Articles | Volume 12, issue 5
https://doi.org/10.5194/bg-12-1415-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/bg-12-1415-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
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05 Mar 2015
Research article | Highlight paper |
| 05 Mar 2015
Use of Ra isotopes to deduce rapid transfer of sediment-derived inputs off Kerguelen
V. Sanial
CORRESPONDING AUTHOR
LEGOS, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, (CNRS-CNES-IRD-UPS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
P. van Beek
LEGOS, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, (CNRS-CNES-IRD-UPS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
B. Lansard
LEGOS, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, (CNRS-CNES-IRD-UPS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
LSCE, Laboratoire des Sciences du Climat et de l'Environnement (IPSL-CEA-CNRS-UVSQ-IPSL), avenue de la Terrasse, 91198 Gif-sur-Yvette, France
M. Souhaut
LEGOS, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, (CNRS-CNES-IRD-UPS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
E. Kestenare
LEGOS, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, (CNRS-CNES-IRD-UPS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
F. d'Ovidio
Sorbonne Universités, UPMC Univ Paris 06, CNRS, LOCEAN-IPSL, 4 place Jussieu, 75005 Paris, France
M. Zhou
Department of Environment Earth and Ocean Sciences, University of Massachusetts Boston, Boston, Massachusetts, USA
S. Blain
Sorbonne Universités, UPMC Univ Paris 06, UMR7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologie, 66650 Banyuls/mer, France
CNRS, UMR7621, Laboratoire d'Océanologie Microbienne, Observatoire Océanologie, 66650 Banyuls/mer, France
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M. Zhou, Y. Zhu, F. d'Ovidio, Y.-H. Park, I. Durand, E. Kestenare, V. Sanial, P. Van-Beek, B. Queguiner, F. Carlotti, and S. Blain
Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-6845-2014, https://doi.org/10.5194/bgd-11-6845-2014, 2014
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Eva Ferreira, Stanley Nmor, Eric Viollier, Bruno Lansard, Bruno Bombled, Edouard Regnier, Gaël Monvoisin, Christian Grenz, Pieter van Beek, and Christophe Rabouille
Biogeosciences, 21, 711–729, https://doi.org/10.5194/bg-21-711-2024, https://doi.org/10.5194/bg-21-711-2024, 2024
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The study provides new insights by examining the short-term impact of winter floods on biogeochemical sediment processes near the Rhône River (NW Mediterranean Sea). This is the first winter monitoring of sediment and porewater in deltaic areas. The coupling of these data with a new model enables us to quantify the evolution of biogeochemical processes. It also provides new perspectives on the benthic carbon cycle in river deltas considering climate change, whereby flooding should intensify.
Nicolas Metzl, Jonathan Fin, Claire Lo Monaco, Claude Mignon, Samir Alliouane, David Antoine, Guillaume Bourdin, Jacqueline Boutin, Yann Bozec, Pascal Conan, Laurent Coppola, Frédéric Diaz, Eric Douville, Xavier Durrieu de Madron, Jean-Pierre Gattuso, Frédéric Gazeau, Melek Golbol, Bruno Lansard, Dominique Lefèvre, Nathalie Lefèvre, Fabien Lombard, Férial Louanchi, Liliane Merlivat, Léa Olivier, Anne Petrenko, Sébastien Petton, Mireille Pujo-Pay, Christophe Rabouille, Gilles Reverdin, Céline Ridame, Aline Tribollet, Vincenzo Vellucci, Thibaut Wagener, and Cathy Wimart-Rousseau
Earth Syst. Sci. Data, 16, 89–120, https://doi.org/10.5194/essd-16-89-2024, https://doi.org/10.5194/essd-16-89-2024, 2024
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This work presents a synthesis of 44 000 total alkalinity and dissolved inorganic carbon observations obtained between 1993 and 2022 in the Global Ocean and the Mediterranean Sea at the surface and in the water column. Seawater samples were measured using the same method and calibrated with international Certified Reference Material. We describe the data assemblage, quality control and some potential uses of this dataset.
Roxane Tzortzis, Andrea M. Doglioli, Monique Messié, Stéphanie Barrillon, Anne A. Petrenko, Lloyd Izard, Yuan Zhao, Francesco d'Ovidio, Franck Dumas, and Gérald Gregori
Biogeosciences, 20, 3491–3508, https://doi.org/10.5194/bg-20-3491-2023, https://doi.org/10.5194/bg-20-3491-2023, 2023
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We studied a finescale frontal structure in order to highlight its influence on the dynamics and distribution of phytoplankton communities. We computed the growth rates of several phytoplankton groups identified by flow cytometry in two water masses separated by the front. We found contrasted phytoplankton dynamics on the two sides of the front, consistent with the distribution of their abundances. Our study gives new insights into the physical and biological coupling on a finescale front.
Stanley I. Nmor, Eric Viollier, Lucie Pastor, Bruno Lansard, Christophe Rabouille, and Karline Soetaert
Geosci. Model Dev., 15, 7325–7351, https://doi.org/10.5194/gmd-15-7325-2022, https://doi.org/10.5194/gmd-15-7325-2022, 2022
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The coastal marine environment serves as a transition zone in the land–ocean continuum and is susceptible to episodic phenomena such as flash floods, which cause massive organic matter deposition. Here, we present a model of sediment early diagenesis that explicitly describes this type of deposition while also incorporating unique flood deposit characteristics. This model can be used to investigate the temporal evolution of marine sediments following abrupt changes in environmental conditions.
Philippe Massicotte, Rainer M. W. Amon, David Antoine, Philippe Archambault, Sergio Balzano, Simon Bélanger, Ronald Benner, Dominique Boeuf, Annick Bricaud, Flavienne Bruyant, Gwenaëlle Chaillou, Malik Chami, Bruno Charrière, Jing Chen, Hervé Claustre, Pierre Coupel, Nicole Delsaut, David Doxaran, Jens Ehn, Cédric Fichot, Marie-Hélène Forget, Pingqing Fu, Jonathan Gagnon, Nicole Garcia, Beat Gasser, Jean-François Ghiglione, Gaby Gorsky, Michel Gosselin, Priscillia Gourvil, Yves Gratton, Pascal Guillot, Hermann J. Heipieper, Serge Heussner, Stanford B. Hooker, Yannick Huot, Christian Jeanthon, Wade Jeffrey, Fabien Joux, Kimitaka Kawamura, Bruno Lansard, Edouard Leymarie, Heike Link, Connie Lovejoy, Claudie Marec, Dominique Marie, Johannie Martin, Jacobo Martín, Guillaume Massé, Atsushi Matsuoka, Vanessa McKague, Alexandre Mignot, William L. Miller, Juan-Carlos Miquel, Alfonso Mucci, Kaori Ono, Eva Ortega-Retuerta, Christos Panagiotopoulos, Tim Papakyriakou, Marc Picheral, Louis Prieur, Patrick Raimbault, Joséphine Ras, Rick A. Reynolds, André Rochon, Jean-François Rontani, Catherine Schmechtig, Sabine Schmidt, Richard Sempéré, Yuan Shen, Guisheng Song, Dariusz Stramski, Eri Tachibana, Alexandre Thirouard, Imma Tolosa, Jean-Éric Tremblay, Mickael Vaïtilingom, Daniel Vaulot, Frédéric Vaultier, John K. Volkman, Huixiang Xie, Guangming Zheng, and Marcel Babin
Earth Syst. Sci. Data, 13, 1561–1592, https://doi.org/10.5194/essd-13-1561-2021, https://doi.org/10.5194/essd-13-1561-2021, 2021
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The MALINA oceanographic expedition was conducted in the Mackenzie River and the Beaufort Sea systems. The sampling was performed across seven shelf–basin transects to capture the meridional gradient between the estuary and the open ocean. The main goal of this research program was to better understand how processes such as primary production are influencing the fate of organic matter originating from the surrounding terrestrial landscape during its transition toward the Arctic Ocean.
Eleonora Fossile, Maria Pia Nardelli, Arbia Jouini, Bruno Lansard, Antonio Pusceddu, Davide Moccia, Elisabeth Michel, Olivier Péron, Hélène Howa, and Meryem Mojtahid
Biogeosciences, 17, 1933–1953, https://doi.org/10.5194/bg-17-1933-2020, https://doi.org/10.5194/bg-17-1933-2020, 2020
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This study focuses on benthic foraminiferal distribution in an Arctic fjord characterised by continuous sea ice production during winter and the consequent cascading of salty and corrosive waters (brine) to the seabed. The inner fjord is dominated by calcareous species (C). In the central deep basins, where brines are persistent, calcareous foraminifera are dissolved and agglutinated (A) dominate. The high A/C ratio is suggested as a proxy for brine persistence and sea ice production.
