Consulta: subjectFacets:"GEOTRACES"
Registros recuperados: 17
Data/hora: 08/06/2024 15:20:46

Intercomparison of dissolved iron isotope profiles from re-occupation of three GEOTRACES stations in the Atlantic Ocean
Provedor de dados: 5
Autores: Conway, T. M.; John, S. G.; Lacan, F.
Intercomparison of trace metal data is a key aspect of the International GEOTRACES program, allowing data from multiple laboratories and countries to be combined to produce high-resolution datasets for the oceans. The use of crossover stations by the GEOTRACES program provides the opportunity both for comparison of analytical techniques and assessment of temporal variability in the cycling of trace metals such as iron (Fe). Here, we present the first comparison of dissolved Fe stable isotope ratio (δ56Fe; relative to IRMM-014) profiles in the oceans, from re-occupations of three locations in the Atlantic Ocean; (1) the Bermuda Atlantic Time Series Station (31.75°N 64.17°W) during the U.S. GEOTRACES IC1 cruise (June 2008) and the U.S. GEOTRACES GA03 cruise...
Tipo: Text
Palavras-chave: Trace metals; GEOTRACES; Biogeochemistry; Intercomparison.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00332/44330/43932.pdf

The Biogeochemistry of Electroactive Humic Substances and Its Connection to Iron Chemistry in the North East Atlantic and the Western Mediterranean Sea
Provedor de dados: 5
Autores: Dulaquais, Gabriel; Waeles, Mathieu; Gerringa, Loes J. A.; Middag, Rob; Rijkenberg, Micha J. A.; Riso, Ricardo.
We present the zonal distribution of electroactive humic-like substances (eHS) along a section from Offshore Portugal in the North East Atlantic to the Sicily Channel in the Mediterranean Sea. The concentrations were normalized to Suwannee River Fulvic Acid and ranged from 11g/L to 81g/L. The vertical distributions were typical of those previously reported for dissolved organic carbon in the Mediterranean Sea. High eHS concentrations were measured in surface water and concentrations decreased with depth before increasing again toward benthic maxima measured at some stations. We estimate that eHS represented a relatively small fraction of the natural organic matter in the Mediterranean Sea (2-5%) but considering their important role in the complexation and...
Tipo: Text
Palavras-chave: Humic substances; Iron; Mediterranean Sea; Biogeochemistry; GEOTRACES.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00616/72781/72218.pdf

Differentiating Lithogenic Supplies, Water Mass Transport, and Biological Processes On and Off the Kerguelen Plateau Using Rare Earth Element Concentrations and Neodymium Isotopic Compositions
Provedor de dados: 5
Autores: Grenier, Melanie; Garcia-solsona, Ester; Lemaitre, Nolwenn; Trull, Thomas W.; Bouvier, Vincent; Nonnotte, Philippe; Van Beek, Pieter; Souhaut, Marc; Lacan, Francois; Jeandel, Catherine.
Distributions of dissolved rare earth element (REE) concentrations and neodymium isotopic compositions (expressed as epsilon(Nd)) of seawater over and off the Kerguelen Plateau in the Southern Ocean are presented. The sampling took place during the austral spring bloom in October-November 2011 (KEOPS2 project, GEOTRACES process study) and aimed to further the investigations of the KEOPS1 austral summer study in terms of sources and transport of lithogenic material, and to investigate the impact of local biogeochemical cycles on the REE distributions. The REE signature of the coastal eastern Kerguelen Islands waters was characterized by negative europium anomalies (Eu/Eu*) and negative epsilon(Nd) in filtered samples. By contrast, the unfiltered sample...
Tipo: Text
Palavras-chave: Southern Ocean; Kerguelen Islands; Rare earth elements; Fractionation; Anomalies; Lithogenic; Biologic; GEOTRACES.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00616/72764/72274.pdf

