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1. Redox Processes Impacting the Flux of Iron(II) from Shelf Sediments to the OMZ along the Peruvian Shelf

Author: Kathrin Wuttig, Maija Heller, and Peter Croot
Subjects: Atmospheric Science, geography, Biogeochemical cycle, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Continental shelf, 010501 environmental sciences, 01 natural sciences, Redox, 6. Clean water, chemistry.chemical_compound, Water column, Nitrate, chemistry, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Environmental chemistry, Benthic boundary layer, Environmental science, Upwelling, Photic zone, 14. Life underwater, 0105 earth and related environmental sciences
Abstract: Iron (Fe) is a limiting nutrient in many regions of the open ocean and can also play a key role in controlling primary productivity in Eastern Boundary Upwelling Systems (EBUS). In EBUS regions, where intense oxygen minimum zones (OMZs) contact the continental shelf, significant iron inputs can result from the supply of Fe(II) from reducing sediments. How much of this iron makes it to the photic zone depends on physical processes mixing over different time scales (minutes to decades) and the kinetics of redox and complexation processes impacting the biogeochemical cycling of iron. In this work we examine the controls on Fe(II) release from shelf sediments across the Peruvian OMZ by measuring Fe(II) and hydrogen peroxide (H 2 O 2 ) in the water column and benthic boundary layer (BBL) and applying a simple 1D mixing model, with either 1 or 2 layers, where the flux of Fe(II) to the water column is treated as analogous to radon, that the decay rate is constant within the mixing layer. Our modeling approach then allows us to compare our estimated decay rate against published oxidation rates for specific oxidants of Fe(II) in OMZ waters and check the validity of our approach. Our data indicate that throughout the OMZ, Fe(II) decay rates may be partially influenced by H 2 O 2 , but it is most likely that nitrate-dependent anaerobic Fe(II) oxidizing (NDFO) bacteria are the main oxidizers. In the secondary nitrite maxima (SNM), abiotic NO 2 - or biotic-mediated processes may also be important. This work highlights the importance and uses of redox species in understanding biogeochemical cycles in the ocean.
Published: 2019
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2. Changing atmospheric acidity as a modulator of nutrient deposition and ocean biogeochemistry

Author: Athanasios Nenes, Morgane M. G. Perron, Manmohan Sarin, Rachel U. Shelley, Cécile Guieu, Natalie M. Mahowald, Maria Kanakidou, Robert A. Duce, Tim Jickells, Stelios Myriokefalitakis, Akinori Ito, Peter Croot, Yuan Gao, David R. Turner, Rob Middag, Alex R. Baker, Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of East Anglia [Norwich] (UEA), University of Crete [Heraklion] (UOC), Foundation for Research and Technology - Hellas (FORTH), Environmental Chemical Processes Laboratory [Heraklion] (ECPL), Department of Chemistry [Heraklion], University of Crete [Heraklion] (UOC)-University of Crete [Heraklion] (UOC), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Department of Atmospheric Sciences [College Station], Texas A&M University [College Station], Beihang University (BUAA), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), School of Environmental Sciences [Norwich], Cornell University [New York], Royal Netherlands Institute for Sea Research (NIOZ), University of Tasmania [Hobart, Australia] (UTAS), Physical Research Laboratory [Ahmedabad] (PRL), Indian Space Research Organisation (ISRO), and University of Gothenburg (GU)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, ph, Environmental Studies, bioavailable phosphorus, Reviews, Review, 010501 environmental sciences, Mineral dust, 01 natural sciences, Sea surface microlayer, soluble organic-matter, nitrogen, Atmosphere, Nutrient, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, iron solubility, 14. Life underwater, skin and connective tissue diseases, southern-ocean, 0105 earth and related environmental sciences, mineral dust, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Multidisciplinary, fungi, Biogeochemistry, Particulates, 15. Life on land, Deposition (aerosol physics), speciation, 13. Climate action, Environmental chemistry, Environmental science, aerosol acidity, Seawater, particle water, sense organs, SciAdv reviews, Deposition (chemistry), geographic locations
Abstract: Changing atmospheric acidity alters the delivery of nutrients to the ocean and affects marine productivity and ecology., Anthropogenic emissions to the atmosphere have increased the flux of nutrients, especially nitrogen, to the ocean, but they have also altered the acidity of aerosol, cloud water, and precipitation over much of the marine atmosphere. For nitrogen, acidity-driven changes in chemical speciation result in altered partitioning between the gas and particulate phases that subsequently affect long-range transport. Other important nutrients, notably iron and phosphorus, are affected, because their soluble fractions increase upon exposure to acidic environments during atmospheric transport. These changes affect the magnitude, distribution, and deposition mode of individual nutrients supplied to the ocean, the extent to which nutrient deposition interacts with the sea surface microlayer during its passage into bulk seawater, and the relative abundances of soluble nutrients in atmospheric deposition. Atmospheric acidity change therefore affects ecosystem composition, in addition to overall marine productivity, and these effects will continue to evolve with changing anthropogenic emissions in the future.
Published: 2021
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3. Research is needed to inform environmental management of hydrothermally inactive and extinct polymetallic sulfide (PMS) deposits

Author: P-Y Qian, Patrick Collins, E Pelleter, Reetu Sharma, A Myhrvold, A Swaddling, C. L. Van Dover, Yeon Jee Suh, Michal Tomczak, Bramley J. Murton, Nélia C. Mestre, Anna Metaxas, Tina N. Molodtsova, Chunhui Tao, J Vermilye, L Cuyvers, SO Popoola, Toshio Fukushima, C Kriete, Rachel E. Boschen-Rose, Jozée Sarrazin, Jens Carlsson, Peter Croot, Ana Colaço, Robert Kennedy, Amy Gartman, and Jason B. Sylvan
Subjects: 0106 biological sciences, Economics and Econometrics, Sulfide, Aquatic Science, Management, Monitoring, Policy and Law, 01 natural sciences, Deep sea, Florr massive sulfides, Environmental risk, Environmental Science(all), Sea-floor, Ecosystem, 14. Life underwater, General Environmental Science, Chemosynthesis, chemistry.chemical_classification, Fields, business.industry, 010604 marine biology & hydrobiology, Environmental resource management, 04 agricultural and veterinary sciences, Exclusive economic zone, Biodiversity, 15. Life on land, Habitat, chemistry, 13. Climate action, 040102 fisheries, 0401 agriculture, forestry, and fisheries, Environmental science, business, Law, Hydrothermal vent
Abstract: Polymetallic sulfide (PMS) deposits produced at hydrothermal vents in the deep sea are of potential interest to miners. Hydrothermally active sulfide ecosystems are valued for the extraordinary chemosynthetic communities that they support. Many countries, including Canada, Portugal, and the United States, protect vent ecosystems in their Exclusive Economic Zones. When hydrothermal activity ceases temporarily (dormancy) or permanently (extinction), the habitat and associated ecosystem change dramatically. Until recently, so-called "inactive sulfide" habitats, either dormant or extinct, received little attention from biologists. However, the need for environmental management of deep-sea mining places new imperatives for building scientific understanding of the structure and function of inactive PMS deposits. This paper calls for actions of the scientific community and the emergent seabed mining industry to i) undertake fundamental ecological descriptions and study of ecosystem functions and services associated with hydrothermally inactive PMS deposits, ii) evaluate potential environmental risks to ecosystems of inactive PMS deposits through research, and iii) identify environmental management needs that may enable mining of inactive PMS deposits. Mining of some extinct PMS deposits may have reduced environmental risk compared to other seabed mining activities, but this must be validated through scientific research on a case-by-case basis. FCT: IF/00029/2014/CP1230/CT0002/ UID/05634/2020/ CEECIND005262017/ UID/MAR/00350/2019; Direcao-Geral de Politica do Mar (DGPM) Mining2/2017/005/ Mining2/2017/001 info:eu-repo/semantics/publishedVersion
Published: 2020
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4. A first global oceanic compilation of observational dissolved aluminum data with regional statistical data treatment

Author: Tomas A. Remenyi, M. D. Gelado-Caballero, Jan-Lukas Menzel Barraqueta, Peter Croot, Bernhard Wenzel, Alakendra N. Roychoudhury, Rob Middag, Ryan Cloete, Tara De Jongh, Saumik Samanta, J. C. Loock, Jessica K. Klar, Eric P. Achterberg, and Andrew R. Bowie
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, lcsh:QH1-199.5, Geotraces, Big data, Ocean Engineering, Context (language use), Aquatic Science, lcsh:General. Including nature conservation, geographical distribution, Oceanography, 01 natural sciences, biogeochemistry, 14. Life underwater, Temporal scales, lcsh:Science, oceans, database, 0105 earth and related environmental sciences, Water Science and Technology, Global and Planetary Change, geography, geography.geographical_feature_category, business.industry, 010604 marine biology & hydrobiology, Ocean chemistry, Sampling (statistics), Data science, GEOTRACES, 13. Climate action, aluminum, compilation, Environmental science, lcsh:Q, Oceanic basin, Scale (map), business
Abstract: Large national and international observational efforts over recent decades have provided extensive and invaluable datasets of a range of ocean variables. Compiled large datasets, structured, or unstructured, are a powerful tool that allow scientists to access and synthesize data collected over large spatial and temporal scales. The data treatment approaches for any element in the ocean could lead to new global perspectives of their distribution patterns and to a better understanding of large-scale oceanic processes and their impact on other biogeochemical cycles, which may not be evident otherwise. Ocean chemistry Big Data analysis may not just be limited to distribution patterns, but may be used to assess how sampling efforts and analytical methodologies can be improved. Furthermore, a systematic global scale assessment of data is important to evaluate the gaps in knowledge and to provide avenues for future research. In this context, here we provide an extensive compilation of oceanic aluminum (Al) concentration data from global ocean basins, including data available in the GEOTRACES Intermediate Data product (Schlitzer et al., 2018), but also thus far unpublished data.
Published: 2020
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5. Global sea-surface iodide observations, 1967-2018

Author: Tim Jickells, Ieuan J. Roberts, Peter Croot, Rajdeep Roy, Mingxi Yang, Anoop S. Mahajan, Alex R. Baker, Gill Malin, He Peng, Kathrin Wuttig, Zhou Peng, Liselotte Tinel, Thomas G. Bell, Hugh W. Ducklow, Alok Kumar Sinha, Tomás Sherwen, Lucy J. Carpenter, Amit Sarkar, Maria Lúcia Arruda de Moura Campos, Babette A A Hoogakker, Rosie Chance, Frances E. Hopkins, Claire Hughes, John Brindle, Dharma Andrea Reyes Macaya, Daniel Phillips, Xiuxian Song, David Loades, and Helge Arne Winkelbauer
Subjects: Statistics and Probability, Data Descriptor, Atmospheric chemistry, Ozone, 010504 meteorology & atmospheric sciences, Iodide, chemistry.chemical_element, 010501 environmental sciences, Library and Information Sciences, Iodine, Atmospheric sciences, 01 natural sciences, Sink (geography), Latitude, Education, chemistry.chemical_compound, Element cycles, 14. Life underwater, Tropospheric ozone, lcsh:Science, Air quality index, 0105 earth and related environmental sciences, chemistry.chemical_classification, geography, geography.geographical_feature_category, Computer Science Applications, Marine chemistry, chemistry, 13. Climate action, Environmental science, lcsh:Q, Statistics, Probability and Uncertainty, Information Systems
Abstract: The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are now being implemented in air quality models, but these are currently a major source of uncertainty. Relatively little observational data is available to estimate the global surface iodide concentrations, and this data has not hitherto been openly available in a collated, digital form. Here we present all available sea surface (, Measurement(s)iodideTechnology Type(s)digital curationFactor Type(s)sampling time and placeSample Characteristic - Environmentsea water • oceanSample Characteristic - LocationEarth (planet) Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.10130129
Published: 2019

6. Microplastic Ingestion by Gelatinous Zooplankton May Lower Efficiency of the Biological Pump

Author: Fabien Lombard, Alina M. Wieczorek, Peter Croot, Jerome Sheahan, and Thomas K. Doyle
Subjects: Gelatinous zooplankton, Microplastics, Salpa fusiformis, 010501 environmental sciences, 01 natural sciences, Zooplankton, Environmental Chemistry, Ingestion, Animals, 14. Life underwater, Ecosystem, 0105 earth and related environmental sciences, South Pacific Gyre, Salp, biology, Chemistry, digestive, oral, and skin physiology, Biological pump, Membrane Transport Proteins, General Chemistry, biology.organism_classification, 13. Climate action, Environmental chemistry, Plastics, Water Pollutants, Chemical, Environmental Monitoring
Abstract: The impacts of microplastics on some individual organisms have been well studied but what is less clear is what impacts microplastics have on wider ecosystem processes. Using salps as model organisms, we studied the effect of microplastic ingestion on the downward flux of high-density particulate organic matter in the form of salp faecal pellets. While to date most microplastic studies used virgin microplastics at unrealistic environmental concentrations here we exposed Salpa fusiformis to fractured and UV exposed polyethylene and polystyrene microplastics possessing a biofilm. It was found that when exposed to environmentally relevant concentrations, reported for the Mediterranean and the South Pacific Gyre, only few faecal pellets had microplastics incorporated within them. Under potential future scenarios, however, up to 46% of faecal pellets contained microplastics. Incorporated microplastics significantly altered the size, density and sinking rates of salp faecal pellets ( p-value < 0.05 in each instance). Sinking rates decreased by 1.35-fold (95% CI = 1.18, 1.56) for faecal pellets with polyethylene microplastics and 1.47-fold (95% CI = 1.34, 1.61) for polystyrene. These results suggest that today, microplastic ingestion by salps has minimal impact on the biological pump. However, under future microplastic concentrations (or in areas such as convergent zones), microplastics may have the potential to lower the efficiency of the biological pump.
Published: 2019

