Consulta: creatorFacets:"Lherminier, Pascale"
Registros recuperados: 53
Data/hora: 06/06/2024 11:52:45

Mercury distribution and transport in the North Atlantic Ocean along the GEOTRACES-GA01 transect
Provedor de dados: 5
Autores: 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 (&lt; 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
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00412/52303/53071.pdf

Variability of the turbulent kinetic energy dissipation along the A25 Greenland-Portugal transect repeated from 2002 to 2012.
Provedor de dados: 5
Autores: 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, &lt;ε2002–2012&gt;, in the upper ocean lies in the range 1–10 × 10-10 W kg-1. At depth, &lt;ε2002–2012&gt; 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
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00333/44463/44141.pdf

Computing inventories of anthropogenic CO2 in the eastern subpolar North Atlantic using OVIDE data
Provedor de dados: 5
Autores: 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
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00270/38170/36314.pdf

Dissolved inorganic carbon budgets in the eastern subpolar North Atlantic in the 2000s from in situ data
Provedor de dados: 5
Autores: 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
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00313/42419/41756.pdf

CAMBIOS, Vessel mounted ADCP data (RDI NB-75)
Provedor de dados: 5
Autores: Gaillard, Fabienne; Lherminier, Pascale; Remy, Elisabeth; Abel, Karine.
This dataset includes the VMADCP data from the 3 CAMBIOS cruises (processing level: L2b, sofware: Cascade)
Tipo: Dataset
Palavras-chave: VMADCP; SADCP; Canary basin; North-East Atlantic; Azores front.
Ano: 2015
URL: http://dx.doi.org/10.17882/40808

North Atlantic Western Boundary Currents Are Intense Dissolved Organic Carbon Streams
Provedor de dados: 5
Autores: Fontela, Marcos; Pérez, Fiz F; Mercier, Herle; Lherminier, Pascale.
In the North Atlantic, there are two main western boundary currents related to the Atlantic Meridional Overturning Circulation (AMOC): the Gulf Stream flowing northward and the Deep Western Boundary Current (DWBC) flowing southward. Here we analyze data from the OVIDE section (GO-SHIP A25 Portugal-Greenland 40–60°N) that crosses the DWBC and the northward extension of the Gulf Stream, the North Atlantic Current. We show that North Atlantic western boundary currents play a key role in the transport of dissolved organic matter, specifically dissolved organic carbon (DOC). Revisited transports and budgets of DOC with new available data identify the eastern Subpolar North Atlantic (eSPNA) as an important source of locally produced organic matter for the North...
Tipo: Text
Palavras-chave: Dissolved organic carbon; North Atlantic; Carbon budget; Carbon dioxide; Biogeochemistry; Atlantic Meridional Overturning Circulation.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00661/77268/78702.pdf

Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00412/52307/53112.pdf

Introduction to the French GEOTRACES North Atlantic Transect (GA01): GEOVIDE cruise
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00470/58178/60685.pdf

Recent changes in the Greenland-Scotland overflow-derived water transport inferred from hydrographic observations in the southern Irminger Sea
Provedor de dados: 5
Autores: 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
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6633.pdf

Altimetry combined with hydrography for ocean transport estimation
Provedor de dados: 5
Autores: 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
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00038/14921/13751.pdf

Inputs and processes affecting the distribution of particulate iron in the North Atlantic along the GEOVIDE (GEOTRACES GA01) section
Provedor de dados: 5
Autores: 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
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59676/62747.pdf

Internal and forced variability along a section between Greenland and Portugal in the CLIPPER Atlantic model
Provedor de dados: 5
Autores: 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

Transport and storage of anthropogenic C in the North Atlantic Subpolar Ocean
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56587/58275.pdf

Evidence of strong inertia-gravity wave activity during the POMME experiment
Provedor de dados: 5
Autores: 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

Particulate Rare Earth Element behavior in the North Atlantic (GEOVIDE cruise)
Provedor de dados: 5
Autores: 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
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00601/71323/69750.pdf

The 1992-2009 transport variability of the East Greenland-Irminger Current at 60 degrees N
Provedor de dados: 5
Autores: 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

CAMBIOS, Station profiles: CTD and LADCP
Provedor de dados: 5
Autores: Gaillard, Fabienne; Lherminier, Pascale; Lagadec, Catherine; Branellec, Pierre.
The Cambios cruises aimed at studying the variability of the circulation in the Canary basin, specifically: the evolution of the Azores front and the detection of meddies. The dataset includes the vertical profiles collected with the CTD and LADCP equipment.
Tipo: Dataset
Palavras-chave: LADCP; CTD; North-East Atlantic; Azores front; Meddies.
Ano: 2015
URL: http://dx.doi.org/10.17882/40905

