Articles | Volume 12, issue 6
https://doi.org/10.5194/bg-12-1713-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/bg-12-1713-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
17 Mar 2015
Research article |
| 17 Mar 2015
Early spring mesopelagic carbon remineralization and transfer efficiency in the naturally iron-fertilized Kerguelen area
S. H. M. Jacquet
CORRESPONDING AUTHOR
Aix Marseille Université, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288 Marseille, France
F. Dehairs
Vrije Universiteit Brussel, Analytical, Environmental & Geo-Chemistry and Earth System Sciences, Brussels, Belgium
D. Lefèvre
Aix Marseille Université, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288 Marseille, France
A. J. Cavagna
Vrije Universiteit Brussel, Analytical, Environmental & Geo-Chemistry and Earth System Sciences, Brussels, Belgium
F. Planchon
Laboratoire des Sciences de l'Environnement Marin (LEMAR), Université de Brest, CNRS, IRD, UMR6539, IUEM; Technopôle Brest Iroise, Place Nicolas Copernic, 29280 Plouzané, France
U. Christaki
INSU-CNRS, UMR8187 LOG, Laboratoire d'Océanologie et de Géosciences, Université du Littoral Côte d'Opale, ULCO, 32 avenue Foch, 62930 Wimereux, France
L. Monin
Earth Sciences Department, Royal Museum for Central Africa, Leuvensesteenweg 13, Tervuren, 3080, Belgium
L. André
Earth Sciences Department, Royal Museum for Central Africa, Leuvensesteenweg 13, Tervuren, 3080, Belgium
I. Closset
Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, 4 place Jussieu, 75005 Paris, France
D. Cardinal
Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, 4 place Jussieu, 75005 Paris, France
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Emilie Le Roy, Virginie Sanial, Matthew A. Charette, Pieter van Beek, François Lacan, Stéphanie H. M. Jacquet, Paul B. Henderson, Marc Souhaut, Maribel I. García-Ibáñez, Catherine Jeandel, Fiz F. Pérez, and Géraldine Sarthou
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Primary production, NO3- and NH4+ uptake, and nitrification rates were measured during the KEOPS 2 cruise (austral spring 2011) in the Kerguelen Plateau area. Natural iron fertilization stimulated primary production which is much higher in the fertilized areas compared to the HNLC site. We report high rates of nitrification in the mixed layer below the euphotic zone. We conclude that high productivity in deep mixing system stimulates the N cycle by increasing both assimilation and regeneration.
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Iron biogeochemical budgets during the natural ocean fertilisation experiment KEOPS-2 showed that complex circulation and transport pathways were responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. The exchange of iron between dissolved, biogenic and lithogenic pools was highly dynamic, resulting in a decoupling of iron supply and carbon export and controlling the efficiency of fertilization.
F. Planchon, D. Ballas, A.-J. Cavagna, A. R. Bowie, D. Davies, T. Trull, E. C. Laurenceau-Cornec, P. Van Der Merwe, and F. Dehairs
Biogeosciences, 12, 3831–3848, https://doi.org/10.5194/bg-12-3831-2015, https://doi.org/10.5194/bg-12-3831-2015, 2015
F. Dehairs, F. Fripiat, A.-J. Cavagna, T. W. Trull, C. Fernandez, D. Davies, A. Roukaerts, D. Fonseca Batista, F. Planchon, and M. Elskens
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We investigated the nitrate N, O isotopic composition for the Southern Ocean Kerguelen Plateau area, aiming at understanding the N-cycling in this naturally iron fertilized area characterized by large recurrent phytoplankton blooms. The system is characterized by moderate consumption of nitrate over the season while silicic acid, on the contrary, becomes depleted, suggesting significant recycling of N. Mixed layer nitrate isotopic signatures corroborate this.
T. W. Trull, D. M. Davies, F. Dehairs, A.-J. Cavagna, M. Lasbleiz, E. C. Laurenceau-Cornec, F. d'Ovidio, F. Planchon, K. Leblanc, B. Quéguiner, and S. Blain
Biogeosciences, 12, 1029–1056, https://doi.org/10.5194/bg-12-1029-2015, https://doi.org/10.5194/bg-12-1029-2015, 2015
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The KEOPS2 oceanographic study surveyed more than 30 sites downstream from the Kerguelen Islands in the Southern Ocean to examine the degree of variation in phytoplankton community responses to natural iron inputs. Our observations of community structure based on the chemical compositions of six microbial size fractions suggest that early spring trophodynamic and export responses differed between regions with persistently low levels versus punctually high levels of iron fertilisation.
E. C. Laurenceau-Cornec, T. W. Trull, D. M. Davies, S. G. Bray, J. Doran, F. Planchon, F. Carlotti, M.-P. Jouandet, A.-J. Cavagna, A. M. Waite, and S. Blain
Biogeosciences, 12, 1007–1027, https://doi.org/10.5194/bg-12-1007-2015, https://doi.org/10.5194/bg-12-1007-2015, 2015
P. van der Merwe, A. R. Bowie, F. Quéroué, L. Armand, S. Blain, F. Chever, D. Davies, F. Dehairs, F. Planchon, G. Sarthou, A. T. Townsend, and T. W. Trull
Biogeosciences, 12, 739–755, https://doi.org/10.5194/bg-12-739-2015, https://doi.org/10.5194/bg-12-739-2015, 2015
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Trace metal analysis of suspended and settling particles and underlying sediment was undertaken to elucidate the source to sink progression of the particulate trace metal pool near Kerguelen Island (Southern Ocean). Findings indicate that the Kerguelen Plateau is a source of trace metals via resuspended shelf sediments, especially below the mixed layer. However, glacial/fluvial runoff into shallow coastal waters is an important mode of fertilisation to areas downstream of Kerguelen Island.
M. L. González, V. Molina, L. Florez-Leiva, L. Oriol, A. J. Cavagna, F. Dehairs, L. Farias, and C. Fernandez
Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-17151-2014, https://doi.org/10.5194/bgd-11-17151-2014, 2014
Revised manuscript not accepted
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This study shows for first time N2 fixation is occurring in the HNLC area of Southern Ocean and in naturally iron-fertilized waters, at rates exceeding previous reports for high latitudes (up to 20.11 nmol N L-1 d-1). Diazotrophs were identified as heterotrophic bacterioplankton; with an indirect role of dFe in the regulation of this process. Fertilization enhancing regenerated primary production may control N2 fixation via the availability od DOM for heterotrophic bacterioplankton.
I. Closset, M. Lasbleiz, K. Leblanc, B. Quéguiner, A.-J. Cavagna, M. Elskens, J. Navez, and D. Cardinal
Biogeosciences, 11, 5827–5846, https://doi.org/10.5194/bg-11-5827-2014, https://doi.org/10.5194/bg-11-5827-2014, 2014
F. Tamooh, A. V. Borges, F. J. R. Meysman, K. Van Den Meersche, F. Dehairs, R. Merckx, and S. Bouillon
Biogeosciences, 10, 6911–6928, https://doi.org/10.5194/bg-10-6911-2013, https://doi.org/10.5194/bg-10-6911-2013, 2013
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Knowledge of carbon isotope fractionation is important for the assessment of the pathways involved in the degradation of organic matter. Propionate is an important intermediate. In the presence of sulfate, it was degraded by Syntrophobacter species via acetate to CO2. In the absence of sulfate, it was mainly consumed by Smithella and methanogenic archaeal species via butyrate and acetate to CH4. However, stable carbon isotope fractionation during the degradation process was quite small.
Alessandro Zanchetta, Linda M. J. Kooijmans, Steven van Heuven, Andrea Scifo, Hubertus A. Scheeren, Ivan Mammarella, Ute Karstens, Jin Ma, Maarten Krol, and Huilin Chen
Biogeosciences, 20, 3539–3553, https://doi.org/10.5194/bg-20-3539-2023, https://doi.org/10.5194/bg-20-3539-2023, 2023
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Carbonyl sulfide (COS) has been suggested as a tool to estimate carbon dioxide (CO2) uptake by plants during photosynthesis. However, understanding its sources and sinks is critical to preventing biases in this estimate. Combining observations and models, this study proves that regional sources occasionally influence the measurements at the 60 m tall Lutjewad tower (1 m a.s.l.; 53°24′ N, 6°21′ E) in the Netherlands. Moreover, it estimates nighttime COS fluxes to be −3.0 ± 2.6 pmol m−2 s−1.
Joel T. Bostic, David M. Nelson, and Keith N. Eshleman
Biogeosciences, 20, 2485–2498, https://doi.org/10.5194/bg-20-2485-2023, https://doi.org/10.5194/bg-20-2485-2023, 2023
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Land-use changes can affect water quality. We used tracers of pollution sources and water flow paths to show that an urban watershed exports variable sources during storm events relative to a less developed watershed. Our results imply that changing precipitation patterns combined with increasing urbanization may alter sources of pollution in the future.