7. The Weddell Gyre, Southern Ocean: Present Knowledge and Future Challenges

Author: Oliver J. Lechtenfeld, A. C. Naveira Garabato, Sunke Schmidtko, Boris P. Koch, Matthew R. Mazloff, Maria Vernet, Walter Geibert, Tore Hattermann, Ariane Verdy, Christian Haas, Claus-Dieter Hillenbrand, Volker Strass, Judith Hauck, M.M. Rutgers Loeff, Oliver Huhn, Loïc Jullion, Michael P. Meredith, Sinhue Torres-Valdes, Clara Jule Marie Hoppe, Peter Croot, Dorothee C. E. Bakker, Peter J. Brown, Mario Hoppema, Hartmut Hellmer, Ilka Peeken, Eva-Maria Nöthig, Wilfried Jokat, J. A. Brearley, Michael Schröder, Institut méditerranéen d'océanologie (MIO), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Prime meridian, 010502 geochemistry & geophysics, 01 natural sciences, law.invention, Atmosphere, regional models, law, Ocean gyre, Sea ice, 14. Life underwater, oceanography, 0105 earth and related environmental sciences, geography, Weddell Sea, geography.geographical_feature_category, Polar night, Ocean current, Weddell Gyre, Westerlies, Circumpolar star, long-termsampling, Geophysics, Oceanography, 13. Climate action, [SDU]Sciences of the Universe [physics], Environmental science, Antarctica
Abstract: International audience; The Weddell Gyre (WG) is one of the main oceanographic features of the Southern Ocean south of the Antarctic Circumpolar Current which plays an influential role in global ocean circulation as well as gas exchange with the atmosphere. We review the state-of-the art knowledge concerning the WG from an interdisciplinary perspective, uncovering critical aspects needed to understand this system's role in shaping the future evolution of oceanic heat and carbon uptake over the next decades. The main limitations in our knowledge are related to the conditions in this extreme and remote environment, where the polar night, very low air temperatures, and presence of sea ice year-round hamper field and remotely sensed measurements. We highlight the importance of winter and under-ice conditions in the southern WG, the role that new technology will play to overcome present-day sampling limitations, the importance of the WG connectivity to the low-latitude oceans and atmosphere, and the expected intensification of the WG circulation as the westerly winds intensify. Greater international cooperation is needed to define key sampling locations that can be visited by any research vessel in the region. Existing transects sampled since the 1980s along the Prime Meridian and along an East-West section at 62°S should be maintained with regularity to provide answers to the relevant questions. This approach will provide long-term data to determine trends and will improve representation of processes for regional, Antarctic-wide, and global modeling efforts—thereby enhancing predictions of the WG in global ocean circulation and climate.
Published: 2019
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8. The GEOTRACES Intermediate Data Product 2017

Author: Thomas J. Browning, Hans-Jürgen Brumsack, Katharina Pahnke, Saeed Roshan, Stephanie Owens, Rosie Chance, Peter Croot, Steven van Heuven, Alison E. Hartman, Mercedes López-Lora, Pu Zhang, Heather A. Bouman, Géraldine Sarthou, François Lacan, Robyn E. Tuerena, José Marcus Godoy, Ester Garcia-Solsona, Steven L. Goldstein, Hans A. Slagter, Celia Venchiarutti, A. Russell Flegal, Emily Townsend, Ralph Till, Christopher T. Hayes, Melanie Gault-Ringold, Ros Watson, Peter N. Sedwick, Chandranath Basak, Bronwyn Wake, Loes J. A. Gerringa, Noriko Nakayama, Lars-Eric Heimbürger, Paul J. Morris, François Fripiat, Paul B. Henderson, Chris J. Daniels, Catherine Jeandel, Helen M. Snaith, Patrizia Ziveri, Toshitaka Gamo, Yanbin Lu, Oliver J. Lechtenfeld, Yingzhe Wu, Andreas Wisotzki, Hajime Obata, Cynthia Dumousseaud, Ashley T. Townsend, Sebastian Mieruch, Donna Cockwell, Laurent Bopp, Elena Masferrer Dodas, Bernhard Schnetger, J. K. Klar, Sunil K. Singh, Joaquin E. Chaves, Kuo-Fang Huang, Louise A. Zimmer, Laura F. Robinson, Michiel M Rutgers van der Loeff, Corey Archer, Feifei Deng, Karen Grissom, Robert Rember, Nicholas J. Hawco, Jingfeng Wu, Robert M. Sherrell, Rachel U. Shelley, Jan-Lukas Menzel Barraqueta, E. Malcolm S. Woodward, Fanny Chever, Yuichiro Kumamoto, Hélène Planquette, Dorothea Bauch, Frank Dehairs, Daniel C. Ohnemus, Akira Nishiuchi, Paul D. Quay, Sanjin Mehic, Zichen Xue, Maxi Castrillejo, Brian Peters, Michael J. Ellwood, Stephen R. Rintoul, Tobias Roeske, Jing Zhang, Gretchen J. Swarr, Peng Ho, Ken O. Buesseler, Gwenaelle Moncoiffe, Martin Frank, Maureen E. Auro, Abby Bull, David Kadko, Montserrat Roca-Martí, Maeve C. Lohan, Roulin Khondoker, Patricia Cámara Mor, Melissa Gilbert, Sebastian M. Vivancos, Erin E. Black, Santiago R. Gonzalez, Gideon M. Henderson, David J. Janssen, Sylvain Rigaud, Amandine Radic, Maxence Paul, Cyril Abadie, Ana Aguliar-Islas, Seth G. John, Marie Boye, Evgenia Ryabenko, Abigail E. Noble, Luke Bridgestock, Brian Duggan, Hisayuki Yoshikawa, Jun Nishioka, Kathrin Wuttig, Pieter van Beek, Jana Friedrich, Thomas M. Church, Maija Heller, Stephen J.G. Galer, Pier van der Merwe, Claire P. Till, Xin Yuan Zheng, Henning Fröllje, John Niedermiller, Howie D. Scher, Johnny Stutsman, Patricia Zunino, Christel S. Hassler, Ye Zhao, Tim M. Conway, William M. Landing, Yang Xiang, Katrin Bluhm, Maria T. Maldonado, Elena Chamizo, Sabrina Speich, Claudine H. Stirling, Guillaume Brissebrat, Matthew A. Charette, Jeremy E. Jacquot, Yu-Te Hsieh, Pinghe Cai, Ivia Closset, Yoshiki Sohrin, Ejin George, Jong-Mi Lee, Leopoldo D. Pena, Edward Mawji, Damien Cardinal, Catherine Pradoux, Martin Q. Fleisher, Virginie Sanial, Derek Vance, Craig A. Carlson, Pere Masqué, Katlin L. Bowman, Evaline M. van Weerlee, Oliver Baars, Ruifang C. Xie, María Villa-Alfageme, Hein J W de Baar, M. Alexandra Weigand, Tina van de Flierdt, J. Bown, Timothy C. Kenna, Kenneth W. Bruland, Jeroen E. Sonke, Hai Cheng, Mark J. Warner, Sven Ober, Rob Middag, Jessica N. Fitzsimmons, Emilie Le Roy, Yishai Weinstein, Nicholas R. Bates, Joerg Rickli, Daniel M. Sigman, Hendrik M. van Aken, Angela Milne, Cheryl M. Zurbrick, Gregory A. Cutter, Igor Semiletov, Marie Labatut, Torben Stichel, Pascale Lherminier, Gabriel Dulaquais, Jay T. Cullen, Christopher I. Measures, Mark Rosenberg, Tomoharu Minami, Mariko Hatta, Alexander L. Thomas, Gonzalo Carrasco, Karel Bakker, Clifton S. Buck, Maarten B Klunder, Willard S. Moore, Reiner Schlitzer, Tomas A. Remenyi, Susan H. Little, Eberhard Fahrbach, Charles R. McClain, Edward A. Boyle, Ursula Schauer, Linjie Zheng, Alex R. Baker, Emma Slater, Kay Thorne, Patrick Laan, Christina Schallenberg, Reiner Steinfeldt, Benjamin S. Twining, Yolanda Echegoyen-Sanz, Neil J. Wyatt, Alison M. Agather, Viena Puigcorbé, Peter Scott, Gillian Stewart, Matthew P. Humphreys, Frédéric A. C. Le Moigne, Phoebe J. Lam, Núria Casacuberta, Josh Helgoe, Edward C.V. Butler, Mark Rehkämper, Elizabeth M. Jones, Karen L. Casciotti, James W. Moffett, Tristan J. Horner, Sue Velazquez, Yuzuru Nakaguchi, Micha J.A. Rijkenberg, Antje H L Voelker, Joseph A. Resing, Lesley Salt, Eric P. Achterberg, Sven Kretschmer, Jan van Ooijen, Dominik J. Weiss, Moritz Zieringer, Carl H. Lamborg, Rick Kayser, Pierre Branellec, John M. Rolison, Sara Rauschenberg, Walter Geibert, Raja S. Ganeshram, Myriam Lambelet, Janice L. Jones, Chad R. Hammerschmidt, William J. Jenkins, Jordi Garcia-Orellana, Alessandro Tagliabue, Philip W. Boyd, Alan M. Shiller, Marcus Christl, Mark Baskaran, Mak A. Saito, Huong Thi Dieu, Morten B. Andersen, Kenji Isshiki, Taejin Kim, Christian Schlosser, Melanie K. Behrens, Albert S. Colman, Frédéric Planchon, Bettina Sohst, Andrew R. Bowie, Mark A. Brzezinski, R. Lawrence Edwards, Kristen N. Buck, Jeanette O'Sullivan, William M. Smethie, Wafa Abouchami, Valentí Rodellas, Ed C Hathorne, Robert F. Anderson, James H. Swift, Frank J. Pavia, Daniel Cossa, Lauren Kipp, Peter L. Morton, Fabien Quéroué, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Centre for Automotive Safety Research, University of Adelaide, University of California, National Oceanography Centre (NOC), Scottish Association for Marine Science (SAMS), Department of Oceanography [Cape Town], University of Cape Town, Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, University of Toyama, Department of Marine Chemistry and Geochemistry (WHOI), Woods Hole Oceanographic Institution (WHOI), Royal Netherlands Institute for Sea Research (NIOZ), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Department of Geology, Wayne State University [Detroit], The Bartlett, University College of London [London] (UCL), Institute for Environmental Research, Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Department of Earth Sciences [Oxford], University of Oxford [Oxford], Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Universitaire Européen de la Mer (IUEM), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute for Research on Learning, Services communs OMP - UMS 831 (UMS 831), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Marine Science Institute [Santa Barbara] (MSI), University of California [Santa Barbara] (UCSB), University of California-University of California, National Oceanography Centre [Southampton] (NOC), University of Southampton, Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), University of Victoria [Canada] (UVIC), Massachusetts Institute of Technology (MIT), Universidad de Dakota del Sur, Analytical, Environmental and Geo- Chemistry, Vrije Universiteit [Brussels] (VUB), Wright State University, School of Geography, Earth and Environmental Sciences [Plymouth] (SoGEES), Plymouth University, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Alfred Wegener Institute [Potsdam], Institute of Global Environmental Change [China] (IGEC), Xi'an Jiaotong University (Xjtu), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics and Science, National Taiwan Normal University (NTNU), School of Information Technology [Kharagpur], Indian Institute of Technology Kharagpur (IIT Kharagpur), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), University of California [Davis] (UC Davis), Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona [Barcelona] (UAB), Institute of Low Temperature Science, Hokkaido University, The University of Tokyo, Institute for Marine and Antarctic Studies [Horbat] (IMAS), University of Tasmania (UTAS), Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington [Seattle], Institute of Geochemistry and Petrology, Détection, évaluation, gestion des risques CHROniques et éMErgents (CHROME) / Université de Nîmes (CHROME), Université de Nîmes (UNIMES), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), School of Earth and Ocean Sciences, University of Victoria, Knowledge Media Institute (KMI), The Open University [Milton Keynes] (OU), Bermuda Biological Station for Research (BBSR), Bermuda Biological Station for Research, Department of Geosciences [Princeton], Princeton University, Kyoto University [Kyoto], Géochimie des Isotopes Stables (GIS), Géosciences Environnement Toulouse (GET), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES), School of Earth and Environmental Sciences [Queens New York], Queens College [New York], City University of New York [New York] (CUNY)-City University of New York [New York] (CUNY), SOEST, University of Hawai‘i [Mānoa] (UHM), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Bigelow Laboratory for Ocean Sciences, Department of Earth Science and Technology [Imperial College London], Imperial College London, Plymouth Marine Laboratory, Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami [Coral Gables], Tsinghua National Laboratory for Information Science and Technology (TNList), RITE, Research Institute of Innovative Technology for the Earth, Agricultural Information Institute (AII), Chinese Academy of Agricultural Sciences (CAAS), Department of Mathematics [Shanghai], Shanghai Jiao Tong University [Shanghai], University of California [Irvine] (UCI), Institute of Environmental Science and Technology [Barcelona] (ICTA), University of California (UC), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Oxford, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Southern California (USC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Vrije Universiteit Brussel (VUB), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Florida International University [Miami] (FIU), Department of Earth Science and Engineering [Imperial College London], Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Universitat Autònoma de Barcelona (UAB), British Oceanographic Data Centre (BODC), Institute of Low Temperature Science [Sapporo], Hokkaido University [Sapporo, Japan], The University of Tokyo (UTokyo), Institute of Geochemistry and Petrology [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), College of Earth, Ocean, and Environment [Newark] (CEOE), University of Delaware [Newark], Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Knowledge Media Institute (KMi), Kyoto University, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Academia Sinica, University of California [Irvine] (UC Irvine), Danish Technological Institute (DTI), Scientific Committee on Oceanic Research (SCOR) from the U.S. National Science Foundation [OCE-0608600, OCE-0938349, OCE-1243377, OCE-1546580], UK Natural Environment Research Council (NERC), Ministry of Earth Science of India, Centre National de Recherche Scientifique, l'Universite Paul Sabatier de Toulouse, Observatoire Midi-Pyrenees Toulouse, Universitat Autonoma de Barcelona, Kiel Excellence Cluster The Future Ocean, Swedish Museum of Natural History, University of Tokyo, University of British Columbia, Royal Netherlands Institute for Sea Research, GEOMAR-Helmholtz Centre for Ocean Research Kiel, Alfred Wegener Institute, Scientific Committee on Oceanic Research, National Science Foundation (US), Natural Environment Research Council (UK), Ministry of Earth Sciences (India), Centre National de la Recherche Scientifique (France), Université Toulouse III Paul Sabatier, Observatoire Midi-Pyrénées (France), Universidad Autónoma de Barcelona, Helmholtz Centre for Ocean Research Kiel, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), Schlitzer, Reiner [0000-0002-3740-6499], Masferrer Dodas, Elena [0000-0003-0879-1954], Chamizo, Elena [0000-0001-8266-6129], Christl, M. [0000-0002-3131-6652], Masqué, Pere [0000-0002-1789-320X], Villa-Alfageme, María [0000-0001-7157-8588], Universitat de Barcelona, Natural Environment Research Council (NERC), Leverhulme Trust, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Carrasco Rebaza, Gonzalo, Echegoyen Sanz, Yolanda, Kayser, Richard A, Isotope Research, Ocean Ecosystems, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Hassler, Christel, Schlitzer, Reiner, Masferrer Dodas, Elena, Chamizo, Elena, Christl, M., Masqué, Pere, and Villa-Alfageme, María
Subjects: Geochemistry & Geophysics, 010504 meteorology & atmospheric sciences, Isòtops, sub-01, Geotraces, MODELS, Digital data, Context (language use), 010502 geochemistry & geophysics, 01 natural sciences, IDP2017, Isotopes, Geochemistry and Petrology, Oceans, Electronic atlas, ddc:550, 0402 Geochemistry, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, NetCDF, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Trace elements, Science & Technology, Information retrieval, ACL, Geology, computer.file_format, Ocean Data View, Metadata, Data processing, GEOTRACES, 0403 Geology, Data extraction, 13. Climate action, Data quality, Physical Sciences, [SDE]Environmental Sciences, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, 0406 Physical Geography and Environmental Geoscience, computer, Processament de dades, Trace elements Isotopes
Abstract: The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017. This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González., National Science Foundation (U.S.) (Grant OCE-0608600), National Science Foundation (U.S.) (Grant OCE0938349), National Science Foundation (U.S.) (Grant OCE-1243377), National Science Foundation (U.S.) (Grant OCE-1546580)
Published: 2018
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9. Basin scale survey of marine humic fluorescence in the Atlantic: Relationship to iron solubility and H2O2