BOCATS 2016. CTD-O2 data report
Provedor de dados: 5
Autores: 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
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00480/59190/61877.pdf

OVIDE : Rapport de données Eulériennes
Provedor de dados: 5
Autores: 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
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00211/32202/30638.pdf

Variability of the meridional overturning circulation at the Greenland–Portugal OVIDE section from 1993 to 2010
Provedor de dados: 5
Autores: 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
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00165/27583/25742.pdf

On the Cascading of Dense Shelf Waters in the Irminger Sea
Provedor de dados: 5
Autores: 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) &gt; 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
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00130/24160/22255.pdf

North Atlantic Ocean circulation: the OVIDE project
Provedor de dados: 5
Autores: Mercier, Herle; Lherminier, Pascale; Gourcuff, Claire.
The OVIDE project studies the variability of the north Atlantic subbpolar gyre circulation based on repeated hydrography and current measurements, satellite observations, diagnostic and prognostic models. Here, we present an analysis of volume and heat transports between Greenland and Portugal from the 2002 OVIDE data. The results are compared to a previous analysis based on 1997 data (4x project). We focus on the thermohaline circulation. The thermohaline circulation, deep western boundary current and heat flux variability are correlated.
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6102.pdf

Assessing decadal changes in the Deep Western Boundary Current absolute transport southeast of Cape Farewell, Greenland, from hydrography and altimetry
Provedor de dados: 5
Autores: Sarafanov, Artem; Falina, Anastasia; Lherminier, Pascale; Mercier, Herle; Sokov, Alexey; Gourcuff, Claire.
[1] In earlier studies, the decadal variability of the Deep Western Boundary Current (DWBC) transport in the vicinity of Cape Farewell, Greenland, has been assessed from changes in the baroclinic velocities computed from hydrographic data and referenced to 1000 m depth. The main limitation of using such an estimate as an index for the DWBC absolute transport variability comes from the unaccounted for decadal velocity changes at the reference level (1000 m). These changes may substantially contribute to the DWBC absolute transport variability by compensating for or adding to the baroclinic transport changes. To assess this contribution to variability, we quantify the decadal velocity changes which occurred at 1000 m depth southeast of Cape Farewell since...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00017/12855/9820.pdf

Atlantic Ocean CO2 uptake reduced by weakening of the meridional overturning circulation
Provedor de dados: 5
Autores: 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
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00135/24625/22712.pdf

Transports across the 2002 Greenland-Portugal Ovide section and comparison with 1997 - art. no. C07003
Provedor de dados: 5
Autores: Lherminier, Pascale; Mercier, Herle; Gourcuff, Claire; Alvarez, M; Bacon, S; Kermabon, Catherine.
The first Ovide cruise occurred in June-July 2002 on R/V Thalassa between Greenland and Portugal. The absolute transports across the Ovide line are estimated using a box inverse model constrained by direct acoustic Doppler current profiler velocity measurements and by an overall mass balance (+/-3 Sv, where 1 Sv = 10(6) m(3) s(-1)) across the section. Main currents are studied and compared to the results of the similar Fourex section performed in August 1997 and revisited here. The meridional overturning cell (MOC) is estimated in two different ways, both leading to a significantly lower value in June 2002 than in August 1997, consistent with the relative strength of the main components of the MOC (North Atlantic Current and deep western boundary current)....
Tipo: Text
Palavras-chave: Hydrographic section; Cell; Meridional overturning; North Atlantic circulation.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3296.pdf

Dissipation Rate Estimates from Microstructure and Finescale Internal Wave Observations along the A25 Greenland–Portugal OVIDE Line
Provedor de dados: 5
Autores: Ferron, Bruno; Kokoszka, Florian; Mercier, Herle; Lherminier, Pascale.
A total of 96 finestructure and 30 microstructure full-depth vertical profiles were collected along the A25 Greenland–Portugal Observatoire de la Variabilité Interannuelle et Décennale en Atlantique Nord (OVIDE) hydrographic line in 2008. The microstructure of the horizontal velocity was used to calculate turbulent kinetic energy dissipation rates εvmp, where vmp refers to the vertical microstructure profiler. The lowest dissipation values (εvmp &lt; 0.5 × 10−10 W kg−1) are found below 2000 m in the Iberian Abyssal Plain and in the center of the Irminger basin; the largest values (&gt;5 × 10−10 W kg−1) are found in the main thermocline, around the Reykjanes Ridge, and in a 1000-m-thick layer above the bottom near 48°N. The finestructure of density was used...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00240/35130/33628.pdf

