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| Registros recuperados: 53 | |
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| Fontela, Marcos; Perez, Fiz F; Carracedo, Lidia; Padín, Xosé A.; Velo, Antón; García-ibañez, Maribel I.; Lherminier, Pascale. |
| The oceanic uptake of atmospheric carbon dioxide (CO2) emitted by human activities alters the seawater carbonate system. Here, the chemical status of the Northeast Atlantic is examined by means of a high-quality database of carbon variables based on the GO-SHIP A25 section (1997–2018). The increase of atmospheric CO2 leads to an increase in ocean anthropogenic carbon (Cant) and a decrease in carbonate that is unequivocal in the upper and mid-layers (0–2,500 m depth). In the mid-layer, the carbonate content in the Northeast Atlantic is maintained by the interplay between the northward spreading of recently conveyed Mediterranean Water with excess of carbonate and the arrival of subpolar-origin waters close to carbonate undersaturation. In this study we show... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00646/75822/76790.pdf |
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| Lagarde, Marion; Lemaitre, Nolwenn; Planquette, Helene; Grenier, Mélanie; Belhadj, Moustafa; Lherminier, Pascale; Jeandel, Catherine. |
| Particulate concentrations of the fourteen Rare Earth Elements (PREE), yttrium and 232-thorium have been measured in two hundred samples collected in the epipelagic (ca. 0–200 m) and the mesopelagic (ca. 200–1000 m) zones of the North Atlantic, during the GEOVIDE cruise (May/June 2014, R/V Pourquoi Pas ?, GEOTRACES GA01). Particulate cerium (PCe) concentrations vary from 0.2 pmol L−1 to 16 pmol L−1, particulate neodymium (PNd) ones from 0.09 pmol L−1 to 6.1 pmol L−1 and particulate ytterbium (PYb) ones from 0.01 pmol L−1 to 0.5 pmol L−1. PREE concentrations are higher close to the Iberian margin and on the Greenland shelf, where PREE concentrations normalized to Post Archean Australian Shale (PAAS) display a positive Ce anomaly between 0.3 and 3, and a... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71323/69750.pdf |
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| Garcia-ibanez, Maribel I.; Pardo, Paula C.; Carracedo, Lidia; Mercier, Herle; Lherminier, Pascale; Rios, Aida F.; Perez, Fiz F.. |
| We discuss the distributions and transports of the main water masses in the North Atlantic Subpolar Gyre (NASPG) for the mean of the period 2002–2010 (OVIDE sections 2002–2010 every other year), as well as the inter-annual variability of the water mass structure from 1997 (4x and METEOR sections) to 2010. The water mass structure of the NASPG, quantitatively assessed by means of an Optimum MultiParameter analysis (with 14 water masses), was combined with the velocity fields resulting from previous studies using inverse models to obtain the water mass volume transports. We also evaluate the relative contribution to the Atlantic Meridional Overturning Circulation (AMOC) of the main water masses characterizing the NASPG, identifying the water masses that... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00268/37968/36867.pdf |
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| Sarafanov, Artem; Falina, Anastasia; Mercier, Herle; Lherminier, Pascale; Sokov, Alexey. |
| Recent decadal changes (1955-2007) in the baroclinic transport (TBC) of the Deep Western Boundary Current (DWBC) carrying the Greenland-Scotland overflow-derived waters along the East Greenland slope are quantified from a set of hydrographic sections in vicinity of Cape Farewell. The updated historical record of TBC shows clear decadal variability (+/- 2-2.5 Sv) with the transport minima in the 1950s and mid-1990s, maximum in the early 1980s and moderate-to-high transport in the 2000s. Since the mid-1990s, the DWBC TBC has increased by similar to 2 Sv (significant at the 99.9% level), which constitute similar to 20% of the mean absolute transport (9.0 Sv) as obtained from three cruises in 2002-2006. The DWBC TBC anomalies negatively correlate (R = -0.80)... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6633.pdf |
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| Fan, Xue; Send, Uwe; Testor, Pierre; Karstensen, Johannes; Lherminier, Pascale. |
| Mesoscale anticyclonic eddies in the Irminger Sea are observed using a mooring and a glider. Between 2002 and 2009, the mooring observed 53 anticyclones. Using a kinematic model, objective estimates of eddy length scales and velocity structure are made for 16 eddies. Anticyclones had a mean core diameter of 12 km, and their mean peak observed azimuthal speed was 0.1 m s(-1). They had core salinities and potential temperatures of 34.91-34.98 and 4.488-5.34 degrees C, respectively, making them warm and salty features. These properties represent a typical salinity anomaly of 0.03 and a temperature anomaly of 0.28 degrees C from noneddy values. All eddies had small (<< 1) Rossby numbers. In 2006, the glider observed two anticyclones having diameters of... |