Robin Havas, Christophe Thomazo, Miguel Iniesto, Didier Jézéquel, David Moreira, Rosaluz Tavera, Jeanne Caumartin, Elodie Muller, Purificación López-García, and Karim Benzerara
Biogeosciences, 20, 2405–2424, https://doi.org/10.5194/bg-20-2405-2023, https://doi.org/10.5194/bg-20-2405-2023, 2023
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Dissolved organic carbon (DOC) is a reservoir of prime importance in the C cycle of both continental and marine systems. It has also been suggested to influence the past Earth climate but is still poorly characterized in ancient-Earth-like environments. In this paper we show how DOC analyses from modern redox-stratified lakes can evidence specific metabolic reactions and environmental factors and how these can help us to interpret the C cycle of specific periods in the Earth's past.
Robin Havas, Christophe Thomazo, Miguel Iniesto, Didier Jézéquel, David Moreira, Rosaluz Tavera, Jeanne Caumartin, Elodie Muller, Purificación López-García, and Karim Benzerara
Biogeosciences, 20, 2347–2367, https://doi.org/10.5194/bg-20-2347-2023, https://doi.org/10.5194/bg-20-2347-2023, 2023
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We describe the C cycle of four modern stratified water bodies from Mexico, a necessary step to better understand the C cycle of primitive-Earth-like environments, which were dominated by these kinds of conditions. We highlight the importance of local external factors on the C cycle of these systems. Notably, they influence the sensitivity of the carbonate record to environmental changes. We also show the strong C-cycle variability among these lakes and their organic C sediment record.
Yifan Ma, Kuanbo Zhou, Weifang Chen, Junhui Chen, Jin-Yu Terence Yang, and Minhan Dai
Biogeosciences, 20, 2013–2030, https://doi.org/10.5194/bg-20-2013-2023, https://doi.org/10.5194/bg-20-2013-2023, 2023
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We distinguished particulate organic carbon (POC) export fluxes out of the nutrient-depleted layer (NDL) and the euphotic zone. The amount of POC export flux at the NDL base suggests that the NDL could be a hotspot of particle export. The substantial POC export flux at the NDL base challenges traditional concepts that the NDL was limited in terms of POC export. The dominant nutrient source for POC export fluxes should be subsurface nutrients, which was determined by 15N isotopic mass balance.
Clémence Paul, Clément Piel, Joana Sauze, Nicolas Pasquier, Frédéric Prié, Sébastien Devidal, Roxanne Jacob, Arnaud Dapoigny, Olivier Jossoud, Alexandru Milcu, and Amaëlle Landais
Biogeosciences, 20, 1047–1062, https://doi.org/10.5194/bg-20-1047-2023, https://doi.org/10.5194/bg-20-1047-2023, 2023
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To improve the interpretation of the δ18Oatm and Δ17O of O2 in air bubbles in ice cores, we need to better quantify the oxygen fractionation coefficients associated with biological processes. We performed a simplified analogue of the terrestrial biosphere in a closed chamber. We found a respiration fractionation in agreement with the previous estimates at the microorganism scale, and a terrestrial photosynthetic fractionation was found. This has an impact on the estimation of the Dole effect.
Adam Francis, Raja S. Ganeshram, Robyn E. Tuerena, Robert G. M. Spencer, Robert M. Holmes, Jennifer A. Rogers, and Claire Mahaffey
Biogeosciences, 20, 365–382, https://doi.org/10.5194/bg-20-365-2023, https://doi.org/10.5194/bg-20-365-2023, 2023
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Climate change is causing extensive permafrost degradation and nutrient releases into rivers with great ecological impacts on the Arctic Ocean. We focused on nitrogen (N) release from this degradation and associated cycling using N isotopes, an understudied area. Many N species are released at degradation sites with exchanges between species. N inputs from permafrost degradation and seasonal river N trends were identified using isotopes, helping to predict climate change impacts.
Mohamed Ayache, Jean-Claude Dutay, Kazuyo Tachikawa, Thomas Arsouze, and Catherine Jeandel
Biogeosciences, 20, 205–227, https://doi.org/10.5194/bg-20-205-2023, https://doi.org/10.5194/bg-20-205-2023, 2023
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The neodymium (Nd) is one of the most useful tracers to fingerprint water mass provenance. However, the use of Nd is hampered by the lack of adequate quantification of the external sources. Here, we present the first simulation of dissolved Nd concentration and Nd isotopic composition in the Mediterranean Sea using a high-resolution model. We aim to better understand how the various external sources affect the Nd cycle and particularly assess how it is impacted by atmospheric inputs.
Marta Santos-Garcia, Raja S. Ganeshram, Robyn E. Tuerena, Margot C. F. Debyser, Katrine Husum, Philipp Assmy, and Haakon Hop
Biogeosciences, 19, 5973–6002, https://doi.org/10.5194/bg-19-5973-2022, https://doi.org/10.5194/bg-19-5973-2022, 2022
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Terrestrial sources of nitrate are important contributors to the nutrient pool in the fjords of Kongsfjorden and Rijpfjorden in Svalbard during the summer, and they sustain most of the fjord primary productivity. Ongoing tidewater glacier retreat is postulated to favour light limitation and less dynamic circulation in fjords. This is suggested to encourage the export of nutrients to the middle and outer part of the fjord system, which may enhance primary production within and in offshore areas.
Marlene Dordoni, Michael Seewald, Karsten Rinke, Kurt Friese, Robert van Geldern, Jakob Schmidmeier, and Johannes A. C. Barth
Biogeosciences, 19, 5343–5355, https://doi.org/10.5194/bg-19-5343-2022, https://doi.org/10.5194/bg-19-5343-2022, 2022
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Organic matter (OM) turnover into dissolved inorganic carbon (DIC) was investigated by means of carbon isotope mass balances in Germany's largest water reservoir. This includes a metalimnetic oxygen minimum (MOM). Autochthonous particulate organic carbon (POC) was the main contributor to DIC, with rates that were highest for the MOM. Generally low turnover rates outline the environmental fragility of this water body in the case that OM loads increase due to storm events or land use changes.
Frédérique M. S. A. Kirkels, Hugo J. de Boer, Paulina Concha Hernández, Chris R. T. Martes, Marcel T. J. van der Meer, Sayak Basu, Muhammed O. Usman, and Francien Peterse
Biogeosciences, 19, 4107–4127, https://doi.org/10.5194/bg-19-4107-2022, https://doi.org/10.5194/bg-19-4107-2022, 2022
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The distinct carbon isotopic values of C3 and C4 plants are widely used to reconstruct past hydroclimate, where more C3 plants reflect wetter and C4 plants drier conditions. Here we examine the impact of regional hydroclimatic conditions on plant isotopic values in the Godavari River basin, India. We find that it is crucial to identify regional plant isotopic values and consider drought stress, which introduces a bias in C3 / C4 plant estimates and associated hydroclimate reconstructions.
Mhlangabezi Mdutyana, Tanya Marshall, Xin Sun, Jessica M. Burger, Sandy J. Thomalla, Bess B. Ward, and Sarah E. Fawcett
Biogeosciences, 19, 3425–3444, https://doi.org/10.5194/bg-19-3425-2022, https://doi.org/10.5194/bg-19-3425-2022, 2022
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Nitrite-oxidizing bacteria in the winter Southern Ocean show a high affinity for nitrite but require a minimum (i.e., "threshold") concentration before they increase their rates of nitrite oxidation significantly. The classic Michaelis–Menten model thus cannot be used to derive the kinetic parameters, so a modified equation was employed that also yields the threshold nitrite concentration. Dissolved iron availability may play an important role in limiting nitrite oxidation.
Weitian Ding, Urumu Tsunogai, Fumiko Nakagawa, Takashi Sambuichi, Hiroyuki Sase, Masayuki Morohashi, and Hiroki Yotsuyanagi
Biogeosciences, 19, 3247–3261, https://doi.org/10.5194/bg-19-3247-2022, https://doi.org/10.5194/bg-19-3247-2022, 2022
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Excessive leaching of nitrate from forested catchments during storm events degrades water quality and causes eutrophication in downstream areas. Thus, tracing the source of nitrate increase during storm events in forested streams is important for sustainable forest management. Based on the isotopic compositions of stream nitrate, including Δ17O, this study clarifies that the source of stream nitrate increase during storm events was soil nitrate in the riparian zone.