CATARINA 2012-Leg 1 - CTD-O2 Data report
Provedor de dados: 5
Autores: Branellec, Pierre; Lherminier, Pascale; Desprez De Gesincourt, Floriane.
The CATARINA Leg1 cruise was carried out from June 22 to July 24 2012 on board the B/O Sarmiento de Gamboa, under the scientific supervision of Aida Rios (CSIC-IIM). It included the occurrence of the OVIDE hydrological section that was performed in June 2002, 2004, 2006, 2008 and 2010, as part of the CLIVAR program (name A25) ), and under the supervision of Herlé Mercier (CNRSLPO). This section begins near Lisbon (Portugal), runs through the West European Basin and the Iceland Basin, crosses the Reykjanes Ridge (300 miles north of Charlie-Gibbs Fracture Zone, and ends at Cape Hoppe (southeast tip of Greenland). The objective of this repeated hydrological section is to monitor the variability of water mass properties and main current transports in the...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00353/46406/46280.pdf

Composition of freshwater in the spring of 2014 on the southern Labrador shelf and slope
Provedor de dados: 5
Autores: 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
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00365/47667/47778.pdf

Observations of Irminger Sea Anticyclonic Eddies
Provedor de dados: 5
Autores: 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 (&lt;&lt; 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

The GEOVIDE cruise in May–June 2014 reveals an intense Meridional Overturning Circulation over a cold and fresh subpolar North Atlantic
Provedor de dados: 5
Autores: 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
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00412/52302/53069.pdf

Campagne OVIDE 2008 : Rapport de données CTD-O2
Provedor de dados: 5
Autores: Branellec, Pierre; Ferron, Bruno; Lherminier, Pascale.
La campagne Ovide 4, réalisée du 9 juin au 10 juillet 2008 sur le N/O Thalassa, est la quatrième d'une série de 5 campagnes océanographiques dont le but est d'établir un observatoire de la variabilité climatique du tourbillon subpolaire de l'océan Atlantique Nord. Le projet Ovide est dirigé par Herlé Mercier et il est principalement financé par Ifremer, INSU (LEFE-IDAO) et UBO. Les trois premières campagnes Ovide ont été réalisées à la même période de l'année en 2002, 2004, 2006 et le long du même trajet entre l'extrémité sud-est du Groenland et la Péninsule Ibérique (section Ovide, également appelée A25 dans le programme CLIVAR) via la Mer d'Irminger, le Bassin d'Islande et le Bassin Ouest Européen, légèrement au nord de la section FourEx d'août 1997...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00210/32124/30568.pdf

Sources and distribution of fresh water around Cape Farewell in 2014
Provedor de dados: 5
Autores: Benetti, M.; Reverdin, G.; Clarke, J.s.; Tynan, E.; Holliday, N.p.; Torres‐valdes, S.; Lherminier, Pascale; Yashayaev, I.
We investigate the origin of freshwater on the shelves near Cape Farewell (south Greenland) using sections of three hydrographic cruises in May (HUD2014007) and June 2014 (JR302 and Geovide) 2014. We partition the freshwater between meteoric water sources and sea ice melt or brine formation using the δ18O of sea water. The sections illustrate the presence of the East Greenland Coastal Current (EGCC) close to shore east of Cape Farewell. West of Cape Farewell, it partially joins the shelf break, with a weaker near‐surface remnant of the EGCC observed on the shelf southwest and west of Cape Farewell. The EGCC traps the freshest waters close to Greenland, and carries a brine signature below 50m depth. The cruises illustrate a strong increase in meteoric water...
Tipo: Text
Palavras-chave: Fresh water; Water isotopes; South Greenland currents.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00591/70349/68413.pdf

