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| Registros recuperados: 76 | |
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| Gohin, Francis; Bryere, Philippe; Perrot, Laurie. |
| After several years of experience in providing daily merged products of non-algal Suspended Particulate Matters (SPM) for forcing the light in the ecological model of Previmer ECO-MARS-3D, we have often observed poor quality SPM fields in winter due to the cloud cover. For this reason we propose a new interpolation scheme, multisensor and multitemporal, based on a first-guess field of daily SPM derived from a biweekly satellite climatology modified to take into account dynamically the effects of waves and tides. The contribution of waves and tide is simulated through a simple statistical model (multiplicative effects of the significant wave heights and tidal intensity) summing up the information coming out from the historical data set of SPM. On an... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30799/29168.pdf |
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| Flamant, C; Pelon, J; Hauser, D; Quentin, C; Drennan, Wm; Gohin, Francis; Chapron, Bertrand; Gourrion, Jerome. |
| [1] Acombination of surface wind speed (SWS) and sea state variables, derived from quasi-simultaneous airborne lidar and radar measurements, made in the framework of the Flux, Etat de mer et Teledetection en Condition de fetcH variable (FETCH) experiment, is used to analyze the evolution of surface roughness length, neutral drag coefficient, and friction velocity coefficient with fetch in the first hundred kilometers offshore over the Gulf of Lion, Western Mediterranean. The study focuses on the Tramontane/ Mistral event documented in the afternoon of 24 March 1998. Particular attention is given to SWS derived from nadir lidar measurements. The SWS retrieval methodology developed and validated for open ocean conditions by Flamant et al. [1998] has been... |
| Tipo: Text |
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| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10174/9582.pdf |
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| Gohin, Francis. |
| Sea surface temperature, chlorophyll, and turbidity are three variables of the coastal environment commonly measured by monitoring networks. The observation networks are often based on coastal stations, which do not provide a sufficient coverage to validate the model outputs or to be used in assimilation over the continental shelf. Conversely, the products derived from satellite reflectance generally show a decreasing quality shoreward, and an assessment of the limitation of these data is required. The annual cycle, mean, and percentile 90 of the chlorophyll concentration derived from MERIS/ESA and MODIS/NASA data processed with a dedicated algorithm have been compared to in-situ observations at twenty-six selected stations from the Mediterranean Sea to... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00052/16299/13812.pdf |
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| Bizzozero, Lucie; Gohin, Francis; Lampert, Luis; Fortune, Mireille; Cochennec-laureau, Nathalie. |
| Afin de répondre aux objectifs de la Directive Cadre sur l’eau, l’Ifremer met en oeuvre, en appui à l’Agence de l’eau Loire Bretagne, la surveillance de l’élément de qualité phytoplancton. Le suivi sur des points fixes et à une fréquence mensuelle ne permet pas de suivre l’ensemble des masses d’eau du bassin Loire Bretagne. C’est pourquoi l’évaluation de l’indicateur phytoplancton a été complétée par une évaluation à partir des images satellite, notamment sur les masses d’eau non suivies. L’indice biomasse (représenté par le percentile 90 de la Chl-a) a pu être calculé à partir des données satellite pour la quasi-totalité des masses d’eau côtières RCS et non RCS, c’est-à-dire 34 masses d’eau sur 39. Pour les cinq masses d’eau restantes, les limites liées à... |
| Tipo: Text |
Palavras-chave: Images satellite; Indice Biomasse; Directive Cadre sur l’eau; Chlorophylle a; Bassin Loire Bretagne; Qualité des masses d’eau; Indicateur Phytoplancton. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56465/58162.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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| Lazure, Pascal; Huret, Martin; Gohin, Francis; Menesguen, Alain; Lecornu, Fabrice; Le Traon, Pierre-yves; Thomin, Pascale; Jegou, P.; Baraer, F.; Corre, Gilles; Louazel, Stephanie; Equipe projet PREVIMER. |
| Sommaire * Météo et débits des fleuves.....2 * Caractéristiques des masses d’eau côtières..............5 * Production biologique............11 * Rappel des objectifs du bulletin PREVIMER..................13 * Les moyens d’observations et de prévisions de l’état des mers côtières...........................13 * Glossaire..................................15 |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00242/35367/33866.pdf |
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| Lazure, Pascal; Huret, Martin; Gohin, Francis; Sourisseau, Marc; Saulquin, Bertrand; Lecornu, Fabrice; De Roeck, Yann-herve; Legrand, Jacques; Thomin, Pascale; Aoustin, Yannick; Jegou, P.; Baraer, F.; Le Stum, M.; Louazel, Stephanie; Equipe projet PREVIMER. |