| Tipo: Text |
Palavras-chave: North Atlantic Ocean; Eddies; Mesoscale processes. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00137/24832/22921.pdf |
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| Gourain, Arthur; Planquette, Helene; Cheize, Marie; Lemaitre, Nolwenn; Menzel Barraqueta, Jan-lukas; Shelley, Rachel; Lherminier, Pascale; Sarthou, Geraldine. |
| The GEOVIDE cruise (May–June 2014, R/V Pourquoi Pas?) aimed to provide a better understanding on trace metal biogeochemical cycles in the North Atlantic. As particles play a key role in the global biogeochemical cycle of trace elements in the ocean, we discuss the distribution of particulate iron (PFe), in light of particulate aluminium (PAl), manganese (PMn) and phosphorus (PP) distributions. Overall, 32 full vertical profiles were collected for trace metal analyses, representing more than 500 samples. This resolution provides a solid basis for assessing concentration distributions, elemental ratios, size-fractionation, or adsorptive scavenging processes in key areas of the thermohaline circulation. Total particulate iron (PFe) concentrations ranged from... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59676/62747.pdf |
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| Falina, Anastasia; Sarafanov, Artem; Mercier, Herle; Lherminier, Pascale; Sokov, Alexey; Daniault, Nathalie. |
| Hydrographic data collected in the Irminger Sea in the 1990s-2000s indicate that dense shelf waters carried by the East Greenland Current south of the Denmark Strait intermittently descend (cascade) down the continental slope and merge with the deep waters originating from the Nordic Seas overflows. Repeat measurements on the East Greenland shelf at similar to 200 km south of the Denmark Strait (65 degrees-66 degrees N) reveal that East Greenland shelf waters in the Irminger Sea are occasionally as dense (sigma(0) > 27.80) as the overflow-derived deep waters carried by the Deep Western Boundary Current (DWBC). Clear hydrographic traces of upstream cascading of dense shelf waters are found over the continental slope at 64.3 degrees N, where the densest... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00130/24160/22255.pdf |
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| Zunino, Patricia; Lherminier, Pascale; Mercier, Herle; Daniault, Nathalie; Garcia-ibanez, Maribel L.; Perez, Fiz F.. |
| The GEOVIDE cruise was carried out in the subpolar North Atlantic (SPNA) along the OVIDE section and across the Labrador Sea in May–June 2014. It was planned to clarify the distribution of the trace elements and their isotopes in the SPNA as part of the GEOTRACES international program. This paper focuses on the state of the circulation and distribution of thermohaline properties during the cruise. In terms of circulation, the comparison with the 2002–2012 mean state shows a more intense Irminger Current and also a weaker North Atlantic Current, with a transfer of volume transport from its northern to its central branch. However, those anomalies are compatible with the variability already observed along the OVIDE section in the 2000s. In terms of... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00412/52302/53069.pdf |
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| Benetti, M.; Reverdin, G.; Lique, Camille; Yashayaev, I.; Holliday, N. P.; Tynan, E.; Torres-valdes, S.; Lherminier, Pascale; Treguer, P.; Sarthou, G.. |
| The Labrador Current is an important conduit of freshwater from the Arctic to the interior North Atlantic subpolar gyre. Here, we investigate the spatial variability of the freshwater sources over the southern Labrador shelf and slope during May-June 2014. Using measurements of seawater properties such as temperature, salinity, nutrients and oxygen isotopic composition, we estimate the respective contributions of saline water of Atlantic and Pacific origins, of brines released during sea ice formation, and of freshwater from sea ice melt and meteoric water origins. On the southern Labrador shelf, we find a large brine signal and Pacific Water influence indicating a large contribution of water from the Canadian Arctic. The brine signal implies that more... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00365/47667/47778.pdf |
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| Daniault, N.; Mercier, Herle; Lherminier, Pascale. |
| The East Greenland Irminger Current (EGIC) decadal transport variability likely influences deep convection intensity in the Labrador and Irminger Seas but is poorly known yet. The EGIC transport west of the 2000 m isobath was estimated, for the first time, between 1992 and 2009 by combining surface geostrophic velocities derived from altimetry with an estimate of the vertical structure of the transport variability statistically determined from a moored array deployed in 2004-2006. The reconstructed 17-year time series of the EGIC transport was then validated against independent estimates confirming that, indeed, the vertical distribution of the EGIC variability has not changed significantly over the last two decades. The 1992-2009 mean transport is 19.5 Sv... |