The GEOTRACES Intermediate Data Product 2017
Provedor de dados: 5
Autores: Schlitzer, Reiner; Anderson, Robert F.; Dodas, Elena Masferrer; Lohan, Maeve; Geibere, Walter; Tagliabue, Alessandro; Bowie, Andrew; Jeandel, Catherine; Maldonado, Maria T.; Landing, William M.; Cockwell, Donna; Abadie, Cyril; Abouchami, Wafa; Achterberg, Eric P.; Agather, Alison; Aguliar-islas, Ana; Van Aken, Hendrik M.; Andersen, Morten; Archer, Corey; Auro, Maureen; De Baar, Hein J.; Baars, Oliver; Baker, Alex R.; Bakker, Karel; Basak, Chandranath; Baskaran, Mark; Bates, Nicholas R.; Bauch, Dorothea; Van Beek, Pieter; Behrens, Melanie K.; Black, Erin; Bluhm, Katrin; Bopp, Laurent; Bouman, Heather; Bowman, Katlin; Bown, Johann; Boyd, Philip; Boye, Marie; Boyle, Edward A.; Branellec, Pierre; Bridgestock, Luke; Brissebrat, Guillaume; Browning, Thomas; Bruland, Kenneth W.; Brumsack, Hans-juergen; Brzezinski, Mark; Buck, Clifton S.; Buck, Kristen N.; Buesseler, Ken; Bull, Abby; Butler, Edward; Cai, Pinghe; Camara Mor, Patricia; Cardinal, Damien; Carlson, Craig; Carrasco, Gonzalo; Casacuberta, Nuria; Casciotti, Karen L.; Castrillejo, Maxi; Chamizo, Elena; Chance, Rosie; Charette, Matthew A.; Chaves, Joaquin E.; Cheng, Hai; Chever, Fanny; Christl, Marcus; Church, Thomas M.; Closset, Ivia; Colman, Albert; Conway, Tim M.; Cossa, Daniel; Croot, Peter; Cullen, Jay T.; Cutter, Gregory A.; Daniels, Chris; Dehairs, Frank; Deng, Feifei; Dieu, Huong Thi; Duggan, Brian; Dulaquais, Gabriel; Dumousseaud, Cynthia; Echegoyen-sanz, Yolanda; Edwards, R. Lawrence; Ellwood, Michael; Fahrbach, Eberhard; Fitzsimmons, Jessica N.; Flegal, A. Russell; Fleisher, Martin Q.; Van De Flierdt, Tina; Frank, Martin; Friedrich, Jana; Fripiat, Francois; Froellje, Henning; Galer, Stephen J. G.; Gamo, Toshitaka; Ganeshram, Raja S.; Garcia-orellana, Jordi; Garcia-solsona, Ester; Gault-ringold, Melanie; George, Ejin; Gerringa, Loes J. A.; Gilbert, Melissa; Godoy, Jose M.; Goldstein, Steven L.; Gonzalez, Santiago R.; Grissom, Karen; Hammerschmidt, Chad; Hartman, Alison; Hassler, Christel S.; Hathorne, Ed C.; Hatta, Mariko; Hawco, Nicholas; Hayes, Christopher T.; Heimburger, Lars-eric; Helgoe, Josh; Heller, Maija Iris; Henderson, Gideon M.; Henderson, Paul B.; Van Heuven, Steven; Ho, Peng; Horner, Tristan J.; Hsieh, Yu-te; Huang, Kuo-fang; Humphreys, Matthew P.; Isshiki, Kenji; Jacquot, Jeremy E.; Janssen, David J.; Jenkins, William J.; John, Seth; Jones, Elizabeth M.; Jones, Janice L.; Kadko, David C.; Kayser, Rick; Kenna, Timothy C.; Khondoker, Roulin; Kim, Taejin; Kipp, Lauren; Klar, Jessica K.; Klunder, Maarten; Kretschmer, Sven; Kumamoto, Yuichiro; Laan, Patrick; Labatut, Marie; Lacan, Francois; Lam, Phoebe J.; Lambelet, Myriam; Lamborg, Carl H.; Le Moigne, Frederic A. C.; Le Roy, Emilie; Lechtenfeld, Oliver J.; Lee, Jong-mi; Lherminier, Pascale; Little, Susan; Lopez-lora, Mercedes; Lu, Yanbin; Masque, Pere; Mawji, Edward; Mcclain, Charles R.; Measures, Christopher; Mehic, Sanjin; Barraqueta, Jan-lukas Menzel; Van Der Merwe, Pier; Middag, Rob; Mieruch, Sebastian; Milne, Angela; Minami, Tomoharu; Moffett, James W.; Moncoiffe, Gwenaelle; Moore, Willard S.; Morris, Paul J.; Morton, Peter L.; Nakaguchi, Yuzuru; Nakayama, Noriko; Niedermiller, John; Nishioka, Jun; Nishiuchi, Akira; Noble, Abigail; Obata, Hajime; Ober, Sven; Ohnemus, Daniel C.; Van Ooijen, Jan; O'Sullivan, Jeanette; Owens, Stephanie; Pahnke, Katharina; Paul, Maxence; Pavia, Frank; Pena, Leopoldo D.; Petersh, Brian; Planchon, Frederic; Planquette, Helene; Pradoux, Catherine; Puigcorbe, Viena; Quay, Paul; Queroue, Fabien; Radic, Amandine; Rauschenberg, S.; Rehkamper, Mark; Rember, Robert; Remenyi, Tomas; Resing, Joseph A.; Rickli, Joerg; Rigaud, Sylvain; Rijkenberg, Micha J. A.; Rintoul, Stephen; Robinson, Laura F.; Roca-marti, Montserrat; Rodellas, Valenti; Roeske, Tobias; Rolison, John M.; Rosenberg, Mark; Roshan, Saeed; Van Der Loaff, Michiel M. Rutgers; Ryabenko, Evgenia; Saito, Mak A.; Salt, Lesley A.; Sanial, Virginie; Sarthou, Geraldine; Schallenberg, Christina; Schauer, Ursula; Scher, Howie; Schlosser, Christian; Schnetger, Bernhard; Scott, Peter; Sedwick, Peter N.; Semiletov, Igor; Shelley, Rachel; Sherrell, Robert M.; Shiller, Alan M.; Sigman, Daniel M.; Singh, Sunil Kumar; Slagter, Hans A.; Slater, Emma; Smethie, William M.; Snaith, Helen; Sohrin, Yoshiki; Sohst, Bettina; Sonke, Jeroen E.; Speich, Sabrina; Steinfeldt, Reiner; Stewart, Gillian; Stichel, Torben; Stirling, Claudine H.; Stutsman, Johnny; Swarr, Gretchen J.; Swift, James H.; Thomas, Alexander; Thorne, Kay; Till, Claire P.; Till, Ralph; Townsend, Ashley T.; Townsend, Emily; Tuerena, Robyn; Twining, Benjamin S.; Vance, Derek; Velazquez, Sue; Venchiarutti, Celia; Villa-alfageme, Maria; Vivancos, Sebastian M.; Voelker, Antje H. L.; Wake, Bronwyn; Warner, Mark J.; Watson, Ros; Van Weerlee, Evaline; Weigand, M. Alexandra; Weinstein, Yishai; Weiss, Dominik; Wisotzki, Andreas; Woodward, E. Malcolm S.; Wu, Jingfeng; Wu, Yingzhe; Wuttig, Kathrin; Wyatt, Neil; Xiang, Yang; Xie, Ruifang C.; Xue, Zichen; Yoshikawa, Hisayuki; Zhang, Jing; Zhang, Pu; Zhao, Ye; Zheng, Linjie; Zheng, Xin-yuan; Zieringer, Moritz; Zimmer, Louise A.; Ziveri, Patrizia; Zunino, Patricia; Zurbrick, Cheryl.
The new IDP2017 is a significant improvement over the earlier IDP2014 and roughly doubles the number of included cruises, stations, samples and parameters. The IDP2017 is a truly international product containing data from 326 researchers from 25 countries. The IDP2017 provides data for the Pacific Ocean, and the Mediterranean and Black seas, in addition to Atlantic, Arctic and Indian Oceans that were already represented in the previous data product. For the first time, the IDP2017 contains significant amounts of biogeochemistry data as well as TEI data for aerosols and rain. As before, users can obtain complete IDP2017 data sets as bulk downloads. Alternatively, there is now a customisable online data extraction service that allows data selections by...
Tipo: Text
Palavras-chave: GEOTRACES; Trace elements; Isotopes; Electronic atlas; IDP2017.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00442/55362/56877.pdf