Jens Rassmann, Eryn M. Eitel, Bruno Lansard, Cécile Cathalot, Christophe Brandily, Martial Taillefert, and Christophe Rabouille
Biogeosciences, 17, 13–33, https://doi.org/10.5194/bg-17-13-2020, https://doi.org/10.5194/bg-17-13-2020, 2020
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In this paper, we use a large set of measurements made using in situ and lab techniques to elucidate the cause of dissolved inorganic carbon fluxes in sediments from the Rhône delta and its companion compound alkalinity, which carries the absorption capacity of coastal waters with respect to atmospheric CO2. We show that sediment processes (sulfate reduction, FeS precipitation and accumulation) are crucial in generating the alkalinity fluxes observed in this study by in situ incubation chambers.
Jens K. Ehn, Rick A. Reynolds, Dariusz Stramski, David Doxaran, Bruno Lansard, and Marcel Babin
Biogeosciences, 16, 1583–1605, https://doi.org/10.5194/bg-16-1583-2019, https://doi.org/10.5194/bg-16-1583-2019, 2019
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Beam attenuation at 660 nm and suspended particle matter (SPM) relationships were determined during the MALINA cruise in August 2009 to the Canadian Beaufort Sea in order to expand our knowledge of particle distributions in Arctic shelf seas. The relationship was then used to determine SPM distributions for four other expeditions to the region. SPM patterns on the shelf were explained by an interplay between wind forcing, river discharge, and melting sea ice that controls the circulation.
Géraldine Sarthou, Pascale Lherminier, Eric P. Achterberg, Fernando Alonso-Pérez, Eva Bucciarelli, Julia Boutorh, Vincent Bouvier, Edward A. Boyle, Pierre Branellec, Lidia I. Carracedo, Nuria Casacuberta, Maxi Castrillejo, Marie Cheize, Leonardo Contreira Pereira, Daniel Cossa, Nathalie Daniault, Emmanuel De Saint-Léger, Frank Dehairs, Feifei Deng, Floriane Desprez de Gésincourt, Jérémy Devesa, Lorna Foliot, Debany Fonseca-Batista, Morgane Gallinari, Maribel I. García-Ibáñez, Arthur Gourain, Emilie Grossteffan, Michel Hamon, Lars Eric Heimbürger, Gideon M. Henderson, Catherine Jeandel, Catherine Kermabon, François Lacan, Philippe Le Bot, Manon Le Goff, Emilie Le Roy, Alison Lefèbvre, Stéphane Leizour, Nolwenn Lemaitre, Pere Masqué, Olivier Ménage, Jan-Lukas Menzel Barraqueta, Herlé Mercier, Fabien Perault, Fiz F. Pérez, Hélène F. Planquette, Frédéric Planchon, Arnout Roukaerts, Virginie Sanial, Raphaëlle Sauzède, Catherine Schmechtig, Rachel U. Shelley, Gillian Stewart, Jill N. Sutton, Yi Tang, Nadine Tisnérat-Laborde, Manon Tonnard, Paul Tréguer, Pieter van Beek, Cheryl M. Zurbrick, and Patricia Zunino
Biogeosciences, 15, 7097–7109, https://doi.org/10.5194/bg-15-7097-2018, https://doi.org/10.5194/bg-15-7097-2018, 2018
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The GEOVIDE cruise (GEOTRACES Section GA01) was conducted in the North Atlantic Ocean and Labrador Sea in May–June 2014. In this special issue, results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 17 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.
Mathieu Rembauville, Stéphane Blain, Clara Manno, Geraint Tarling, Anu Thompson, George Wolff, and Ian Salter
Biogeosciences, 15, 3071–3084, https://doi.org/10.5194/bg-15-3071-2018, https://doi.org/10.5194/bg-15-3071-2018, 2018
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Sinking phytoplankton from the surface ocean provide the principal energy source to deep-ocean ecosystems. Our aim was to understand how different phytoplankton communities impact the chemical nature of this sinking material. We show certain types of phytoplankton can preferentially export energy-rich storage compounds to the seafloor. Any climate-driven effects on phytoplankton community structure could thus impact remote deep-ocean ecosystems thousands of kilometres beneath the surface.
Emilie Le Roy, Virginie Sanial, Matthew A. Charette, Pieter van Beek, François Lacan, Stéphanie H. M. Jacquet, Paul B. Henderson, Marc Souhaut, Maribel I. García-Ibáñez, Catherine Jeandel, Fiz F. Pérez, and Géraldine Sarthou
Biogeosciences, 15, 3027–3048, https://doi.org/10.5194/bg-15-3027-2018, https://doi.org/10.5194/bg-15-3027-2018, 2018
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We report detailed sections of radium-226 (226Ra, T1/2 = 1602 y) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal–Greenland–Canada) in the framework of the international GEOTRACES program (GA01 section–GEOVIDE project, May–July 2014). Dissolved 226Ra and Ba are strongly correlated along the section, which may reflect their similar chemical behavior.
Ivia Closset, Damien Cardinal, Mathieu Rembauville, François Thil, and Stéphane Blain
Biogeosciences, 13, 6049–6066, https://doi.org/10.5194/bg-13-6049-2016, https://doi.org/10.5194/bg-13-6049-2016, 2016
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Isotopic measurements were used to investigate the seasonal evolution of the silicon (Si) biogeochemical cycle in a naturally iron-fertilized area of the Southern Ocean. When comparing data from early spring and summer periods, the relationship between Si depletion, biogenic silica production, and their isotopic composition appears decoupled in this region. Considering these results, we refined the seasonal net Si production that was mainly sustained by surface phytoplankton populations.
Jens Rassmann, Bruno Lansard, Lara Pozzato, and Christophe Rabouille
Biogeosciences, 13, 5379–5394, https://doi.org/10.5194/bg-13-5379-2016, https://doi.org/10.5194/bg-13-5379-2016, 2016
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In situ O2 and pH measurements as well as determination of porewater concentrations of dissolved inorganic carbon, total alkalinity, sulfate and calcium have been measured in the sediments of the Rhône prodelta. Biogeochemical activity decreased with distance from the river mouth. Oxic processes decreased the carbonate saturation state (Ω) by lowering pH, whereas anaerobic organic matter degradation, dominated by sulfate reduction, was accompanied by increasing Ω and carbonate precipitation.
A. J. Cavagna, F. Fripiat, M. Elskens, P. Mangion, L. Chirurgien, I. Closset, M. Lasbleiz, L. Florez-Leiva, D. Cardinal, K. Leblanc, C. Fernandez, D. Lefèvre, L. Oriol, S. Blain, B. Quéguiner, and F. Dehairs
Biogeosciences, 12, 6515–6528, https://doi.org/10.5194/bg-12-6515-2015, https://doi.org/10.5194/bg-12-6515-2015, 2015
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Primary production, NO3- and NH4+ uptake, and nitrification rates were measured during the KEOPS 2 cruise (austral spring 2011) in the Kerguelen Plateau area. Natural iron fertilization stimulated primary production which is much higher in the fertilized areas compared to the HNLC site. We report high rates of nitrification in the mixed layer below the euphotic zone. We conclude that high productivity in deep mixing system stimulates the N cycle by increasing both assimilation and regeneration.
F. d'Ovidio, A. Della Penna, T. W. Trull, F. Nencioli, M.-I. Pujol, M.-H. Rio, Y.-H. Park, C. Cotté, M. Zhou, and S. Blain
Biogeosciences, 12, 5567–5581, https://doi.org/10.5194/bg-12-5567-2015, https://doi.org/10.5194/bg-12-5567-2015, 2015
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Field campaigns are instrumental in providing ground truth for understanding and modeling global ocean biogeochemical budgets. A survey however can only inspect a fraction of the global oceans, typically a region hundreds of kilometers wide for a temporal window of the order of (at most) several weeks. In this spatiotemporal domain, mesoscale variability can mask climatological contrasts. Here we propose the use of multisatellite-based Lagrangian diagnostics to solve this issue.
F. Carlotti, M.-P. Jouandet, A. Nowaczyk, M. Harmelin-Vivien, D. Lefèvre, P. Richard, Y. Zhu, and M. Zhou
Biogeosciences, 12, 4543–4563, https://doi.org/10.5194/bg-12-4543-2015, https://doi.org/10.5194/bg-12-4543-2015, 2015
A. R. Bowie, P. van der Merwe, F. Quéroué, T. Trull, M. Fourquez, F. Planchon, G. Sarthou, F. Chever, A. T. Townsend, I. Obernosterer, J.-B. Sallée, and S. Blain
Biogeosciences, 12, 4421–4445, https://doi.org/10.5194/bg-12-4421-2015, https://doi.org/10.5194/bg-12-4421-2015, 2015
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Iron biogeochemical budgets during the natural ocean fertilisation experiment KEOPS-2 showed that complex circulation and transport pathways were responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. The exchange of iron between dissolved, biogenic and lithogenic pools was highly dynamic, resulting in a decoupling of iron supply and carbon export and controlling the efficiency of fertilization.