Nutrient Fluxes Associated With Submarine Groundwater Discharge From Karstic Coastal Aquifers (Côte Bleue, French Mediterranean Coastline)
Provedor de dados: 5
Autores: Bejannin, Simon; Tamborski, Joseph James; Van Beek, Pieter; Souhaut, Marc; Stieglitz, Thomas; Radakovitch, Olivier; Claude, Christelle; Conan, Pascal; Pujo-pay, Mireille; Crispi, Olivier; Le Roy, Emilie; Estournel, Claude.
Determination of submarine groundwater discharge (SGD) from karstic coastal aquifers is important to constrain hydrological and biogeochemical cycles. However, SGD quantification using commonly employed geochemical methods can be difficult to constrain under the presence of large riverine inputs, and is further complicated by the determination of the karstic groundwater endmember. Here, we investigated a coastal region where groundwater discharges from a karstic aquifer system using airborne thermal infrared mapping and geochemical sampling conducted along offshore transects. We report radium data (223Ra, 224Ra, 228Ra) that we used to derive fluxes (water, nutrients) associated with terrestrial groundwater discharge and/or seawater circulation through the...
Tipo: Text
Palavras-chave: Submarine groundwater discharge; Mediterranean sea; Radium isotopes; Thermal infrared remote sensing; Nutrient fluxes; GEOTRACES.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72171/70945.pdf

Iron sources and dissolved-particulate interactions in the seawater of the Western Equatorial Pacific, iron isotope perspectives
Provedor de dados: 5
Autores: Labatut, M.; Lacan, F.; Pradoux, C.; Chmeleff, J.; Radic, A.; Murray, J. W.; Poitrasson, F.; Johansen, A. M.; Thil, F.
This work presents iron isotope data in the western equatorial Pacific. Marine aerosols and top core margin sediments display a slightly heavy Fe isotopic composition (Fe-56) of 0.330.11 (2SD) and 0.140.07, respectively. Samples reflecting the influence of Papua New Guinea runoff (Sepik River and Rabaul volcano water) are characterized by crustal values. In seawater, Fe is mainly supplied in the particulate form and is found with a Fe-56 between -0.49 and 0.34 +/- 0.07 parts per thousand. The particulate Fe seems to be brought mainly by runoff and transported across continental shelves and slopes. Aerosols are suspected to enrich the surface Vitiaz Strait waters, while hydrothermal activity likely enriched New Ireland waters. Dissolved Fe isotopic ratios...
Tipo: Text
Palavras-chave: Iron isotopes; Particles; Equatorial Pacific; Papua New Guinea; Seawater; GEOTRACES.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00290/40074/39162.pdf

Developing Autonomous Observing Systems for Micronutrient Trace Metals
Provedor de dados: 5
Autores: Grand, Maxime M.; Laes, Agathe; Fietz, Susanne; Resing, Joseph A.; Obata, Hajime; Luther, George W.; Tagliabue, Alessandro; Achterberg, Eric P.; Middag, Rob; Tovar-sánchez, Antonio; Bowie, Andrew R.
Trace metal micronutrients are integral to the functioning of marine ecosystems and the export of particulate carbon to the deep ocean. Although much progress has been made in mapping the distributions of metal micronutrients throughout the ocean over the last 30 years, there remain information gaps, most notable during seasonal transitions and in remote regions. The next challenge is to develop in situ sensing technologies necessary to capture the spatial and temporal variabilities of micronutrients characterized with short residence times, highly variable source terms, and sub-nanomolar concentrations in open ocean settings. Such an effort will allow investigation of the biogeochemical processes at the necessary resolution to constrain fluxes, residence...
Tipo: Text
Palavras-chave: Trace metals; Micronutrients; In situ chemical analyzers; In situ sensors; GEOTRACES; OceanObs'19; Ocean observing time series.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59337/62116.pdf

Pervasive sources of isotopically light zinc in the North Atlantic Ocean
Provedor de dados: 5
Autores: Lemaitre, Nolwenn; De Souza, Gregory F.; Archer, Corey; Wang, Ruo-mei; Planquette, Helene; Sarthou, Geraldine; Vance, Derek.
In this study, we report seawater dissolved zinc (Zn) concentration and isotope composition (Zn) from the GEOTRACES GA01 (GEOVIDE) section in the North Atlantic. Across the transect, three subsets of samples stand out due to their isotopically light signature: those close to the Reykjanes Ridge, those close to the sediments, and those, pervasively, in the upper ocean. Similar to observations at other locations, the hydrothermal vent of the Reykjanes Ridge is responsible for the isotopically light Zn composition of the surrounding waters, with an estimated source Zn of -0.42 ‰. This isotopically light Zn is then transported over a distance greater than 1000 km from the vent. Sedimentary inputs are also evident all across the trans-Atlantic section,...
Tipo: Text
Palavras-chave: Zinc isotopes; North Atlantic; Zinc sources; GEOTRACES; GEOVIDE.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00618/73035/72166.pdf

