hydrographic and Oceanographic Service of the Navy (SHOM). We consider the ocean variability, historically sampled with temperature measurements, from a geostatistical point of view. Thanks to an appropriate model of the thermal structures and using the "kriging" method, we proceed to monthly mean optimal estimations on a regular gridnet. For this purpose, we choose a random function model able to take several scales of phenomena into account. In practice, a structural analysis is first performed from the monthly files by computing the experimental variogram. Secondly, we exclude the incoherent... |
Tipo: Text |
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Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00101/21249/18892.pdf |
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Guillou, Nicolas; Rivier, Aurelie; Chapalain, Georges; Gohin, Francis. |
Numerous ecological problems of continental shelf ecosystems require a refined knowledge of the evolution of suspended sediment concentrations (SSC). The present investigation focuses on the spatial and temporal variabilities of near-surface SSC in coastal waters of the English Channel (western Europe) by exploiting numerical predictions from the Regional Ocean Modeling System ROMS. Extending previous investigations of ROMS performances in the Channel, this analysis refines, with increased spatial and temporal resolutions, the characterization of near-surface SSC patterns revealing areas where concentrations are highly correlated with evolutions of tides and waves. Significant tidal modulations of near-surface concentrations are thus found in the eastern... |
Tipo: Text |
Palavras-chave: Sediment transport; Numerical modeling; Satellite; ROMS; MERIS; MODIS. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00345/45607/45227.pdf |
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Auber, Arnaud; Gohin, Francis; Goascoz, Nicolas; Schlaich, Ivan. |
A growing number of studies have documented increasing dominance of warm-water fish species (“tropicalisation”) in response to ocean warming. Such reorganization of communities is starting to occur in a multitude of local ecosystems, implying that tropicalisation of marine communities could become a global phenomenon. Using 32 years of trawl surveys in the Bay of Somme (English Channel, France), we aimed to investigate the existence of a tropicalisation in the fish community at the local scale of the estuary during the mid-1990s, a period where an exceptional temperature rise occurred in Northeast Atlantic. A long-term response occurred (with a major transition over 6 years) that was characterized by a marked diminution in the abundance of cold-water... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00374/48551/48873.pdf |
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Von Schuckmann, Karina; Le Traon, Pierre-yves; Smith, Neville; Pascual, Ananda; Djavidnia, Samuel; Gattuso, Jean-pierre; Grégoire, Marilaure; Nolan, Glenn; Aaboe, Signe; Aguiar, Eva; Álvarez Fanjul, Enrique; Alvera-azcárate, Aida; Aouf, Lotfi; Barciela, Rosa; Behrens, Arno; Belmonte Rivas, Maria; Ben Ismail, Sana; Bentamy, Abderrahim; Borgini, Mireno; Brando, Vittorio E.; Bensoussan, Nathaniel; Blauw, Anouk; Bryère, Philippe; Buongiorno Nardelli, Bruno; Caballero, Ainhoa; Çağlar Yumruktepe, Veli; Cebrian, Emma; Chiggiato, Jacopo; Clementi, Emanuela; Corgnati, Lorenzo; De Alfonso, Marta; De Pascual Collar, Álvaro; Deshayes, Julie; Di Lorenzo, Emanuele; Dominici, Jean-marie; Dupouy, Cécile; Drévillon, Marie; Echevin, Vincent; Eleveld, Marieke; Enserink, Lisette; García Sotillo, Marcos; Garnesson, Philippe; Garrabou, Joaquim; Garric, Gilles; Gasparin, Florent; Gayer, Gerhard; Gohin, Francis; Grandi, Alessandro; Griffa, Annalisa; Gourrion, Jerome; Hendricks, Stefan; Heuzé, Céline; Holland, Elisabeth; Iovino, Doroteaciro; Juza, Mélanie; Kurt Kersting, Diego; Kipson, Silvija; Kizilkaya, Zafer; Korres, Gerasimos; Kõuts, Mariliis; Lagemaa, Priidik; Lavergne, Thomas; Lavigne, Heloise; Ledoux, Jean-baptiste; Legeais, Jean Francois; Lehodey, Patrick; Linares, Cristina; Liu, Ye; Mader, Julien; Maljutenko, Ilja; Mangin, Antoine; Manso-narvarte, Ivan; Mantovani, Carlo; Markager, Stiig; Mason, Evan; Mignot, Alexandre; Menna, Milena; Monier, Maeva; Mourre, Baptiste; Müller, Malte; Nielsen, Jacob Woge; Notarstefano, Giulio; Ocaña, Oscar; Pascual, Ananda; Patti, Bernardo; Payne, Mark R.; Peirache, Marion; Pardo, Silvia; Pérez Gómez, Begoña; Pisano, Andrea; Perruche, Coralie; Peterson, K. Andrew; Pujol, Marie-isabelle; Raudsepp, Urmas; Ravdas, Michalis; Raj, Roshin P.; Renshaw, Richard; Reyes, Emma; Ricker, Robert; Rubio, Anna; Sammartino, Michela; Santoleri, Rosalia; Sathyendranath, Shubha; Schroeder, Katrin; She, Jun; Sparnocchia, Stefania; Staneva, Joanna; Stoffelen, Ad; Szekely, Tanguy; Tilstone, Gavin H.; Tinker, Jonathan; Tintoré, Joaquín; Tranchant, Benoît; Uiboupin, Rivo; Van Der Zande, Dimitry; Wood, Richard; Woge Nielsen, Jacob; Zabala, Mikel; Zacharioudaki, Anna; Zuberer, Frédéric; Zuo, Hao. |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00515/62637/67004.pdf |
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Registros recuperados: 76 | |
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