Author: Diego M. Gaiero, Maija Heller, and Peter Croot
Subjects: 0106 biological sciences, Atmospheric Science, Global and Planetary Change, Biogeochemical cycle, Remineralisation, 010504 meteorology & atmospheric sciences, Chemistry, 010604 marine biology & hydrobiology, 01 natural sciences, Redox, Colored dissolved organic matter, Environmental chemistry, Phytoplankton, Environmental Chemistry, Photic zone, Seawater, 14. Life underwater, Solubility, 0105 earth and related environmental sciences, General Environmental Science
Abstract: Iron (Fe) is a limiting nutrient for phytoplankton productivity in many different oceanic regions. A critical aspect underlying iron limitation is its low solubility in seawater as this controls the distribution and transport of iron through the ocean. Processes which enhance the solubility of iron in seawater, either through redox reactions or organic complexation, are central to understanding the biogeochemical cycling of iron. In this work we combined iron solubility measurements with parallel factor (PARAFAC) data analysis of CDOM fluorescence along a meridional transect through the Atlantic (PS ANT XXVI-4) to examine the hypothesis that marine humic fluorescence is a potential proxy for iron solubility in the surface ocean. PARAFAC analysis revealed 4 components, two humic like substances and two protein-like. Overall none of the 4 components were significantly correlated with iron solubility, though humic-like components were weakly correlated with iron solubility in iron replete waters. Our analysis suggests that the ligands responsible for maintaining iron in solution in the euphotic zone are sourced from both remineralisation processes and specific ligands produced in response to iron stress and are not easily related to bulk CDOM properties. The humic fluorescence signal was sharply attenuated in surface waters presumably most likely due to photo bleaching, though there was only a weak correlation with the transient photo product H2O2, suggesting longer lifetimes in the photic zone for the fluorescent components identified here. Key Points: - humic-like components correlated with Fe solubility in iron repleted water - ligands are sourced from remineralisation processes produced to Fe stress - humic flu sharply attenuated in surface waters, but only weak corr. with H2O2
Published: 2013
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10. Identifying the Sources and Sinks of CDOM/FDOM across the Mauritanian Shelf and Their Potential Role in the Decomposition of Superoxide (O2-)

Author: Peter Croot, Maija Heller, Kathrin Wuttig, and ~|1267880|~
Subjects: Earth science, lcsh:QH1-199.5, 010504 meteorology & atmospheric sciences, hydrogen peroxide, Ocean Engineering, lcsh:General. Including nature conservation, geographical distribution, 010501 environmental sciences, Aquatic Science, Oceanography, Fluorescence dissolved organicmatter (FDOM), 01 natural sciences, Sink (geography), fluorescence dissolved organic matter (FDOM), Dissolved organic carbon, Marine Science, Organic matter, 14. Life underwater, lcsh:Science, Atlantic Ocean, 0105 earth and related environmental sciences, Water Science and Technology, reactive oxygen species, chemistry.chemical_classification, Global and Planetary Change, geography, Reactive oxygen species, geography.geographical_feature_category, Chemistry, Continental shelf, Ecology, Superoxide, Superoxide dismutase, superoxide dismutase, Colored dissolved organic matter, 13. Climate action, colored dissolved organic matter (CDOM), Environmental chemistry, Ocean science, Mauritanian Shelf, Upwelling, lcsh:Q, parafac, Seawater, excitation emission matrix fluorescence
Abstract: Superoxide (O−2O2-) is a short lived reactive oxygen species (ROS) formed in seawater by photochemical or biological sources, it is important in the redox cycling of trace elements and organic matter in the ocean. The photoproduction of O−2O2- is now thought to involve reactions between O2 and reactive reducing (radical) intermediates formed from dissolved organic matter (DOM) via intramolecular reactions between excited singlet state donors and ground-state acceptors (Zhang et al., 2012). In seawater the main pathways identified for the decomposition of O−2O2- into H2O2 and O2, involve reactions with Cu, Mn, and DOM. In productive regions of the ocean, the reaction between DOM and O−2O2- can be a significant sink for O−2O2-. Thus, DOM is a key component of both the formation and decomposition of O−2O2- and formation of H2O2. In the present work we examined the relationships between O−2O2- decay rates and parameters associated with chromophoric dissolved organic matter (CDOM) and fluorescent dissolved organic matter (FDOM) by using the thermal O−2O2- source SOTS-1. Filtered samples (0.2 μm) were run both in the presence, and absence, of the metal chelator diethylenetriaminepentaacetic acid (DTPA) to determine the contribution from DOM. Samples were collected along a transect across the continental shelf of the Mauritanian continental shelf during a period of upwelling. In this region we found that reactions with DOM, are a significant sink for O−2O2- in the Mauritanian Upwelling, constituting on average 58 ± 13% of the O−2O2- loss rates. Superoxide reactivity with organic matter showed no clear correlation with bulk CDOM or FDOM properties (as assessed by PARAFAC analysis) suggesting that future work should concentrate at the functional group level to clearly elucidate which molecular species are involved as bulk properties represent a wide spread of chemical moieties with different O−2O2- reactivities. Analysis of FDOM parameters indicates that many of the markers used previously for terrestrial sources of DOM and FDOM are called into question as marine sources exist. In particular recent work (Rico et al., 2013) indicates that algal species may also produce syringic, vanillic, and cinnamic acids, which had previously been ascribed solely to terrestrial vegetation. MH's participation was financially supported by the German BMBF project SOPRAN III (FKZ 03F0611A and 03F0662A, PC co-PI) that forms part of the German contribution to SOLAS (Surface Ocean Lower Atmosphere Studies). Funding for the participation of KW was awarded to PC from the DFG (CR145/17-1). Research work at sea was funded through SFB754 (DFG), project B5 (PC). peer-reviewed
Published: 2016
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11. Diazotrophic bacteria respond to Saharan dust additions

Author: Matthew M. Mills, Julie LaRoche, Peter Croot, Rebecca Langlois, Celine Ridame, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 0106 biological sciences, Phylotype, 010504 meteorology & atmospheric sciences, Ecology, biology, 010604 marine biology & hydrobiology, Aquatic Science, Mineral dust, biology.organism_classification, 01 natural sciences, Nutrient, Trichodesmium, [SDE]Environmental Sciences, Botany, Nitrogen fixation, 14. Life underwater, Diazotroph, Proteobacteria, ComputingMilieux_MISCELLANEOUS, Ecology, Evolution, Behavior and Systematics, Bacteria, 0105 earth and related environmental sciences
Abstract: Three bioassay experiments were performed to study the effects of nutrient and Saharan dust additions on natural diazotrophic communities in the tropical North Atlantic Ocean. Samples for nucleic acid analysis were collected at the beginning and end of 48 h incubations. TaqMan probes specific to 7 diazotrophic phylotypes, viz. filamentous cyanobacteria (Trichodesmium spp.), unicellular cyanobacterial (UCYN) Groups A, B, and C, Gamma A and P Proteobacteria, and Cluster III, were used to quantify nifH DNA abundances. N-2 fixation rates were measured in the same experiments using the N-15(2) gas bubble injection method. N-2 fixation was co-limited by P and Fe. Total nifH abundances increased relative to the control with additions of either Fe or P or both in combination. Additions of dissolved N, alone or in combination with phosphate, induced increases in UCYN-A and Gamma A nifH compared with the control. Saharan dust additions significantly stimulated fixation rates. Abundances of all cyanobacterial and Gamma A nifH phylotypes at least doubled after Saharan dust additions where surface water dissolved Fe concentrations were
Published: 2012
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12. Effects of iron surface adsorption and sample handling on iron solubility measurements

Author: C. L. De La Rocha, Peter Croot, Christian Schlosser, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), National Oceanography Centre [Southampton] (NOC), University of Southampton, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Alfred Wegener Institute for Polar and Marine Research (AWI), Plymouth Marine Laboratory (PML), Plymouth Marine Laboratory, and This work was supported by the DFG-Schwerpunktprogramm 1158 Anarktisforschung and DFG grants awarded to Peter L. Croot (CR145/5 and CR145/11-1, contribution to SOPRAN (German SOLAS)) and to Christina De La Rocha (DE1455/1-1)
Subjects: 0106 biological sciences, Sample handling, business.product_category, 010504 meteorology & atmospheric sciences, Chemistry, 010604 marine biology & hydrobiology, Inorganic chemistry, Sorption, General Chemistry, Oceanography, 01 natural sciences, Dissociation (chemistry), Fe solubility, Colloid, Adsorption, Bottle, Environmental Chemistry, Seawater, 14. Life underwater, Solubility, Southern Ocean, business, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Water Science and Technology
Abstract: International audience; Seawater samples from two separate cruises in the Southern Ocean (ANTXXI/3 (EIFeX) and ANTXXIII/9) were collected for measurements of iron solubility by 55Fe addition. For both sets of samples, a significant loss of the dissolved portion of the added Fe was observed during the 72 hour duration of each Fe solubility measurement incubation. The decrease in dissolved Fe was related to Fe precipitation and adsorption onto bottle walls. The dissolved Fe data can be successfully modeled assuming that two colloidal Fe species (organically complexed Fe and inorganic Fe) were quickly formed following the addition of dissolved Fe(III) to the seawater. Model results indicate that Fe dissociated from weak organic complexes was the main contributor to wall sorption during the first 6 h following Fe addition, and that most of the Fe deposited after the first 6 h arose from the dissociation of colloidal inorganic species. Effects of sample freezing on Fe solubility measurements are also discussed.
Published: 2011
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13. Distribution of iodide and iodate in the Atlantic sector of the southern ocean during austral summer

Author: Katrin Bluhm, Gerd Rohardt, Karin Lochte, Oliver Huhn, and Peter Croot
Subjects: 0106 biological sciences, Weddell Sea Bottom Water, chemistry.chemical_classification, Pycnocline, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Iodide, chemistry.chemical_element, Oceanography, Iodine, 01 natural sciences, chemistry.chemical_compound, chemistry, Phytoplankton, Seawater, Photic zone, 14. Life underwater, Iodate, 0105 earth and related environmental sciences
Abstract: The biogeochemistry of iodine in the waters of the Atlantic sector of the Southern Ocean was investigated during the Polarstern cruise ANTXXIV-3 ZERO&DRAKE. The speciation and distribution of iodine (iodate and iodide) in seawater was examined across gradients of iron concentrations and phytoplankton abundance, ranging from an open ocean region along the Zero Meridian to the Weddell Sea and Drake Passage. Iodine cycling in high latitudes differs from that in low latitudes due to differences in the plankton community composition and the physicochemical characteristics. Iodate concentrations ranged between 400 and 450 nmol L(-1) from the surface to the bottom. Surface concentrations of iodide (17 to over 60 nmol L(-1)) were about an order of magnitude higher than below the pycnocline. The peak values of iodide lay nearly always within the euphotic zone and showed a weak, positive correlation with nitrite concentrations in the upper 200 m. In all vertical profiles a pronounced sub-surface maximum in iodide appears between 50 and 200 m depth indicating an iodide drawdown at the near surface. Iodide distribution in the Weddell Sea showed elevated levels in Weddell Sea Bottom Water (WSBW) indicating slow oxidation kinetics and the potential for iodide as a tracer of WSBW formation. (C) 2011 Elsevier Ltd. All rights reserved.
Published: 2011
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14. Synoptic transects on the distribution of trace elements (Hg, Pb, Cd, Cu, Ni, Zn, Co, Mn, Fe, and Al) in surface waters of the Northern- and Southern East Atlantic

Author: Peter Croot, T. Daberkow, Christa Pohl, M. M. Rutgers van der Loeff, U. Hennings, and Gereon Budéus
Subjects: Cadmium, 010504 meteorology & atmospheric sciences, Geotraces, chemistry.chemical_element, Mineralogy, Manganese, Zinc, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, Copper, Mercury (element), chemistry, 13. Climate action, Environmental chemistry, Seawater, 14. Life underwater, Transect, Ecology, Evolution, Behavior and Systematics, Geology, 0105 earth and related environmental sciences
Abstract: Surface seawater samples were taken in the framework of the GEOTRACES program on “POLARSTERN” expedition ANT XXIII/1 in the Eastern Atlantic in 2005 to study the distribution of the trace elements Hg (mercury), Pb (lead), Cd (cadmium), Cu (copper), Ni (nickel), Zn (zinc), Co (cobalt), Mn (manganese), Fe (iron), and Al (aluminium). With the exception of Hg, results were compared to earlier datasets from 1989 to 1990. The particulate fraction averaged over the transect was calculated to be 49% for Cd, 23% for Mn and 50% for Fe indicating a release of these TEI's (trace elements and their isotopes) from a leachable SPM fraction in the stored and acidified samples. Total Pb concentrations ranged between 5 and 20 pmol kg− 1 in 2005 with highest values in the ITCZ (intertropical convergence zone). In 1989 Pb concentrations were twice as high in the region of the ITCZ, while by a factor of 10–15 higher values were obtained in the North Atlantic. Total Cd and Co are dominated, by different seasonal upwelling regimes (Equatorial upwelling, Guinea Dome, Angola Dome). Total Cu, Ni, Fe, Mn and Al show nearly identical concentrations in 1990 and 2005. For total manganese and aluminium strong maxima (3–4 nmol kg− 1 and 55 nmol kg− 1 respectively) are observed between 23°N and 0°, while the Fe maximum (6–9 nmol kg− 1) is located at 7°N. Total Hg concentrations ranged between 0.5 and 4.5 pmol kg− 1.
Published: 2011
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15. Atmospheric and marine controls on aerosol iron solubility in seawater

Author: Peter Croot and Alex R. Baker
Subjects: 010504 meteorology & atmospheric sciences, chemistry.chemical_element, General Chemistry, 010501 environmental sciences, Oceanography, 01 natural sciences, Aerosol, Atmosphere, chemistry, Environmental chemistry, Phytoplankton, Environmental Chemistry, Seawater, 14. Life underwater, Experimental methods, Solubility, Carbon, Dissolution, 0105 earth and related environmental sciences, Water Science and Technology
Abstract: The fraction of atmospherically deposited iron which dissolves in seawater, or becomes available to phytoplankton for growth, is a key determinant of primary productivity in many open ocean regions. As such this parameter plays an important part in the global oceanic cycles of iron and carbon, and yet the factors that control iron dissolution from aerosol are very poorly understood. In this manuscript we seek to synthesise the available knowledge of these factors, which operate in the atmosphere and in seawater. A conceptual model of the overall aerosol iron solubility is presented, in which we liken the various controls on iron solubility to sets of parallel electrical resistors. We also discuss experimental methods for the determination of iron solubility and make recommendations for future studies in this area.
Published: 2010
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16. Significant portion of dissolved organic Fe complexes in fact is Fe colloids

