Consulta: creatorFacets:"Sarthou, G."
Registros recuperados: 10
Data/hora: 09/06/2024 15:51:29

Physical speciation of iron in the Atlantic sector of the Southern Ocean along a transect from the subtropical domain to the Weddell Sea Gyre
Provedor de dados: 5
Autores: Chever, Fanny; Bucciarelli, Eva; Sarthou, G.; Speich, Sabrina; Arhan, Michel; Penven, Pierrick; Tagliabue, A.
[1] Distributions of total dissolvable iron (TDFe; unfiltered), dissolved iron (DFe; 0.2 mu m filtered), and soluble iron (SFe; 0.02 mu m filtered) were investigated during the BONUS-GoodHope cruise in the Atlantic sector of the Southern Ocean (34 degrees S/17 degrees E-57 degrees S/0 degrees, February-March 2008). In the mixed layer, mean values of 0.43 +/- 0.28 and 0.22 +/- 0.18 nmol L-1 were measured for TDFe and DFe, respectively. In deeper waters, TDFe and DFe concentrations were 1.07 +/- 0.68 and 0.52 +/- 0.30 nmol L-1, respectively. DFe concentrations decreased from the north (subtropical waters) to the south (Weddell Sea Gyre). In the subtropical domain, dusts coming from Patagonia and southern Africa and inputs from the African continental margin...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00017/12808/9763.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

Iron biogeochemistry across marine systems - progress from the past decade
Provedor de dados: 5
Autores: Breitbarth, E.; Achterberg, E. P.; Ardelan, M. V.; Baker, A. R.; Bucciarelli, E.; Chever, F.; Croot, P. L.; Duggen, S.; Gledhill, M.; Hassellov, M.; Hassler, C.; Hoffmann, L. J.; Hunter, K. A.; Hutchins, D. A.; Ingri, J.; Jickells, T.; Lohan, M. C.; Nielsdottir, M. C.; Sarthou, G.; Schoemann, V.; Trapp, J. M.; Turner, D. R.; Ye, Y.
Based on an international workshop (Gothenburg, 14-16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas.
Tipo: Text
Palavras-chave: Sub-arctic pacific; Dissolved organic carbon; Field flow fractionation; Phytoplankton community structure; Cathodic stripping voltammetry; Continuous culture system; Export experiment crozex; Eastern north atlantic; Light co-limitation; Southern ocean.
Ano: 2010
URL: https://archimer.ifremer.fr/doc/00205/31606/30034.pdf

Dissolved greenhouse gases (nitrous oxide and methane) associated with the naturally iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean
Provedor de dados: 5
Autores: Farias, L.; Florez-leiva, L.; Besoain, V.; Sarthou, G.; Fernandez, Camino.
The concentrations of greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), were measured in the Kerguelen Plateau region (KPR). The KPR is affected by an annual microalgal bloom caused by natural iron fertilization, and this may stimulate the microbes involved in GHG cycling. This study was carried out during the KEOPS 2 cruise during the austral spring of 2011. Oceanographic variables, including N2O and CH4, were sampled (from the surface to 500 m depth) in two transects along and across the KRP, the north south (TNS) transect (46 degrees-51 degrees S, similar to 72 degrees E) and the east west (TEW) transect (66 degrees -75 degrees E, similar to 48.3 degrees S), both associated with the presence of a plateau, polar front (PF) and other...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00260/37141/35669.pdf

Contribution of resuspended sedimentary particles to dissolved iron and manganese in the ocean: An experimental study
Provedor de dados: 5
Autores: Cheize, Marie; Planquette, H.f.; Fitzsimmons, J.n.; Pelleter, Ewan; Sherrell, R.m.; Lambert, Christophe; Bucciarelli, E.; Sarthou, G.; Le Goff, Marion; Liorzou, Celine; Chéron, Sandrine; Viollier, E.; Gayet, Nicolas.
A number of trace metals play essential roles in marine ecosystem structure and biological productivity. Until recently, it has been argued that phytoplankton access primarily dissolved iron, while particulate iron was considered a refractory material with little use biologically and limited interaction with the dissolved pool. In order to assess the transfer mechanisms between sediment-sourced particulate trace metals and the dissolved pool, we conducted a 14-month incubation that reacted resuspended sediments with natural seawater, both originating from the Kerguelen area (KEOPS cruises; Southern Ocean), in the dark, and at concentrations replicating natural conditions. Three types of sediments were investigated (named BioSi, BioSi + Ca, and Basalt),...
Tipo: Text
Palavras-chave: Suspended particle dissolution; Sediment; Iron; Manganese; Biogenic silica; Southern Ocean; Kerguelen.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00460/57197/59166.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