F. Quéroué, G. Sarthou, H. F. Planquette, E. Bucciarelli, F. Chever, P. van der Merwe, D. Lannuzel, A. T. Townsend, M. Cheize, S. Blain, F. d'Ovidio, and A. R. Bowie
Biogeosciences, 12, 3869–3883, https://doi.org/10.5194/bg-12-3869-2015, https://doi.org/10.5194/bg-12-3869-2015, 2015
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Dissolved Fe (dFe) concentrations were measured in the vicinity of the Kerguelen Islands. Direct island runoff, glacial melting, and resuspended sediments were identified as important inputs of dFe that could potentially fertilise the northern part of the plateau. Overall, heterogeneous sources of Fe over and off the plateau, in addition to strong variability in Fe supply by vertical or horizontal transport, may explain the high variability in dFe concentrations observed during this study.
M. Rembauville, I. Salter, N. Leblond, A. Gueneugues, and S. Blain
Biogeosciences, 12, 3153–3170, https://doi.org/10.5194/bg-12-3153-2015, https://doi.org/10.5194/bg-12-3153-2015, 2015
M. Rembauville, S. Blain, L. Armand, B. Quéguiner, and I. Salter
Biogeosciences, 12, 3171–3195, https://doi.org/10.5194/bg-12-3171-2015, https://doi.org/10.5194/bg-12-3171-2015, 2015
I. Obernosterer, M. Fourquez, and S. Blain
Biogeosciences, 12, 1983–1992, https://doi.org/10.5194/bg-12-1983-2015, https://doi.org/10.5194/bg-12-1983-2015, 2015
M. Fourquez, I. Obernosterer, D. M. Davies, T. W. Trull, and S. Blain
Biogeosciences, 12, 1893–1906, https://doi.org/10.5194/bg-12-1893-2015, https://doi.org/10.5194/bg-12-1893-2015, 2015
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In this manuscript, we present the results of iron uptake measured in the naturally iron-fertilized area during the Kerguelen Ocean and Plateau compared Study 2 cruise (KEOPS2). Iron uptake by bulk community and several size fractions (microplankton, pico-nanoplankton and bacteria) are presented, compared and discussed in the present paper. This work also presents first investigations on the potential competition between bacteria and phytoplankton for access to iron.
T. W. Trull, D. M. Davies, F. Dehairs, A.-J. Cavagna, M. Lasbleiz, E. C. Laurenceau-Cornec, F. d'Ovidio, F. Planchon, K. Leblanc, B. Quéguiner, and S. Blain
Biogeosciences, 12, 1029–1056, https://doi.org/10.5194/bg-12-1029-2015, https://doi.org/10.5194/bg-12-1029-2015, 2015
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The KEOPS2 oceanographic study surveyed more than 30 sites downstream from the Kerguelen Islands in the Southern Ocean to examine the degree of variation in phytoplankton community responses to natural iron inputs. Our observations of community structure based on the chemical compositions of six microbial size fractions suggest that early spring trophodynamic and export responses differed between regions with persistently low levels versus punctually high levels of iron fertilisation.
E. C. Laurenceau-Cornec, T. W. Trull, D. M. Davies, S. G. Bray, J. Doran, F. Planchon, F. Carlotti, M.-P. Jouandet, A.-J. Cavagna, A. M. Waite, and S. Blain
Biogeosciences, 12, 1007–1027, https://doi.org/10.5194/bg-12-1007-2015, https://doi.org/10.5194/bg-12-1007-2015, 2015
P. van der Merwe, A. R. Bowie, F. Quéroué, L. Armand, S. Blain, F. Chever, D. Davies, F. Dehairs, F. Planchon, G. Sarthou, A. T. Townsend, and T. W. Trull
Biogeosciences, 12, 739–755, https://doi.org/10.5194/bg-12-739-2015, https://doi.org/10.5194/bg-12-739-2015, 2015
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Trace metal analysis of suspended and settling particles and underlying sediment was undertaken to elucidate the source to sink progression of the particulate trace metal pool near Kerguelen Island (Southern Ocean). Findings indicate that the Kerguelen Plateau is a source of trace metals via resuspended shelf sediments, especially below the mixed layer. However, glacial/fluvial runoff into shallow coastal waters is an important mode of fertilisation to areas downstream of Kerguelen Island.
S. Blain, J. Capparos, A. Guéneuguès, I. Obernosterer, and L. Oriol
Biogeosciences, 12, 623–635, https://doi.org/10.5194/bg-12-623-2015, https://doi.org/10.5194/bg-12-623-2015, 2015
C. Lo Monaco, N. Metzl, F. D'Ovidio, J. Llort, and C. Ridame
Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-17543-2014, https://doi.org/10.5194/bgd-11-17543-2014, 2014
Revised manuscript has not been submitted
U. Christaki, D. Lefèvre, C. Georges, J. Colombet, P. Catala, C. Courties, T. Sime-Ngando, S. Blain, and I. Obernosterer
Biogeosciences, 11, 6739–6753, https://doi.org/10.5194/bg-11-6739-2014, https://doi.org/10.5194/bg-11-6739-2014, 2014
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The concurrent investigation of several parameters has provided insight into two key roles of heterotrophic bacteria, and the microbial food web functioning, at the onset and late phase of the spring phytoplankton bloom induced by natural iron fertilization in the Southern Ocean.
M. Lasbleiz, K. Leblanc, S. Blain, J. Ras, V. Cornet-Barthaux, S. Hélias Nunige, and B. Quéguiner
Biogeosciences, 11, 5931–5955, https://doi.org/10.5194/bg-11-5931-2014, https://doi.org/10.5194/bg-11-5931-2014, 2014
M.-P. Jouandet, G. A. Jackson, F. Carlotti, M. Picheral, L. Stemmann, and S. Blain
Biogeosciences, 11, 4393–4406, https://doi.org/10.5194/bg-11-4393-2014, https://doi.org/10.5194/bg-11-4393-2014, 2014
M. Zhou, Y. Zhu, F. d'Ovidio, Y.-H. Park, I. Durand, E. Kestenare, V. Sanial, P. Van-Beek, B. Queguiner, F. Carlotti, and S. Blain
Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-6845-2014, https://doi.org/10.5194/bgd-11-6845-2014, 2014
Revised manuscript has not been submitted
C. Guinet, X. Xing, E. Walker, P. Monestiez, S. Marchand, B. Picard, T. Jaud, M. Authier, C. Cotté, A. C. Dragon, E. Diamond, D. Antoine, P. Lovell, S. Blain, F. D'Ortenzio, and H. Claustre
Earth Syst. Sci. Data, 5, 15–29, https://doi.org/10.5194/essd-5-15-2013, https://doi.org/10.5194/essd-5-15-2013, 2013
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Nitrite cycling in the primary nitrite maxima of the eastern tropical North Pacific
Hotspots and drivers of compound marine heatwaves and low net primary production extremes
Ecosystem impacts of marine heat waves in the northeast Pacific
Tracing the role of Arctic shelf processes in Si and N cycling and export through the Fram Strait: insights from combined silicon and nitrate isotopes
Controls on the relative abundances and rates of nitrifying microorganisms in the ocean
The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
Influence of GEOTRACES data distribution and misfit function choice on objective parameter retrieval in a marine zinc cycle model
Physiological flexibility of phytoplankton impacts modelled chlorophyll and primary production across the North Pacific Ocean
Observation-constrained estimates of the global ocean carbon sink from Earth system models
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)
Controlling factors on the global distribution of a representative marine non-cyanobacterial diazotroph phylotype (Gamma A)
Summer trends and drivers of sea surface fCO2 and pH changes observed in the southern Indian Ocean over the last two decades (1998–2019)
Global nutrient cycling by commercially targeted marine fish
Major processes of the dissolved cobalt cycle in the North and equatorial Pacific Ocean
The impact of the South-East Madagascar Bloom on the oceanic CO2 sink
Nitrite regeneration in the oligotrophic Atlantic Ocean
Bridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the ocean
Biological production in two contrasted regions of the Mediterranean Sea during the oligotrophic period: an estimate based on the diel cycle of optical properties measured by BioGeoChemical-Argo profiling floats
Acidification of the Nordic Seas
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, Joaquín Ortiz, Stephen D. Archer, Andrea Ludwig, and Ulf Riebesell
Biogeosciences, 21, 2859–2876, https://doi.org/10.5194/bg-21-2859-2024, https://doi.org/10.5194/bg-21-2859-2024, 2024
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Our planet is facing a climate crisis. Scientists are working on innovative solutions that will aid in capturing the hard to abate emissions before it is too late. Exciting research reveals that ocean alkalinity enhancement, a key climate change mitigation strategy, does not harm phytoplankton, the cornerstone of marine ecosystems. Through meticulous study, we may have uncovered a positive relationship: up to a specific limit, enhancing ocean alkalinity boosts photosynthesis by certain species.