Author: Hein J W de Baar, Klaas R. Timmermans, Marie Boye, Volker Strass, Peter Croot, Patrick Laan, Shigenobu Takeda, Jun Nishioka, Ocean Ecosystems, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Royal Netherlands Institute for Sea Research (NIOZ), Institute of Low Temperature Science [Sapporo], Hokkaido University [Sapporo, Japan], Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Department of Aquatic Bioscience, and The University of Tokyo (UTokyo)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Iron, Inorganic chemistry, Mineralogy, Fractionation, Oceanography, 01 natural sciences, Dissociation (chemistry), Colloid, Iron cycle, Environmental Chemistry, 14. Life underwater, Southern Ocean, 0105 earth and related environmental sciences, Water Science and Technology, Chemistry, Ligand, 010604 marine biology & hydrobiology, General Chemistry, Size fractionation, 13. Climate action, [SDE]Environmental Sciences, Seawater, Complexation, Surface water, Tampon
Abstract: International audience; Vertical distributions of iron and iron binding ligands were determined in 2 size classes (dissolved < 0.2 μm, soluble < 200 kDa, e.g., ~ 0.03 μm) in the Southern Ocean. Colloidal iron and complexing capacity (> 200 kDa-< 0.2 μm) were inferred as the difference between the dissolved and soluble fractions. Dissolved iron and ligands exist primarily in the soluble size range in the surface waters, although iron-complexing colloids still represent a significant portion of the dissolved pool and this fraction increases markedly with depth. This work presents evidence for the colloidal nature of a significant portion (37-51% on average) of the 'dissolved' organic Fe pool in these oceanic waters. From the data it was not possible to discern whether iron colloids exist as discrete organic complexes and/or inorganic amorphous colloids. Iron-complexing colloids are the most saturated with iron at the thermodynamic equilibrium, whereas soluble organic ligands occur in larger excess compared to soluble iron. It suggests that the exchangeable fraction for iron uptake through dissociation of Fe complexes likely occurs in the soluble fraction, and that soluble ligands have the potential to buffer iron inputs to surface waters whereas iron colloids may aggregate and settle. Expectations based on Fe diffusion rates, distributions and the stability of the soluble iron complexes and iron colloids also suggest that the weaker soluble Fe complexes may be more bio-available, while the strongest colloids may be a major route for iron removal from oceanic waters. Investigations of the size classes of the dissolved organic iron thus can significantly increase our understanding of the oceanic iron cycle.
Published: 2010
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17. Superoxide Decay Kinetics in the Southern Ocean

Author: Peter Croot and Maija Heller
Subjects: Order of reaction, 010504 meteorology & atmospheric sciences, Chemistry, Oceans and Seas, Mineralogy, chemistry.chemical_element, General Chemistry, Hydrogen-Ion Concentration, 010501 environmental sciences, 01 natural sciences, Copper, Chemical kinetics, Kinetics, Water column, Superoxides, Environmental chemistry, Dissolved organic carbon, Environmental Chemistry, Seawater, Chelation, Titration, 14. Life underwater, 0105 earth and related environmental sciences
Abstract: Measurements of superoxide (O(2)(-)) reaction kinetics were made during a transect with the research icebreaker Polarstern (ANT24-3) in the Antarctic through the Drake Passage in austral autumn 2008. Our sampling strategy was designed to investigate the sinks of superoxide in Polar waters; principally through reactions with dissolved organic matter (DOM) or metals (copper and iron). We modified an existing chemiluminescence flow injection system using methyl Cypridina luciferin analog (MCLA) for the detection of O(2)(-) and added O(2)(-) using KO(2) as the source. Our results indicate that O(2)(-) in ambient seawater had a half-life ranging from 9.3 to 194 s. DTPA additions to seawater, to remove the effects of reactions with metals, revealed O(2)(-) decay rates consistent with a second order reaction, indicating that the dismutation reaction dominated and that reactions with DOM were not significant. Titrations of seawater by the addition of nanomolar amounts of iron or copper revealed the importance of organic chelation of Fe and/or Cu in controlling the reactivity with O(2)(-). Throughout the water column reactions with Cu appeared to be the major sink for superoxide in the Southern Ocean. This new strategy suggests an alternative approach for speciation measurements of Fe and Cu in seawater.
Published: 2009
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18. Application of cross-flow filtration for determining the solubility of iron species in open ocean seawater

Author: Peter Croot and Christian Schlosser
Subjects: 010504 meteorology & atmospheric sciences, Chemistry, Inorganic chemistry, Ultrafiltration, Ocean Engineering, 010501 environmental sciences, Permeation, 01 natural sciences, 6. Clean water, Cross-flow filtration, Filter (aquarium), Membrane, Adsorption, Seawater, 14. Life underwater, Solubility, 0105 earth and related environmental sciences
Abstract: Measurements of soluble iron species (organic and inorganic) are important for understanding the transport of iron within the ocean and its bioavailability. Recent developments in ultrafiltration equipment and analytical detection techniques for low level Fe determination has turned the spotlight on obtaining data on soluble iron species. However there have, until now, been few studies that have characterized the performance of an ultrafiltration system with respect to well described soluble iron complexes. In the present work, we describe a methodological study characterizing the behavior of soluble and colloidal iron species in seawater by combining a crossflow ultrafiltration system (Vivaflow 50TM) with a radioisotope (55Fe). During this study, we were able to maintain excellent mass balances by including all components: not only the solution phases (retentate and permeate) but wall-adsorbed and filter-adsorbed iron, which were recovered by an acid-rinsing step. Wall and filter adsorption were unavoidable when solutions were saturated with respect to Fe'. However in undersaturated solutions, such as with an excess of desferrioxamine B, wall and filter adsorption were minimized, indicating that these effects should be slight for natural samples where iron-binding ligands are in excess. Our results have important implications for the use of ultrafiltration membranes for open ocean iron biogeochemical studies.
Published: 2008
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19. The geotraces intermediate data product 2014

Author: Edward Mawji, Andrew R. Bowie, François Lacan, Kenneth W. Bruland, Oliver J. Lechtenfeld, Laura F. Robinson, Martin Frank, Kuo-Fang Huang, Louise A. Zimmer, Loes J. A. Gerringa, Tobias Roeske, Jingfeng Wu, Célia Venchiarutti, Yanbin Lu, Géraldine Sarthou, Reiner Schlitzer, Tomas A. Remenyi, Yuichiro Kumamoto, Hein J W de Baar, Santiago R. Gonzalez, Mark J. Warner, Mak A. Saito, Peter N. Sedwick, Daniel C. Ohnemus, Evgenia Ryabenko, Emilie Grossteffan, Moritz Zieringer, William J. Jenkins, Gregory F. de Souza, Pinghe Cai, Martin Q. Fleisher, Johnny Stutsman, Yolanda Echegoyen-Sanz, Alessandro Tagliabue, Delphine Lannuzel, Mark Rehkämper, Abigail E. Noble, A. Radic, Lijuan Sha, Micha J. A. Rijkenberg, Mark A. Brzezinski, François Fripiat, Nicholas R. Bates, Toshitaka Gamo, Hisayuki Yoshikawa, Maija Heller, Alan M. Shiller, William M. Smethie, Joaquin E. Chaves, Elena Masferrer Dodas, Torben Stichel, Mark Rosenberg, Hai Cheng, Alicia Navidad, Patrick Laan, Peter Scott, Mark Baskaran, Stephen J.G. Galer, Frédéric Planchon, Jan van Ooijen, Huong Thi Dieu, Steven van Heuven, Feifei Deng, José Marcus Godoy, Catherine Jeandel, Xin Yuan Zheng, Frank Dehairs, Stephen R. Rintoul, Wafa Abouchami, R. Lawrence Edwards, Gideon M. Henderson, Eberhard Fahrbach, Yoshiki Sohrin, Tim M. Conway, Bronwyn Wake, Urumu Tsunogai, Evaline van Weerlee, Maeve C. Lohan, Katrin Bluhm, Robert F. Anderson, Eva Bucciarelli, Ken O. Buesseler, Marie Labatut, Peter Croot, Jana Friedrich, Christopher T. Hayes, Hendrik M. van Aken, James H. Swift, Seth G. John, Sven Kretschmer, Zichen Xue, Karel Bakker, Albert S. Colman, Pierre Branellec, Timothy C. Kenna, Benjamin S. Twining, Marie Boye, Alexander L. Thomas, Karen L. Casciotti, Jessica N. Fitzsimmons, Sabrina Speich, Jun Nishioka, Thomas M. Church, Mariko Hatta, Pere Masqué, Damien Cardinal, Charles R. McClain, Oliver Baars, Frederique le Moigne, Geoffrey J. Smith, Daniel M. Sigman, Edward A. Boyle, Ursula Schauer, Stephanie Owens, E. Malcolm S. Woodward, Maarten B Klunder, Lesley Salt, Gregory A. Cutter, Christopher I. Measures, Hajime Obata, Catherine Pradoux, Ester Garcia Solsona, James W. Moffett, Antje H L Voelker, Gabriel Dulaquais, Paul D. Quay, Saeed Roshan, Rob Middag, Johann Bown, Neil J. Wyatt, Phoebe J. Lam, Edward C.V. Butler, Michiel M Rutgers van der Loeff, Fanny Chever, Cyril Abadie, Viena Puigcorbé, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Department of Geosciences [Princeton], Princeton University, Institute for Environmental Research, Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), Institute for Marine and Antarctic Studies [Horbat] (IMAS), University of Tasmania [Hobart, Australia] (UTAS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), University of California, Marine Science Institute [Santa Barbara] (MSI), University of California [Santa Barbara] (UCSB), University of California-University of California, Woods Hole Oceanographic Institution (WHOI), Australian Institute of Marine Science (AIMS), State Key Laboratory of Marine Environmental Science (MEL), Xiamen University, Biogéochimie-Traceurs-Paléoclimat (BTP), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), NASA Goddard Space Flight Center (GSFC), Institute of Global Environmental Change [China] (IGEC), Xi'an Jiaotong University (Xjtu), Department of Earth Sciences [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Bonn University Hospital, College of Earth, Ocean, and Environment [Newark] (CEOE), University of Delaware [Newark], University College of London [London] (UCL), Department of Earth and Ocean Sciences [Columbia], University of South Carolina [Columbia], Old Dominion University [Norfolk] (ODU), Royal Netherlands Institute for Sea Research (NIOZ), Instituto de Química, Universidade de São Paulo, British Oceanographic Data Centre (BODC), National Oceanography Centre (NOC), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Massachusetts Institute of Technology (MIT), Universidad de Dakota del Sur, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Bermuda Institute of Ocean Sciences (BIOS), Vrije Universiteit Brussel (VUB), Department of Mathematics and Science, National Taiwan Normal University (NTNU), GEOMAR LEGOS, Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Department of Chemistry, School of Life Sciences, University of Sussex, National Oceanography Centre [Southampton] (NOC), University of Southampton, Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), Oceans Institute and School of Physics, The University of Western Australia (UWA), School of Natural Sciences and Centre for Marine Ecosystems Research, Edith Cowan University, EDITH COWAN UNIVERSITY-EDITH COWAN UNIVERSITY, Department of Chemistry [Dunedin], University of Otago [Dunedin, Nouvelle-Zélande], Atmosphere and Ocean Research Institute [Kashiwa-shi] (AORI), The University of Tokyo (UTokyo), Bermuda Biological Station for Research (BBSR), Bermuda Biological Station for Research, Kyoto University [Kyoto], Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), SOEST, University of Hawai‘i [Mānoa] (UHM), FM-GEOMAR, Leibniz Institute of Marine Sciences at the University of Kiel, Department of Earth Ocean and Ecological Sciences [Liverpool], University of Liverpool, Bigelow Laboratory for Ocean Sciences, Department of Biology, Tufts University [Medford], RITE, Research Institute of Innovative Technology for the Earth, Royal Museum for Central Africa [Tervuren] (RMCA), IMT Lille Douai, Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Analytical, Environmental and Geo- Chemistry, Chemistry, Analytical and Environmental Chemistry, Earth System Sciences, Analytical, Environmental & Geo-Chemistry, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), University of Tasmania (UTAS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD), University of Minnesota [Twin Cities], Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Universitat Autònoma de Barcelona [Barcelona] (UAB), The University of Tokyo, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Marine and Antarctic Studies [Hobart] (IMAS), University of California (UC), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University Hospital Bonn, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), University of Sussex, Kyoto University, Laboratoire de physique des océans (LPO), Natural Environment Research Council (NERC), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Boyle, Edward A, Fitzsimmons, Jessica Nicole, Echegoyen Sanz, Yolanda, Ocean Ecosystems, and Isotope Research
Subjects: Chemistry, Multidisciplinary, Geotraces, Digital data, trace elements, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Biology, Oceanography, ASCII, Isotopes, 0399 Other Chemical Sciences, Electronic atlas, GEOTRACES, Trace elements, 0402 Geochemistry, Environmental Chemistry, Bathymetry, 0405 Oceanography, 14. Life underwater, isotopes, Water Science and Technology, Stable isotopes, NetCDF, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Science & Technology, Information retrieval, ACL, General Chemistry, computer.file_format, Seawater samples, Ocean Data View, Metadata, Marine Sciences, Chemistry, electronic atlas, 13. Climate action, Data quality, Physical Sciences, geotraces, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, computer
Abstract: 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 (TEIs) 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 comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes., National Science Foundation (U.S.) (OCE-0608600), National Science Foundation (U.S.) (OCE-0938349), National Science Foundation (U.S.) (OCE-1243377)
Published: 2015
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20. Picophytoplankton; a comparative study of their biochemical composition and photosynthetic properties

