Articles | Volume 16, issue 2
https://doi.org/10.5194/bg-16-309-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/bg-16-309-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Jan 2019
Research article |
| 24 Jan 2019
| 24 Jan 2019
The export flux of particulate organic carbon derived from 210Po∕210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise
Earth and Environmental Sciences, the Graduate Center, City
University of New York, New York, USA
School of Earth and Environmental Sciences, Queens College, City
University of New York, Flushing, USA
Nolwenn Lemaitre
Department of Earth Sciences, Institute of Geochemistry and
Petrology, ETH-Zürich, Zürich, Switzerland
Maxi Castrillejo
Laboratory of Ion Beam Physics, ETH-Zürich, Otto Stern Weg 5,
Zürich, 8093, Switzerland
Institut de Ciència i Tecnologia Ambientals and Departament de
Física, Universitat Autònoma de Barcelona, Barcelona, Spain
Montserrat Roca-Martí
Institut de Ciència i Tecnologia Ambientals and Departament de
Física, Universitat Autònoma de Barcelona, Barcelona, Spain
Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
Pere Masqué
Institut de Ciència i Tecnologia Ambientals and Departament de
Física, Universitat Autònoma de Barcelona, Barcelona, Spain
School of Science and Centre for Marine Ecosystems Research, Edith
Cowan University, Joondalup, Western Australia, Australia
Gillian Stewart
CORRESPONDING AUTHOR
School of Earth and Environmental Sciences, Queens College, City
University of New York, Flushing, USA
Earth and Environmental Sciences, the Graduate Center, City
University of New York, New York, USA
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The GEOVIDE cruise (GEOTRACES Section GA01) was conducted in the North Atlantic Ocean and Labrador Sea in May–June 2014. In this special issue, results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 17 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue.
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We investigated the surface particulate organic carbon export fluxes in the North Atlantic with the objective of better understanding the biological carbon pump. Our results highlighted that exports depended on the intensity and stage of the bloom, the phytoplankton size and community structures. After comparing with primary production, we concluded that, during our study, the North Atlantic behaves like most of the highly productive areas in the world's ocean, with a low export efficiency.
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We measured two natural radio-isotopes, 210Po and 210Pb, in the dissolved and particulate phase along the GEOVIDE cruise track to try to understand the cycling of these isotopes across a diverse combination of currents, basins, and conditions in the North Atlantic Ocean. Other groups collected data on many other trace elements and isotopes in order to map them as part of the GEOTRACES program. We found that Po and Pb activity was concentrated on small particles and varied within/between basins.
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Sarah Paradis, Antonio Pusceddu, Pere Masqué, Pere Puig, Davide Moccia, Tommaso Russo, and Claudio Lo Iacono
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Chronic deep bottom trawling in the Gulf of Castellammare (SW Mediterranean) erodes large volumes of sediment, exposing over-century-old sediment depleted in organic matter. Nevertheless, the arrival of fresh and nutritious sediment recovers superficial organic matter in trawling grounds and leads to high turnover rates, partially and temporarily mitigating the impacts of bottom trawling. However, this deposition is ephemeral and it will be swiftly eroded by the passage of the next trawler.
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Biogeosciences, 16, 1563–1582, https://doi.org/10.5194/bg-16-1563-2019, https://doi.org/10.5194/bg-16-1563-2019, 2019
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The GEOVIDE cruise (May–June 2014, R/V Pourquoi Pas?) aimed to provide a better understanding of trace metal biogeochemical cycles in the North Atlantic. As particles play a key role in the global biogeochemical cycle of trace elements in the ocean, we discuss the distribution of particulate iron (PFe). Lithogenic sources appear to dominate the PFe cycle through margin and benthic inputs.
Debany Fonseca-Batista, Xuefeng Li, Virginie Riou, Valérie Michotey, Florian Deman, François Fripiat, Sophie Guasco, Natacha Brion, Nolwenn Lemaitre, Manon Tonnard, Morgane Gallinari, Hélène Planquette, Frédéric Planchon, Géraldine Sarthou, Marc Elskens, Julie LaRoche, Lei Chou, and Frank Dehairs
Biogeosciences, 16, 999–1017, https://doi.org/10.5194/bg-16-999-2019, https://doi.org/10.5194/bg-16-999-2019, 2019
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Feifei Deng, Gideon M. Henderson, Maxi Castrillejo, Fiz F. Perez, and Reiner Steinfeldt
Biogeosciences, 15, 7299–7313, https://doi.org/10.5194/bg-15-7299-2018, https://doi.org/10.5194/bg-15-7299-2018, 2018
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Géraldine Sarthou, Pascale Lherminier, Eric P. Achterberg, Fernando Alonso-Pérez, Eva Bucciarelli, Julia Boutorh, Vincent Bouvier, Edward A. Boyle, Pierre Branellec, Lidia I. Carracedo, Nuria Casacuberta, Maxi Castrillejo, Marie Cheize, Leonardo Contreira Pereira, Daniel Cossa, Nathalie Daniault, Emmanuel De Saint-Léger, Frank Dehairs, Feifei Deng, Floriane Desprez de Gésincourt, Jérémy Devesa, Lorna Foliot, Debany Fonseca-Batista, Morgane Gallinari, Maribel I. García-Ibáñez, Arthur Gourain, Emilie Grossteffan, Michel Hamon, Lars Eric Heimbürger, Gideon M. Henderson, Catherine Jeandel, Catherine Kermabon, François Lacan, Philippe Le Bot, Manon Le Goff, Emilie Le Roy, Alison Lefèbvre, Stéphane Leizour, Nolwenn Lemaitre, Pere Masqué, Olivier Ménage, Jan-Lukas Menzel Barraqueta, Herlé Mercier, Fabien Perault, Fiz F. Pérez, Hélène F. Planquette, Frédéric Planchon, Arnout Roukaerts, Virginie Sanial, Raphaëlle Sauzède, Catherine Schmechtig, Rachel U. Shelley, Gillian Stewart, Jill N. Sutton, Yi Tang, Nadine Tisnérat-Laborde, Manon Tonnard, Paul Tréguer, Pieter van Beek, Cheryl M. Zurbrick, and Patricia Zunino
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Ariane Arias-Ortiz, Pere Masqué, Jordi Garcia-Orellana, Oscar Serrano, Inés Mazarrasa, Núria Marbà, Catherine E. Lovelock, Paul S. Lavery, and Carlos M. Duarte
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Efforts to include tidal marsh, mangrove and seagrass ecosystems in existing carbon mitigation strategies are limited by a lack of estimates of carbon accumulation rates (CARs). We discuss the use of 210Pb dating to determine CARs in these habitats, which are often composed of heterogeneous sediments and affected by sedimentary processes. Results show that obtaining reliable geochronologies in these systems is ambitious, but estimates of mean 100-year CARs are mostly secure within 20 % error.