France Van Wambeke, Pascal Conan, Mireille Pujo-Pay, Vincent Taillandier, Olivier Crispi, Alexandra Pavlidou, Sandra Nunige, Morgane Didry, Christophe Salmeron, and Elvira Pulido-Villena
Biogeosciences, 21, 2621–2640, https://doi.org/10.5194/bg-21-2621-2024, https://doi.org/10.5194/bg-21-2621-2024, 2024
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Phosphomonoesterase (PME) and phosphodiesterase (PDE) activities over the epipelagic zone are described in the eastern Mediterranean Sea in winter and autumn. The types of concentration kinetics obtained for PDE (saturation at 50 µM, high Km, high turnover times) compared to those of PME (saturation at 1 µM, low Km, low turnover times) are discussed in regard to the possible inequal distribution of PDE and PME in the size continuum of organic material and accessibility to phosphodiesters.
Jenny Hieronymus, Magnus Hieronymus, Matthias Gröger, Jörg Schwinger, Raffaele Bernadello, Etienne Tourigny, Valentina Sicardi, Itzel Ruvalcaba Baroni, and Klaus Wyser
Biogeosciences, 21, 2189–2206, https://doi.org/10.5194/bg-21-2189-2024, https://doi.org/10.5194/bg-21-2189-2024, 2024
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The timing of the net primary production annual maxima in the North Atlantic in the period 1750–2100 is investigated using two Earth system models and the high-emissions scenario SSP5-8.5. It is found that, for most of the region, the annual maxima occur progressively earlier, with the most change occurring after the year 2000. Shifts in the seasonality of the primary production may impact the entire ecosystem, which highlights the need for long-term monitoring campaigns in this area.
Nicole M. Travis, Colette L. Kelly, and Karen L. Casciotti
Biogeosciences, 21, 1985–2004, https://doi.org/10.5194/bg-21-1985-2024, https://doi.org/10.5194/bg-21-1985-2024, 2024
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We conducted experimental manipulations of light level on microbial communities from the primary nitrite maximum. Overall, while individual microbial processes have different directions and magnitudes in their response to increasing light, the net community response is a decline in nitrite production with increasing light. We conclude that while increased light may decrease net nitrite production, high-light conditions alone do not exclude nitrification from occurring in the surface ocean.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
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The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences, 21, 1191–1211, https://doi.org/10.5194/bg-21-1191-2024, https://doi.org/10.5194/bg-21-1191-2024, 2024
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The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit these autonomous measurements platforms. By applying the Argo correction routines to float pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Charly Andre Moras, Tyler Cyronak, Lennart Thomas Bach, Renaud Joannes-Boyau, and Kai Georg Schulz
EGUsphere, https://doi.org/10.5194/egusphere-2024-645, https://doi.org/10.5194/egusphere-2024-645, 2024
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We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain size dissolved faster, but calcium carbonate precipitated earlier, suggesting that medium grain size is optimum for both kinetics.
Sabine Mecking and Kyla Drushka
Biogeosciences, 21, 1117–1133, https://doi.org/10.5194/bg-21-1117-2024, https://doi.org/10.5194/bg-21-1117-2024, 2024
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This study investigates whether northeastern North Pacific oxygen changes may be caused by surface density changes in the northwest as water moves along density horizons from the surface into the subsurface ocean. A correlation is found with a lag that about matches the travel time of water from the northwest to the northeast. Salinity is the main driver causing decadal changes in surface density, whereas salinity and temperature contribute about equally to long-term declining density trends.
Rosie M. Sheward, Christina Gebühr, Jörg Bollmann, and Jens O. Herrle
EGUsphere, https://doi.org/10.5194/egusphere-2024-349, https://doi.org/10.5194/egusphere-2024-349, 2024
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How quickly do marine microorganisms respond to salinity stress? Our experiments with the calcifying marine plankton Emiliania huxleyi show that growth and cell morphology responded to salinity stress within as little as 24–48 hours, demonstrating that morphology and calcification is sensitive to salinity over a range of timescales. Our results have implications for understanding the short-term role of E. huxleyi in biogeochemical cycles and size-based paleoproxies for salinity.
Takamitsu Ito, Hernan E. Garcia, Zhankun Wang, Shoshiro Minobe, Matthew C. Long, Just Cebrian, James Reagan, Tim Boyer, Christopher Paver, Courtney Bouchard, Yohei Takano, Seth Bushinsky, Ahron Cervania, and Curtis A. Deutsch
Biogeosciences, 21, 747–759, https://doi.org/10.5194/bg-21-747-2024, https://doi.org/10.5194/bg-21-747-2024, 2024
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This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainty comes from the statistical gap-filling methods. Outputs from Earth system models are used to generate synthetic observations where oxygen data are extracted from the model output at the location and time of historical oceanographic cruises. Reconstructed oxygen trend is approximately two-thirds of the true trend.
Robert W. Izett, Katja Fennel, Adam C. Stoer, and David P. Nicholson
Biogeosciences, 21, 13–47, https://doi.org/10.5194/bg-21-13-2024, https://doi.org/10.5194/bg-21-13-2024, 2024
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This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array.
Qian Liu, Yingjie Liu, and Xiaofeng Li
Biogeosciences, 20, 4857–4874, https://doi.org/10.5194/bg-20-4857-2023, https://doi.org/10.5194/bg-20-4857-2023, 2023
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In the Southern Ocean, abundant eddies behave opposite to our expectations. That is, anticyclonic (cyclonic) eddies are cold (warm). By investigating the variations of physical and biochemical parameters in eddies, we find that abnormal eddies have unique and significant effects on modulating the parameters. This study fills a gap in understanding the effects of abnormal eddies on physical and biochemical parameters in the Southern Ocean.
Precious Mongwe, Matthew Long, Takamitsu Ito, Curtis Deutsch, and Yeray Santana-Falcón
EGUsphere, https://doi.org/10.5194/egusphere-2023-2822, https://doi.org/10.5194/egusphere-2023-2822, 2023
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We use a collection of measurements that captures the physiological sensitivity of organisms to temperature and oxygen, and a model to investigate how natural climate variations and climate warming will impact the ability of marine heterotrophic marine organisms to support habitat in the future. We find that warming and the related loss of marine dissolved oxygen over the next several decades will reduce the volume of ocean habitat, and increasing vulnerability to temperature-oxygen extremes.
Caroline Ulses, Claude Estournel, Patrick Marsaleix, Karline Soetaert, Marine Fourrier, Laurent Coppola, Dominique Lefèvre, Franck Touratier, Catherine Goyet, Véronique Guglielmi, Fayçal Kessouri, Pierre Testor, and Xavier Durrieu de Madron
Biogeosciences, 20, 4683–4710, https://doi.org/10.5194/bg-20-4683-2023, https://doi.org/10.5194/bg-20-4683-2023, 2023
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Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles in the Mediterranean Sea, considered to be a hotspot of biodiversity and climate change. In this study, we investigate the seasonal and annual budget of dissolved inorganic carbon in the deep-convection area of the northwestern Mediterranean Sea.
Daniela König and Alessandro Tagliabue
Biogeosciences, 20, 4197–4212, https://doi.org/10.5194/bg-20-4197-2023, https://doi.org/10.5194/bg-20-4197-2023, 2023
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Using model simulations, we show that natural and anthropogenic changes in the global climate leave a distinct fingerprint in the isotopic signatures of iron in the surface ocean. We find that these climate effects on iron isotopes are often caused by the redistribution of iron from different external sources to the ocean, due to changes in ocean currents, and by changes in algal growth, which take up iron. Thus, isotopes may help detect climate-induced changes in iron supply and algal uptake.
Chloé Baumas, Robin Fuchs, Marc Garel, Jean-Christophe Poggiale, Laurent Memery, Frédéric A. C. Le Moigne, and Christian Tamburini
Biogeosciences, 20, 4165–4182, https://doi.org/10.5194/bg-20-4165-2023, https://doi.org/10.5194/bg-20-4165-2023, 2023
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Through the sink of particles in the ocean, carbon (C) is exported and sequestered when reaching 1000 m. Attempts to quantify C exported vs. C consumed by heterotrophs have increased. Yet most of the conducted estimations have led to C demands several times higher than C export. The choice of parameters greatly impacts the results. As theses parameters are overlooked, non-accurate values are often used. In this study we show that C budgets can be well balanced when using appropriate values.