Author: Bas van der Wagt, Marcel J.W. Veldhuis, Klaas R. Timmermans, and Peter Croot
Subjects: 0106 biological sciences, Biomass (ecology), 010504 meteorology & atmospheric sciences, biology, Ecology, 010604 marine biology & hydrobiology, Aquatic Science, Plankton, Oceanography, biology.organism_classification, Synechococcus, 01 natural sciences, Trichodesmium, Water column, 13. Climate action, Phytoplankton, Photic zone, 14. Life underwater, Prochlorococcus, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract: Picophytoplankton are a small or major component of the phytoplankton community and present in all oceanic systems, from pole to pole. They dominate in the low chlorophyll biomass areas, such as the (sub)tropical regions, but also contribute considerably (up to 20%) in the high chlorophyll biomass areas. The ecosystems of occurrence contrast significantly in physical and chemical settings. This includes a strongly mixed upper water column replete in nutrients as well as a strongly thermally stratified euphotic zone depleted in nutrients at the surface with a steep inverse light and nutrient gradient. These changes impose a strong impact on the composition of the picophytoplankton community but also on the biochemical and physiological properties of the species present. In particular, the pigmentation and cellular carbon, nitrogen and phosphorus quota and requirement will differ from a stratified compared to a well-mixed water column. As a result no characteristic values for the parameters required for this specific algal group in a global phytoplankton carbon model (the SWAMCO model,Lancelot et al. (2000), Deep-Sea Res. I, 47, 1621) can be given. In the present paper an inventory is made of the biochemical, physiological and photosynthetic parameters of two species of cyanobacteria (Prochlorococcus and Synechococcus) and the pico-size class fraction of the eukaryote phytoplankton component. Other groups of phytoplankton, such as diatoms, Trichodesmium, Phaeocystis and coccolithophorids, will be discussed in separate papers in this issue. This inventory is a mixture of laboratory experiments using well-defined algal populations as well as data derived from field surveys including a mixture of species. Where possible, the relevance of the parameters will be discussed in relation to the nature of the physico-chemical conditions of the area of occurrence.
Published: 2005
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21. Atmospheric iron deposition and sea-surface dissolved iron concentrations in the eastern Atlantic Ocean

Author: Peter Croot, Hein J W de Baar, Alex R. Baker, Marie Boye, Patrick Laan, Paul J. Worsfold, Andrew R. Bowie, Eric P. Achterberg, Géraldine Sarthou, Tim Jickells, Stéphane Blain, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Environmental Sciences [Norwich], University of East Anglia [Norwich] (UEA), Laboratoire d'océanographie et de biogéochimie (LOB), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Oceanography Centre [Southampton] (NOC), University of Southampton, Royal Netherlands Institute for Sea Research (NIOZ), Department of Environmental Sciences, Plymouth University, and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Iron supply, Aquatic Science, Mineral dust, Oceanography, Atmospheric sciences, 01 natural sciences, Iron cycle, 14. Life underwater, Precipitation, Transect, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Sea surface, Aerosol iron, Residence time, 010604 marine biology & hydrobiology, Dissolved iron, Chemical oceanography, Plume, 13. Climate action, Atmospheric (wet and dry) deposition, Environmental science, Seawater
Abstract: Atmospheric iron and underway sea-surface dissolved (
Published: 2003
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22. Dissolved cadmium in the Southern Ocean: Distribution, speciation, and relation to phosphate

Author: Marie Boye, Oliver Baars, Stephen J.G. Galer, Peter Croot, Wafa Abouchami, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Department of Geosciences [Princeton], Princeton University, Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, Institut für Mineralogie, Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Ocean Sciences [Galway], National University of Ireland [Galway] (NUI Galway), Westfälische Wilhelms-Universität Münster (WWU), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atlantic Sector, Subantarctic Mode Water, cadmium, complexation, [SDE.MCG]Environmental Sciences/Global Changes, Aquatic Science, Oceanography, ligand, circumpolar current, Ocean gyre, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Circumpolar deep water, Phytoplankton, 14. Life underwater, Southern Ocean, phosphate, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, nutrient limitation, Weddell Sea, Antarctic Intermediate Water, geography.geographical_feature_category, concentration (composition), spatial distribution, ACL, North Atlantic Deep Water, gyre, dilution, mode water, speciation (chemistry), upwelling, electrochemistry, 13. Climate action, Upwelling, Mode water, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, bioavailability, Geology, deep water
Abstract: International audience; We report isotope dilution analyses of dissolved cadmium (Cd) and electrochemical Cd speciation measurements in the Atlantic sector of the Southern Ocean. Bioavailable inorganic Cd is > 100 times higher in near-surface waters south of the Polar Front compared to the Subantarctic Zone because of upwelling and reduced complexation by organic Cd ligands. To trace local changes in the relation between Cd and P, we examine the deviations from a linear deep-water Cd vs. P relation (Cd*), and find that changes in Cd* coincide with the position of frontal systems and covary with primary productivity and total dissolved Mn and Fe concentrations. These covariations agree with potential local changes in phytoplankton Cd uptake rates, resulting from differences in the availability of Cd, Zn, Mn, and Fe. A band of negative Cd* values is associated with formation of Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW). In contrast to SAMW, which may export low Cd: P ratios from the Southern Ocean, the Cd: P ratios in AAIW increase by mixing with underlying Upper Circumpolar Deep Water before being exported from the Southern Ocean. Deep waters show constant Cd: P ratios, and both elements behave conservatively with end-member mixing between deep waters of the Weddell Gyre, the Antarctic Circumpolar Current, and inflowing North Atlantic Deep Water. Overall, our results support the hypothesis that the kink in the global Cd vs. P relation is largely caused by high Cd: P uptake ratios in the trace-nutrient-limited Southern Ocean
Published: 2014
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23. Facets of diazotrophy in the oxygen minimum zone waters off peru

Author: Sven C. Neulinger, Ruth A. Schmitz, Julie LaRoche, Marcel M. M. Kuypers, Carolin R Loescher, Diana Gill, Gaute Lavik, Peter Croot, Christian Schlosser, Tobias Großkopf, Falguni Desai, Nicole Pinnow, and Harald Schunck
Subjects: Ocean deoxygenation, oxygen minimum zone off peru, Denitrification, 010504 meteorology & atmospheric sciences, Oceans and Seas, nitrogen-fixation, Biology, heterotrophic n-2 fixation, Oxygen minimum zone, Cyanobacteria, 01 natural sciences, Microbiology, n-2 fixation, diversity, 03 medical and health sciences, Microbial ecology, Nitrogen Fixation, Peru, Proteobacteria, expression, Seawater, 14. Life underwater, north-atlantic, Ecology, Evolution, Behavior and Systematics, Phylogeny, 030304 developmental biology, 0105 earth and related environmental sciences, atlantic-ocean, Ecological niche, 0303 health sciences, Nitrates, Bacteria, Ecology, Heterotrophic Processes, Archaea, Oxygen, 13. Climate action, Anammox, nifh genes, Nitrogen fixation, Original Article, nifh diversity, sea-water, Diazotroph, Oxidoreductases, dinitrogen-fixation, pacific-ocean
Abstract: Nitrogen fixation, the biological reduction of dinitrogen gas (N2) to ammonium (NH4(+)), is quantitatively the most important external source of new nitrogen (N) to the open ocean. Classically, the ecological niche of oceanic N2 fixers (diazotrophs) is ascribed to tropical oligotrophic surface waters, often depleted in fixed N, with a diazotrophic community dominated by cyanobacteria. Although this applies for large areas of the ocean, biogeochemical models and phylogenetic studies suggest that the oceanic diazotrophic niche may be much broader than previously considered, resulting in major implications for the global N-budget. Here, we report on the composition, distribution and abundance of nifH, the functional gene marker for N2 fixation. Our results show the presence of eight clades of diazotrophs in the oxygen minimum zone (OMZ) off Peru. Although proteobacterial clades dominated overall, two clusters affiliated to spirochaeta and archaea were identified. N2 fixation was detected within OMZ waters and was stimulated by the addition of organic carbon sources supporting the view that non-phototrophic diazotrophs were actively fixing dinitrogen. The observed co-occurrence of key functional genes for N2 fixation, nitrification, anammox and denitrification suggests that a close spatial coupling of N-input and N-loss processes exists in the OMZ off Peru. The wide distribution of diazotrophs throughout the water column adds to the emerging view that the habitat of marine diazotrophs can be extended to low oxygen/high nitrate areas. Furthermore, our statistical analysis suggests that NO2(-) and PO4(3-) are the major factors affecting diazotrophic distribution throughout the OMZ. In view of the predicted increase in ocean deoxygenation resulting from global warming, our findings indicate that the importance of OMZs as niches for N2 fixation may increase in the future.
Published: 2014

24. Perception of Environmental Signals by a Marine Diatom

Author: Peter Croot, Chris Bowler, Maurizio Ribera d'Alcalà, and Angela Falciatore
Subjects: 0106 biological sciences, Biogeochemical cycle, Iron, Ferric Compounds, 01 natural sciences, 03 medical and health sciences, Aequorin, Transformation, Genetic, Nutrient, Chlorides, Algae, Osmotic Pressure, Phytoplankton, Homeostasis, Seawater, Marine ecosystem, Calcium Signaling, Transgenes, 14. Life underwater, Phaeodactylum tricornutum, 030304 developmental biology, Diatoms, 0303 health sciences, Multidisciplinary, biology, Ecology, 010604 marine biology & hydrobiology, Osmolar Concentration, fungi, Biological Transport, Hydrogen-Ion Concentration, biology.organism_classification, Adaptation, Physiological, Culture Media, Kinetics, Diatom, Calcium, Stress, Mechanical, Adaptation
Abstract: Diatoms are a key component of marine ecosystems and are extremely important for the biogeochemical cycling of silica and as contributors to global fixed carbon. However, the answers to fundamental questions such as what diatoms can sense in their environment, how they respond to external signals, and what factors control their life strategies are largely unknown. We generated transgenic diatom cells containing the calcium-sensitive photoprotein aequorin to determine whether changes in calcium homeostasis are used to respond to relevant environmental stimuli. Our results reveal sensing systems for detecting and responding to fluid motion (shear stress), osmotic stress, and iron, a key nutrient that controls diatom abundance in the ocean.
Published: 2000
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25. Particulate and dissolved aluminum and titanium in the upper water column of the Atlantic Ocean

Author: Thibaut Wagener, Peter Croot, Dieter Garbe-Schönberg, Anna Dammshäuser, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institute of Geosciences [Kiel], Christian-Albrechts-Universität zu Kiel (CAU), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Particle (ecology), Aquatic Science, Particulates, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Adsorption, Water column, 13. Climate action, Environmental chemistry, 14. Life underwater, Transect, Dissolution, Scavenging, Surface water, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: This study investigates the oceanic behavior of the lithogenic trace elements Al and Ti in the upper 200 m of the Atlantic Ocean. The distribution of both metals in the dissolved and particulate phases was assessed along an E-W transect in the eastern tropical North Atlantic (December 2009) and along a meridional Atlantic transect (April-May 2010). The surface water concentrations of particulate and dissolved Al and Ti reflected the previously observed pattern of atmospheric inputs into the Atlantic Ocean. Subsurface minima at stations with pronounced fluorescence maxima were observed, suggesting a link between biological productivity and the removal of both dissolved and particulate Al and Ti. This may include uptake mechanisms, adsorption and aggregation processes on biogenic particle surfaces and the formation of large, fast sinking biogenic particles, e.g., fecal pellets. Residence times in the upper water column (100 m) of the tropical and subtropical North Atlantic were estimated to range in the order of days to weeks in the particulate phases (Al: 3-22 days, Ti: 4-37 days) and were 0.9-3.8 years for Al and 10-31 years for Ti in the dissolved phases. Longer residence times in both phases in the South Atlantic are consistent with lower biological productivity and decreased removal rates. In the upper water column, Al was predominantly present in the dissolved form, whereas Ti mostly occurred in the particulate form. Largest deviations in the partition coefficients between the particulate and dissolved phases were found in the surface waters, together with excess dissolved Al over Ti compared to the crustal source. This likely reflects elevated dissolution of Al compared to Ti from atmospheric mineral particles
Published: 2013
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26. Geochemical evidence of oceanic iron fertilization by the Kasatochi volcanic eruption in 2008 and the potential impacts on Pacific sockeye salmon

Author: Peter Croot, Baerbel Langmann, Svend Duggen, Linn Hoffmann, Nazli Olgun, Matthias Hort, and C. F. Waythomas
Subjects: 0106 biological sciences, surface ocean, 010504 meteorology & atmospheric sciences, Iron fertilization, fe limitation, Aquatic Science, 01 natural sciences, Zooplankton, Algal bloom, sockeye salmon, fraser-river, primary productivity, hnlc waters, Ocean gyre, volcanic ash, oncorhynchus-nerka, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Vulcanian eruption, Ecology, biology, 010604 marine biology & hydrobiology, fungi, ash, 16. Peace & justice, biology.organism_classification, gulf of alaska, marine growth, enrichment experiments, Oceanography, diatom bloom, kasatochi eruption, Oncorhynchus, Environmental science, ne pacific, Bloom, sub-arctic pacific, geographic locations, Volcanic ash
Abstract: The Kasatochi volcanic eruption that occurred in the central Aleutian Islands in Alaska, USA, in August 2008 is thought to have induced a massive diatom bloom in the iron-limited waters of the Gulf of Alaska, which potentially affected the oceanic food web by increasing the abundance of zooplankton and sockeye salmon Oncorhynchus nerka in the northeast Pacific Ocean. We report the first seawater experiments involving volcanic ash ejected from the Kasatochi eruption, showing that the ash released 61 to 83 nmol Fe, 374 to 410 nmol NO3-, 5 to 6 nmol PO43- and 170 to 585 nmol SiO2 when it contacted seawater. Our study suggests that the amount of iron released from Kasatochi ash (an increase of 2.0 to 2.8 nM Fe) was indeed sufficient to cause the observed phytoplankton bloom in the northeastern Pacific Gyre, while the impact of macronutrient release was minimal. We further evaluated the multiple, interdependent processes in the oceanic food web related to the diatom bloom, involving the ocean survival of juvenile salmon that entered the northeast Pacific Ocean in the summer of 2008.
Published: 2013

27. Deep carbon export from a Southern Ocean iron-fertilized diatom bloom

Author: Martin Losch, Matthew M. Mills, Philipp Assmy, Adrian Webb, Boris Cisewski, Gry Mine Berg, Jesús M. Arrieta, Jill Nicola Schwarz, Linn Hoffmann, Ulrich Bathmann, Volker Strass, Ilka Peeken, Harry Leach, Marina Montresor, Eberhard Sauter, Maike M. Schmidt, Victor Smetacek, Christine Klaas, Francesco d'Ovidio, Anja Terbrüggen, Dieter Wolf-Gladrow, Oliver Sachs, Joachim Henjes, Rüdiger Röttgers, Craig Neill, Gerhard J. Herndl, Richard G. J. Bellerby, Nicolas Savoye, Peter Croot, Santiago F. Gonzalez, Couplage physique-biogéochimie-carbone (PHYBIOCAR), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636))
Subjects: 0106 biological sciences, Carbon Sequestration, Time Factors, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Iron, Oceans and Seas, [SDE.MCG]Environmental Sciences/Global Changes, chemistry.chemical_element, cycles, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Carbon sequestration, 01 natural sciences, Atmosphere, chemistry.chemical_compound, Phytoplankton, 14. Life underwater, 0105 earth and related environmental sciences, Diatoms, Biomass (ecology), atmospheric co2, Multidisciplinary, model, biology, 010604 marine biology & hydrobiology, fungi, Carbon Dioxide, biology.organism_classification, Carbon, Diatom, Oceanography, chemistry, 13. Climate action, Carbon dioxide, Environmental science, sea-floor, Bloom
Abstract: International audience; Fertilization of the ocean by adding iron compounds has induced diatom-dominated phytoplankton blooms accompanied by considerable carbon dioxide drawdown in the ocean surface layer. However, because the fate of bloom biomass could not be adequately resolved in these experiments, the timescales of carbon sequestration from the atmosphere are uncertain. Here we report the results of a five-week experiment carried out in the closed core of a vertically coherent, mesoscale eddy of the Antarctic Circumpolar Current, during which we tracked sinking particles from the surface to the deep-sea floor. A large diatom bloom peaked in the fourth week after fertilization. This was followed by mass mortality of several diatom species that formed rapidly sinking, mucilaginous aggregates of entangled cells and chains. Taken together, multiple lines of evidence--although each with important uncertainties--lead us to conclude that at least half the bloom biomass sank far below a depth of 1,000 metres and that a substantial portion is likely to have reached the sea floor. Thus, iron-fertilized diatom blooms may sequester carbon for timescales of centuries in ocean bottom water and for longer in the sediments.
Published: 2012
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28. Solubility of iron in the Southern Ocean

