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| Registros recuperados: 99 | |
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| Poitevin, Pierre; Thébault, Julien; Siebert, Valentin; Donnet, Sébastien; Archambault, Philippe; Doré, Justine; Chauvaud, Laurent; Lazure, Pascal. |
| The Northwest Atlantic is a key region with an essential role in global climate regulation, redistributing heat and influencing the carbon cycle. However, little is known about its evolution before 1950, mainly because of the lack of long-term instrumental measurements. The hard parts of long-lived marine biota hold the potential to extend instrumentally derived observation by several decades or centuries and enhance our understanding of global climate processes. Here, we investigate the effects of local, regional, and large-scale climate variability on the marine bivalve, Arctica islandica (Linnaeus, 1767) from Saint-Pierre and Miquelon (SPM). This archipelago lies at the boundary zone between the cold Labrador Current in the north and the warm Gulf... |
| Tipo: Text |
Palavras-chave: Arctica islandica; Paleoecology; North Atlantic; Sub polar gyre; Labrador current; Bivalve; Sclerochronology; Climate change. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62050/66198.pdf |
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| Ayata, Sakina-dorothee; Lazure, Pascal; Thiebaut, Eric. |
| For many marine species, larval dispersal plays a crucial role in population persistence, re-colonization of disturbed areas, and distribution of species range limits through the control of population connectivity. Along the French Atlantic coast (NE Atlantic), a biogeographical transition zone has been reported between temperate and cold-temperate marine faunal assemblages. Hydrodynamics in this area are highly complex and variable including numerous mesoscale features (e.g. river plumes, fronts, upwellings, low salinity lenses), which could constrain larval transport and connectivity. In this context, the aim of this study was to assess how hydrodynamic conditions and biological traits influence larval transport and contribute to population connectivity... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00030/14174/11506.pdf |
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| Puillat, Ingrid; Lazure, Pascal; Jegou, Anne-marie; Lampert, Luis; Miller, P. |
| A synthesis of 9 years of hydrographic measurements, acquired during approximately 25 cruises (1992-2000) on the French continental shelf of the Bay of Biscay, is presented. The main focus is upon salinity distribution, as it is little known in this area. The whole of the data set covers I I months of the year, with some sampling fields repeated several times a year, for multiple years. This time-series allows temperature and salinity distributions to be studied together with their seasonal, inter-annual and mesoscale variability. The seasonal trend in temperature can be described in three stages, which are in agreement with past studies. Thermal stratification occurs between May and mid-September in a layer similar to 50 m in thickness, whereas the... |
| Tipo: Text |
Palavras-chave: Upwelling; Cold pool; River plumes; Seasonal variability; Salinity; Hydrography. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-779.pdf |
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| Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
| In October and early November 1999, the GOGP99 experiment collected hydrological, currentmeter, tide recorder, thermistor and drifting buoy data near the Strait of Hormuz. Data analysis provides the water mass structure in the Strait: Persian Gulf Water (PGW) core is banked against the Omani coast, while Indian Ocean Surface Water (IOSW) lies near the Iranian coast. These water masses are most often covered by a homogeneous surface layer. Thermohaline characteristics of the PGW core decrease substantially downstream, from the Persian/Arabian Gulf to the Gulf of Oman. PGW and IOSW thermohaline characteristics and distribution also exhibit notable changes at periods shorter than a month as shown by repeated hydrological sections. The tidal signal measured... |
| Tipo: Text |
Palavras-chave: Oceanography; Hydrology; Hormuz. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-389.pdf |
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| Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
| Hydrological, ADCP, and drifting buoy data obtained during the GOGP99 Experiment in October and early November 1999 are analyzed to describe the Persian Gulf Water (PGW) core and the regional circulation in the Gulf of Oman. The warm and salty PGW core flows out of the Strait of Hormuz heading southeastward unto (25degrees20'N, 57degreesE), approximately. From there, it cascades down the continental slope, veers southwestward, and joins the Omani coast near (24degrees50'N, 56degrees50'E) to form a slope current. This PGW current has then thermohaline maxima on isopycnal sigma(0) = 26.5, near 220 m depth. Its thermohaline characteristics decrease along its progression to Ra's al Hadd ( and then offshore into the Arabian Sea) but maintain a sharp contrast... |
| Tipo: Text |
Palavras-chave: Persian Gulf Water outflow; Regional circulation; Gulf of Oman. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-390.pdf |
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| Gailhard-rocher, Isabelle; Huret, Martin; Lazure, Pascal; Vandermeirsch, Frederic; Gatti, Julie; Garreau, Pierre; Gohin, Francis. |