Lyuba Novi, Annalisa Bracco, Takamitsu Ito, and Yohei Takano
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-129, https://doi.org/10.5194/bg-2023-129, 2023
Revised manuscript accepted for BG
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We explored the relationship between oxygen and stratification in the North Pacific Ocean, using a combination of data mining and machine learning. We used isopycnic potential vorticity (IPV) as an indicator to quantify ocean ventilation and we analyzed its predictability, a strong O2-IPV connection and predictability for IPV in the tropical Pacific. This open new routes to monitor ocean O2 through few observational sites co-located with more abundant IPV measurements in the tropical Pacific.
Anna Belcher, Sian F. Henley, Katharine Hendry, Marianne Wootton, Lisa Friberg, Ursula Dallman, Tong Wang, Christopher Coath, and Clara Manno
Biogeosciences, 20, 3573–3591, https://doi.org/10.5194/bg-20-3573-2023, https://doi.org/10.5194/bg-20-3573-2023, 2023
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The oceans play a crucial role in the uptake of atmospheric carbon dioxide, particularly the Southern Ocean. The biological pumping of carbon from the surface to the deep ocean is key to this. Using sediment trap samples from the Scotia Sea, we examine biogeochemical fluxes of carbon, nitrogen, and biogenic silica and their stable isotope compositions. We find phytoplankton community structure and physically mediated processes are important controls on particulate fluxes to the deep ocean.
Stephanie Delacroix, Tor Jensen Nystuen, Erik Höglund, and Andrew L. King
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-138, https://doi.org/10.5194/bg-2023-138, 2023
Revised manuscript accepted for BG
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The addition of alkaline minerals into the oceans might reduce the excessive anthropogenic CO2 emissions. Magnesium hydroxide can be added in large amount because of its low seawater solubility without reaching harmful pH levels. The toxicity effect results of magnesium hydroxide, by simulating expected concentrations from a ships’ dispersion scenario, demonstrated low impacts on both sensitive and local assemblages of marine microalgae when compared to calcium hydroxide and sodium hydroxide.
Reiner Steinfeldt, Monika Rhein, and Dagmar Kieke
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-113, https://doi.org/10.5194/bg-2023-113, 2023
Revised manuscript accepted for BG
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We calculate the amount of anthropogenic carbon (Cant) that is stored in the Atlantic Ocean for the years 1990, 2000, 2010. Cant is the carbon that is taken up by the ocean due to the rising atmospheric CO2 concentrations as a result of manmade CO2 emissions. However, most of the carbon in the ocean is natural. In order to determine the amount of Cant, we apply a special technique which is based on the observation of other manmade gases (e.g. CFCs).
Asmita Singh, Susanne Fietz, Sandy J. Thomalla, Nicolas Sanchez, Murat V. Ardelan, Sébastien Moreau, Hanna M. Kauko, Agneta Fransson, Melissa Chierici, Saumik Samanta, Thato N. Mtshali, Alakendra N. Roychoudhury, and Thomas J. Ryan-Keogh
Biogeosciences, 20, 3073–3091, https://doi.org/10.5194/bg-20-3073-2023, https://doi.org/10.5194/bg-20-3073-2023, 2023
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Despite the scarcity of iron in the Southern Ocean, seasonal blooms occur due to changes in nutrient and light availability. Surprisingly, during an autumn bloom in the Antarctic sea-ice zone, the results from incubation experiments showed no significant photophysiological response of phytoplankton to iron addition. This suggests that ambient iron concentrations were sufficient, challenging the notion of iron deficiency in the Southern Ocean through extended iron-replete post-bloom conditions.
Benoît Pasquier, Mark Holzer, Matthew A. Chamberlain, Richard J. Matear, Nathaniel L. Bindoff, and François W. Primeau
Biogeosciences, 20, 2985–3009, https://doi.org/10.5194/bg-20-2985-2023, https://doi.org/10.5194/bg-20-2985-2023, 2023
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Modeling the ocean's carbon and oxygen cycles accurately is challenging. Parameter optimization improves the fit to observed tracers but can introduce artifacts in the biological pump. Organic-matter production and subsurface remineralization rates adjust to compensate for circulation biases, changing the pathways and timescales with which nutrients return to the surface. Circulation biases can thus strongly alter the system’s response to ecological change, even when parameters are optimized.
Priyanka Banerjee
Biogeosciences, 20, 2613–2643, https://doi.org/10.5194/bg-20-2613-2023, https://doi.org/10.5194/bg-20-2613-2023, 2023
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This study shows that atmospheric deposition is the most important source of iron to the upper northern Indian Ocean for phytoplankton growth. This is followed by iron from continental-shelf sediment. Phytoplankton increase following iron addition is possible only with high background levels of nitrate. Vertical mixing is the most important physical process supplying iron to the upper ocean in this region throughout the year. The importance of ocean currents in supplying iron varies seasonally.
Iris Kriest, Julia Getzlaff, Angela Landolfi, Volkmar Sauerland, Markus Schartau, and Andreas Oschlies
Biogeosciences, 20, 2645–2669, https://doi.org/10.5194/bg-20-2645-2023, https://doi.org/10.5194/bg-20-2645-2023, 2023
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Global biogeochemical ocean models are often subjectively assessed and tuned against observations. We applied different strategies to calibrate a global model against observations. Although the calibrated models show similar tracer distributions at the surface, they differ in global biogeochemical fluxes, especially in global particle flux. Simulated global volume of oxygen minimum zones varies strongly with calibration strategy and over time, rendering its temporal extrapolation difficult.
John C. Tracey, Andrew R. Babbin, Elizabeth Wallace, Xin Sun, Katherine L. DuRussel, Claudia Frey, Donald E. Martocello III, Tyler Tamasi, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 20, 2499–2523, https://doi.org/10.5194/bg-20-2499-2023, https://doi.org/10.5194/bg-20-2499-2023, 2023
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Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic.
Amanda Gerotto, Hongrui Zhang, Renata Hanae Nagai, Heather M. Stoll, Rubens César Lopes Figueira, Chuanlian Liu, and Iván Hernández-Almeida
Biogeosciences, 20, 1725–1739, https://doi.org/10.5194/bg-20-1725-2023, https://doi.org/10.5194/bg-20-1725-2023, 2023
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Based on the analysis of the response of coccolithophores’ morphological attributes in a laboratory dissolution experiment and surface sediment samples from the South China Sea, we proposed that the thickness shape (ks) factor of fossil coccoliths together with the normalized ks variation, which is the ratio of the standard deviation of ks (σ) over the mean ks (σ/ks), is a robust and novel proxy to reconstruct past changes in deep ocean carbon chemistry.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences, 20, 1671–1690, https://doi.org/10.5194/bg-20-1671-2023, https://doi.org/10.5194/bg-20-1671-2023, 2023
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We present a new method for reconstructing ocean carbon using climate models and temperature and salinity observations. To test this method, we reconstruct modelled carbon using synthetic observations consistent with current sampling programmes. Sensitivity tests show skill in reconstructing carbon trends and variability within the upper 2000 m. Our results indicate that this method can be used for a new global estimate for ocean carbon content.
Alexandre Mignot, Hervé Claustre, Gianpiero Cossarini, Fabrizio D'Ortenzio, Elodie Gutknecht, Julien Lamouroux, Paolo Lazzari, Coralie Perruche, Stefano Salon, Raphaëlle Sauzède, Vincent Taillandier, and Anna Teruzzi
Biogeosciences, 20, 1405–1422, https://doi.org/10.5194/bg-20-1405-2023, https://doi.org/10.5194/bg-20-1405-2023, 2023
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Numerical models of ocean biogeochemistry are becoming a major tool to detect and predict the impact of climate change on marine resources and monitor ocean health. Here, we demonstrate the use of the global array of BGC-Argo floats for the assessment of biogeochemical models. We first detail the handling of the BGC-Argo data set for model assessment purposes. We then present 23 assessment metrics to quantify the consistency of BGC model simulations with respect to BGC-Argo data.
Alban Planchat, Lester Kwiatkowski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschön, Tomas Lovato, Roland Séférian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jörg Schwinger, Jerry Tjiputra, John P. Dunne, and Charles Stock
Biogeosciences, 20, 1195–1257, https://doi.org/10.5194/bg-20-1195-2023, https://doi.org/10.5194/bg-20-1195-2023, 2023
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Ocean alkalinity is critical to the uptake of atmospheric carbon and acidification in surface waters. We review the representation of alkalinity and the associated calcium carbonate cycle in Earth system models. While many parameterizations remain present in the latest generation of models, there is a general improvement in the simulated alkalinity distribution. This improvement is related to an increase in the export of biotic calcium carbonate, which closer resembles observations.