Aluminium in the North Atlantic Ocean and the Labrador Sea (GEOTRACES GA01 section): roles of continental inputs and biogenic particle removal
Provedor de dados: 5
Autores: Barraqueta, Jan-lukas Menzel; Schlosser, Christian; Planquette, Helene; Gourain, Arthur; Cheize, Marie; Boutorh, Julia; Shelley, Rachel; Pereira, Leonardo Contreira; Gledhill, Martha; Hopwood, Mark J.; Lacan, Francois; Lherminier, Pascale; Sarthou, Geraldine; Achterberg, Eric P.
The distribution of dissolved aluminium (dAl) in the water column of the North Atlantic and Labrador Sea was studied along GEOTRACES section GA01 to unravel the sources and sinks of this element. Surface water dAl concentrations were low (median of 2.5 nM) due to low aerosol deposition and removal by phytoplankton. However, surface water dAl concentrations were enhanced on the Iberian and Greenland shelves (up to 30.9 nM) due to continental inputs (rivers, glacial flour and ice melt). A negative correlation was observed between dAl in surface waters and primary production, phytoplankton community structure and biogenic opal production. The abundance of diatoms exerted a significant (p &lt; 0.01) control on the surface particulate Al (pAl) to dAl ratios by...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00422/53359/54197.pdf