| Tipo: Text |
Palavras-chave: Keywords: East Greenland Current; Irminger Current; Transport variability. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00033/14467/11763.pdf |
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| Branellec, Pierre; Lherminier, Pascale. |
| Le projet Ovide, sous la direction d'Herlé Mercier, a pour objectif d'établir un observatoire de la variabilité de la circulation dans l'océan Atlantique Nord. Le projet s'articule principalement autour de la répétition tous les deux ans d'une section hydrologique de Cap Hoppe au sud-est du Groenland à Cap Mendocino au Portugal, répertoriée sous le nom de A25 dans le programme international CLIVAR (Climate Variability). Elle traverse la Mer d'Irminger, la dorsale de Reykjanes, le Bassin d'Islande, le Bassin Ouest Européen (au sud du plateau de Rockall) et la Plaine Abyssale Ibérique, perpendiculairement aux courants principaux. La répétition de campagnes le long de ce trajet tous les deux ans pendant une période de dix ans permet de documenter l'évolution... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00210/32103/30560.pdf |
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| Perez, Fiz F.; Mercier, Herle; Vazquez-rodriguez, Marcos; Lherminier, Pascale; Velo, Anton; Pardo, Paula C.; Roson, Gabriel; Rios, Aida F.. |
| Uptake of atmospheric carbon dioxide in the subpolar North Atlantic Ocean declined rapidly between 1990 and 2006. This reduction in carbon dioxide uptake was related to warming at the sea surface, which-according to model simulations-coincided with a reduction in the Atlantic meridional overturning circulation. The extent to which the slowdown of this circulation system-which transports warm surface waters to the northern high latitudes, and cool deep waters south-contributed to the reduction in carbon uptake has remained uncertain. Here, we use data on the oceanic transport of volume, heat and carbon dioxide to track carbon dioxide uptake in the subtropical and subpolar regions of the North Atlantic Ocean over the past two decades. We separate... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00135/24625/22712.pdf |
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| Castrillejo, Maxi; Casacuberta, Nuria; Christl, Marcus; Vockenhuber, Christof; Synal, Hans-arno; Garcia-ibanez, Maribel; Lherminier, Pascale; Sarthou, Geraldine; Garcia-orellana, Jordi; Masque, Pere. |
| Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide complementary information to improve the current understanding of the circulation in the SPNA. To this end, we present the first simultaneous distribution of artificial 129I and 236U in 14 depth profiles and in surface waters along the GEOVIDE section covering a zonal transect through the SPNA in spring 2014. Our results show that the two tracers are distributed following the water mass structure and that their presence is largely influenced by the global fallout (GF)... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00457/56873/58725.pdf |
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| Desbruyeres, Damien; Mercier, Herle; Thierry, Virginie; Lherminier, Pascale; Gula, Jonathan; Cyr, F; Kieke, D; Holliday, P; Smeed, D. |
| An observational experimental setup will be proposed to investigate the dynamics and thermodynamics of the deep western boundary current in the “transition zone” of the North Atlantic, around Flemish Cap, Newfoundland. Located between the international RAPID and OSNAP mooring arrays, this region represents a unique choke point for most of the North Atlantic large-scale currents and water masses involved in the Atlantic Meridional Overturning Circulation (AMOC). Horizontal export and latitudinal coherence, water mass transformation and vertical motions, as well as shelf-slope-interior exchanges will be studied with repeat hydrography, moorings, drifting and profiling floats, and gliders. Multidisciplinary approaches are likely, including biogeochemistry and... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61502/65316.pdf |
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| Sarthou, Geraldine; Lherminier, Pascale; Achterberg, Eric P.; Alonso-perez, Fernando; Bucciarelli, Eva; Boutorh, Julia; Bouvier, Vincent; Boyle, Edward A.; Branellec, Pierre; Carracedo, Lidia I.; Casacuberta, Nuria; Castrillejo, Maxi; Cheize, Marie; Pereira, Leonardo Contreira; Cossa, Daniel; Daniault, Nathalie; De Saint-leger, Emmanuel; Dehairs, Frank; Deng, Feifei; De Gesincourt, Floriane Desprez; Devesa, Jeremy; Foliot, Lorna; Fonseca-batista, Debany; Gallinari, Morgane; Garcia-ibanez, Maribel I.; Gourain, Arthur; Grossteffan, Emilie; Hamon, Michel; Heimburger, Lars Eric; Henderson, Gideon M.; Jeandel, Catherine; Kermabon, Catherine; Lacan, Francois; Le Bot, Philippe; Le Goff, Manon; Le Roy, Emilie; Lefebvre, Alison; Leizour, Stephane; Lemaitre, Nolwenn; Masque, Pere; Menage, Olivier; Barraqueta, Jan-lukas Menzel; Mercier, Herle; Perault, Fabien; Perez, Fiz F; Planquette, Helene; Planchon, Frederic; Roukaerts, Arnout; Sanial, Virginie; Sauzede, Raphaelle; Schmechtig, Catherine; Shelley, Rachel U.; Stewart, Gillian; Sutton, Jill; Tang, Yi; Tisnerat-laborde, Nadine; Tonnard, Manon; Treguer, Paul; Van Beek, Pieter; Zurbrick, Cheryl M.; Zunino Rodriguez, Patricia. |