Jérôme Pinti, Tim DeVries, Tommy Norin, Camila Serra-Pompei, Roland Proud, David A. Siegel, Thomas Kiørboe, Colleen M. Petrik, Ken H. Andersen, Andrew S. Brierley, and André W. Visser
Biogeosciences, 20, 997–1009, https://doi.org/10.5194/bg-20-997-2023, https://doi.org/10.5194/bg-20-997-2023, 2023
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Large numbers of marine organisms such as zooplankton and fish perform daily vertical migration between the surface (at night) and the depths (in the daytime). This fascinating migration is important for the carbon cycle, as these organisms actively bring carbon to depths where it is stored away from the atmosphere for a long time. Here, we quantify the contributions of different animals to this carbon drawdown and storage and show that fish are important to the biological carbon pump.
Alastair J. M. Lough, Alessandro Tagliabue, Clément Demasy, Joseph A. Resing, Travis Mellett, Neil J. Wyatt, and Maeve C. Lohan
Biogeosciences, 20, 405–420, https://doi.org/10.5194/bg-20-405-2023, https://doi.org/10.5194/bg-20-405-2023, 2023
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Iron is a key nutrient for ocean primary productivity. Hydrothermal vents are a source of iron to the oceans, but the size of this source is poorly understood. This study examines the variability in iron inputs between hydrothermal vents in different geological settings. The vents studied release different amounts of Fe, resulting in plumes with similar dissolved iron concentrations but different particulate concentrations. This will help to refine modelling of iron-limited ocean productivity.
Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
Biogeosciences, 20, 325–347, https://doi.org/10.5194/bg-20-325-2023, https://doi.org/10.5194/bg-20-325-2023, 2023
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The primary nitrite maximum is a ubiquitous upper ocean feature where nitrite accumulates, but we still do not understand its formation and the co-occurring microbial processes involved. Using correlative methods and rates measurements, we found strong spatial patterns between environmental conditions and depths of the nitrite maxima, but not the maximum concentrations. Nitrification was the dominant source of nitrite, with occasional high nitrite production from phytoplankton near the coast.
Natacha Le Grix, Jakob Zscheischler, Keith B. Rodgers, Ryohei Yamaguchi, and Thomas L. Frölicher
Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth system models. The models share similar drivers in the low latitudes but disagree in the high latitudes due to divergent factors limiting phytoplankton production.
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022, https://doi.org/10.5194/bg-19-5689-2022, 2022
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Marine heat waves (MHWs) are a frequent event in the northeast Pacific, with a large impact on the region's ecosystems. Large phytoplankton in the North Pacific Transition Zone are greatly affected by decreased nutrients, with less of an impact in the Alaskan Gyre. For small phytoplankton, MHWs increase the spring small phytoplankton population in both regions thanks to reduced light limitation. In both zones, this results in a significant decrease in the ratio of large to small phytoplankton.
Margot C. F. Debyser, Laetitia Pichevin, Robyn E. Tuerena, Paul A. Dodd, Antonia Doncila, and Raja S. Ganeshram
Biogeosciences, 19, 5499–5520, https://doi.org/10.5194/bg-19-5499-2022, https://doi.org/10.5194/bg-19-5499-2022, 2022
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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We use a microbial ecosystem model to quantitatively explain the mechanisms controlling observed relative abundances and nitrification rates of ammonia- and nitrite-oxidizing microorganisms in the ocean. We also estimate how much global carbon fixation can be associated with chemoautotrophic nitrification. Our results improve our understanding of the controls on nitrification, laying the groundwork for more accurate predictions in global climate models.
Zuozhu Wen, Thomas J. Browning, Rongbo Dai, Wenwei Wu, Weiying Li, Xiaohua Hu, Wenfang Lin, Lifang Wang, Xin Liu, Zhimian Cao, Haizheng Hong, and Dalin Shi
Biogeosciences, 19, 5237–5250, https://doi.org/10.5194/bg-19-5237-2022, https://doi.org/10.5194/bg-19-5237-2022, 2022
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Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
Claudia Eisenring, Sophy E. Oliver, Samar Khatiwala, and Gregory F. de Souza
Biogeosciences, 19, 5079–5106, https://doi.org/10.5194/bg-19-5079-2022, https://doi.org/10.5194/bg-19-5079-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Yoshikazu Sasai, Sherwood Lan Smith, Eko Siswanto, Hideharu Sasaki, and Masami Nonaka
Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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We have investigated the adaptive response of phytoplankton growth to changing light, nutrients, and temperature over the North Pacific using two physical-biological models. We compare modeled chlorophyll and primary production from an inflexible control model (InFlexPFT), which assumes fixed carbon (C):nitrogen (N):chlorophyll (Chl) ratios, to a recently developed flexible phytoplankton functional type model (FlexPFT), which incorporates photoacclimation and variable C:N:Chl ratios.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Nolwenn Lemaitre, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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This study quantifies the role of commercially targeted fish biomass in the cycling of three important nutrients (N, P, and Fe), relative to nutrients otherwise available in water and to nutrients required by primary producers, and the impact of fishing. We use a model of commercially targeted fish biomass constrained by fish catch and stock assessment data to assess the contributions of fish at the global scale, at the time of the global peak catch and prior to industrial fishing.
Rebecca Chmiel, Nathan Lanning, Allison Laubach, Jong-Mi Lee, Jessica Fitzsimmons, Mariko Hatta, William Jenkins, Phoebe Lam, Matthew McIlvin, Alessandro Tagliabue, and Mak Saito
Biogeosciences, 19, 2365–2395, https://doi.org/10.5194/bg-19-2365-2022, https://doi.org/10.5194/bg-19-2365-2022, 2022
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Dissolved cobalt is present in trace amounts in seawater and is a necessary nutrient for marine microbes. On a transect from the Alaskan coast to Tahiti, we measured seawater concentrations of dissolved cobalt. Here, we describe several interesting features of the Pacific cobalt cycle including cobalt sources along the Alaskan coast and Hawaiian vents, deep-ocean particle formation, cobalt activity in low-oxygen regions, and how our samples compare to a global biogeochemical model’s predictions.
Nicolas Metzl, Claire Lo Monaco, Coraline Leseurre, Céline Ridame, Jonathan Fin, Claude Mignon, Marion Gehlen, and Thi Tuyet Trang Chau
Biogeosciences, 19, 1451–1468, https://doi.org/10.5194/bg-19-1451-2022, https://doi.org/10.5194/bg-19-1451-2022, 2022
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During an oceanographic cruise conducted in January 2020 in the south-western Indian Ocean, we observed very low CO2 concentrations associated with a strong phytoplankton bloom that occurred south-east of Madagascar. This biological event led to a strong regional CO2 ocean sink not previously observed.
Darren R. Clark, Andrew P. Rees, Charissa M. Ferrera, Lisa Al-Moosawi, Paul J. Somerfield, Carolyn Harris, Graham D. Quartly, Stephen Goult, Glen Tarran, and Gennadi Lessin
Biogeosciences, 19, 1355–1376, https://doi.org/10.5194/bg-19-1355-2022, https://doi.org/10.5194/bg-19-1355-2022, 2022
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Measurements of microbial processes were made in the sunlit open ocean during a research cruise (AMT19) between the UK and Chile. These help us to understand how microbial communities maintain the function of remote ecosystems. We find that the nitrogen cycling microbes which produce nitrite respond to changes in the environment. Our insights will aid the development of models that aim to replicate and ultimately project how marine environments may respond to ongoing climate change.
Martí Galí, Marcus Falls, Hervé Claustre, Olivier Aumont, and Raffaele Bernardello
Biogeosciences, 19, 1245–1275, https://doi.org/10.5194/bg-19-1245-2022, https://doi.org/10.5194/bg-19-1245-2022, 2022
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Part of the organic matter produced by plankton in the upper ocean is exported to the deep ocean. This process, known as the biological carbon pump, is key for the regulation of atmospheric carbon dioxide and global climate. However, the dynamics of organic particles below the upper ocean layer are not well understood. Here we compared the measurements acquired by autonomous robots in the top 1000 m of the ocean to a numerical model, which can help improve future climate projections.
Marie Barbieux, Julia Uitz, Alexandre Mignot, Collin Roesler, Hervé Claustre, Bernard Gentili, Vincent Taillandier, Fabrizio D'Ortenzio, Hubert Loisel, Antoine Poteau, Edouard Leymarie, Christophe Penkerc'h, Catherine Schmechtig, and Annick Bricaud
Biogeosciences, 19, 1165–1194, https://doi.org/10.5194/bg-19-1165-2022, https://doi.org/10.5194/bg-19-1165-2022, 2022
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This study assesses marine biological production in two Mediterranean systems representative of vast desert-like (oligotrophic) areas encountered in the global ocean. We use a novel approach based on non-intrusive high-frequency in situ measurements by two profiling robots, the BioGeoChemical-Argo (BGC-Argo) floats. Our results indicate substantial yet variable production rates and contribution to the whole water column of the subsurface layer, typically considered steady and non-productive.