Trends of anthropogenic CO2 storage in North Atlantic water masses
Provedor de dados: 5
Autores: Perez, F. F; Vazquez-rodriguez, M.; Mercier, Herle; Velo, A.; Lherminier, Pascale; Rios, A. F.
A high-quality inorganic carbon system database, spanning over three decades (1981-2006) and comprising of 13 cruises, has allowed the applying of the phi C degrees(T) method and coming up with estimates of the anthropogenic CO2 (C-ant) stored in the main water masses of the North Atlantic. In the studied region, strong convective processes convey surface properties, like C-ant, into deeper ocean layers and grants this region an added oceanographic interest from the point of view of air-sea CO2 exchanges. Generally, a tendency for decreasing C-ant storage rates towards the deep layers has been observed. In the Iberian Basin, the North Atlantic Deep Water has low C-ant concentrations and negligible storage rates, while the North Atlantic Central Water in...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00006/11706/8362.pdf

XBT Temperature Errors during French Research Cruises (1999-2007)
Provedor de dados: 5
Autores: Reverdin, Gilles; Marin, Frederic; Bourles, Bernard; Lherminier, Pascale.
Data from French cruises in 1999-2007, a period during which Deep Blue (DB) or T7 expendable bathythermographs (XBTs) were deployed, and for which ancillary temperature data are available in the northeast Atlantic and equatorial Atlantic regions, are examined. There was a total of 16 cruises with XBTs launched between conductivity-temperature-depth (CTD) stations; during most of these, as well as during three additional cruises that were also considered, intake temperature was measured. XBT data from two voluntary observing ships in the North Atlantic subpolar gyre for which intake temperature was measured were also investigated. There is an XBT cold bias due to stirring of a stratified upper layer by the ship, resulting in differences between XBT...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00133/24380/22391.pdf

The Atlantic Meridional Overturning Circulation and the subpolar gyre observed at the A25-OVIDE section in June 2002 and 2004
Provedor de dados: 5
Autores: Lherminier, Pascale; Mercier, Herle; Huck, Thierry; Gourcuff, Claire; Perez, Fiz F.; Morin, Pascal; Sarafanov, Artem; Falina, Anastasia.
The horizontal circulation of the subpolar gyre and the Meridional Overturning Circulation (MOC) are investigated here by comparing two snapshots of the North Atlantic as delivered by two hydrographic sections between Greenland and Portugal. The corresponding cruises were carried out in June–July 2002 and June–July 2004 on R/V Thalassa within the framework of the Ovide project. The absolute transports in June 2004 are described in detail, and then compared with transports in June 2002. The MOC (in density coordinates), driven by the volume balance between the northward North Atlantic Current (NAC) and the net southward export of dense water from the subpolar gyre, did not change: View the MathML source (1 Sv=106 m3 s−1). Its upper limb, above σ1=32.1, is...
Tipo: Text
Palavras-chave: North Atlantic; Subpolar gyre; Meridional Overturning Circulation; OVIDE; Hydrology; ADCP.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00011/12272/9057.pdf

Tracing water masses with 129I and 236U in the subpolar North Atlantic along the GEOTRACES GA01 section
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00457/56873/58725.pdf

Diagnosing Surface Mixed Layer Dynamics from High-Resolution Satellite Observations: Numerical Insights
Provedor de dados: 5
Autores: Ponte, Aurelien; Klein, Patrice; Capet, Xavier; Le Traon, Pierre-yves; Chapron, Bertrand; Lherminier, Pascale.
High-resolution numerical experiments of ocean mesoscale eddy turbulence show that the wind-driven mixed layer (ML) dynamics affects mesoscale motions in the surface layers at scales lower than O(60 km). At these scales, surface horizontal currents are still coherent to, but weaker than, those derived from sea surface height using geostrophy. Vertical motions, on the other hand, are stronger than those diagnosed using the adiabatic quasigeotrophic (QG) framework. An analytical model, based on a scaling analysis and on simple dynamical arguments, provides a physical understanding and leads to a parameterization of these features in terms of vertical mixing. These results are valid when the wind-driven velocity scale is much smaller than that associated with...
Tipo: Text
Palavras-chave: Mesoscale processes; Ocean dynamics; Turbulence.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00170/28076/26291.pdf

CASCADE V6.1 : Logiciel de validation et de visualisation des mesures ADCP de coque
Provedor de dados: 5
Autores: Le Bot, Philippe; Kermabon, Catherine; Lherminier, Pascale; Gaillard, Fabienne.
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00342/45285/44750.pdf