Nicolas Séon, Romain Amiot, Guillaume Suan, Christophe Lécuyer, François Fourel, Fabien Demaret, Arnauld Vinçon-Laugier, Sylvain Charbonnier, and Peggy Vincent
Biogeosciences, 19, 2671–2681, https://doi.org/10.5194/bg-19-2671-2022, https://doi.org/10.5194/bg-19-2671-2022, 2022
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We analysed the oxygen isotope composition of bones and teeth of four marine species possessing regional heterothermies. We observed a consistent link between oxygen isotope composition and temperature heterogeneities recorded by classical methods. This opens up new perspectives on the determination of the thermoregulatory strategies of extant marine vertebrates where conventional methods are difficult to apply, but also allows us to investigate thermophysiologies of extinct vertebrates.
Yuwei Liu, Guofeng Zhu, Zhuanxia Zhang, Zhigang Sun, Leilei Yong, Liyuan Sang, Lei Wang, and Kailiang Zhao
Biogeosciences, 19, 877–889, https://doi.org/10.5194/bg-19-877-2022, https://doi.org/10.5194/bg-19-877-2022, 2022
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We took the water cycle process of soil–plant–atmospheric precipitation as the research objective. In the water cycle of soil–plant–atmospheric precipitation, precipitation plays the main controlling role. The main source of replenishment for alpine meadow plants is precipitation and alpine meltwater; the main source of replenishment for forest plants is soil water; and the plants in the arid foothills mainly use groundwater.
Roberto Velázquez-Ochoa, María Julia Ochoa-Izaguirre, and Martín Federico Soto-Jiménez
Biogeosciences, 19, 1–27, https://doi.org/10.5194/bg-19-1-2022, https://doi.org/10.5194/bg-19-1-2022, 2022
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Our research is the first approximation to understand the δ13C macroalgal variability in one of the most diverse marine ecosystems in the world, the Gulf of California. The life-form is the principal cause of δ13C macroalgal variability, mainly taxonomy. However, changes in habitat characteristics and environmental conditions also influence the δ13C macroalgal variability. The δ13C macroalgae is indicative of carbon concentration mechanisms and isotope discrimination during carbon assimilation.
Raquel F. Flynn, Thomas G. Bornman, Jessica M. Burger, Shantelle Smith, Kurt A. M. Spence, and Sarah E. Fawcett
Biogeosciences, 18, 6031–6059, https://doi.org/10.5194/bg-18-6031-2021, https://doi.org/10.5194/bg-18-6031-2021, 2021
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Biological activity in the shallow Weddell Sea affects the biogeochemistry of recently formed deep waters. To investigate the drivers of carbon and nutrient export, we measured rates of primary production and nitrogen uptake, characterized the phytoplankton community, and estimated nutrient depletion ratios across the under-sampled western Weddell Sea in mid-summer. Carbon export was highest at the ice shelves and was determined by a combination of physical, chemical, and biological factors.
Stéphanie H. M. Jacquet, Christian Tamburini, Marc Garel, Aurélie Dufour, France Van Vambeke, Frédéric A. C. Le Moigne, Nagib Bhairy, and Sophie Guasco
Biogeosciences, 18, 5891–5902, https://doi.org/10.5194/bg-18-5891-2021, https://doi.org/10.5194/bg-18-5891-2021, 2021
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We compared carbon remineralization rates (MRs) in the western and central Mediterranean Sea in late spring during the PEACETIME cruise, as assessed using the barium tracer. We reported higher and deeper (up to 1000 m depth) MRs in the western basin, potentially sustained by an additional particle export event driven by deep convection. The central basin is the site of a mosaic of blooming and non-blooming water masses and showed lower MRs that were restricted to the upper mesopelagic layer.
Shinsuke Kawagucci, Yohei Matsui, Akiko Makabe, Tatsuhiro Fukuba, Yuji Onishi, Takuro Nunoura, and Taichi Yokokawa
Biogeosciences, 18, 5351–5362, https://doi.org/10.5194/bg-18-5351-2021, https://doi.org/10.5194/bg-18-5351-2021, 2021
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Hydrogen and carbon isotope ratios of methane as well as the relevant biogeochemical parameters and microbial community compositions in hydrothermal plumes in the Okinawa Trough were observed. We succeeded in simultaneously determining hydrogen and carbon isotope fractionation factors associated with aerobic oxidation of methane in seawater (εH = 49.4 ± 5.0 ‰, εC = 5.2 ± 0.4 ‰) – the former being the first of its kind ever reported.
Nicolai Schleinkofer, David Evans, Max Wisshak, Janina Vanessa Büscher, Jens Fiebig, André Freiwald, Sven Härter, Horst R. Marschall, Silke Voigt, and Jacek Raddatz
Biogeosciences, 18, 4733–4753, https://doi.org/10.5194/bg-18-4733-2021, https://doi.org/10.5194/bg-18-4733-2021, 2021
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We have measured the chemical composition of the carbonate shells of the parasitic foraminifera Hyrrokkin sarcophaga in order to test if it is influenced by the host organism (bivalve or coral). We find that both the chemical and isotopic composition is influenced by the host organism. For example strontium is enriched in foraminifera that grew on corals, whose skeleton is built from aragonite, which is naturally enriched in strontium compared to the bivalves' calcite shell.
Lena Rohe, Traute-Heidi Anderson, Heinz Flessa, Anette Goeske, Dominika Lewicka-Szczebak, Nicole Wrage-Mönnig, and Reinhard Well
Biogeosciences, 18, 4629–4650, https://doi.org/10.5194/bg-18-4629-2021, https://doi.org/10.5194/bg-18-4629-2021, 2021
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This is the first experimental setup combining a complex set of methods (microbial inhibitors and isotopic approaches) to differentiate between N2O produced by fungi or bacteria during denitrification in three soils. Quantifying the fungal fraction with inhibitors was not successful due to large amounts of uninhibited N2O production. All successful methods suggested a small or missing fungal contribution. Artefacts occurring with microbial inhibition to determine N2O fluxes are discussed.
Inga Köhler, Raul E. Martinez, David Piatka, Achim J. Herrmann, Arianna Gallo, Michelle M. Gehringer, and Johannes A. C. Barth
Biogeosciences, 18, 4535–4548, https://doi.org/10.5194/bg-18-4535-2021, https://doi.org/10.5194/bg-18-4535-2021, 2021
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We investigated how high Fe(II) levels influence the O2 budget of a circum-neutral Fe(II)-rich spring and if a combined study of dissolved O (DO) and its isotopic composition can help assess this effect. We showed that dissolved Fe(II) can exert strong effects on the δ18ODO even though a constant supply of atmospheric O2 occurs. In the presence of photosynthesis, direct effects of Fe oxidation become masked. Critical Fe(II) concentrations indirectly control the DO by enhancing photosynthesis.
Owen A. Sherwood, Samuel H. Davin, Nadine Lehmann, Carolyn Buchwald, Evan N. Edinger, Moritz F. Lehmann, and Markus Kienast
Biogeosciences, 18, 4491–4510, https://doi.org/10.5194/bg-18-4491-2021, https://doi.org/10.5194/bg-18-4491-2021, 2021
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Pacific water flowing eastward through the Canadian Arctic plays an important role in redistributing nutrients to the northwest Atlantic Ocean. Using samples collected from northern Baffin Bay to the southern Labrador Shelf, we show that stable isotopic ratios in seawater nitrate reflect the fraction of Pacific to Atlantic water. These results provide a new framework for interpreting patterns of nitrogen isotopic variability recorded in modern and archival organic materials in the region.
Franziska Slotta, Lukas Wacker, Frank Riedel, Karl-Uwe Heußner, Kai Hartmann, and Gerhard Helle
Biogeosciences, 18, 3539–3564, https://doi.org/10.5194/bg-18-3539-2021, https://doi.org/10.5194/bg-18-3539-2021, 2021
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The African baobab is a challenging climate and environmental archive for its semi-arid habitat due to dating uncertainties and parenchyma-rich wood anatomy. Annually resolved F14C data of tree-ring cellulose (1941–2005) from a tree in Oman show the annual character of the baobab’s growth rings but were up to 8.8 % lower than expected for 1964–1967. Subseasonal δ13C and δ18O patterns reveal years with low average monsoon rain as well as heavy rainfall events from pre-monsoonal cyclones.
Peter M. J. Douglas, Emerald Stratigopoulos, Sanga Park, and Dawson Phan
Biogeosciences, 18, 3505–3527, https://doi.org/10.5194/bg-18-3505-2021, https://doi.org/10.5194/bg-18-3505-2021, 2021
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Hydrogen isotopes could be a useful tool to help resolve the geographic distribution of methane emissions from freshwater environments. We analyzed an expanded global dataset of freshwater methane hydrogen isotope ratios and found significant geographic variation linked to water isotopic composition. This geographic variability could be used to resolve changing methane fluxes from freshwater environments and provide more accurate estimates of the relative balance of global methane sources.