Trace element and isotope deposition across the air-sea interface: progress and research needs
Provedor de dados: 5
Autores: Baker, A. R.; Landing, W. M.; Bucciarelli, E.; Cheize, Marie; Fietz, S.; Hayes, C. T.; Kadko, D.; Morton, P. L.; Rogan, N.; Sarthou, G.; Shelley, R. U.; Shi, Z.; Shiller, A.; Van Hulten, M. M. P.
The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field...
Tipo: Text
Palavras-chave: Air-sea exchange; Atmospheric deposition; Trace element solubility; Biogeochemical impacts; Mineral dust; Anthropogenic aerosols.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00369/48045/48131.pdf

Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics
Provedor de dados: 5
Autores: Van Der Merwe, P.; Bowie, A. R.; Queroue, F.; Armand, L.; Blain, S.; Chever, Fanny; Davies, D.; Dehairs, F.; Planchon, F.; Sarthou, G.; Townsend, A. T.; Trull, T. W.
The KEOPS2 project aims to elucidate the role of natural Fe fertilisation on biogeochemical cycles and ecosystem functioning, including quantifying the sources and processes by which iron is delivered in the vicinity of the Kerguelen Archipelago, Southern Ocean. The KEOPS2 process study used an upstream high-nutrient, low-chlorophyll (HNLC), deep water (2500 m), reference station to compare with a shallow (500 m), strongly fertilised plateau station and continued the observations to a downstream, bathymetrically trapped recirculation of the Polar Front where eddies commonly form and persist for hundreds of kilometres into the Southern Ocean. Over the Kerguelen Plateau, mean particulate (1-53 mu m) Fe and Al concentrations (pFe = 13.4 nM, pAl = 25.2 nM)...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00256/36676/35276.pdf

Labile Fe(II) concentrations in the Atlantic sector of the Southern Ocean along a transect from the subtropical domain to the Weddell Sea Gyre
Provedor de dados: 5
Autores: Sarthou, G.; Bucciarelli, Eva; Chever, Fanny; Hansard, S. P.; Gonzalez-davila, M.; Santana-casiano, J. M.; Planchon, F.; Speich, Sabrina.
Labile Fe(II) distributions were investigated in the Sub-Tropical South Atlantic and the Southern Ocean during the BONUS-GoodHope cruise from 34 to 57 degrees S (February-March 2008). Concentrations ranged from below the detection limit (0.009 nM) to values as high as 0.125 nM. In the surface mixed layer, labile Fe(II) concentrations were always higher than the detection limit, with values higher than 0.060nM south of 47 degrees S, representing between 39% and 63% of dissolved Fe (DFe). Apparent biological production of Fe(II) was evidenced. At intermediate depth, local maxima were observed, with the highest values in the Sub-Tropical domain at around 200 m, and represented more than 70% of DFe. Remineralization processes were likely responsible for those...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00048/15918/13345.pdf

An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean)
Provedor de dados: 5
Autores: Chever, F.; Sarthou, G.; Bucciarelli, E.; Blain, S.; Bowie, A. R.
Total dissolvable iron (TDFe) was measured in the water column above and in the surrounding of the Kerguelen Plateau (Indian sector of the Southern Ocean) during the KErguelen Ocean Plateau compared Study (KEOPS) cruise. TDFe concentrations ranged from 0.90 to 65.6 nmol L-1 above the plateau and from 0.34 to 2.23 nmol L-1 offshore of the plateau. Station C1 located south of the plateau, near Heard Island, exhibited very high values (329-770 nmol L-1). Apparent particulate iron (Fe-app), calculated as the difference between the TDFe and the dissolved iron measured on board (DFe) represented 95 +/- 5% of the TDFe above the plateau, suggesting that particles and refractory colloids largely dominated the iron pool. This paper presents a budget of DFe and...
Tipo: Text
Palavras-chave: Phytoplankton bloom; Dissolved iron; Atlantic ocean; Central california; Carbon sequestration; Coastal waters; Surface waters; Plateau region; Organic carbon; Bound iron.
Ano: 2010
URL: https://archimer.ifremer.fr/doc/00205/31605/30036.pdf