The Northeast Atlantic is running out of excess carbonate in the horizon of cold-water corals communities
Provedor de dados: 5
Autores: 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
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00646/75822/76790.pdf

Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution
Provedor de dados: 5
Autores: Sarafanov, Artem; Mercier, Herle; Falina, Anastasia; Sokov, Alexey; Lherminier, Pascale.
Recent decadal salinity changes in the Greenland-Scotland overflow-derived deep waters are quantified using CTD data from repeated hydrographic sections in the Irminger Sea. The Denmark Strait Overflow Water salinity record shows the absence of any net change over the 1980s-2000s; changes in the Iceland-Scotland Overflow Water (ISOW) and in the deep water column (Sigma(0) &gt; 27.82), enclosing both overflows, show a distinct freshening reversal in the early 2000s. The observed freshening reversal is a lagged consequence of the persistent ISOW salinification that occurred upstream, in the Iceland Basin, after 1996 in response to salinification of the northeast Atlantic waters entrained into the overflow. The entrainment salinity increase is explained by...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/2010/publication-7325.pdf

Sources, cycling and transfer of mercury in the Labrador Sea (Geotraces -Geovide cruise)
Provedor de dados: 5
Autores: Cossa, Daniel; Heimburger, L. E.; Sonke, J. E.; Planquette, H.; Lherminier, Pascale; Garcia-ibanez, Maria Isabel; Perez, Ff; Sarthou, G.
The Labrador Sea links the Arctic and North Atlantic oceans and constitutes one of the main entrances of atmospheric inputs into the Ocean's interior. We report here the first high-resolution Hg distribution pattern along a transect from Greenland to Labrador coasts sampled after the 2014 winter convection. Total Hg concentrations in unfiltered (HgTUNF) samples ranged from 0.25 pmol L− 1 to 0.67 pmol L− 1 averaging 0.44 ± 0.10 pmol L− 1 (n = 113, 1σ). Concentrations in filtered samples (HgTF, &lt; 0.45 μm) represented from 62 to 92% of the HgTUNF and exhibited a similar distribution. High HgTUNF concentrations were found (i) in the waters of the Labrador Current, which receive desalted waters from the Canadian Arctic Archipelago, and (ii) in the waters...
Tipo: Text
Palavras-chave: Labrador Sea; Mercury; North Atlantic.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00411/52207/52929.pdf

A Long-Lasting Mode Water Vortex in the Northeast Atlantic Ocean
Provedor de dados: 5
Autores: 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
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6357.pdf

The northern North Atlantic Ocean mean circulation in the early 21st Century
Provedor de dados: 5
Autores: Daniault, Nathalie; Mercier, Herle; Lherminier, Pascale; Sarafanov, Artem; Falina, Anastasia; Zunino, Patricia; Perezf, Fiz F.; Rios, Aida F.; Ferron, Bruno; Huck, Thierry; Thierry, Virginie; Gladyshev, Sergey.
The decadal mean circulation in the northern North Atlantic was assessed for the early 21st century from repeated ship-based measurements along the Greenland-Portugal OVIDE line, from satellite altimetry and from earlier reported transports across 59.5°N and at the Greenland-Scotland sills. The remarkable quantitative agreement between all data sets allowed us to draw circulation pathways with a high level of confidence. The North Atlantic Current (NAC) system is composed of three main branches, referred to as the northern, central and southern branches, which were traced from the Mid-Atlantic Ridge (MAR), to the Irminger Sea, the Greenland-Scotland Ridge and the subtropical gyre. At OVIDE, the northern and central branches of the NAC fill the whole water...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00345/45569/45177.pdf

Variability of the transport of anthropogenic CO2 at the Greenland-Portugal OVIDE section: controlling mechanisms
Provedor de dados: 5
Autores: Zunino Rodriguez, Patricia; Garcia-ibanez, Maria Isabel; Lherminier, Pascale; Mercier, Herle; Rios, A. F.; Perez, Ff.
The interannual to decadal variability in the transport of anthropogenic CO2 (Cant) across the subpolar North Atlantic (SPNA) is investigated, using summer data of the FOUREX and OVIDE high-resolution transoceanic sections, from Greenland to Portugal, occupied six times from 1997 to 2010. The transport of Cant across this section, T-cant hereafter, is northward, with a mean value of 254 +/- 29 kmol s(-)1 over the 1997-2010 period. We find that T-cant undergoes interannual variability, masking any trend different from 0 for this period. In order to understand the mechanisms controlling the variability of T-cant across the SPNA, we propose a new method that quantifies the transport of Cant caused by the diapycnal and isopycnal circulation. The diapycnal...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00192/30317/28792.pdf