| Dans le contexte de l’évaluation initiale des eaux communautaires demandée par la Directive cadre stratégie pour le milieu marin (DCSMM), les états membres sont chargés de décrire les types d’habitats dominants de la colonne d’eau pour chaque sous-région marine. La présente étude s’inscrit dans ce contexte et a pour objectif de décrire les principales structures hydrologiques de la colonne d’eau. Sur la base des données existantes et des travaux antérieurs, il s’agit de classer les masses d'eau en fonction de critères physiques (température, salinité, turbidité, stratification), reconnus d’intérêt pour les espèces pélagiques et l’écosystème en général, et ainsi de définir une cartographie de l’habitat pélagique moyen. Les données utilisées correspondent... |
| Tipo: Text |
Palavras-chave: DCSMM; Habitat pélagique; Classification; Indices hydrologiques; Distribution des espèces; KeywordsMSFD; Pelagic Habitat; Clustering; Hydrological indices; Species distribution. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00069/18018/15547.pdf |
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| Batifoulier, Francois; Kervella, Youen; Laborde, Renaud; Cuny, Jérôme; Caillaud, Matthieu; Lazure, Pascal; Cayocca, Florence. |
| Les fortes vitesses rencontrées à l’entrée de la Baie du Mont Saint-Michel font de cet environnement macro-tidal un endroit privilégié, en termes de ressources énergétiques, pour l’implantation d’une ferme d’hydroliennes. Afin d’établir plus précisément son potentiel énergétique et d’évaluer l’impact de l’implantation de telles machines sur son hydrodynamisme, une modélisation hydrodynamique de la Baie du Mont Saint-Michel est mise en oeuvre à l’aide du modèle de circulation régionale MARS3D (LAZURE & DUMAS, 2008) dans sa version tridimensionnelle. La validation hydrodynamique de cette configuration est réalisée à partir de comparaisons à des mesures courantologiques récentes (KERVELLA, 2010). A partir de cette modélisation, une cartographie du... |
| Tipo: Text |
Palavras-chave: Modélisation régionale; Hydroliennes; Baie du Mont Saint-Michel; Hydrodynamisme; Potentiel énergétique. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00195/30599/29055.pdf |
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| Labry, Claire; Herbland, Alain; Delmas, Daniel; Laborde, P; Lazure, Pascal; Froidefond, J; Jegou, Anne-marie; Sautour, B. |
| Thermostratification and seasonal Light increase are generally considered the first causes of phytoplankton spring blooms in temperate waters. The objective of this study is to confirm the existence of winter phytoplankton blooms, responsible for the early exhaustion of phosphate, within the Gironde plume waters (southeast Bay of Biscay), and to understand what may initiate them so early. Two cruises, BIOMET 2 and BIOMET 3, were carried out respectively in early (8 to 21 January) and late winter 1998 (25 February to 11 March). An increase of phytoplankton biomass (chl a) between the 2 cruises and non-conservative nutrients observed in late winter confirm an early phytoplankton growth both in the Gironde plume and adjacent oceanic waters. Among factors that... |
| Tipo: Text |
Palavras-chave: Vertical attenuation coefficient; Halostratification; Light availability; Winter blooms. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-810.pdf |
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| Oms, Pierre-emmanuel; Bailly Du Bois, Pascal; Dumas, Franck; Lazure, Pascal; Morillon, Mehdi; Voiseux, Claire; Le Corre, Cedric; Cossonnet, Catherine; Solier, Luc; Morin, Pascal. |
| Tritium concentrations in oceans were compiled from the literature, online databases and original measurements in order to determine the global distribution of tritium concentrations according to latitude and depth in all oceans. The total inventory of tritium decay corrected in 2016 has been estimated using evaluation of the natural and artificial contributions in 23 spatial subdivisions of the total ocean. It is determined equal to 26.8 ± 14 kg including 3.8 kg of cosmogenic tritium. That is in agreement with the total atmospheric input of tritium from nuclear bomb tests and the natural inventory at steady-state estimated from natural production rates in the literature (27.8–29.3 kg in the Earth). We confirm the global increase in tritium according to... |
| Tipo: Text |
Palavras-chave: Radionuclide; Tracer; Database; Background concentration. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00470/58157/60653.pdf |
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| Lazure, Pascal; Le Cann, Bernard; Bezaud, Marion. |
| Here, we report large, near-daily oscillations of near-bottom temperatures, with ranges of up to 11.5 °C at depths of 30–60 m in September 2011 around the Saint Pierre and Miquelon archipelago (south-eastern Canada). These oscillations were detected on velocity and temperature profiles from moorings in Miquelon Bay and on an array of near-bottom temperature sensors around the archipelago. The oscillations coincided with the seasonal stratification period. In addition to their remarkable range, they exhibited a near-diurnal period centred on the O1 tidal component (~26 h), contrasting with the dominant semi-diurnal sea-level periodicity in the area. They appear to be the manifestation of an internal wave, triggered by the diurnal surface tide and trapped by... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00457/56850/58687.pdf |