Author: Christian Schlosser, Peter Croot, Christina L. De La Rocha, Peter Streu, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), National Oceanography Centre [Southampton] (NOC), University of Southampton, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Plymouth Marine Laboratory (PML), and Plymouth Marine Laboratory
Subjects: 0106 biological sciences, In situ, 010504 meteorology & atmospheric sciences, Chemistry, 010604 marine biology & hydrobiology, Analytical chemistry, Mineralogy, Fraction (chemistry), Aquatic Science, Oceanic zone, Oceanography, 01 natural sciences, Coastal zone, Cathodic stripping voltammetry, [SDE]Environmental Sciences, 14. Life underwater, Solubility, 0105 earth and related environmental sciences
Abstract: International audience; Iron solubility (cFe S) ranged from 0.4 to 1.5 nmol L -1, decreasing from south to north in three different Southern Ocean zones (the Coastal Zone, the Antarctic Zone, and the Polar Frontal Zone plus the Subantarctic Zone). This decrease was at times correlated with an increase in temperature. Organic Fe solubility (cFe S,org), which was obtained by subtracting from total measured Fe solubility the solubility of inorganic species of iron (Fe) at the measurement temperature (20°C), ranged from 0.3 to 1.3 nmol L -1, representing an average of 32 ± 14% of the concentration of ligands in the dissolved size fraction as determined via competitive ligand exchange- absorptive cathodic stripping voltammetry (barring a handful of extremely high values from a transect run to the east of Prydz Bay). Values of cFe S were mainly lower than the predicted value for inorganic Fe solubility at the in situ temperature. Total in situ Fe solubility (cFe S,adj) was therefore estimated by adjusting for inorganic Fe solubility at in situ temperatures (between -2°C and +18°C). Because in situ temperatures in the Antarctic Circumpolar Current were mostly lower than +3°C, such cFe S,adj values, ranging from 0.5 to 1.8 nmol L -1, were roughly twice as large as cFe S,org. The adjustment relies heavily on model calculations of inorganic Fe solubility but, if correct, indicates that the bulk of the solubility of Fe in the cold waters of the Southern Ocean is tied to the solubility of inorganic Fe rather than to Fe ligands in the soluble size fraction.
Published: 2012
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29. Effect of wind speed on aerosol optical depth over remote oceans, based on data from the Maritime Aerosol Network

Author: Yann Courcoux, N. C. Hsu, Brent N. Holben, Peter Croot, S. Kinne, Sergey Gulev, Norman B. Nelson, Timothy J Smyth, Rémi Losno, Alexander Smirnov, Stuart Piketh, Andrew M. Sayer, Vladimir F. Radionov, Patricia K. Quinn, Sergey M. Sakerin, Jean Sciare, Andreas Macke, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Chimie Atmosphérique Expérimentale (CAE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Meteorology, 010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, 02 engineering and technology, Atmospheric sciences, 01 natural sciences, Wind speed, 010305 fluids & plasmas, Wind profile power law, Wind shear, Linear regression, 0103 physical sciences, Range (statistics), 14. Life underwater, lcsh:TA170-171, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:TA715-787, lcsh:Earthwork. Foundations, lcsh:Environmental engineering, Aerosol, Current (stream), 13. Climate action, Environmental science, Satellite
Abstract: The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. The MAN archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we investigate correlations between ship-borne aerosol optical depth (AOD) and near-surface wind speed, either measured (onboard or from satellite) or modeled (NCEP). According to our analysis, wind speed influences columnar aerosol optical depth, although the slope of the linear regression between AOD and wind speed is not steep (~0.004–0.005), even for strong winds over 10 m s−1. The relationships show significant scatter (correlation coefficients typically in the range 0.3–0.5); the majority of this scatter can be explained by the uncertainty on the input data. The various wind speed sources considered yield similar patterns. Results are in good agreement with the majority of previously published relationships between surface wind speed and ship-based or satellite-based AOD measurements. The basic relationships are similar for all the wind speed sources considered; however, the gradient of the relationship varies by around a factor of two depending on the wind data used.
Published: 2012
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30. Utilizing Radioisotopes for Trace Metal Speciation Measurements in Seawater

Author: Christian Schlosser, Peter Croot, Maija Heller, Kathrin Wuttig, and Singh, N.
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Trace metal speciation, Chemical speciation, Chemistry, 010604 marine biology & hydrobiology, Inorganic chemistry, Biogeochemistry, 01 natural sciences, Trace (semiology), 13. Climate action, Environmental chemistry, Seawater, 14. Life underwater, 0105 earth and related environmental sciences
Abstract: The chemical speciation of trace metals in seawater is of critical importance to studies in marine biogeochemistry; as such information is essential for interpreting and understanding the chemical reactivity of trace metals in the environment.
Published: 2011
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31. Surface ocean iron fertilization: The role of airborne volcanic ash from subduction zone and hot spot volcanoes and related iron fluxes into the Pacific Ocean

Author: Nazli Olgun, Pierre Delmelle, Svend Duggen, Niels Oskarsson, Peter Croot, Heiner Dietze, Dieter Garbe-Schönberg, Claus Siebe, Andreas Auer, and Ulrike Schacht
Subjects: Atmospheric Science, Global and Planetary Change, geography, Biogeochemical cycle, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Earth science, Iron fertilization, Mineralogy, Mineral dust, 010502 geochemistry & geophysics, 01 natural sciences, Flux (metallurgy), Volcano, Iron cycle, 13. Climate action, Environmental Chemistry, Seawater, 14. Life underwater, Geology, 0105 earth and related environmental sciences, General Environmental Science, Volcanic ash
Abstract: Surface ocean iron (Fe) fertilization can affect the marine primary productivity (MPP), thereby impacting on CO2 exchanges at the atmosphere-ocean interface and eventually on climate. Mineral (aeolian or desert) dust is known to be a major atmospheric source for the surface ocean biogeochemical iron cycle, but the significance of volcanic ash is poorly constrained. We present the results of geochemical experiments aimed at determining the rapid release of Fe upon contact of pristine volcanic ash with seawater, mimicking their dry deposition into the surface ocean. Our data show that volcanic ash from both subduction zone and hot spot volcanoes (n = 44 samples) rapidly mobilized significant amounts of soluble Fe into seawater (35–340 nmol/g ash), with a suggested global mean of 200 ± 50 nmol Fe/g ash. These values are comparable to the range for desert dust in experiments at seawater pH (10–125 nmol Fe/g dust) presented in the literature (Guieu et al., 1996; Spokes et al., 1996). Combining our new Fe release data with the calculated ash flux from a selected major eruption into the ocean as a case study demonstrates that single volcanic eruptions have the potential to significantly increase the surface ocean Fe concentration within an ash fallout area. We also constrain the long-term (millennial-scale) airborne volcanic ash and mineral dust Fe flux into the Pacific Ocean by merging the Fe release data with geological flux estimates. These show that the input of volcanic ash into the Pacific Ocean (128–221 × 1015 g/ka) is within the same order of magnitude as the mineral dust input (39–519 × 1015 g/ka) (Mahowald et al., 2005). From the similarity in both Fe release and particle flux follows that the flux of soluble Fe related to the dry deposition of volcanic ash (3–75 × 109 mol/ka) is comparable to that of mineral dust (1–65 × 109 mol/ka). Our study therefore suggests that airborne volcanic ash is an important but hitherto underestimated atmospheric source for the Pacific surface ocean biogeochemical iron cycle.
Published: 2011
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32. Variation in particulate C and N isotope composition following iron fertilization in two successive phytoplankton communities in the Southern Ocean

Author: Richard G. J. Bellerby, Kevin R. Arrigo, Matthew C. Long, Matthew M. Mills, Rüdiger Röttgers, Nicolas Savoye, Gry Mine Berg, Volker Strass, Peter Croot, and Adrian Webb
Subjects: 0106 biological sciences, Polar front, Atmospheric Science, Global and Planetary Change, Biomass (ecology), 010504 meteorology & atmospheric sciences, Chemistry, Stable isotope ratio, 010604 marine biology & hydrobiology, Iron fertilization, Particulates, 01 natural sciences, Substrate (marine biology), Oceanography, Environmental chemistry, Phytoplankton, Environmental Chemistry, 14. Life underwater, Growth rate, 0105 earth and related environmental sciences, General Environmental Science
Abstract: [1] Surface δ15NPON increased 3.92 ± 0.48‰ over the course of 20 days following additions of iron (Fe) to an eddy in close proximity to the Antarctic Polar Front in the Atlantic sector of the Southern Ocean. The change in δ15NPON was associated with an increase in the >20 μm size fraction, leading to a maximal difference of 6.23‰ between the >20 μm and
Published: 2011
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33. Maritime Aerosol Network as a component of AERONET - First results and comparison with global aerosol models and satellite retrievals

Author: Jan Griesfeller, Peter Croot, Giuseppe Zibordi, Norman T. O'Neill, Michael Schulz, Norman B. Nelson, Thomas Diehl, Richard G. Kleidman, Jianglong Zhang, Brent N. Holben, E. Joseph, David M. Giles, Nicholas R. Nalli, Barbara J. Gaitley, Simon Bélanger, Rémi Losno, Alexander Smirnov, J. S. Reid, Pierre Larouche, Carlos M. Duarte, Colette L. Heald, Sergey M. Sakerin, Q. Tan, Andreas Macke, Mian Chin, K. Lapina, Lorraine A. Remer, Gennadi Milinevsky, Mike Harvey, E. Horne, D. S. Covert, Sergey Gulev, Ilya Slutsker, Ralph A. Kahn, Timothy J Smyth, S. Kinne, Yann Courcoux, Kenneth J. Voss, Tymon Zielinski, Jean Sciare, Vladimir F. Radionov, Thomas F. Eck, Patricia K. Quinn, K. Krishna Moorthy, Joaquim I. Goes, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Chimie Atmosphérique Expérimentale (CAE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Meteorology, 010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, 02 engineering and technology, 010502 geochemistry & geophysics, Pacific ocean, 01 natural sciences, 14. Life underwater, lcsh:TA170-171, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Data collection, Atmospheric models, lcsh:TA715-787, lcsh:Earthwork. Foundations, The arctic, Aerosol, AERONET, lcsh:Environmental engineering, Indian ocean, Climatology, Environmental science, Satellite
Abstract: The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. Over 80 cruises were completed through early 2010 with deployments continuing. Measurements areas included various parts of the Atlantic Ocean, the Northern and Southern Pacific Ocean, the South Indian Ocean, the Southern Ocean, the Arctic Ocean and inland seas. MAN deploys Microtops hand-held sunphotometers and utilizes a calibration procedure and data processing traceable to AERONET. Data collection included areas that previously had no aerosol optical depth (AOD) coverage at all, particularly vast areas of the Southern Ocean. The MAN data archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we present results of AOD measurements over the oceans, and make a comparison with satellite AOD retrievals and model simulations. © Author(s) 2011.
Published: 2011
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34. Kinetics of superoxide reactions with dissolved organic matter in tropical Atlantic surface waters near Cape Verde (TENATSO)

Author: Peter Croot and Maija Heller
Subjects: Atmospheric Science, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Soil Science, 010501 environmental sciences, Aquatic Science, Tropical Atlantic, Oceanography, 01 natural sciences, Cape verde, Geochemistry and Petrology, Phytoplankton, Dissolved organic carbon, Earth and Planetary Sciences (miscellaneous), Organic matter, 14. Life underwater, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, chemistry.chemical_classification, Ecology, Paleontology, Forestry, Colored dissolved organic matter, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Environmental chemistry, Seawater
Abstract: The decay kinetics of superoxide (O2−) reacting with organic matter was examined in oligotrophic waters at, and nearby, the TENATSO ocean observatory adjacent to the Cape Verde archipelago. Superoxide is the short-lived primary photochemical product of colored dissolved organic matter (CDOM) photolysis and also reacts with CDOM or trace metals (Cu, Fe) to form H2O2. In the present work we focused our investigations on reactions between CDOM and superoxide. O2− decay kinetics experiments were performed by adding KO2 to diethylenetriaminepentaacetic acid (DTPA) amended seawater and utilizing an established chemiluminescence technique for the detection of O2− at nM levels. In Cape Verdean waters we found a significant reactivity of superoxide with CDOM with maximal rates adjacent to the chlorophyll maximum, presumably from production of new CDOM from bacteria/phytoplankton. This work highlights a poorly understood process which impacts on the biogeochemical cycling of CDOM and trace metals in the open ocean.
Published: 2010
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35. Oceanic distribution of inorganic germanium relative to silicon: Germanium discrimination by diatoms