Campagne OVIDE 2006 : Rapport de données CTD-O2
Provedor de dados: 5
Autores: 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
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00210/32103/30560.pdf

Sustainable observations of the AMOC: Methodology and Technology
Provedor de dados: 5
Autores: Mccarthy, G.d.; Brown, P.j.; Flagg, C.n.; Goni, G.; Houpert, L.; Hughes, C.w.; Hummels, R.; Inall, M.; Jochumsen, K.; Larsen, K.m.h.; Lherminier, Pascale; Meinen, C.s.; Moat, B.i.; Rayner, D.; Rhein, M.; Roessler, A.; Schmid, C.; Smeed, D.a.
The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism of heat, freshwater, and carbon redistribution in the climate system. The precept that the AMOC has changed abruptly in the past, notably during and at the end of the last ice age, and that it is ‘very likely’ to weaken in the coming century due to anthropogenic climate change is a key motivation for sustained observations of the AMOC. This paper reviews the methodology and technology used to observe the AMOC and assesses these ideas and systems for accuracy, shortcomings, potential improvements and sustainability. We review hydrographic techniques and look at how these traditional techniques can meet modern requirements. Transport mooring arrays provide the ‘gold standard’ for...
Tipo: Text
Palavras-chave: Ocean Observing; AMOC; Ocean Circulation.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00595/70674/68872.pdf

Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE section (GEOTRACES section GA01)
Provedor de dados: 5
Autores: Tonnard, Manon; Planquette, Hélène; Bowie, Andrew R.; Van Der Merwe, Pier; Gallinari, Morgane; Desprez De Gésincourt, Floriane; Germain, Yoan; Gourain, Arthur; Benetti, Marion; Reverdin, Gilles; Tréguer, Paul; Boutorh, Julia; Cheize, Marie; Menzel Barraqueta, Jan-lukas; Pereira-contreira, Leonardo; Shelley, Rachel; Lherminier, Pascale; Sarthou, Géraldine.
Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf

Structure, transports and transformations of the water masses in the Atlantic Subpolar Gyre
Provedor de dados: 5
Autores: 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
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00268/37968/36867.pdf

Meridional overturning circulation conveys fast acidification to the deep Atlantic Ocean
Provedor de dados: 5
Autores: Perez, Fiz F; Fontela, Marcos; Garcia-ibanez, Maria Isabel; Mercier, Herle; Velo, Anton; Lherminier, Pascale; Zunino, Patricia; De La Paz, Mercedes; Alonso-perez, Fernando; Guallart, Elisa E.; Padin, Xose A.
Since the Industrial Revolution, the North Atlantic Ocean has been accumulating anthropogenic carbon dioxide (CO2) and experiencing ocean acidification1, that is, an increase in the concentration of hydrogen ions (a reduction in pH) and a reduction in the concentration of carbonate ions. The latter causes the ‘aragonite saturation horizon’—below which waters are undersaturated with respect to a particular calcium carbonate, aragonite—to move to shallower depths (to shoal), exposing corals to corrosive waters2,3. Here we use a database analysis to show that the present rate of supply of acidified waters to the deep Atlantic could cause the aragonite saturation horizon to shoal by 1,000–1,700 metres in the subpolar North Atlantic within the next three...
Tipo: Text
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00426/53783/55106.pdf

Mean full-depth summer circulation and transports at the northern periphery of the Atlantic Ocean in the 2000s
Provedor de dados: 5
Autores: Sarafanov, Artem; Falina, Anastasia; Mercier, Herle; Sokov, Alexey; Lherminier, Pascale; Gourcuff, Claire; Gladyshev, Sergey; Gaillard, Fabienne; Daniault, Nathalie.
A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in between Cape Farewell (Greenland), Scotland and the Greenland-Scotland Ridge (GSR) is assessed by combining 2002–2008 yearly hydrographic measurements at 59.5°N, mean dynamic topography, satellite altimetry data and available estimates of the Atlantic–Nordic Seas exchange. The mean absolute transports by the upper-ocean, mid-depth and deep currents and the Meridional Overturning Circulation (MOCσ = 16.5 ± 2.2 Sv, at σ0 = 27.55) at 59.5°N are quantified in the density space. Inter-basin and diapycnal volume fluxes in between the 59.5°N section and the GSR are then estimated from a box model. The dominant components of the meridional exchange across 59.5°N are the North...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00059/16997/14499.pdf

CROSSROAD. Climatic ROle of Subpolar Slopes: a Regional Observational Array off NewfoundlanD
Provedor de dados: 5
Autores: 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
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00503/61502/65316.pdf