Veronica R. Rollinson, Julie Granger, Sydney C. Clark, Mackenzie L. Blanusa, Claudia P. Koerting, Jamie M. P. Vaudrey, Lija A. Treibergs, Holly C. Westbrook, Catherine M. Matassa, Meredith G. Hastings, and Craig R. Tobias
Biogeosciences, 18, 3421–3444, https://doi.org/10.5194/bg-18-3421-2021, https://doi.org/10.5194/bg-18-3421-2021, 2021
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We measured nutrients and the naturally occurring nitrogen (N) and oxygen (O) stable isotope ratios of nitrate discharged from a New England river over an annual cycle, to monitor N loading and identify dominant sources from the watershed. We uncovered a seasonality to loading and sources of N from the watershed. Seasonality in the nitrate isotope ratios also informed on N cycling, conforming to theoretical expectations of riverine nutrient cycling.
Zixun Chen, Xuejun Liu, Xiaoqing Cui, Yaowen Han, Guoan Wang, and Jiazhu Li
Biogeosciences, 18, 2859–2870, https://doi.org/10.5194/bg-18-2859-2021, https://doi.org/10.5194/bg-18-2859-2021, 2021
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δ13C in plants is a sensitive long-term indicator of physiological acclimatization. The present study suggests that precipitation change and increasing atmospheric N deposition have little impact on δ13C of H. ammodendron, a dominant plant in central Asian deserts, but affect its gas exchange. In addition, this study shows that δ13C of H. ammodendron could not indicate its water use efficiency (WUE), suggesting that whether δ13C of C4 plants indicates WUE is species-specific.
Petra Zahajská, Carolina Olid, Johanna Stadmark, Sherilyn C. Fritz, Sophie Opfergelt, and Daniel J. Conley
Biogeosciences, 18, 2325–2345, https://doi.org/10.5194/bg-18-2325-2021, https://doi.org/10.5194/bg-18-2325-2021, 2021
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The drivers of high accumulation of single-cell siliceous algae (diatoms) in a high-latitude lake have not been fully characterized before. We studied silicon cycling of the lake through water, radon, silicon, and stable silicon isotope balances. Results showed that groundwater brings 3 times more water and dissolved silica than the stream inlet. We demonstrate that groundwater discharge and low sediment deposition have driven the high diatom accumulation in the studied lake in the past century.
Yu-Te Hsieh, Walter Geibert, E. Malcolm S. Woodward, Neil J. Wyatt, Maeve C. Lohan, Eric P. Achterberg, and Gideon M. Henderson
Biogeosciences, 18, 1645–1671, https://doi.org/10.5194/bg-18-1645-2021, https://doi.org/10.5194/bg-18-1645-2021, 2021
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The South Atlantic near 40° S is one of the high-productivity and most dynamic nutrient regions in the oceans, but the sources and fluxes of trace elements (TEs) to this region remain unclear. This study investigates seawater Ra-228 and provides important constraints on ocean mixing and dissolved TE fluxes to this region. Vertical mixing is a more important source than aeolian or shelf inputs in this region, but particulate or winter deep-mixing inputs may be required to balance the TE budgets.
Zhongjie Yu and Emily M. Elliott
Biogeosciences, 18, 805–829, https://doi.org/10.5194/bg-18-805-2021, https://doi.org/10.5194/bg-18-805-2021, 2021
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In this study, we demonstrated distinct nitrogen isotope effects for nitric oxide (NO) production from major microbial and chemical NO sources in an agricultural soil. These results highlight characteristic bond-forming and breaking mechanisms associated with microbial and chemical NO production and implicate that simultaneous isotopic analyses of NO and nitrous oxide (N2O) can lead to unprecedented insights into the sources and processes controlling NO and N2O emissions from agricultural soils.
Daniel A. Frick, Rainer Remus, Michael Sommer, Jürgen Augustin, Danuta Kaczorek, and Friedhelm von Blanckenburg
Biogeosciences, 17, 6475–6490, https://doi.org/10.5194/bg-17-6475-2020, https://doi.org/10.5194/bg-17-6475-2020, 2020
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Silicon is taken up by some plants to increase structural stability and to develop stress resistance and is rejected by others. To explore the underlying mechanisms, we used the stable isotopes of silicon that shift in their relative abundance depending on the biochemical transformation involved. On species with a rejective (tomato, mustard) and active (wheat) uptake mechanism, grown in hydroculture, we found that the transport of silicic acid is controlled by the precipitation of biogenic opal.
Quentin Charbonnier, Julien Bouchez, Jérôme Gaillardet, and Éric Gayer
Biogeosciences, 17, 5989–6015, https://doi.org/10.5194/bg-17-5989-2020, https://doi.org/10.5194/bg-17-5989-2020, 2020
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The abundance and isotope composition of the trace metal barium (Ba) allows us to track and quantify nutrient cycling throughout the Amazon Basin. In particular, we show that the Ba biological fingerprint evolves from that of a strong net nutrient uptake in the mountainous area of the Andes towards efficient nutrient recycling on the plains of the Lower Amazon. Our study highlights the fact that the geochemical signature of rock-derived nutrients transported by the Amazon is scarred by life.
Ajinkya G. Deshpande, Thomas W. Boutton, Ayumi Hyodo, Charles W. Lafon, and Georgianne W. Moore
Biogeosciences, 17, 5639–5653, https://doi.org/10.5194/bg-17-5639-2020, https://doi.org/10.5194/bg-17-5639-2020, 2020
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Wetland forests in the southern USA are threatened by changing climate and human-induced pressures. We used tree ring widths and C isotopes as indicators of forest growth and physiological stress, respectively, and compared these to past climate data. We observed that vegetation growing in the drier patches is susceptible to stress, while vegetation growth and physiology in wetter patches is less sensitive to unfavorable environmental conditions, highlighting the importance of optimal wetness.
Dominika Lewicka-Szczebak, Maciej Piotr Lewicki, and Reinhard Well
Biogeosciences, 17, 5513–5537, https://doi.org/10.5194/bg-17-5513-2020, https://doi.org/10.5194/bg-17-5513-2020, 2020
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We present the first validation of N2O isotopic approaches for estimating N2O source pathways and N2O reduction. These approaches are widely used for tracing soil nitrogen cycling, but the results of these estimations are very uncertain. Here we report the results from parallel treatments allowing for precise validation of these approaches, and we propose the best strategies for results interpretation, including the new idea of an isotope model integrating three isotopic signatures of N2O.
Markus Raitzsch, Claire Rollion-Bard, Ingo Horn, Grit Steinhoefel, Albert Benthien, Klaus-Uwe Richter, Matthieu Buisson, Pascale Louvat, and Jelle Bijma
Biogeosciences, 17, 5365–5375, https://doi.org/10.5194/bg-17-5365-2020, https://doi.org/10.5194/bg-17-5365-2020, 2020
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The isotopic composition of boron in carbonate shells of marine unicellular organisms is a popular tool to estimate seawater pH. Usually, many shells need to be dissolved and measured for boron isotopes, but the information on their spatial distribution is lost. Here, we investigate two techniques that allow for measuring boron isotopes within single shells and show that they yield robust mean values but provide additional information on the heterogeneity within and between single shells.
Florian Einsiedl, Anja Wunderlich, Mathieu Sebilo, Ömer K. Coskun, William D. Orsi, and Bernhard Mayer
Biogeosciences, 17, 5149–5161, https://doi.org/10.5194/bg-17-5149-2020, https://doi.org/10.5194/bg-17-5149-2020, 2020
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Nitrate pollution of freshwaters and methane emissions into the atmosphere are crucial factors in deteriorating the quality of drinking water and in contributing to global climate change. Here, we report vertical concentration and stable isotope profiles of CH4, NO3-, NO2-, and NH4+ in the water column of Fohnsee (southern Bavaria, Germany) that may indicate linkages between nitrate-dependent anaerobic methane oxidation and the anaerobic oxidation of ammonium.
Ruifang C. Xie, Frédéric A. C. Le Moigne, Insa Rapp, Jan Lüdke, Beat Gasser, Marcus Dengler, Volker Liebetrau, and Eric P. Achterberg
Biogeosciences, 17, 4919–4936, https://doi.org/10.5194/bg-17-4919-2020, https://doi.org/10.5194/bg-17-4919-2020, 2020
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Thorium-234 (234Th) is widely used to study carbon fluxes from the surface ocean to depth. But few studies stress the relevance of oceanic advection and diffusion on the downward 234Th fluxes in nearshore environments. Our study in offshore Peru showed strong temporal variations in both the importance of physical processes on 234Th flux estimates and the oceanic residence time of 234Th, whereas salinity-derived seawater 238U activities accounted for up to 40 % errors in 234Th flux estimates.