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| Pineau-guillou, Lucia; Lazure, Pascal; Woppelmann, Guy. |
| We investigated the long-term changes of the principal tidal component M2 over the North Atlantic coasts, from 1846 to 2018. We analysed 9 tide gauges with time series starting no later than 1920. The longest is Brest with 165 years of observations. We carefully processed the data, particularly to remove the 18.6-year nodal modulation. We found that M2 variations are consistent at all the stations in the North East Atlantic (Newlyn, Brest, Cuxhaven), whereas some discrepancies appear in the North West Atlantic. The changes started long before the XXth century, and are not linear. The trends vary from a station to another; they are overall positive, up to 0.7 mm/yr. Since 1990, the trends switch from positive to negative values. Concerning the possible... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00635/74732/74722.pdf |
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| Poitevin, Pierre; Thebault, Julien; Schoene, Bernd R.; Jolivet, Aurelie; Lazure, Pascal; Chauvaud, Laurent. |
| The Atlantic surfclam (Spisula solidissima) is a commercially important species in North American waters, undergoing biological and ecological shifts. These are attributed, in part, to environmental modifications in its habitat and driven by climate change. Investigation of shell growth patterns, trace elements, and isotopic compositions require an examination of growth lines and increments preserved in biogenic carbonates. However, growth pattern analysis of S. solidissima is challenging due to multiple disturbance lines caused by environmental stress, erosion in umbonal shell regions, and constraints related to sample size and preparation techniques. The present study proposes an alternative method for describing chronology. First, we analyzed growth... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00444/55597/57229.pdf |
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| Kelly Gerreyn, B; Hydes, D; Jegou, Anne-marie; Lazure, Pascal; Fernand, L; Puillat, I; Garcia Soto, C. |
| Low salinity (< 35) surface waters (LSSW) at the southern entrance to the western English Channel (48.5 degrees N, 5.1 degrees W, near Ushant) were observed in late winter (March-April) in three successive years (2002-04) during near continuous ship of opportunity operations. The source of the LSSW is the northward spreading plumes from the Loire (47.5 degrees N, 2.5 degrees W) and Gironde (45.6 degrees N, 1.2 degrees W) along the French Atlantic coast. Fastest plume travel times were associated with northeasterly winds, consistent with Ekman theory. Differences between years in the mean winter (January-March) combined river discharges (D) was consistent with the minimum salinities (S-min) of the LSSW (2004: D = 4211 m(3) s(-1), S-min = 33.68; 2003: D =... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; English Channel; River plume; Ferrybox; Low salinity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3524.pdf |
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| Puillat, I; Lazure, Pascal; Jegou, Anne-marie; Lampert, Luis; Miller, P. |
| On the French continental shelf of the Bay of Biscay the variability of the surface salinity distribution has been mainly investigated at the seasonal and inter-annual scales. Here, new mesoscale features such as lower-salinity lenses observed in model results are investigated by hydrological measurements acquired during 8 cruises (1997-2000). These lenses are 50-80 km wide and similar to 30 m thick and occur during westerly to northerly wind events that push offshore the less saline water of river Plumes. These water masses detached from the coast are replaced with upwelled saltier water at the coast, so coastal upwelling is often observed at the same time along Landes and southern Brittany coasts. We show that in addition to the influence of seasonal and... |
| Tipo: Text |
Palavras-chave: River plume; Upwelling; Lens; Mesoscale; Salinity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3958.pdf |
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| Huret, Martin; Struski, Caroline; Leger, Fabien; Petitgas, Pierre; Lazure, Pascal; Sourisseau, Marc. |
| Une simulation 'hindcast' de la dynamique physique et biogéochimique du golfe de Gascogne a été réalisée pour la période 1971-2007 à l'aide du modèle ECO-MARS3D. Ce modèle couplant physique et biogéochimie fournit une série longue de données simulées, moyennées ou intégrées sur 3 jours (température, salinité, sels nutritifs, phytoplancton, zooplancton), qui sont ensuite utilisées pour des calculs d'indices hydrologiques 2D synthétiques (indices méso-échelle : stratification, upwellings, surface tourbillonnaire ; indices biologiques : chlorophylle-a de surface, production primaire intégrée). Nous nous proposons dans ce document de présenter la configuration et les forçages utilisés pour cette simulation, et de lister les différentes variables sauvegardées... |
| Tipo: Text |
Palavras-chave: Projet FP6 RECLAIM; Halieutique; Indices hydrologiques; Hindcast; ECO MARS3D; Modélisation couplée; Golfe de Gascogne. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-5164.pdf |
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| Registros recuperados: 99 | |
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