Contrasting biogeochemical cycles of cobalt in the surface western Atlantic Ocean
Provedor de dados: 5
Autores: Dulaquais, Gabriel; Boye, Marie; Middag, Rob; Owens, Stephanis; Puigcorbe, Viena; Buesseler, Ken; Masque, Pere; De Baar, Hein J. W.; Carton, Xavier.
Dissolved cobalt (DCo; &lt;0.2 µm; 14 to 93 pM) and the apparent particulate cobalt (PCo; &gt;0.2 µm; &lt;1 to 15 pM) were determined in the upper water column (&lt;1000 m) of the western Atlantic Ocean along the GEOTRACES-A02 section (64°N to 50°S). The lowest DCo concentrations, typical of a nutrient-type distribution were observed in surface waters of the subtropical domains. Strong linear relationships between DCo and phosphate (P) as well as meridional gradients of decreasing DCo from high latitudes were characterized and both linked to the Co biological requirement. External sources such as the Amazon and the atmospheric deposition were found to contribute significantly (&gt;10%) to the DCo stock of the mixed layer in the equatorial and north...
Tipo: Text
Palavras-chave: Cobalt; Biogeochemistry; Atlantic Ocean; Chemical Oceanography; GEOTRACES.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00241/35222/33732.pdf

Study of the phytoplankton plume dynamics off the Crozet Islands (Southern Ocean): A geochemical-physical coupled approach
Provedor de dados: 5
Autores: Sanial, Virginie; Van Beek, Pieter; Lansard, Bruno; D'Ovidio, Francesco; Kestenare, Elodie; Souhaut, Marc; Zhou, Meng; Blain, Stephane.
Study of the natural iron fertilization in the Southern Ocean Combined geochemical-physical approach to investigate the exchange rates of waters
Tipo: Text
Palavras-chave: Southern Ocean; Crozet Islands; Iron fertilization; Radium; Altimetry; GEOTRACES.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00226/33749/32162.pdf