Ralf A. Oeser and Friedhelm von Blanckenburg
Biogeosciences, 17, 4883–4917, https://doi.org/10.5194/bg-17-4883-2020, https://doi.org/10.5194/bg-17-4883-2020, 2020
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We present a novel strategy to decipher the relative impact of biogenic and abiotic drivers of weathering. We parameterized the nutrient fluxes in four ecosystems along a climate and vegetation gradient situated on the Chilean Coastal Cordillera. We investigated how nutrient demand by plants drives weathering. We found that the increase in biomass nutrient demand is accommodated by faster nutrient recycling rather than an increase in the weathering–release rates.
Tito Arosio, Malin M. Ziehmer, Kurt Nicolussi, Christian Schlüchter, and Markus Leuenberger
Biogeosciences, 17, 4871–4882, https://doi.org/10.5194/bg-17-4871-2020, https://doi.org/10.5194/bg-17-4871-2020, 2020
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Stable isotopes in tree-ring cellulose are tools for climatic reconstructions, but interpretation is challenging due to nonclimate trends. We analyzed the tree-age trends in tree-ring isotopes of deciduous larch and evergreen cembran pine. Samples covering the whole Holocene were collected at the tree line in the Alps. For cambial ages over 100 years, we prove the absence of age trends in δD, δ18O, and δ13C for both species. For lower cambial ages, trends differ for each isotope and species.
Yuyang He, Xiaobin Cao, and Huiming Bao
Biogeosciences, 17, 4785–4795, https://doi.org/10.5194/bg-17-4785-2020, https://doi.org/10.5194/bg-17-4785-2020, 2020
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Different carbon sites in a large organic molecule have different isotope compositions. Different carbon sites may not have the chance to exchange isotopes at all. The lack of appreciation of this notion might be blamed for an unsettled debate on the thermodynamic state of an organism. Here we demonstrate using minerals, N2O, and acetic acid that the dearth of exchange among different carbon sites renders them as independent as if they were different elements in organic molecules.
Felix M. Spielmann, Albin Hammerle, Florian Kitz, Katharina Gerdel, and Georg Wohlfahrt
Biogeosciences, 17, 4281–4295, https://doi.org/10.5194/bg-17-4281-2020, https://doi.org/10.5194/bg-17-4281-2020, 2020
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Carbonyl sulfide (COS) can be used as a proxy for plant photosynthesis on an ecosystem scale. However, the relationships between COS and CO2 fluxes and their dependence on daily to seasonal changes in environmental drivers are still poorly understood. We examined COS and CO2 ecosystem fluxes above an agriculturally used mountain grassland for 6 months. Harvesting of the grassland disturbed the otherwise stable COS-to-CO2 uptake ratio. We even found the canopy to release COS during those times.
Getachew Agmuas Adnew, Thijs L. Pons, Gerbrand Koren, Wouter Peters, and Thomas Röckmann
Biogeosciences, 17, 3903–3922, https://doi.org/10.5194/bg-17-3903-2020, https://doi.org/10.5194/bg-17-3903-2020, 2020
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We measured the effect of photosynthesis, the largest flux in the carbon cycle, on the triple oxygen isotope composition of atmospheric CO2 at the leaf level during gas exchange using three plant species. The main factors that limit the impact of land vegetation on the triple oxygen isotope composition of atmospheric CO2 are identified, characterized and discussed. The effect of photosynthesis on the isotopic composition of CO2 is commonly quantified as discrimination (ΔA).
Moritz Schroll, Frank Keppler, Markus Greule, Christian Eckhardt, Holger Zorn, and Katharina Lenhart
Biogeosciences, 17, 3891–3901, https://doi.org/10.5194/bg-17-3891-2020, https://doi.org/10.5194/bg-17-3891-2020, 2020
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Fungi have recently been identified to produce the greenhouse gas methane. Here, we investigated the stable carbon isotope values of methane produced by saprotrophic fungi. Our results show that stable isotope values of methane from fungi are dependent on the fungal species and the metabolized substrate. They cover a broad range and overlap with stable carbon isotope values of methane reported for methanogenic archaea, the thermogenic degradation of organic matter, and other eukaryotes.
Pranav Hirave, Guido L. B. Wiesenberg, Axel Birkholz, and Christine Alewell
Biogeosciences, 17, 2169–2180, https://doi.org/10.5194/bg-17-2169-2020, https://doi.org/10.5194/bg-17-2169-2020, 2020
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Sediment input into water bodies is a prominent threat to freshwater ecosystems. We tested the stability of tracers employed in freshwater sediment tracing based on compound-specific isotope analysis during early degradation in soil. While bulk δ13C values showed no stability, δ13C values of plant-derived fatty acids and n-alkanes were stably transferred to the soil without soil particle size dependency after an early degradation in organic horizons, thus indicating their suitability as tracers.
Caroline Thaler, Amandine Katz, Magali Bonifacie, Bénédicte Ménez, and Magali Ader
Biogeosciences, 17, 1731–1744, https://doi.org/10.5194/bg-17-1731-2020, https://doi.org/10.5194/bg-17-1731-2020, 2020
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Paleoenvironment reconstructions, retrieved from δ18O and Δ47 values measured in carbonate, are compromised when crystallization occurs in isotopic disequilibrium. We show that some paleoenvironmental information can still be retrieved from these paired disequilibrium Δ47 and δ18O values. The possibility of retrieving information on paleowaters, sediments' interstitial waters, or organisms' body water at the carbonate precipitation loci will help understand past Earth and life evolution.
Guillaume Humbert, Mathieu Sébilo, Justine Fiat, Longqi Lang, Ahlem Filali, Véronique Vaury, Mathieu Spérandio, and Anniet M. Laverman
Biogeosciences, 17, 979–993, https://doi.org/10.5194/bg-17-979-2020, https://doi.org/10.5194/bg-17-979-2020, 2020
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Mitigating emissions of the greenhouse gas N2O requires understanding of the relative contribution of its producing processes in response to environmental variables. We show, using isotopic analysis, that N2O emissions from a nitrifying system were sensitive to oxygenation, temperature and NH4+ concentrations with nitrite reduction being the main N2O source. Temperature appears to be the main control on N2O production, due to its dissimilar effects on ammonium and nitrite oxidizing activities.
Oguz Yigiterhan, Ebrahim Mohd Al-Ansari, Alex Nelson, Mohamed Alaa Abdel-Moati, Jesse Turner, Hamood Abdulla Alsaadi, Barbara Paul, Ibrahim Abdullatif Al-Maslamani, Mehsin Abdulla Al-Ansi Al-Yafei, and James W. Murray
Biogeosciences, 17, 381–404, https://doi.org/10.5194/bg-17-381-2020, https://doi.org/10.5194/bg-17-381-2020, 2020
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We analyze net-tow samples of plankton and associated particulate matter from the Exclusive Economic Zone, Qatar, Arabian Gulf, using net tows with mesh sizes of 50 and 200 μm to examine the composition of plankton populations. We also focus on the role and composition of the atmospheric dust, representative of terrigenous material, deposited in the Gulf. We concluded that Al, Fe, Cr, Co, Mn, Ni, Pb, and Li are of dust origin and As, Cd, Cu, Mo, Zn, and Ca are of anthropogenic/biogenic origin.
Clare Woulds, James B. Bell, Adrian G. Glover, Steven Bouillon, and Louise S. Brown
Biogeosciences, 17, 1–12, https://doi.org/10.5194/bg-17-1-2020, https://doi.org/10.5194/bg-17-1-2020, 2020
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Sedimented hydrothermal vents occur where heated, mineral-rich (hydrothermal) water seeps through seafloor sediments. They host chemosynthetic microbes, which use chemical energy to fix dissolved carbon dioxide into sugars (chemosynthesis). We conducted carbon tracing experiments, and observed chemosynthesis at both vent and non-vent sites. Thus, chemosynthesis occurred over a much larger area than expected, suggesting it is more widespread than previously thought.
Cited articles
Armand, L. K., Crosta, X., Quéguiner, B., Mosseri, J., and Garcia, N.: Diatoms preserved in surface sediments of the northeastern Kerguelen Plateau, Deep- Sea Res. Pt. II, 55, 677–692, 2008.
Blain, S., Tréguer, P., Belviso, S., Bucciarelli, E., Denis, M., Desabre, S., Fiala, M., Martin Jézéquel, V., Le Fèvre, J., Mayzaud, P., Marty, J.-C., and Razouls, S.: A biogeochemical study of the island mass effect in the context of the iron hypothesis: Kerguelen Islands, Southern Ocean, Deep-Sea Res. Pt. I, 48, 163–187, 2001.