| The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this special issue (https://www.biogeosciences.net/special_ issue900.html), results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 18 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue. |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58178/60685.pdf |
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| Treguier, Anne-marie; Gourcuff, Claire; Lherminier, Pascale; Mercier, Herle; Barnier, Bernard; Madec, Gurvan; Molines, Jean-marc; Penduff, Thierry; Czeschel, Lars; Boning, Claus. |
| Numerical models are used to estimate the meridional overturning and transports along the paths of two hydrographic cruises, carried out in 1997 and 2002 from Greenland to Portugal. We have examined the influence of the different paths of the two cruises and found that it could explain 0.4 to 2 Sv of difference in overturning (the precise value is model-dependent). Models show a decrease in the overturning circulation between 1997 and 2002, with different amplitudes. The CLIPPER ATL6 model reproduces well the observed weakening of the overturning in density coordinates between the cruises; in the model, the change is due to the combination of interannual and high-frequency forcing and internal variability associated with eddies and meanders. Examination of... |
| Tipo: Text |
Palavras-chave: Ocean model; Thermohaline circulation; North Atlantic; Climate variability; Oceanography. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2199.pdf |
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| Racape, Virginie; Zunino, Patricia; Mercier, Herle; Lherminier, Pascale; Bopp, Laurent; Perez, Fiz F; Gehlen, Marion. |
| The North Atlantic Ocean is a major sink region for atmospheric CO2 and contributes to the storage of anthropogenic carbon (Cant). While there is general agreement that the intensity of the meridional overturning circulation (MOC) modulates uptake, transport and storage of Cant in the North Atlantic Subpolar Ocean, processes controlling their recent variability and evolution over the 21st century remain uncertain. This study investigates the relationship between transport, air-sea flux and storage rate of Cant in the North Atlantic Subpolar Ocean over the past 53 years. Its relies on the combined analysis of a multiannual in situ data set and outputs from a global biogeochemical ocean general circulation model (NEMO-PISCES) at 1/2 degrees spatial... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56587/58275.pdf |
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| Reverdin, Gilles; Gascard, Jean-claude; Le Cann, Bernard; Prieur, Loic; Assenbaum, Michel; Lherminier, Pascale. |
| An anticyclonic mode water vortex and its environment were investigated from November 2000 to September 2001 in the northeast Atlantic (near 43.5 degrees N, 15 degrees-19 degrees W) with neutrally buoyant drifting floats, moored current meters, satellite altimetric sea surface height, and several hydrological surveys and sections. These observations reveal a coherent inner core (similar to 0 km in diameter) made of very oxygenated northeast Atlantic central waters (11 degrees-12.7 degrees C and 35.5-35.7 on the 1978 practical salinity scale) from 150 m down to about 750-m depth. The core presents high relative vorticity (up to approximately -0.5 times the Coriolis frequency f) within at least 10 km of its center, near 400-700 m. Peak velocity along the... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6357.pdf |
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| Gourcuff, Claire; Lherminier, Pascale; Mercier, Herle; Le Traon, Pierre-yves. |
| A method to estimate mass and heat transports across hydrographic sections using hydrography together with altimetry data in a geostrophic box inverse model is presented. Absolute surface velocities computed from AVISO altimetry products made up of a combination of sea surface height measurements and geoid estimate are first compared to Ship Acoustic Doppler Current Profiler (S-ADCP) measurements of the Ovide project along hydrographic sections repeated every 2 years in summer from Portugal to Greenland. The rms difference between S-ADCP and altimetry velocities averaged on distances of about a hundred km accounts to 3.3 cm s−1. Considering that the uncertainty of S-ADCP velocities is found at 1.5 cm s−1, altimetry errors are estimated at 3 cm s−1.... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00038/14921/13751.pdf |
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| Registros recuperados: 53 | |
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