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| Registros recuperados: 53 | |
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| Cossa, Daniel; Heimburger, Lars-eric; Perez, Fiz F; Garcia-ibanez, Maria Isabel; Sonke, Jeroen E.; Planquette, Helene; Lherminier, Pascale; Boutorh, Julia; Cheize, Marie; Barraqueta, Jan Lukas Menzel; Shelley, Rachel; Sarthou, Geraldine. |
| We report here the results of total mercury (HgT) determinations along the 2014 GEOTRACES GEOVIDE cruise (GA01 transect) in the North Atlantic Ocean (NA) from Lisbon (Portugal) to the Labrador coast (Canada). Ninety-seven percent of the HgT concentrations of unfiltered samples (HgTUNF) ranged between 0.16 and 1.00 pmol L−1. The geometric mean was 0.51 pmol L−1 for the 535 samples analysed. The dissolved fraction (< 0.45 μm) of HgT, determined on 141 samples, averaged 78 % of the HgTUNF for the whole water column. HgTUNF concentrations increased eastwards and with depth from Greenland to Europe and from sub-surface to bottom waters, respectively. The Hg distribution mirrored that of dissolved oxygen concentration, with highest HgTUNF levels associated... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00412/52303/53071.pdf |
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| Ferron, Bruno; Kokoszka, Florian; Mercier, Herle; Lherminier, Pascale; Huck, Thierry; Rios, Aida; Thierry, Virginie. |
| The variability of the turbulent kinetic energy dissipation due to internal waves is quantified using a finescale parameterisation applied to the A25 Greenland-Portugal transect repeated every two years from 2002 to 2012. The internal wave velocity shear and strain are estimated for each cruise at 91 stations from full depth vertical profiles of density and velocity. The 2002–2012 averaged dissipation rate, <ε2002–2012>, in the upper ocean lies in the range 1–10 × 10-10 W kg-1. At depth, <ε2002–2012> is smaller than 1 × 10-10 W kg-1 except over rough topography found at the continental slopes, the Reykjanes Ridge and in a region delimited by the Azores-Biscay Rise and Eriador Seamount. There, the vertical energy flux of internal waves is... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44463/44141.pdf |
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| Zunino Rodriguez, Patricia; Perez, Fiz F.; Lherminier, Pascale; Mercier, Herle. |
| The highest anthropogenic CO2 (Cant) inventories of all the oceans are found in the subpolar North Atlantic (SPNA). The OVIDE section crosses the SPNA from Greenland to Portugal and is repeated biennially since 2002. Therefore, OVIDE data allow evaluating the evolution of inventories of anthropogenic CO2 (Cant) in the SPNA. This oceanic region is known to host water formation and ventilation processes that change the water mass volumetric census year by year. Changes in the volumetric census cause differences in the Cant inventory estimates (Pérez et al., 2008). Consequently, Pérez et al. (2010) proposed a method for computing Cant inventory in the SPNA taking into account the volumetric census variability and a bathymetric adjustment. This method has been... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38170/36314.pdf |
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| Zunino, Patricia; Lherminier, Pascale; Mercier, Herle; Padin, Xose A.; Rios, Aida F.; Perez, Fiz F.. |
| The subpolar North Atlantic (SPNA) is important in the global carbon cycle because of the deep water ventilation processes that lead to both high uptake of atmospheric CO2 and large inventories of anthropogenic CO2 (C-ant). Thus, it is crucial to understand its response to increasing anthropogenic pressures. In this work, the budgets of dissolved inorganic carbon (DIC), C-ant and natural DIC (DICnat) in the eastern SPNA in the 2000s, are jointly analyzed using in situ data. The DICnat budget is found to be in steady state, confirming a long-standing hypothesis from in situ data for the first time. The biological activity is driving the uptake of natural CO2 from the atmosphere. The C-ant increase in the ocean is solely responsible of the DIC storage rate... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00313/42419/41756.pdf |
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| Garcia-ibanez, Maria Isabel; Perez, Fiz F.; Lherminier, Pascale; Zunino, Patricia; Mercier, Herle; Treguer, Paul. |