Blain, S., Queguiner, B., Armand, L., Belviso, S., Bombled, B., Bopp, L., Bowie, A., Brunet, C., Brussaard, C., Carlotti, F., Christaki, U., Corbiere, A., Durand, I., Ebersbach, F., Fuda, J. -L., Garcia, N., Gerringa, L., Griffiths, B., Guigue, C., Guillerm, C., Jacquet, S., Jeandel, C., Laan, P., Lefevre, D., Lo Monaco, C., Malits, A., Mosseri, J., Obernosterer, I., Park, Y. -H., Picheral, M., Pondaven, P., Remenyi, T., Sandroni, V., Sarthou, G., Savoye, N., Scouarnec, L., Souhaut, M., Thuiller, D., Timmermans, K., Trull, T., Uitz, J., van Beek, P., Veldhuis, M., Vincent, D., Viollier, E., Vong, L., and Wagener, T.: Effect of natural iron fertilization on carbon sequestration in the Southern Ocean, Nature, 446, 1070–1074, 2007.
Blain, S., Quéguiner, B., and Trull, T.: The natural iron fertilization experiment keops (kerguelen ocean and plateau compared study): An overview, Deep-Sea Res. Pt. II, 55, 559–565, 2008.
Boyd, P. W., Watson, A. J., Law, C. S., Abraham, E. R., Trull, T., Murdoch, R., Bakker, D. C. E., Bowie, A. R., Buesseler, K. O., Chang, H., Charette, M., Croot, P., Downing, K., Frew, R., Gall, M., Hadfield, M., Hall, J., Harvey, M., Jameson, G., LaRoche, J., Liddicoat, M., Ling, R., Maldonado, M. T., McKay, R. M., Nobber, S., Pickmere, S., Pridmore, R., Rintoul, S., Safi, K., Sutton, P., Strzepek, R., Tanneberger, K., Turner, S., Waite, A., and Zeldis, J.: Phytoplankton bloom upon mesoscale iron fertilization of polar Southern Ocean water, Nature, 407, 695–702, 2000.
Boyd, P. W., Law, C. S., Wong, C. S., Nojiri, Y., Tsuda, A., Levasseur, M., Takeda, S., Rivkin, R., Harrison, P. J., Strzepek, R., Gower, J., McKay, R. M., Abraham, E., Arychuk, M., Barwell-Clarke, J., Crawford, W., Crawford, D., Hale, M., Harada, K., Johnson, K., Kiyosawa, H., Kudo, I., Marchetti, A., Miller, W., Needoba, J., Nishioka, J., Ogawa, H., Page, J., Robert, M., Saito, H., Sastri, A., Sherry, N., Soutar, T., Sutherland, N., Taira, Y., Whitney, F., Wong, S. K. E., and Yoshimura, T.: The decline and fate of an iron-induced subarctic phytoplankton bloom, Nature, 428, 549–553, 2004.
Boyd, P. W., Bakker, D. C. E., and Chandler, C.: A new database to explore the findings from large-scale ocean iron enrichments experiments, Oceanography, 25, 64–71, https://doi.org/10.5670/oceanog.2012.104, 2012.
Bowie, A. R., van der Merwe, P., Quéroué, F., Trull, T., Fourquez, M., Planchon, F., Sarthou, G., Chever, F., Townsend, A. T., Obernosterer, I., Sallée, J.-B., and Blain, S.: Iron budgets for three distinct biogeochemical sites around the Kerguelen archipelago (Southern Ocean) during the natural fertilisation experiment KEOPS-2, Biogeosciences Discuss., 11, 17861–17923, https://doi.org/10.5194/bgd-11-17861-2014, 2014.
Broecker, W. S., Takahashi, T., and Takahashi, T.: Sources and flow patterns of deep-ocean waters as deduced from potential temperature, salinity and initial phosphate concentration, J. Geophys. Res., 90, 6925–6939, 1985.
Buesseler, K. O. and Boyd, P. W.: Shedding light on processes that control particle export and flux attenuation in the twilight zone, Limnol. Oceanogr., 54, 1210–1232, 2009.
Buesseler, K. O., Andrews, J. E., Pike, S. M., and Charette, M. A.: The effect of iron fertilization on carbon sequestration in the Southern Ocean, Science, 304, 414–417, 2004.
Buesseler, K. O., Andrews, J. E., Pike, S. M., Charette, M. A., Goldson, L. E., Brzezinski, M. A., and Lance, V. P.: Particle export during the Southern Ocean Iron Experiment (SOFeX), Limnol. Oceanogr., 50, 311–327, 2005.
Buesseler, K. O., Antia, A. N., Chen, M., Fowler, S. W., Gardner, W. D., Gustaffson, Ö., Harada, K., Michaels, A. F., Rutgers van der Loeff, M., Sarin, M., Steinberg, D. K., and Trull, T.: An assessment of the use of sediment traps for estimating upper ocean particle fluxes, J. Mar. Res., 65, 345–416, 2007a.
Buesseler, K. O., Lamborg, C. H., Boyd, P. W., Lam, P. J., Trull, T. W., Bidigare, R. R., Bishop, J. K. B., Casciotti, K. L., Dehairs, F. , Elskens, M., Honda, M. , Karl, D. M., Siegel, D. A., Silver, M. W., Steinberg, D. K. , Valdes, J., Van Mooy, B., and Wilson, S.: Revisiting carbon flux through the ocean's twilight zone, Science, 316, 567–569, 2007b.
Cardinal, D., Dehairs, F., Cattaldo, T., and André, L.: Constraints on export and advection in the Subantarctic and Polar Front Zones, south of Australia from the geochemistry of suspended particles, J. Geophys. Res.-Oceans, 106, 31637–31656, 2001
Cardinal, D., Savoye, N., Trull., T.W., André, L., Kopczynska, E., and Dehairs, F.:, Particulate Ba distributions and fluxes suggest latitudinal variations of carbon mineralization in the Southern ocean, Deep-Sea Res. Pt. I, 52, 355–370, 2005.
Carlotti, F., Jouandet, M.-P., Nowaczyk, A., Harmelin-Vivien, M., Lefèvre, D., Guillou, G., Zhu, Y., and Zhou, M.: Mesozooplankton structure and functioning during the onset of the Kerguelen Bloom during Keops2 survey, Iogeosci. Iscuss., 12, 2381–2427, 2015.
Cavagna, A. J., Fripiat, F., Elskens, M., Dehairs, F., Mangion, P., Chirurgien, L., Closset, I., Lasbleiz, M., Flores–Leiva, L., Cardinal, D., Leblanc, K., Fernandez, C., Lefèvre, D., Oriol, L., Blain, S., and Quéguiner, B.: Biological productivity regime and associated N cycling in the vicinity of Kerguelen Island area, Southern Ocean, Biogeosciences Discuss., 11, 18073–18104, https://doi.org/10.5194/bgd-11-18073-2014, 2014.
Closset, I., Lasbleiz, M., Leblanc, K., Quéguiner, B., Cavagna, A.-J., Elskens, M., Navez, J., and Cardinal, D.: Seasonal evo- lution of net and regenerated silica production around a natu- ral Fe-fertilized area in the Southern Ocean estimated from Si isotopic approaches, Biogeosciences, 11, 5827–5846, https://doi.org/10.5194/bg-11-5827-2014, 2014.
Christaki, U., Obernosterer, I., VanWambeke, F., Veldhuis, M., Garcia, N., and Catala, P.: Microbial food web structure in a naturally iron fertilized area in the southern ocean (Kerguelen plateau), Deep-Sea Res. Pt. II, 55, 706–719, 2008.
Christaki, U., Lefèvre, D., Geoges, C., Colombet, J., catala, P., Courties, C., Sime-Ngando, T., Blain, S., and Obernosterer, I.: Microbial food web dynamics during spring phytoplankton blooms in the naturally iron-fertilized Kerguelen area (Southern Ocean), Biogeosciences, 11, 6739–3753, https://doi.org/10.5194/bg-11-6739-2014, 2014.
de Baar, H. J. W., Boyd, P. W., Coale, K. H., Landry, M. R., Tsud, A., Assmy, P., Bakker, D. C. E, Bozec, Y., Barber, R. T., Brzezinski, M. A., Buesseler, K. O., Boyé, M., Croot, P. L., Gervais, F., Gorbunov, Y., Harrison, P. J., Hiscock, W. T., Laan, P., Lancelot, C., Law, C. S., Levasseur, M., Marchetti, A., Millero, F. J., Nishika, J., Nojiri, Y., van Oijen, T., Riebesell, U., Rijkenberg, M. J. A., Saito, H., Takeda, S., Timmermans, K. R., Veldhuis, J. W., Waite, A. M., and Wong, C. S.: Synthesis of iron fertilization experiments: From the iron age in the age of enlightenment, J. Geophys. Res., 110, C09S16, https://doi.org/10.1029/2004JC002601, 2005.