Filippa Fransner, Friederike Fröb, Jerry Tjiputra, Nadine Goris, Siv K. Lauvset, Ingunn Skjelvan, Emil Jeansson, Abdirahman Omar, Melissa Chierici, Elizabeth Jones, Agneta Fransson, Sólveig R. Ólafsdóttir, Truls Johannessen, and Are Olsen
Biogeosciences, 19, 979–1012, https://doi.org/10.5194/bg-19-979-2022, https://doi.org/10.5194/bg-19-979-2022, 2022
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Ocean acidification, a direct consequence of the CO2 release by human activities, is a serious threat to marine ecosystems. In this study, we conduct a detailed investigation of the acidification of the Nordic Seas, from 1850 to 2100, by using a large set of samples taken during research cruises together with numerical model simulations. We estimate the effects of changes in different environmental factors on the rate of acidification and its potential effects on cold-water corals.
Cited articles
Annett, A. L., Henley, S. F., Van Beek, P., Souhaut, M., Ganeshram, R., Venables, H. J., Meredith, M. P., and Geibert, W.: Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula, Antarct. Sci., 25, 445–456, https://doi.org/10.1017/S0954102012000892, 2013
Arrigo, K. R., van Dijken, G. L., and Bushinsky, S.: Primary production in the Southern Ocean, 1997–2006, J. Geophys. Res.-Oceans, 113, C08004, https://doi.org/10.1029/2007JC004551, 2008.
Belkin, I. M. and Gordon, A. L.: Southern Ocean fronts from the Greenwich meridian to Tasmania, J. Geophys. Res.-Oceans, 101, 3675–3696, https://doi.org/10.1029/95JC02750, 1996.
Blain, S., Tréguer, P., Belviso, S., Bucciarelli, E., Denis, M., Desabre, S., Fiala, M., Martin Jézéquel, V., Le Fèvre, J., Mayzaud, P., Marty, J.-C., and Razouls, S.: A biogeochemical study of the island mass effect in the context of the iron hypothesis: Kerguelen Islands, Southern Ocean, Deep Sea Res. Pt. I, 48, 163–187, https://doi.org/10.1016/S0967-0637(00)00047-9, 2001.
Blain, S., Quéguiner, B., Armand, L., Belviso, S., Bombled, B., Bopp, L., Bowie, A., Brunet, C., Brussaard, C., Carlotti, F., Christaki, U., Corbière, A., Durand, I., Ebersbach, F., Fuda, J.-L., Garcia, N., Gerringa, L., Griffiths, B., Guigue, C., Guillerm, C., Jacquet, S., Jeandel, C., Laan, P., Lefèvre, D., Lo Monaco, C., Malits, A., Mosseri, J., Obernosterer, I., Park, Y.-H., Picheral, M., Pondaven, P., Remenyi, T., Sandroni, V., Sarthou, G., Savoye, N., Scouarnec, L., Souhaut, M., Thuiller, D., Timmermans, K., Trull, T., Uitz, J., Van Beek, P., Veldhuis, M., Vincent, D., Viollier, E., Vong, L., and Wagener, T.: Effect of natural iron fertilization on carbon sequestration in the Southern Ocean, Nature, 446, 1070–1074, https://doi.org/10.1038/nature05700, 2007.
Bowie, A. R., van der Merwe, P., Quéroué, F., Trull, T., Fourquez, M., Planchon, F., Sarthou, G., Chever, F., Townsend, A. T., Obernosterer, I., Sallée, J.-B., and Blain, S.: Iron budgets for three distinct biogeochemical sites around the Kerguelen archipelago (Southern Ocean) during the natural fertilisation experiment KEOPS-2, Biogeosciences Discuss., 11, 17861–17923, https://doi.org/10.5194/bgd-11-17861-2014, 2014.
Cai, P., Shi, X., Moore, W. S., and Dai, M.: Measurement of 224Ra:228Th disequilibrium in coastal sediments using a delayed coincidence counter, Mar. Chem., 138–139, 1–6, https://doi.org/10.1016/j.marchem.2012.05.004, 2012.
Charette, M. A., Buesseler, K. O., and Andrews, J. E.: Utility of radium isotopes for evaluating the input and transport of ground-water-drived nitrogen to a Cape Cod estuary, Limnol. Oceanogr., 46, 465–470, 2001.
Charette, M. A., Gonneea, M. E., Morris, P. J., Statham, P., Fones, G., Planquette, H., Salter, I., and Garabato, A. N.: Radium isotopes as tracers of iron sources fueling a Southern Ocean phytoplankton bloom, Deep Sea Res. Pt. II, 54, 1989–1998, https://doi.org/10.1016/j.dsr2.2007.06.003, 2007.
Charrassin, J.-B., Park, Y.-H., Le Maho, Y., and Bost, C.-A.: Fine resolution 3D temperature fields off Kerguelen from instrumented penguins, Deep Sea Res. Pt. I, 51, 2091–2103, https://doi.org/10.1016/j.dsr.2004.07.019, 2004.
Chever, F., Sarthou, G., Bucciarelli, E., Blain, S., and Bowie, A. R.: An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean), Biogeosciences, 7, 455–468, https://doi.org/10.5194/bg-7-455-2010, 2010.
De Baar, H. J. W., De Jong, J. T. M., Bakker, D. C. E., Löscher, B. M., Veth, C., Bathmann, U., and Smetacek, V.: Importance of iron for plankton blooms and carbon dioxide drawdown in the Southern Ocean, Nature, 373, 412–415, https://doi.org/10.1038/373412a0, 1995.
Dibarboure, G., Pujol, M.-I., Briol, F., Traon, P. Y. L., Larnicol, G., Picot, N., Mertz, F., and Ablain, M.: Jason-2 in DUACS: Updated System Description, First Tandem Results and Impact on Processing and Products, Mar. Geod., 34, 214–241, https://doi.org/10.1080/01490419.2011.584826, 2011.
d'Ovidio, F., De Monte, S., Alvain, S., Dandonneau, Y., and Levy, M.: Fluid dynamical niches of phytoplankton types, P. Natl. Acad. Sci. USA, 107, 18366–18370, https://doi.org/10.1073/pnas.1004620107, 2010.
Dulaiova, H., Ardelan, M. V., Henderson, P. B., and Charette, M. A.: Shelf-derived iron inputs drive biological productivity in the southern Drake Passage, Glob. Biogeochem. Cy., 23, GB4014, https://doi.org/10.1029/2008GB003406, 2009.
Emery, W. J. and Meincke, J.: Global water masses: summary and review, Oceanol. Acta, 9, 383–391, 1986.
Garcia-Solsona, E., Garcia-Orellana, J., Masqué, P., and Dulaiova, H.: Uncertainties associated with 223Ra and 224Ra measurements in water via a Delayed Coincidence Counter (RaDeCC), Mar. Chem., 109, 198–219, https://doi.org/10.1016/j.marchem.2007.11.006, 2008.
Grenier, M., Garcia-Solsona, E., Lemaitre, N., Bouvier, V., Nonnotte, P., and Jeandel, C.: Differentiating lithogenic supplies, water mass transport and biological processes on and off the Kerguelen Plateau using the rare earth data, in preparation, 2015.
Hanfland, C.: Radium-226 and Radium-228 in the Atlantic Sector of the Southern Ocean, thesis, Alfred Wegener Institute, Bremerhaven, Allemagne, 2002.
Jeandel, C., Ruiz-Pino, D., Gjata, E., Poisson, A., Brunet, C., Charriaud, E., dehairs, F., delille, D., Fiala, M., Fravalo, C., Carlos Miquel, J., Park, Y., Pondaven, P., Queguiner, B., Razouls, S., Shauer, B., and Treguer, P.: KERFIX, a time-series station in the Southern Ocean: a presentation, J. Mar. Syst., 17, 555–569, https://doi.org/10.1016/S0924-7963(98)00064-5, 1998.
Kaufman, A., Trier, R. M., Broecker, W. S., and Feely, H. W.: Distribution of 228Ra in the world ocean, J. Geophys. Res., 78, 8827–8848, https://doi.org/10.1029/JC078i036p08827, 1973.
Korb, R. E., Whitehouse, M. J., and Ward, P.: SeaWiFS in the southern ocean: spatial and temporal variability in phytoplankton biomass around South Georgia, Deep Sea Res. Pt. II, 51, 99–116, https://doi.org/10.1016/j.dsr2.2003.04.002, 2004.
Martin, J. H., Fitzwater, S. E., and Gordon, R. M.: Iron deficiency limits phytoplankton growth in Antarctic waters, Global Biogeochem. Cy., 4, 5–12, https://doi.org/10.1029/GB004i001p00005, 1990.