| Sommaire * Météo, états de mer et débits des fleuves.....................2 * Caractéristiques des masses d’eau côtières..............6 * Production biologique............11 * Les faits marquants................12 * Rappel des objectifs du bulletin PREVIMER..................13 * Les moyens d’observations et de prévisions de l’état des mers côtières...........................13 * Glossaire..................................15 |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00242/35360/33860.pdf |
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| Perrot, Laurie; Gohin, Francis; Ruiz-pino, Diana; Lampert, Luis; Huret, Martin; Dessier, Aurelie; Malestroit, Pascale; Dupuy, Christine; Bourriau, Paul. |
| Coccolithophore blooms occur regularly from April to June in the Bay of Biscay where they have been observed for many years from ocean-colour imagery thanks to the ability of their calcite plates to scatter light. They are easily depicted on interpolated images of non-algal Suspended Particulate Matter (SPM) derived from satellite reflectance data in May, at the time of the PELGAS (PELagique GAScogne) annual surveys. Over the springs 2012 to 2015, the PELGAS surveys provided in-situ data on the turbidity throughout the water column and on the hydrological environment prevailing during the blooms in the vicinity of the continental shelf break. The satellite-derived SPM in the area of coccolithophore blooms was closely related to measured turbidity in the... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Ocean colour; Suspended particulate matter; Turbidity; Coccoliths; Stratification. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52790/53689.pdf |
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| Renosh, Pannimpullath R.; Jourdin, Frederic; Charantonis, Anastase A.; Yala, Khalil; Rivier, Aurelie; Badran, Fouad; Thiria, Sylvie; Guillou, Nicolas; Leckler, Fabien; Gohin, Francis; Garlan, Thierry. |
| Hydro-sedimentary numerical models have been widely employed to derive suspended particulate matter (SPM) concentrations in coastal and estuarine waters. These hydro-sedimentary models are computationally and technically expensive in nature. Here we have used a computationally less-expensive, well-established methodology of self-organizing maps (SOMs) along with a hidden Markov model (HMM) to derive profiles of suspended particulate inorganic matter (SPIM). The concept of the proposed work is to benefit from all available data sets through the use of fusion methods and machine learning approaches that are able to process a growing amount of available data. This approach is applied to two different data sets entitled “Hidden” and “Observable”. The hidden... |
| Tipo: Text |
Palavras-chave: Suspended particulate inorganic matter; Self-organizing maps; Hidden Markov Model; Machine learning; English Channel; ROMS. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00415/52653/53511.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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| 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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| Kifani, S; Gohin, Francis. |
| A space-time approach is adopted in an attempt to understand changes in the availability of the central sardine stock along the northwestern Moroccan coast. The warming observed in 1987 and 1989, due to the decline in wind activity, seems to have some repercussions on sardine distribution. The decrease in upwelling activity seems to have favoured concentration in the vicinity of Safi, and thus rendered the sardines more vulnerable to the purse-seiners of this port. We seek to explain the failure of the link established by Belveze and Erzini (1983) between sardine availability and upwelling activity in thc northern area. Two hypotheses, taking into account the local hydrology or the tendency of pelagic species to aggregate in time and space, have been put... |
| Tipo: Text |
Palavras-chave: UPWELLING; MOROCCO; SARDINE; SEA SURFACE TEMPERATURE. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00100/21151/18770.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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| Buestel, Dominique; Dao, Jean-claude; Gohin, Francis. |
| The efficiency of the scallop dredge used in baie de St Brieuc (Britany) has been directly determined by divers swimming along the track marks left on the bottom. Results, concerning essentially year class two, show that efficiency and damage caused by the dredge on scallops are highly variable according to nature of the sea bed. On smooth grounds, the average efficiency is 67% and the average percentage for severely damged scallops is 2% ; on rough grounds, theses percentages are respectively 30% and 17%. These results associated with a dredge survey on a particular area of the baie de St Brieuc allow an assessment of scallops abundance. The statistical method used, relevant to the geostatistic theory, takes into account the scallop spatial distribution... |
| Tipo: Text |
Palavras-chave: Estimation stock; Coquille Saint Jacques; Dragage; Saint-Brieuc; Méthode géostatistique; Bretagne. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/00009/12001/8695.pdf |
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| Registros recuperados: 76 | |
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