Dehairs, F., Chesselet, R., and Jedwab, J.: Discrete suspended particles of barite and the barium cycle in the open ocean, Earth Planet. Sc. Lett., 49, 40–42, 1980.
Dehairs, F., Baeyens, W., and Goeyens, L.: Accumulation of suspended barite at mesopelagic depths and export production in the Southern Ocean, Science, 258, 1332–1335, 1992.
Dehairs, F., Shopova, D., Ober, S., Veth, C., and Goeyens, L.: Particulate barium stocks and oxygen consumption in the Southern Ocean mesopelagic water column during spring and early summer: Relationship with export production, Deep-Sea Res. Pt. II, 44, 497–516, 1997.
Dehairs, F., Jacquet, S. H. M., Savoye, N., van Mooy, B., Buesseler, K., Bishop, J., Lamborg, C., Elskens, M., Baeyens, W., Casciotti K., and Monnin, C.: Barium in twilight zone suspended matter as proxy for organic carbon mineralization: results for the North Pacific, Deep-Sea Res. Pt. II, 55, 1673–1683, 2008.
Dehairs, F., Fripiat, F., Cavagna, A.-J., Trull, T. W., Fernandez, C., Davies, D., Roukaerts, A., Fonseca Batista, D., Planchon, F., and Elskens, M.: Nitrogen cycling in the Southern Ocean Kerguelen Plateau area: evidence for significant surface nitrification from nitrate isotopic compositions, Biogeosciences Discuss., 11, 13905–13955, https://doi.org/10.5194/bgd-11-13905-2014, 2014.
D'Ovidio, F., Della Penna, A., Trull, T. W., Nencioli, F., Pujol, I., Rio, M. H., Park, Y. H., Cotté, C., Zhou, M., and Blain, S.: The biogeochemical structuring role of horizontal stirring: Lagrangian perspectives on iron delivery downstream of the Kerguelen plateau, Biogeosciences Discuss., 12, 779–814, https://doi.org/10.5194/bdg-12-779-2015, 2015.
Dymond, J. R., Suess, E., and Lyle, M.: Barium in deep-sea sediment: a geochemical proxy for paleoproductivity, Paleoceanography, 7, 163–181, 1992.
Ellison, Eurachem/CITAC Guide CG4, Quantifying Uncertainty in Analytical Measurement, edited by: Ellison, S.L.R., Rosslein, M., and Williams, A., Second edition ISBN 0948926 15 5, 120 pp., 2000.
François, R., Honjo, S., Krishfield, R., and Manganini, S.: Factors controlling the flux of organic carbon to the bathypelagic zone of the ocean, Global Biogeochem. Cy., 16, 1087, https://doi.org/10.1029/2001GB001722, 2002.
Gervais, F., Riebesell, U., and Gorbunov, M. Y.: Changes in primary productivity and chlorophyll a in response to iron fertilization in the southern Polar Frontal Zone, Limnol. Oceanogr., 47, 1324–1335, 2002.
Henson, S., Sanders, R., Madsen, E., Morris, P., Le Moigne, F., and Quartly, G.: A reduced estimate of the strength of the ocean\bf 's biological carbon pump, Geophys. Res. Lett., 38, L04606, 2011.
Hoffmann, L., Peeken, I., Lochte, K., Assmy, P., and Veldhuis, M.: Different reactions of Southern Ocean phytoplankton size classes to iron fertilization, Limnol. Oceanogr, 51, 1217–1229, 2006.
Jacquet, S. H. M., Dehairs, F., Cardinal, D., Navez, J., and Delille, B.: Barium distribution across the Southern Ocean Frontal system in the Crozet-Kerguelen Basin, Mar. Chem., 95, 149–162, 2005.
Jacquet, S. H. M., Dehairs, F., Elskens, M., Savoye, N., and Cardinal, D.: Barium cycling along WOCE SR3 line in the Southern Ocean, Mar. Chem., 106, 33–45, 2007.
Jacquet, S. H. M., Dehairs, F., Savoye, N., Obernosterer, I., Christaki, U., Monnin, C., and Cardinal, D.: Mesopelagic organic carbon mineralization in the Kerguelen Plateau region tracked by biogenic particulate Ba, Deep-Sea Res. Pt. II, 55, 868–879, 2008a.
Jacquet, S. H. M., Savoye, N Dehairs, F., Strass, V., and Cardinal, D.: Mesopelagic carbon mineralization during the European Iron Fertilization Experiment (EIFEX), Glob. Biogeochem. Cy., 22, GB1023, https://doi.org/10.1029/2006GB002902, 2008b.
Jacquet, S. H. M., Dehairs, F., Becquevort, S., Dumont, I., Cavagna, A., and Cardinal, D.: Twilight zone organic carbon remineralization in the PFZ and SAZ south of Tasmania (Southern Ocean), Deep-Sea Res. Pt. II, 58, 2222–2234 https://doi.org/10.1016/j.dsr2.2011.05.029, 2011a.
Jacquet, S. H. M., Lam, P., Trull ,T., and Dehairs, F.: Carbon export production in the Polar front zone and Subantarctic Zone south of Tasmania, Deep-Sea Res. Pt. II, 58, 2277–2292, 2011b.
Jouandet, M. P., Jackson, G. A., Carlotti, F., Picheral, M., Stemmann, L., and Blain, S.: Rapide formation of large aggregates during the spring bloom of Kerguelen Island: observation and model comparisons, Biogeosciences, 11, 4393–4406, https://doi.org/10.5194/bg-11-4393-2014, 2014 .
Lam, P. J. and Bishop, J. K. B.: High biomass, low export regimes in the Southern Ocean, Deep-Sea Res. Pt. II, 54, 601–638, 2007.
Lampitt, R. S. and Antia, A. N.: Particle flux in deep seas: regional characteristics and temporal variability, Deep-Sea Res. Pt. I, 44, 1377–1403, 1997.
Lampitt, R. S., Achterberg, E. P., Anderson, T. R., Hughes, J. A., Iglesisas-Rodriguez, M. D., Kelly-Gerreyn, B. A., Lucas, M., Popova, E. E., Sanders, R., Shepherd, J. G., Smythe-Wright, D., and Yool, A.: Ocean fertilization: A potential means of geoengineering?, Philos. Trans. R. Soc. A, 366, 3919–3945, 2008.
Lasbleiz, M., Leblanc, K., Blain, S., Ras, J., Cornet-Barthaux, V., Hélias Nunige, S., and Quéguiner, B.: Pigments, elemental composition (C, N, P, and Si), and stoichiometry of particulate matter in the naturally iron fertilized region of Kerguelen in the Southern Ocean, Biogeosciences, 11, 5931–5955, https://doi.org/10.5194/bg-11- 5931-2014, 2014.
Laurenceau-Cornec, E. C., Trull, T. W., Davies, D. M., Bray, S. G., Doran, J., Planchon, F., Carlotti, F., Jouandet, M.-P., Cavagna, A.-J., Waite, A. M., and Blain, S.: The relative importance of phytoplankton aggregates and zooplankton fecal pellets to carbon export: insights from free-drifting sediment trap deployments in naturally iron-fertilised waters near the Kerguelen plateau, Biogeosciences, 12, 1007–1027, https://doi.org/10.5194/bg-12-1007-2015, 2015.
Laws, E. A., Falkowski, P. G., Smith, W. O., Ducklow, H., and McCarthy, J. J.: Temperature effects on export production the ocean, Global Biogeochem. Cy., 14, 1231–1246, 2000.
Lefèvre, D., Guigue, C., and Obernosterer, I.: The metabolic balance at two contrasting sites in the Southern Ocean: the iron-fertilized Kerguelen area and HNLC waters, Deep-Sea Res. Pt. II, 55, 766–776, 2008.
Le Moigne, F. A. C., Moore, C. M., Sanders, R. J., Villa-Alfageme, M., Steigenberger, S., and Achterberg, E. P.: Sequestration efficiency in the iron-limited North Atlantic: Implications for iron supply mode to fertilized blooms, Geophys. Res. Lett., 41, 4619–4627, https://doi.org/10.1002/2014GL060308, 2014.
Longhurst, A. R., Bedo, A. W., Harrison, W. G., Head, E. J. H., and Sameoto, D. D.: Vertical flux of respiratory carbon by oceanic diel migrant biota, Deep-Sea Res, 37, 685–694, 1990.
Maiti, K., Charette, M., Buesseler, K., and Kahru, M.: An inverse relationship between production and export efficiency in the Southern Ocean, Geophys. Res. Lett., 40, 1–5, 2013.