Mongin, M. M., Abraham, E. R., and Trull, T. W.: Winter advection of iron can explain the summer phytoplankton bloom that extends 1000 km downstream of the Kerguelen Plateau in the Southern Ocean, J. Mar. Res., 67, 225–237, https://doi.org/10.1357/002224009789051218, 2009.
Moore, J. K. and Abbott, M. R.: Surface chlorophyll concentrations in relation to the Antarctic Polar Front: seasonal and spatial patterns from satellite observations, J. Mar. Syst., 37, 69–86, https://doi.org/10.1016/S0924-7963(02)00196-3, 2002.
Moore, W. S.: Ages of continental shelf waters determined from 223Ra and 224Ra, J. Geophys. Res., 105, 22117, https://doi.org/10.1029/1999JC000289, 2000.
Moore, W. S.: Fifteen years experience in measuring 224Ra and 223Ra by delayed-coincidence counting, Mar. Chem., 109, 188–197, https://doi.org/10.1016/j.marchem.2007.06.015, 2008.
Moore, W. S. and Arnold, R.: Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter, J. Geophys. Res.-Oceans, 101, 1321–1329, https://doi.org/10.1029/95JC03139, 1996.
Orsi, A. H., Whitworth III, T., and Nowlin Jr., W. D.: On the meridional extent and fronts of the Antarctic Circumpolar Current, Deep Sea Res. Pt. I, 42, 641–673, https://doi.org/10.1016/0967-0637(95)00021-W, 1995.
Park, Y.-H. and Gambéroni, L.: Large-scale circulation and its variability in the south Indian Ocean from TOPEX/POSEIDON altimetry, J. Geophys. Res.-Oceans, 100, 24911–24929, https://doi.org/10.1029/95JC01962, 1995.
Park, Y.-H. and Gamberoni, L.: Cross-frontal exchange of Antarctic Intermediate Water and Antarctic Bottom Water in the Crozet Basin, Deep Sea Res. Pt. II, 44, 963–986, https://doi.org/10.1016/S0967-0645(97)00004-0, 1997.
Park, Y.-H., Gamberoni, L., and Charriaud, E.: Frontal structure, water masses, and circulation in the Crozet Basin, J. Geophys. Res., 98, 12361, https://doi.org/10.1029/93JC00938, 1993.
Park, Charriaud E., and Fieux, M.: Thermohaline structure of the Antarctic Surface Water/Winter Water in the Indian sector of the Southern Ocean, J. Mar. Syst., 17, 5–23, https://doi.org/10.1016/S0924-7963(98)00026-8, 1998.
Park, Y.-H., Charriaud, E., Pino, D. R., and Jeandel, C.: Seasonal and interannual variability of the mixed layer properties and steric height at station KERFIX, southwest of Kerguelen, J. Mar. Syst., 17, 571–586, https://doi.org/10.1016/S0924-7963(98)00065-7, 1998b.
Park, Y.-H., Fuda, J.-L., Durand, I., and Naveira Garabato, A. C.: Internal tides and vertical mixing over the Kerguelen Plateau, Deep Sea Res. Pt. II, 55, 582–593, https://doi.org/10.1016/j.dsr2.2007.12.027, 2008a.
Park, Y.-H., Roquet, F., Durand, I., and Fuda, J.-L.: Large-scale circulation over and around the Northern Kerguelen Plateau, Deep Sea Res. Pt. II, 55, 566–581, https://doi.org/10.1016/j.dsr2.2007.12.030, 2008b.
Park, Y.-H., Vivier, F., Roquet, F., and Kestenare, E.: Direct observations of the ACC transport across the Kerguelen Plateau, Geophys. Res. Lett., 36, L18603, https://doi.org/10.1029/2009GL039617, 2009
Park, Y.-H., Durand, I., Kestenare, E., Rougier, G., Zhou, M., d'Ovidio, F., Cotté, C., and Lee, J.-H.: Polar Front around the Kerguelen Islands: An up-to-date determination and associated circulation of surface/subsurface waters, J. Geophys. Res.-Oceans, 119, 6575–6592, https://doi.org/10.1002/2014JC010061, 2014.
Pollard, R., Lucas, M., and Read, J.: Physical controls on biogeochemical zonation in the Southern Ocean, Deep Sea Res. Pt. II, 49, 3289–3305, https://doi.org/10.1016/S0967-0645(02)00084-X, 2002.
Pollard, R., Sanders, R., Lucas, M., and Statham, P.: The Crozet Natural Iron Bloom and Export Experiment (CROZEX), Deep Sea Res. Pt. II, 54, 1905–1914, https://doi.org/10.1016/j.dsr2.2007.07.023, 2007.
Quéroué, F., Sarthou, G., Planquette, H. F., Bucciarelli, E., Chever, F., van der Merwe, P., Lannuzel, D., Townsend, A. T., Cheize, M., Blain, S., d'Ovidio, F., and Bowie, A. R.: High variability of dissolved iron concentrations in the vicinity of Kerguelen Island (Southern Ocean), Biogeosciences Discuss., 12, 231–270, https://doi.org/10.5194/bgd-12-231-2015, 2015.
Sanial, V., Van Beek, P., Lansard, B., D' Ovidio, F., Kestenare, E., Souhaut, M., Zhou, M., and Blain, S.: Study of the phytoplankton plume dynamics off the Crozet Islands (Southern Ocean): A geochemical-physical coupled approach, J. Geophys. Res. Oceans, 119, 2227–2237, https://doi.org/10.1002/2013JC009305, 2014.
Tagliabue, A., Sallée, J.-B., Bowie, A. R., Lévy, M., Swart, S., and Boyd, P. W.: Surface-water iron supplies in the Southern Ocean sustained by deep winter mixing, Nat. Geosci., 7, 314–320, https://doi.org/10.1038/ngeo2101, 2014.
van Beek, P., Bourquin, M., Reyss, J.-L., Souhaut, M., Charette, M. A., and Jeandel, C.: Radium isotopes to investigate the water mass pathways on the Kerguelen Plateau (Southern Ocean), Deep Sea Res. Pt. II, 55, 622–637, https://doi.org/10.1016/j.dsr2.2007.12.025, 2008.
van Beek, P., Souhaut, M., Lansard, B., Bourquin, M., Reyss, J.-L., Von Ballmoos, P., and Jean, P.: LAFARA: a new underground laboratory in the French Pyrenees for ultra low-level gamma-ray spectrometry, J. Environ. Radioactiv., 116, 152–158, https://doi.org/10.1016/j.jenvrad.2012.10.002, 2013.
van Beek, P., Souhaut, M., and Reyss, J.-L.: Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry, J. Environ. Radioactiv., 101, 521–529, https://doi.org/10.1016/j.jenvrad.2009.12.002, 2010.
van der Merwe, P., Bowie, A. R., Quéroué, F., Armand, L., Blain, S., Chever, F., Davies, D., Dehairs, F., Planchon, F., Sarthou, G., Townsend, A. T., and Trull, T.: Sourcing the iron in the naturally-fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics, Biogeosciences Discuss., 11, 13389–13432, https://doi.org/10.5194/bgd-11-13389-2014, 2014.
Weis, D. and Frey, F. A.: Submarine Basalts of the Northern Kerguelen Plateau: Interaction Between the Kerguelen Plume and the Southeast Indian Ridge Revealed at ODP Site 1140, J. Petrol., 43, 1287–1309, https://doi.org/10.1093/petrology/43.7.1287, 2002.
Zhang, Y., Lacan, F., and Jeandel, C.: Dissolved rare earth elements tracing lithogenic inputs over the Kerguelen Plateau (Southern Ocean), Deep Sea Res. Pt. II, 55, 638–652, https://doi.org/10.1016/j.dsr2.2007.12.029, 2008.
Zhou, M., Zhu, Y., d'Ovidio, F., Park, Y.-H., Durand, I., Kestenare, E., Sanial, V., Van-Beek, P., Queguiner, B., Carlotti, F., and Blain, S.: Surface currents and upwelling in Kerguelen Plateau regions, Biogeosciences Discuss., 11, 6845–6876, https://doi.org/10.5194/bgd-11-6845-2014, 2014.
Short summary
We investigated the origin and mechanisms of the natural iron fertilization that sustains a phytoplankton bloom downstream of the Kerguelen Islands. We used radium isotopes to trace the fate of shelf waters that may transport iron and other micronutrients towards offshore waters. We show that shelf waters are rapidly transferred offshore and may be transported across the polar front (PF). The PF may thus not be a strong physical barrier for chemical elements released by the shelf sediments.
We investigated the origin and mechanisms of the natural iron fertilization that sustains a...
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