Author: Jill N. Sutton, Michael J. Ellwood, Peter Croot, and William A. Maher
Subjects: Atmospheric Science, Global and Planetary Change, Materials science, 010504 meteorology & atmospheric sciences, Silicon, Analytical chemistry, Mineralogy, chemistry.chemical_element, Germanium, Fractionation, 010502 geochemistry & geophysics, 01 natural sciences, Silicon-germanium, Partition coefficient, chemistry.chemical_compound, chemistry, 13. Climate action, Phase (matter), Environmental Chemistry, Seawater, 14. Life underwater, Surface water, 0105 earth and related environmental sciences, General Environmental Science
Abstract: Seventeen inorganic germanium and silicon concentration profiles collected from the Atlantic, southwest Pacific, and Southern oceans are presented. A plot of germanium concentration versus silicon concentration produced a near-linear line with a slope of 0.760 × 10−6 (±0.004) and an intercept of 1.27 (±0.24) pmol L−1 (r2 = 0.993, p < 0.001). When the germanium-to-silicon ratios (Ge/Si) were plotted versus depth and/or silicon concentrations, higher values are observed in surface waters (low in silicon) and decreased with depth (high in silicon). Germanium-to-silicon ratios in diatoms (0.608–1.03 × 10−6) and coupled seawater samples (0.471–7.46 × 10−6) collected from the Southern Ocean are also presented and show clear evidence for Ge/Si fractionation between the water and opal phases. Using a 10 box model (based on PANDORA), Ge/Si fractionation was modeled using three assumptions: (1) no fractionation, (2) fractionation using a constant distribution coefficient (KD) between the water and solid phase, and (3) fractionation simulated using Michaelis-Menten uptake kinetics for germanium and silicon via the silicon uptake system. Model runs indicated that only Ge/Si fractionation based on differences in the Michaelis-Menten uptake kinetics for germanium and silicon can adequately describe the data. The model output using this fractionation process produced a near linear line with a slope of 0.76 × 10−6 and an intercept of 0.92 (±0.28) pmol L−1, thus reflecting the oceanic data set. This result indicates that Ge/Si fractionation in the global ocean occurs as a result of subtle differences in the uptake of germanium and silicon via diatoms in surface waters.
Published: 2010
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36. Application of a Superoxide (O2-) thermal source (SOTS-1) for the determination and calibration of O2- fluxes in seawater

Author: Maija Heller and Peter Croot
Subjects: Inorganic chemistry, 010501 environmental sciences, Benzoates, 01 natural sciences, Biochemistry, Redox, Analytical Chemistry, 03 medical and health sciences, chemistry.chemical_compound, Superoxides, Dissolved organic carbon, Environmental Chemistry, Seawater, 14. Life underwater, Nitrites, Spectroscopy, 030304 developmental biology, 0105 earth and related environmental sciences, chemistry.chemical_classification, 0303 health sciences, Reactive oxygen species, Superoxide, Thermal decomposition, Imidazoles, Temperature, Cytochromes c, Photochemical Processes, Kinetics, chemistry, Hyponitrite, 13. Climate action, Pyrazines, Reagent, Environmental chemistry, Calibration, Luminescent Measurements, Oxidation-Reduction
Abstract: Superoxide (O(2)(-)) is an important short lived transient reactive oxygen species (ROS) in seawater. The main source of O(2)(-) in the ocean is believed to be through photochemical reactions though biological processes may also be important. Sink terms for O(2)(-) include redox reactions with bioactive trace metals, including Cu and Fe, and to a lesser extent dissolved organic matter (DOM). Information on the source fluxes, sinks and concentration of superoxide in the open ocean are crucial to improving our understanding of the biogeochemical cycling of redox active species. As O(2)(-) is a highly reactive transient species present at low concentrations it is not a trivial task to make accurate and precise measurements in seawater. In this study we developed the appropriate numerical analysis tools and investigated a number of superoxide sources and methods for the purposes of calibrating O(2)(-) concentrations and/or fluxes specifically in seawater. We found the superoxide thermal source bis(4-carboxybenzyl)hyponitrite (SOTS)-1 easy to employ as a reliable source of O(2)(-) which could be successfully applied in seawater. The thermal decomposition of SOTS-1 in seawater was evaluated over a range of seawater temperatures using both a flux based detection scheme developed using two spectrophotometric methods: (i) 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and (ii) ferricytochrome c (FC), or a concentration based detection scheme using a chemiluminescence flow injection method based on the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)3-7-dihydroimidazol[1,2-alpha]pyrazin-3-one (MCLA) as reagent. Our results suggest SOTS-1 is the best available O(2)(-) source for determining concentrations and fluxes, all detection systems tested have their pros and cons and the choice of which to use depends more on the duration and type of experiment that is required.
Published: 2010

37. The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: a review

Author: Heiner Dietze, Claudia Teschner, Linn Hoffmann, Svend Duggen, Nazli Olgun, Pierre Delmelle, Peter Croot, University of York, York - Environment dept, and UCL - SST/ELI/ELIE - Environmental Sciences
Subjects: Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Earth science, lcsh:Life, Volcanism, 010502 geochemistry & geophysics, 01 natural sciences, Iron cycle, lcsh:QH540-549.5, Phytoplankton, QD, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, BS, geography, geography.geographical_feature_category, lcsh:QE1-996.5, Géochimie, lcsh:Geology, lcsh:QH501-531, Oceanography, Deposition (aerosol physics), Volcano, 13. Climate action, Aeolian processes, lcsh:Ecology, Volcanic ash, Geology
Abstract: Iron is a key micronutrient for phytoplankton growth in the surface ocean. Yet the significance of volcanism for the marine biogeochemical iron-cycle is poorly constrained. Recent studies, however, suggest that offshore deposition of airborne ash from volcanic eruptions is a way to inject significant amounts of bio-available iron into the surface ocean. Volcanic ash may be transported up to several tens of kilometers high into the atmosphere during large-scale eruptions and fine ash may stay aloft for days to weeks, thereby reaching even the remotest and most iron-starved oceanic regions. Scientific ocean drilling demonstrates that volcanic ash layers and dispersed ash particles are frequently found in marine sediments and that therefore volcanic ash deposition and iron-injection into the oceans took place throughout much of the Earth's history. Natural evidence and the data now available from geochemical and biological experiments and satellite techniques suggest that volcanic ash is a so far underestimated source for iron in the surface ocean, possibly of similar importance as aeolian dust. Here we summarise the development of and the knowledge in this fairly young research field. The paper covers a wide range of chemical and biological issues and we make recommendations for future directions in these areas. The review paper may thus be helpful to improve our understanding of the role of volcanic ash for the marine biogeochemical iron-cycle, marine primary productivity and the ocean-atmosphere exchange of CO2 and other gases relevant for climate in the Earth's history.
Published: 2010

38. Maritime Aerosol Network as a component of Aerosol Robotic Network

Author: Jean Sciare, Andreas Macke, K. Krishna Moorthy, Patricia K. Quinn, E. J. Robertson, Pierre Larouche, Sergey M. Sakerin, Tymon Zielinski, David M. Giles, Norman B. Nelson, Joachim I. Goes, Giuseppe Zibordi, Mike Harvey, S. Kinne, Alexander Smirnov, Philippe Goloub, Stuart Piketh, Frédéric Jourdin, R. Matarrese, Thomas F. Eck, Brent N. Holben, Peter Croot, Ilya Slutsker, Vladimir F. Radionov, Andrey Proshutinsky, Charles R. McClain, Timothy J Smyth, Department of Oceanography, Faculty of Science, Chimie Atmosphérique Expérimentale (CAE), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Service Hydrographique et Océanographique de la Marine (SHOM), Ministère de la Défense, and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, Ships of opportunity, Soil Science, Network, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, Aerosol optical depth, Article, law.invention, Maritime aerosol, Geochemistry and Petrology, law, Component (UML), Earth and Planetary Sciences (miscellaneous), Calibration, 14. Life underwater, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Web site, Remote sensing, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Data processing, Ecology, Paleontology, Forestry, Photometer, Aerosol, AERONET, Geophysics, Space and Planetary Science, Environmental science
Abstract: International audience; The paper presents the current status of the Maritime Aerosol Network (MAN), which has been developed as a component of the Aerosol Robotic Network (AERONET). MAN deploys Microtops handheld Sun photometers and utilizes the calibration procedure and data processing (Version 2) traceable to AERONET. A web site dedicated to the MAN activity is described. A brief historical perspective is given to aerosol optical depth (AOD) measurements over the oceans. A short summary of the existing data, collected on board ships of opportunity during the NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project is presented. Globally averaged oceanic aerosol optical depth (derived from island‐based AERONET measurements) at 500 nm is ∼0.11 and Angstrom parameter (computed within spectral range 440–870 nm) is calculated to be ∼0.6. First results from the cruises contributing to the Maritime Aerosol Network are shown. MAN ship‐based aerosol optical depth compares well to simultaneous island and near‐coastal AERONET site AOD.
Published: 2009
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39. Controls on seawater Fe(III) solubility in the Mauritanian upwelling zone

Author: Christian Schlosser and Peter Croot
Subjects: 0106 biological sciences, chemistry.chemical_classification, Pycnocline, Remineralisation, 010504 meteorology & atmospheric sciences, Mixed layer, 010604 marine biology & hydrobiology, Mineralogy, Phosphate, 01 natural sciences, chemistry.chemical_compound, Geophysics, chemistry, 13. Climate action, Environmental chemistry, General Earth and Planetary Sciences, Upwelling, Organic matter, Seawater, 14. Life underwater, Solubility, Geology, 0105 earth and related environmental sciences
Abstract: Iron solubility measurements in the Mauritanian upwelling and the adjacent Open Ocean of the Tropical Atlantic show for all stations lower values in the surface mixed layer than at depth below the pycnocline. We attribute this distribution to a combination of loss terms, chiefly photo-oxidation of organic ligands in the surface, and supply terms, predominantly from the release of ligands from the decomposition of organic matter. Significant correlations with pH, oxygen and phosphate for all samples below the surface mixed layer indicate that biogenic remineralisation of organic matter results in the release of iron binding ligands into the dissolved phase. The comparison of the cFe(S)/PO(4)(3-) ratio with other published data from intermediate and deep waters in the Pacific suggests an enhanced release of iron chelators in the more productive Mauritanian upwelling zone. Citation: Schlosser, C., and P.L. Croot (2009), Controls on seawater Fe(III) solubility in the Mauritanian upwelling zone
Published: 2009

40. Regeneration of Fe(II) during EIFeX and SOFeX

Author: M. Van Ardelan, Peter Croot, Peter Streu, Christian Schlosser, Katrin Bluhm, Eike Breitbarth, and Russell D. Frew
Subjects: 010504 meteorology & atmospheric sciences, Chemistry, media_common.quotation_subject, 010501 environmental sciences, 01 natural sciences, Speciation, Geophysics, Oceanography, 13. Climate action, Environmental chemistry, General Earth and Planetary Sciences, 14. Life underwater, Cycling, Surface water, Diel vertical migration, Primary productivity, 0105 earth and related environmental sciences, media_common
Abstract: Investigations into Fe(II) cycling during two Southern Ocean mesoscale iron enrichment experiments, SOFeX and EIFeX, clearly show the importance of Fe(II) to iron speciation during these experiments. In both cases the added Fe(II) persisted significantly longer than its expected oxidation time indicating a significant Fe reduction process at work. During EIFeX diel studies showed a strong photochemically induced cycle in Fe(II) production in sunlit surface waters. Our results suggest that the photochemical cycling of iron may also be important in unfertilized waters of the Southern Ocean.
Published: 2008
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41. Identifying the processes controlling the distribution of H2O2 in surface waters along a meridional transect in the eastern Atlantic

Author: Sebastian Steigenberger and Peter Croot
Subjects: Hydrology, 010504 meteorology & atmospheric sciences, Zonal and meridional, 010501 environmental sciences, Plankton, Atmospheric sciences, 01 natural sciences, Colored dissolved organic matter, Geophysics, 13. Climate action, TRACER, Phytoplankton, General Earth and Planetary Sciences, Environmental science, 14. Life underwater, Precipitation, Transect, Surface water, 0105 earth and related environmental sciences
Abstract: Hydrogen peroxide (H2O2) is an important oxidant for many bio-relevant trace metals and organic compounds and has potential as a tracer for mixing in near surface waters. In this study we combine H2O2 and bio-optical measurements with satellite data for a meridional transect from 46 degrees N to 26 degrees S in the eastern Atlantic in order to determine the key processes affecting its distribution. Surface H2O2 ranged from 21 - 123 nmol L-1, with maximum inventories (0 - 200 m) of 5.5 - 5.9 mmol m(-2) found at 30 degrees N and 25 degrees S. Analyses showed a strong positive correlation of surface H2O2 with daily irradiances and recent precipitation, though poor correlations with CDOM suggest sunlight is the limiting reactant for H2O2 formation. Vertical distributions of H2O2 were controlled by a combination of mixing processes and phytoplankton activity. The present study highlights processes controlling global H2O2 distributions and points towards the development of parameterization schemes for prediction via satellite data. Citation: Steigenberger, S., and P. L. Croot (2008), Identifying the processes controlling the distribution of H2O2 in surface waters along a meridional transect in the eastern Atlantic.
Published: 2008

42. Influence of temperature and salinity on the trace element incorporation into statoliths of the common cuttlefish ( Sepia officinalis )

Author: Karsten Zumholz, Uwe Piatkowski, Æ Thor H. Hansteen, and Peter Croot
Subjects: 0106 biological sciences, Cuttlefish, Ecology, biology, 010604 marine biology & hydrobiology, Sepiidae, Temperature salinity diagrams, Trace element, Mineralogy, Aquatic Science, biology.organism_classification, 010603 evolutionary biology, 01 natural sciences, Cephalopod, Salinity, ddc:550, 14. Life underwater, Sepia, Chemical composition, Ecology, Evolution, Behavior and Systematics
Abstract: The use of statolith chemistry to trace migration pathways and distinguish populations of cephalopods is based on the assumption that the elemental composition of statoliths is influenced by physicochemical properties of the ambient environment. However, such influences have not been investigated experimentally up until now. This study presents the first microchemical analyses of cephalopod statoliths obtained from laboratory experiments under different controlled temperature and salinity conditions. Our results show that statolith chemical composition is strongly related to both salinity and temperature in ambient waters. The Ba/Ca ratio is negatively related to temperature and shows no relation to salinity. The I/Ca ratio is positively related to temperature and negatively to salinity. No Sr/Ca relation was found to either salinity or temperature, suggesting that the well-established proxy strontium is not as useful in cephalopod statoliths as in other biomineralized aragonites. Microanalysis of trace elements, however, shows an enormous potential for field studies on distribution, migration and stock separation of cephalopods. Furthermore, Synchrotron X-ray Fluorescence Analysis is introduced as a promising novel method for statolith analysis, providing a spatial resolution of typically 10–15 μm combined with detection limits down to 0.5 ppm.
Published: 2007
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43. FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6tracer experiment in unperturbed low iron waters