The GEOTRACES Intermediate Data Product 2014
Provedor de dados: 5
Autores: Mawji, Edward; Schlitzer, Reiner; Dodas, Elena Masferrer; Abadie, Cyril; Abouchami, Wafa; Anderson, Robert F.; Baars, Oliver; Bakker, Karel; Baskaran, Mark; Bates, Nicholas R.; Bluhm, Katrin; Bowie, Andrew; Bown, Johann; Boye, Marie; Boyle, Edward A.; Branellec, Pierre; Bruland, Kenneth W.; Brzezinski, Mark A.; Bucciarelli, Eva; Buesseler, Ken; Butler, Edward; Cai, Pinghe; Cardinal, Damien; Casciotti, Karen; Chaves, Joaquin; Cheng, Hai; Chever, Fanny; Church, Thomas M.; Colman, Albert S.; Conway, Tim M.; Croot, Peter L.; Cutter, Gregory A.; De Baar, Hein J. W.; De Souza, Gregory F.; Dehairs, Frank; Deng, Feifei; Huong Thi Dieu,; Dulaquais, Gabriel; Echegoyen-sanz, Yolanda; Edwards, R. Lawrence; Fahrbach, Eberhard; Fitzsimmons, Jessica; Fleisher, Martin; Frank, Martin; Friedrich, Jana; Fripiat, Francois; Galer, Stephen J. G.; Gamo, Toshitaka; Solsona, Ester Garcia; Gerringa, Loes J. A.; Godoy, Jose Marcus; Gonzalez, Santiago; Grossteffan, Emilie; Hatta, Mariko; Hayes, Christopher T.; Heller, Maija Iris; Henderson, Gideon; Huang, Kuo-fang; Jeandel, Catherine; Jenkins, William J.; John, Seth; Kenna, Timothy C.; Klunder, Maarten; Kretschmer, Sven; Kumamoto, Yuichiro; Laan, Patrick; Labatut, Marie; Lacan, Francois; Lam, Phoebe J.; Lannuzel, Delphine; Le Moigne, Frederique; Lechtenfeld, Oliver J.; Lohan, Maeve C.; Lu, Yanbin; Masque, Pere; Mcclain, Charles R.; Measures, Christopher; Middag, Rob; Moffett, James; Navidad, Alicia; Nishioka, Jun; Noble, Abigail; Obata, Hajime; Ohnemus, Daniel C.; Owens, Stephanie; Planchon, Frederic; Pradoux, Catherine; Puigcorbe, Viena; Quay, Paul; Radic, Amandine; Rehkaemper, Mark; Remenyi, Tomas; Rijkenberg, Micha J. A.; Rintoul, Stephen; Robinson, Laura F.; Roeske, Tobias; Rosenberg, Mark; Van Der Loeff, Michiel Rutgers; Ryabenko, Evgenia; Saito, Mak A.; Roshan, Saeed; Salt, Lesley; Sarthou, Geraldine; Schauer, Ursula; Scott, Peter; Sedwick, Peter N.; Sha, Lijuan; Shiller, Alan M.; Sigman, Daniel M.; Smethie, William; Smith, Geoffrey J.; Sohrin, Yoshiki; Speich, Sabrina; Stichel, Torben; Stutsman, Johnny; Swift, James H.; Tagliabue, Alessandro; Thomas, Alexander; Tsunogai, Urumu; Twining, Benjamin S.; Van Aken, Hendrik M.; Van Heuven, Steven; Van Ooijen, Jan; Van Weerlee, Evaline; Venchiarutti, Celia; Voelker, Antje H. L.; Wake, Bronwyn; Warner, Mark J.; Woodward, E. Malcolm S.; Wu, Jingfeng; Wyatt, Neil; Yoshikawa, Hisayuki; Zheng, Xin-yuan; Xue, Zichen; Zieringer, Moritz; Zimmer, Louise A.
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEls) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data...
Tipo: Text
Palavras-chave: GEOTRACES; Trace elements; Isotopes; Electronic atlas.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00308/41910/41190.pdf

Processes Driving Iron and Manganese Dispersal From the TAG Hydrothermal Plume (Mid-Atlantic Ridge): Results From a GEOTRACES Process Study
Provedor de dados: 5
Autores: González-santana, David; Planquette, Helene; Cheize, Marie; Whitby, Hannah; Gourain, Arthur; Holmes, Thomas; Guyader, Vivien; Cathalot, Cecile; Pelleter, Ewan; Fouquet, Yves; Sarthou, Geraldine.
Hydrothermal vents are a recognized source of trace elements to the ocean inventory. Nevertheless, the contribution of slow-spreading ridges remains poorly resolved. To address this, high-resolution dissolved (&lt;0.45 μm) iron (dFe) and manganese (dMn) samples were collected during the GEOTRACES HERMINE GApr07 process study at the Mid Atlantic Ridge. Samples were collected at nine stations, from the TAG vent site to 75 km south-southwest following the neutrally buoyant plume. Concentrations of dMn and dFe ranged from 71 ± 6 and 51 ± 2 nmol kg–1 right above the vent site to 0.43 ± 0.01 and 1.56 ± 0.02 nmol kg–1 at the most distal station, respectively. Using a 5-box model coupled with our data, we show that as the plume traveled away from the vent,...
Tipo: Text
Palavras-chave: Iron; Manganese; Hydrothermal; TAG; Mid Atlantic Ridge; GEOTRACES.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75530/76431.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

Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean
Provedor de dados: 5
Autores: Abadie, Cyril; Lacan, Francois; Radic, Amandine; Pradoux, Catherine; Poitrasson, Franck.
As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking DFe isotope minimum (light iron) is observed at intermediate depths (200–1,300 m), contrasting with heavier isotopic composition in deep waters. This unambiguously demonstrates distinct DFe sources and processes dominating the iron cycle in the intermediate and deep layers, a feature impossible to see with only iron concentration data largely used thus far in chemical oceanography. At intermediate depths, the data suggest that the dominant DFe sources are linked to organic matter...
Tipo: Text
Palavras-chave: Iron isotopes; GEOTRACES; South Atlantic; Southern Ocean; Remineralization.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00367/47864/47859.pdf