Martin, J. H., Knauer, G. A., Karl, D. M., and Broenkow, W. W.: VERTEX: carbon cycling in the NE Pacific, Deep-Sea Res., 34, 267–285, 1987.
Monnin, C., Jeandel, C., Cattaldo, T., and Dehairs, F.: The marine barite saturation state of the world's oceans, Mar. Chem., 65, 253–261, 1999.
Morris, P. J. and Charette, M. A.: A synthesis of upper oceancarbon and dissolved iron budgets for Southern Ocean natural iron fertilization studies, Deep-Sea Res., 90, 147–157, 2013.
Mosseri, J., Quéguiner, B., Armand, L. K., and Cornet-Barthaux, V.: Impact of iron on silicon utilization by diatoms in the Southern Ocean: a case study of Si/N cycle decoupling in a naturally iron-enriched area, Deep-Sea Res. Pt. II, 55, 801–819, 2008.
Park, Y.-H., Roquet, F., Durand, I., and Fuda, J.-L.: Large-scale circulation over and around the Northern Kerguelen Plateau, Deep-Sea Res. Pt. II, 55, 566–581, 2008.
Park, Y. H., Durand, I., Kestenare, E., Rougier, G., Zhou, M., d'Ovidio, F., Cotté, C., and Lee J. H.: Polar front around the Kerguelen islands: An up-to-date determination and associated circulation of surface/subsurface water, J. Geophys. Res. Oc., 119, 6575–6592, https://doi.org/10.1002/2014JC010061, 2014.
Passow, U. and Carlson, C. A.: The biological pump in a high CO2 world, Mar. Ecol. Prog. Ser., 470, 249–271, 2012.
Planchon, F., Cavagna A. J., Cardinal, D., André, L., and Dehairs, F.: Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean, Biogeosciences, 10, 803–820, https://doi.org/10.5194/bg-10-803-2013, 2013.
Planchon, F., Ballas, D., Cavagna A. J., Van Der Merwe, P., Bowie, A., Trull, T., Laurenceau-Cornec, E., Davis, D., and Dehairs, F.: Carbon export in the naturally iron fertilized Kerguelen area of the Southern Ocean using 234Th-based approach, Biogeosciences Discuss., 11, 15991–16032, https://doi.org/10.5194/bgd-11-15991-2014, 2014.
Porris, P. J., Sanders, R., Turnewithsch, R., and Thomalla, S.: 234Th-derived particulate organic carbon export from an island-induced phytoplankton blomm in the Southern Ocean,Deep-Sea Res. Pt. II, 24, 2208–2232, 2007.
Quéroué, F., Sarthou, G., Planquette, H. F., Bucciarelli, E., Chever, F., van der Merwe, P., Lannuzel, D., Townsend, A. T., Cheize, M., Blain, S., d'Ovidio, F., and Bowie, A. R.: High variability of dissolved iron concentrations in the vicinity of Kerguelen Island (Southern Ocean), Biogeosciences Discuss., 12, 231–270, https://doi.org/10.5194/bgd-12-231-2015, 2015.
Rembauville, M., Blain, S., Armand, L., Quéguiner, B., and Salter, I.: Export fluxes in a naturally fertilized area of the Southern Ocean, the Kerguelen Plateau: ecological vectors of carbon and biogenic silica to depth (Part 2), Biogeosciences Discuss., 11, 17089–17150, https://doi.org/10.5194/bgd-11-17089-2014, 2014.
Robinson, J., Popova, E. E., Yool, A., Srokosz, M. A., Lampitt, R. S., and Blundell, J. R.: How deep is deep enough? Ocean iron fertilization and carbon sequestration in the Southern Ocean, Geophys. Res. Lett., 41, 2489–2495, 2014.
Salter, I., Lampitt, R. S., Sanders, R., Poulton, A., Kemp, A. E. S., Boorman, B., Saw, K., and Pearce, R.: Estimating carbon, silica and diatom export from a naturally fertilised phytoplankton bloom in the Southern Ocean using PELAGRA: a novel drifting sediment trap, Deep-Sea Res. Pt. II, 54, 2233–2259, 2007.
Sarmiento, J. L., Slater, R. D., Fasham, M. J. R., Ducklow, H. W., and Toggweiler, J. R.: A seasonal three-dimensional ecosystem model of nitrogen cycling in the North Atlantic photic zone, Global Biogeochem. Cy., 7, 417–450, 1993.
Savoye, N., Trull, T., Jacquet, S. H. M., Navez, J., and Dehairs, F.: 234Th-derived export fluxes during a natural iron fertilization experiment (KEOPS), Deep-Sea Res. Pt. II, 55, 841–855, 2008.
Schlitzer, R.: Ocean Data View, http://www.awi-bremerhaven.de/GEO/ODV, 2002.
Schneider, B., Bopp, L., and Gehlen, M.: Assessing the sensitivity of modeled airsea CO2 exchange to the remineralization depth of particulate organic and inorganic carbon, Global Biogeochem. Cy., 22, GB3021, https://doi.org/10.1029/2007GB003100, 2008.
Shopova, D., Dehairs, F., and Baeyens, W.: A simple model of biogeochemical element distribution in the oceanic water column, J. Mar. Sy., 6, 331–344, 1995.
Smetacek, V., Klass, C., Strass, V. H., Assmy, P., Montresor, M., Cisewki, B., Savoye, N., Webb, A., d'Ovidio, F., Arrieta, J. M., Bathmann, U., Bellerby, R., Mine Berg, G., Croot, P., Gonzalez, S., Jenjes, J., Herndl, G. J., Hoffmann, L.J., Leach, H., Losh, M., Mills, M. M., Neill, C., Peeken, I., Rottgers, R., Sachs, O., Sauter, E., Schmidt, M. M., Schwarz, J., Terbruggen, A., and Wolf-Gladrow, D.: Deep carbon export from a Southern Ocean iron-fertilized diatom bloom, Nature, 487, 313–319, 2012.
Sternberg, E., Jeandel, C., Miquel, J.-C., Gasser, B., Souhaut, M., Arraes-Mescoff, R., and Francois R.: Particulate barium fluxes and export production in the northwestern Mediterranean, Mar. Chem. 105, 281–295, 2007.
Sternberg, E., Jeandel, C., Robin, E., and Souhaut, M.: Seasonal cycle of suspended barite in the Mediterranean Sea, Geochim. Cosmochim. Ac., 72, 4020–4034, 2008a.
Sternberg, E., Tang, D., Ho, T. Y., Jeandel, C., and Morel, M. M..: Barium uptake and adsorption in diatoms, Geochim. Cosmochim. Ac., 69, 2745–2752, 2008b.
Strass, V., Cisewski, B., Gonzales, S., Leach, H., Loquay, K.-D., Prandke, H., Rohr, H., and Thomas, M.: The physical setting of the European Iron Fertilization Experiment "EIFEX" in the Southern Ocean, Reports Pol. Mar. Res., 500, 15–49, 2005.
Stroobants, N., Dehairs, F., Goeyens, L., Vanderheijden, N., and Van Grieken, R.: Barite formation in the Southern Ocean water column, Mar. Chem., 35, 411–422, 1991.
Taylor, S. R. and McLennan, S. M.: The continental crust: its composition and evolution, Blackwell Scientif. Publicat., 312 pp., 1985.
van der Merwe, P., Bowie, A. R., Quéroué, F., Armand, L., Blain, S., Chever, F., Davies, D., Dehairs, F., Planchon, F., Sarthou, G., Townsend, A. T., and Trull, T.: Sourcing the iron in the naturally-fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics, Biogeosciences, 12, 739–755, https://doi.org/10.5194/bg-12-739-2015, 2015.
Venchiarutti, C., Jeandel, C., and Roy-Barman, M.: Particle dynamics study in the wake of Kerguelen Island using thorium isotopes, Deep-Sea Res. Pt. I, 55, 1343–1363, 2008.
Williams, P. J. and Jenkinson, N. W.: A transportable microprocessor-controlled precise Winkler titration suitable for field station and shipboard use, Limnol. Oceanogr., 27, 576–585, 1982.
Zhou, M., Zhu, Y., Dorland, R. D., and Measures, C. I.: Dynamics of the current system in the southern Drake Passage, Deep-Sea Res. Pt. I, 57, 1039–1048, 2010.
Zhou, M., Zhu, Y., Measures, C. I., Hatta, M., Charette, M. A., Gille, S. T., Frants, M., Jiang, M., and Mitchell, B. G.: Winter mesoscale circulation on the shelf slope region of the southern Drake Passage, Deep-Sea Res. Pt. II, 90, 4–14, 2013.
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