Author: Sylvia G. Sander, Murray J. Smith, Robert Michael L. McKay, Michael J. Ellwood, David A. Hutchins, Mark G. Hadfield, Edward R. Abraham, Peter Croot, Cécile E. Mioni, Philip W. Boyd, Julie A. Hall, Steven W. Wilhelm, Julie L. Higgins, Russell D. Frew, Keith A. Hunter, Cliff S. Law, Sergio A. Sañudo-Wilhelmy, Peter Hill, Clinton E. Hare, Robert F. Strzepek, Stuart Pickmere, Sara M. Handy, Maria T. Maldonado, Antonio Tovar-Sánchez, Karl A. Safi, Matthew H. Pinkerton, Karine Leblanc, and M Oliver
Subjects: 0106 biological sciences, Atmospheric Science, Global and Planetary Change, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, Mixed layer, 010604 marine biology & hydrobiology, Biogeochemistry, Particulates, Atmospheric sciences, 01 natural sciences, High-Nutrient, low-chlorophyll, Aerosol, chemistry.chemical_compound, Oceanography, Nitrate, chemistry, Iron cycle, 13. Climate action, Environmental Chemistry, 14. Life underwater, Geology, 0105 earth and related environmental sciences, General Environmental Science
Abstract: [1] An improved knowledge of iron biogeochemistry is needed to better understand key controls on the functioning of high-nitrate low-chlorophyll (HNLC) oceanic regions. Iron budgets for HNLC waters have been constructed using data from disparate sources ranging from laboratory algal cultures to ocean physics. In summer 2003 we conducted FeCycle, a 10-day mesoscale tracer release in HNLC waters SE of New Zealand, and measured concurrently all sources (with the exception of aerosol deposition) to, sinks of iron from, and rates of iron recycling within, the surface mixed layer. A pelagic iron budget (timescale of days) indicated that oceanic supply terms (lateral advection and vertical diffusion) were relatively small compared to the main sink (downward particulate export). Remote sensing and terrestrial monitoring reveal 13 dust or wildfire events in Australia, prior to and during FeCycle, one of which may have deposited iron at the study location. However, iron deposition rates cannot be derived from such observations, illustrating the difficulties in closing iron budgets without quantification of episodic atmospheric supply. Despite the threefold uncertainties reported for rates of aerosol deposition (Duce et al., 1991), published atmospheric iron supply for the New Zealand region is ∼50-fold (i.e., 7- to 150-fold) greater than the oceanic iron supply measured in our budget, and thus was comparable (i.e., a third to threefold) to our estimates of downward export of particulate iron. During FeCycle, the fluxes due to short term (hours) biological iron uptake and regeneration were indicative of rapid recycling and were tenfold greater than for new iron (i.e. estimated atmospheric and measured oceanic supply), giving an “fe” ratio (uptake of new iron/uptake of new + regenerated iron) of 0.17 (i.e., a range of 0.06 to 0.51 due to uncertainties on aerosol iron supply), and an “Fe” ratio (biogenic Fe export/uptake of new + regenerated iron) of 0.09 (i.e., 0.03 to 0.24).
Published: 2005
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44. Organic complexation of cobalt across the Antarctic Polar Front in the Southern Ocean

Author: Peter Croot, Marcel J.W. Veldhuis, Michael J. Ellwood, Jeroen de Jong, Marie Boye, Hein J W de Baar, Gerhard Kattner, Constant M.G. van den Berg, and Ocean Ecosystems
Subjects: 0106 biological sciences, Polar front, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Ecology, 010604 marine biology & hydrobiology, fungi, chemistry.chemical_element, Biogeochemistry, Estuary, Aquatic Science, Biology, Plankton, Oceanography, 01 natural sciences, Water column, chemistry, Productivity (ecology), Phytoplankton, 14. Life underwater, Cobalt, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract: There is compelling evidence to demonstrate that phytoplankton in major regions of the world’s oceans are limited by the availability of certain trace elements, notably iron. Cobalt concentrations in open-ocean waters generally range between 10 and 120 pmol L−1 but such levels were not thought to limit phytoplankton growth. Herein, we present data for total dissolved cobalt and cobalt-complexing ligands for two stations located south (station 200) and north (station 204) of the Antarctic Polar Front (APF) along 20°E in the South Atlantic sector of the Southern Ocean. Results indicate that there was little difference between total cobalt concentrations south and north of the APF, whereas ligand concentrations were significantly higher (15–20 pmol L−1) for the upper water column south of the APF. Productivity in these waters was low at the time of this study; however, numbers of large eukaryotic algal species were higher south of the APF, while north of the APF small eukaryotic and prokaryotic species dominated. The higher ligand concentrations measured at the southern station are probably related to higher algal numbers at this site. Because ligand concentrations were higher, inorganic cobalt concentrations (Co′) south of the APF are extremely low, at femtomolar levels, whereas north of the APF calculated Co′ are much higher at picomolar levels where ligand concentrations were lower.
Published: 2005

45. Synthesis of iron fertilization experiments: From the iron age in the age of enlightenment

Author: Hiroaki Saito, Marie Boye, Hein J W de Baar, Philip W. Boyd, Frank J. Millero, Yann Bozec, Mark A. Brzezinski, Jun Nishioka, Yukihiro Nojiri, Adrian Marchetti, Peter Croot, Michael R. Landry, Anya M. Waite, Kenneth H. Coale, Frank Gervais, Cliff S. Law, Richard T. Barber, Marcel J.W. Veldhuis, Philipp Assmy, Shingenobu Takeda, Paul Harrison, Maxim Y. Gorbunov, Micha J. A. Rijkenberg, Ken O. Buesseler, Klaas R. Timmermans, Tim van Oijen, Ulf Riebesell, Chi Shing Wong, William T. Hiscock, Atsushi Tsuda, Maurice Levasseur, Patrick Laan, Christiane Lancelot, and Dorothee C. E. Bakker
Subjects: SUB-ARCTIC PACIFIC, 0106 biological sciences, OPEN SOUTHERN-OCEAN, Atmospheric Science, 010504 meteorology & atmospheric sciences, Mixed layer, Iron fertilization, Soil Science, Aquatic Science, Oceanography, 01 natural sciences, PHYTOPLANKTON GROWTH, ENRICHMENT EXPERIMENT, EXPERIMENT SOFEX, CARBON-DIOXIDE, chemistry.chemical_compound, Geochemistry and Petrology, SULFUR-HEXAFLUORIDE, Phytoplankton, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, EQUATORIAL PACIFIC-OCEAN, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Ecology, biology, 010604 marine biology & hydrobiology, Paleontology, Forestry, AUSTRAL SPRING 1992, biology.organism_classification, High-Nutrient, low-chlorophyll, Dilution, Geophysics, Diatom, chemistry, Space and Planetary Science, Environmental chemistry, Carbon dioxide, RELEASE EXPERIMENT SOIREE, Seawater
Abstract: [1] Comparison of eight iron experiments shows that maximum Chl a, the maximum DIC removal, and the overall DIC/ Fe efficiency all scale inversely with depth of the wind mixed layer (WML) defining the light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, and grazing play additional roles. The Southern Ocean experiments were most influenced by very deep WMLs. In contrast, light conditions were most favorable during SEEDS and SERIES as well as during IronEx-2. The two extreme experiments, EisenEx and SEEDS, can be linked via EisenEx bottle incubations with shallower simulated WML depth. Large diatoms always benefit the most from Fe addition, where a remarkably small group of thriving diatom species is dominated by universal response of Pseudo-nitzschia spp. Significant response of these moderate ( 10 - 30 µm), medium ( 30 - 60 µm), and large (> 60 µm) diatoms is consistent with growth physiology determined for single species in natural seawater. The minimum level of "dissolved'' Fe ( filtrate < 0.2 µm) maintained during an experiment determines the dominant diatom size class. However, this is further complicated by continuous transfer of original truly dissolved reduced Fe(II) into the colloidal pool, which may constitute some 75% of the "dissolved'' pool. Depth integration of carbon inventory changes partly compensates the adverse effects of a deep WML due to its greater integration depths, decreasing the differences in responses between the eight experiments. About half of depth-integrated overall primary productivity is reflected in a decrease of DIC. The overall C/Fe efficiency of DIC uptake is DIC/Fe similar to 5600 for all eight experiments. The increase of particulate organic carbon is about a quarter of the primary production, suggesting food web losses for the other three quarters. Replenishment of DIC by air/sea exchange tends to be a minor few percent of primary CO2 fixation but will continue well after observations have stopped. Export of carbon into deeper waters is difficult to assess and is until now firmly proven and quite modest in only two experiments.
Published: 2005

46. Patterns of nitrogen fixation along 10°N in the tropical Atlantic

Author: Matthew M. Mills, Karin Lochte, Maren Voss, Ilka Peeken, and Peter Croot
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Mixed layer, Amazon rainforest, 010604 marine biology & hydrobiology, River plume, New production, Tropical Atlantic, 01 natural sciences, chemistry.chemical_compound, Geophysics, Oceanography, chemistry, 13. Climate action, Carbon dioxide, Nitrogen fixation, General Earth and Planetary Sciences, Environmental science, 14. Life underwater, Transect, 0105 earth and related environmental sciences
Abstract: [1] Nitrogen fixation supports new production in the oligotrophic oceans and removes dinitrogen and carbon dioxide from mixed layer waters. N-fixation rates have been estimated in various ways but measurements are still too rare and factors limiting N-fixation are not yet fully understood. Here we present data from a transect along 10°N through the tropical Atlantic on the Meteor Cruise 55 where N-fixation rates between 3.7 and 255 μmol N*m−2*d−1 were recorded. The highest rates occurred off Africa in the eastern tropical North Atlantic (ETNA), and in the Amazon River plume in the West and contributed to 1–12.2% of the N-demand of primary production. N-fixation rates correlated with dissolved Fe concentrations, which were 20–280 times greater than the estimated demand. High atmospheric Fe inputs combined with the shallow nutricline make the ETNA a favourable environment for N-fixers.
Published: 2004
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47. Shipboard analytical intercomparison of dissolved iron in surface waters along a north–south transect of the Atlantic Ocean

Author: Paul J. Worsfold, Patrick Laan, Stéphane Blain, Andrew R. Bowie, Peter Croot, Géraldine Sarthou, Hein J W de Baar, Marie Boye, Eric P. Achterberg, Plymouth University, Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Royal Netherlands Institute for Sea Research (NIOZ), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Ocean Ecosystems
Subjects: 010504 meteorology & atmospheric sciences, Mineralogy, Analytical intercomparison, Oceanography, FE, 01 natural sciences, CHELATING RESIN, TRACE-METALS, Cathodic stripping voltammetry, Calibration, Environmental Chemistry, PACIFIC-OCEAN, Seawater, 14. Life underwater, Voltammetry, Atlantic Ocean, COLLOIDAL IRON, 0105 earth and related environmental sciences, Water Science and Technology, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Chemistry, PHYTOPLANKTON BLOOM, 010401 analytical chemistry, Extraction (chemistry), General Chemistry, Dissolved iron, Chemical oceanography, 0104 chemical sciences, FLOW-INJECTION, Certified reference materials, Environmental chemistry, ORGANIC COMPLEXATION, Surface water, CHEMILUMINESCENCE DETECTION
Abstract: A shipboard analytical intercomparison of dissolved (
Published: 2003
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48. Seasonal cycle of copper speciation in Gullmar Fjord, Sweden

Author: Peter Croot
Subjects: 0106 biological sciences, Biogeochemical cycle, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, media_common.quotation_subject, Fjord, Aquatic Science, Spring bloom, Oceanography, 01 natural sciences, 6. Clean water, Speciation, Water column, 13. Climate action, Photic zone, 14. Life underwater, Water quality, Surface water, Geology, 0105 earth and related environmental sciences, media_common
Abstract: The chemical speciation of dissolved Cu was investigated by voltammetric methods in Gullmar Fjord, Sweden, over the course of a year from September 1996 until August 1997. Sampling was carried out on a roughly monthly basis, with an intensive survey carried out in May 1997. Surface water temperatures ranged from 2 1t o 22 8C, whereas bottom waters in the fjord were approximately 68C throughout. Macronutrient concentrations in the fjord during the period of the survey were investigated independently by the Goteborgs och Bohus la Vattenvardsfor- bund (Water Quality Association of Goteborg and Bohus). Surface phosphate concentrations were highest in early spring with low levels (,0.1 mmol kg 21 ) over the late spring and summer. Nitrate and silicate showed a similar pattern to phosphate with the exception of high concentrations encountered in surface waters when low salinity plumes caused by runoff were encountered. A period of calm, sunny weather in January 1997 saw the initiation of the spring bloom some 2 months earlier than usual. Dissolved Cu speciation was dominated by organic complexation (over 99.8%) throughout this study. Strong Cu binding ligands (log K. 12.5) were not detected during the winter or early spring and could be related to the temperature-related seasonal appearance of the cyanobacterium Syne- choccocus in these waters. The appearance of the strong Cu ligands led to a decrease in the concentration of free copper, resulting in a seasonal cycle for free copper in the fjord. This is the first study to examine Cu speciation over an annual cycle in a coastal environment. The distribution and chemical speciation of trace metals in the upper water column plays an important role in the community structure and physiology of phytoplankton (Sun- da 1994). Speciation is important because only particular chemical forms of a given metal may be biologically avail- able. In the upper water column, the speciation of many biologically active trace metals is controlled by complexa- tion with strong organic ligands (Bruland et al. 1991). In general, when a metal is complexed by an organic ligand, the metal becomes less biologically available because the free metal ions are the most labile to the biota (Sunda 1994; Campbell 1995). Organic complexation also can play an im- portant role in the biogeochemical cycling of these elements in the upper ocean. For most elements, organic ligand con- centrations are highest in the euphotic zone (Bruland et al. 1991), which suggests a recent biological source.

49. Iron biogeochemistry across marine systems - progress from the past decade

Author: Eric P. Achterberg, Tim Jickells, David A. Hutchins, Svend Duggen, Ying Ye, Maeve C. Lohan, Eva Bucciarelli, Peter Croot, Géraldine Sarthou, Johan Ingri, Fanny Chever, David R. Turner, Keith A. Hunter, Christel S. Hassler, J. M. Trapp, Eike Breitbarth, Martin Hassellöv, Murat Van Ardelan, Véronique Schoemann, Maria C. Nielsdóttir, Linn Hoffmann, Alex R. Baker, Martha Gledhill, Department of Chemistry, University of Otago, University of Otago [Dunedin, Nouvelle-Zélande], University of Gothenburg (GU), National Oceanography Centre [Southampton] (NOC), University of Southampton, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), School of Environmental Sciences [Norwich], University of East Anglia [Norwich] (UEA), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Centre for Australian Weather and Climate Research (CAWCR), Department of Biological Sciences [Los Angeles], University of Southern California (USC), Luleå University of Technology (LUT), National Oceanography Center, Université libre de Bruxelles (ULB), Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami [Coral Gables], Alfred Wegener Institute for Polar and Marine Research (AWI), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Research areas, Earth science, Iron fertilization, lcsh:Life, Climate change, phytoplankton community structure, 01 natural sciences, Colloidal iron, cathodic stripping voltammetry, eastern north atlantic, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, lcsh:QH540-549.5, Meteorology & Atmospheric Sciences, Environmental impact assessment, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Earth-Surface Processes, southern ocean, export experiment crozex, 010604 marine biology & hydrobiology, Global warming, lcsh:QE1-996.5, Biogeochemistry, Ocean acidification, continuous culture system, field flow fractionation, dissolved organic carbon, lcsh:Geology, lcsh:QH501-531, Oceanography, 13. Climate action, Environmental science, lcsh:Ecology, sub-arctic pacific, light co-limitation
Abstract: Based on an international workshop (Gothenburg, 14–16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas.
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