High-precision measurements of seawater Pb isotope compositions by double spike thermal ionization mass spectrometry
Provedor de dados: 5
Autores: Paul, Maxence; Bridgestock, Luke; Rehkaemper, Mark; Van Deflierdt, Tina; Weiss, Dominik.
A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2 L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage anion exchange procedure. The Pb isotope measurements are subsequently carried out by thermal ionization mass spectrometry using a Pb-207-Pb-204 double spike for correction of instrumental mass fractionation. These methods are associated with a total procedural Pb blank of 28 +/- 21 pg(1sd) and typical Pb recoveries of 40-60%. The Pb concentrations are determined by...
Tipo: Text
Palavras-chave: Seawater; Lead isotope; Double spike; Thermal ionization mass spectrometry; GEOTRACES; Inter-calibration.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00351/46268/46051.pdf

Regulation of the Phytoplankton Heme b Iron Pool During the North Atlantic Spring Bloom
Provedor de dados: 5
Autores: Louropoulou, Evangelia; Gledhill, Martha; Browningi, Thomas J.; Desai, Dhwani K.; Barraqueta, Jan-lukas Menzel; Tonnard, Manon; Sarthou, Geraldine; Planquette, Helene; Bowie, Andrew R.; Schmitz, Ruth A.; Laroche, Julie; Achterberg, Eric P.
Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (&lt; 1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (&gt; 0.7 mu m) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median =...
Tipo: Text
Palavras-chave: Heme b; North Atlantic; Phytoplankton; Diatoms; Iron; Limitation; GEOTRACES; GEOVIDE.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00508/61940/66029.pdf

Rare earth element distribution in the Atlantic sector of the Southern Ocean: The balance between particle scavenging and vertical supply
Provedor de dados: 5
Autores: Hathorne, Ed C.; Stichel, Torben; Brueck, Bastian; Frank, Martin.
The concentrations of rare earth elements (REEs) in seawater display systematic variations related to weathering inputs, particle scavenging and water mass histories. Here we investigate the REE concentrations of water column profiles in the Atlantic sector of the Southern Ocean, a key region of the global circulation and primary production. The data reveal a pronounced contrast between the vertical profiles in the Antarctic Circumpolar Current (ACC) and those south of the ACC in the Weddell Gyre (WG). The ACC profiles exhibit the typical increase of REE concentrations with water depth and a change in the shape of the profiles from near linear for the light REEs to more convex for the heavy REEs. In contrast, the WG profiles exhibit high REE concentrations...
Tipo: Text
Palavras-chave: Rare earth elements; Atlantic sector of the Southern Ocean; Weddell Gyre; GEOTRACES.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00294/40504/83046.pdf

Particulate Trace Element Export in the North Atlantic (GEOTRACES GA01 Transect, GEOVIDE Cruise)
Provedor de dados: 5
Autores: Lemaitre, Nolwenn; Planquette, Helene; Dehairs, Frank; Planchon, Frederic; Sarthou, Geraldine; Gallinari, Morgane; Roig, Stéphane; Jeandel, Catherine; Castrillejo, Maxi.
Vertical export of particulate trace elements (pTEs) is a critically underconstrained aspect of their biogeochemistry. Here, we combine elemental analyses on large (&gt;53 μm) particles and 234Th measurements to determine downward export fluxes from the upper layers (40–110 m) of pTEs (Al, Cd, Co, Cu, Fe, Mn, Ni, P, Ti, V, Zn) and mineral phases (lithogenic, Fe- and Mn-oxides, calcium carbonate, and opal) in the North Atlantic along the GEOVIDE transect (Portugal–Greenland–Canada; GEOTRACES GA01 cruise). The role of lithogenic particles in controlling TE fluxes is obvious at proximity of the Iberian margin where the highest pTE export fluxes were estimated (up to 3912 μg/m2/d for pFe). However, high lithogenic and pTE fluxes are also observed up to 1700 km...
Tipo: Text
Palavras-chave: Particulate trace elements; Export fluxes; Multiple carrier phases; Residence times; GEOTRACES.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00656/76810/78174.pdf