| We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended Optimum MultiParameter (eOMP) analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW) dominated the upper part of the GEOTRACES-GA01 section in 2014. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland–Scotland Overflow Water (ISOW) and North East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00412/52307/53112.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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| 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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| 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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| 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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| 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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| Bouruet-aubertot, Pascale; Mercier, Herle; Gaillard, Fabienne; Lherminier, Pascale. |
| The purpose of this paper is to characterize inertia-gravity waves (IGW) activity and to investigate the variability of these waves in relationship to atmospheric forcing and larger-scale motions. To this aim, we analyzed Eulerian measurements of horizontal currents and temperature collected over 1 year during the Programme Océan Multidisciplinaire Méso Echelle (POMME). We focused on the main frequency components of the IGW spectrum, namely the inertial frequency f and the semidiurnal frequency M2. Time evolution of the relative energy of these two components gave evidence of isolated events of high intensity. We performed a detailed analysis of these events and identified mechanisms of generation of these waves. Localized spots of intense, near-inertial... |
| Tipo: Text |
Palavras-chave: Turbulent mixing; Tnertia gravity waves. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-359.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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| 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. |
| The BOCATS cruise (Biennial Observation of Carbon, Acidification, Transport and Sedimentation) was carried out in the North Atlantic from Vigo (June 18) to Reykjavik (July 31). It was composed of 2 main sections: the OVIDE section coast to coast between Portugal and the south tip of Greenland, followed by the Reykjanes Ridge section, from 55 °N to Iceland. The classical hydrographic rosette was cast 137 times along the route. While the CTD-O2 probe acquired continuous profiles of the “physical” variables (pressure, temperature, salinity and dissolved oxygen), 28 Niskin bottles were closed at different levels during the upcast to provide samples for biogeochemical analysis. We report here an overview of the cruise operations and team, followed by a focus on... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00480/59190/61877.pdf |
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| Branellec, Pierre; Lherminier, Pascale. |
| Complementing the study of the variability of the North Atlantic Subpolar Gyre that is performed in the frame of the Ovide project, the East Greenland/Irminger Current (EGIC) was measured at 60°N between June 2004 to June 2006 by an array of 5 moorings, placed on a section from the shelf to the 1900m isobath. The moorings were equipped with 15 RCM currentmeters and 2 ADCPs to measure the volume transport, and also 5 micro-CTD at mooring heads (about 200m below the surface) to measure the vertical displacement of the moorings and the variability of the warm and salty water masses in the Irminger Current. The highest velocities, about 80 cm/s, are found at the top of mooring B. The core of the current is located between moorings B and C. The current... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00211/32202/30638.pdf |
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| Mercier, Herle; Lherminier, Pascale; Sarafanov, Artem; Gaillard, Fabienne; Daniault, Nathalie; Desbruyeres, Damien; Falina, Anastasia; Ferron, Bruno; Gourcuff, Claire; Huck, Thierry; Thierry, Virginie. |
| The meridional overturning circulation (MOC) in the North Atlantic transports heat from the subtropics to high latitudes and hence plays an important role in the Earth’s climate. A region crucial for the MOC is the northern North Atlantic and the adjacent Nordic Seas, where waters transported northward in the MOC upper limb progressively cool, gain density and eventually sink. Here we discuss the variability of the gyre circulation, the MOC and heat flux as quantified from a joint analysis of hydrographic and velocity data from six repeats of the Greenland to Portugal OVIDE section (1997–2010), satellite altimetry and Argo float measurements. For each repeat of the OVIDE section, the full-depth absolute circulation and transports were assessed using an... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00165/27583/25742.pdf |
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| Registros recuperados: 53 | |
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