Nolwenn Lemaitre, Frédéric Planchon, Hélène Planquette, Frank Dehairs, Debany Fonseca-Batista, Arnout Roukaerts, Florian Deman, Yi Tang, Clarisse Mariez, and Géraldine Sarthou
Biogeosciences, 15, 6417–6437, https://doi.org/10.5194/bg-15-6417-2018, https://doi.org/10.5194/bg-15-6417-2018, 2018
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We investigated the surface particulate organic carbon export fluxes in the North Atlantic with the objective of better understanding the biological carbon pump. Our results highlighted that exports depended on the intensity and stage of the bloom, the phytoplankton size and community structures. After comparing with primary production, we concluded that, during our study, the North Atlantic behaves like most of the highly productive areas in the world's ocean, with a low export efficiency.
Maxi Castrillejo, Núria Casacuberta, Marcus Christl, Christof Vockenhuber, Hans-Arno Synal, Maribel I. García-Ibáñez, Pascale Lherminier, Géraldine Sarthou, Jordi Garcia-Orellana, and Pere Masqué
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Yi Tang, Maxi Castrillejo, Montserrat Roca-Martí, Pere Masqué, Nolwenn Lemaitre, and Gillian Stewart
Biogeosciences, 15, 5437–5453, https://doi.org/10.5194/bg-15-5437-2018, https://doi.org/10.5194/bg-15-5437-2018, 2018
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We measured two natural radio-isotopes, 210Po and 210Pb, in the dissolved and particulate phase along the GEOVIDE cruise track to try to understand the cycling of these isotopes across a diverse combination of currents, basins, and conditions in the North Atlantic Ocean. Other groups collected data on many other trace elements and isotopes in order to map them as part of the GEOTRACES program. We found that Po and Pb activity was concentrated on small particles and varied within/between basins.
Nolwenn Lemaitre, Hélène Planquette, Frédéric Planchon, Géraldine Sarthou, Stéphanie Jacquet, Maribel I. García-Ibáñez, Arthur Gourain, Marie Cheize, Laurence Monin, Luc André, Priya Laha, Herman Terryn, and Frank Dehairs
Biogeosciences, 15, 2289–2307, https://doi.org/10.5194/bg-15-2289-2018, https://doi.org/10.5194/bg-15-2289-2018, 2018
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We present the particulate biogenic barium distributions in the North Atlantic for the first time with the objective of estimating mesopelagic carbon remineralisation fluxes. The remineralisation fluxes balanced or slightly exceeded the upper-ocean carbon export fluxes. This is a key result as the North Atlantic is generally assumed to be efficient in transferring carbon to the deep ocean, but during our study, the North Atlantic was characterized by a near-zero carbon sequestration efficiency.
B. L. Mackinson, S. B. Moran, M. W. Lomas, G. M. Stewart, and R. P. Kelly
Biogeosciences, 12, 3429–3446, https://doi.org/10.5194/bg-12-3429-2015, https://doi.org/10.5194/bg-12-3429-2015, 2015
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Optimal parameters for the ocean's nutrient, carbon, and oxygen cycles compensate for circulation biases but replumb the biological pump
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All about nitrite: exploring nitrite sources and sinks in the eastern tropical North Pacific oxygen minimum zone
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Reconstructing ocean carbon storage with CMIP6 Earth system models and synthetic Argo observations
Using machine learning and Biogeochemical-Argo (BGC-Argo) floats to assess biogeochemical models and optimize observing system design
The representation of alkalinity and the carbonate pump from CMIP5 to CMIP6 Earth system models and implications for the carbon cycle
Model estimates of metazoans' contributions to the biological carbon pump
Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean
Nitrite cycling in the primary nitrite maxima of the eastern tropical North Pacific
Hotspots and drivers of compound marine heatwaves and low net primary production extremes
Ecosystem impacts of marine heat waves in the northeast Pacific
Tracing the role of Arctic shelf processes in Si and N cycling and export through the Fram Strait: insights from combined silicon and nitrate isotopes
Controls on the relative abundances and rates of nitrifying microorganisms in the ocean
The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
Influence of GEOTRACES data distribution and misfit function choice on objective parameter retrieval in a marine zinc cycle model
Physiological flexibility of phytoplankton impacts modelled chlorophyll and primary production across the North Pacific Ocean
Observation-constrained estimates of the global ocean carbon sink from Earth system models
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Controlling factors on the global distribution of a representative marine non-cyanobacterial diazotroph phylotype (Gamma A)
Summer trends and drivers of sea surface fCO2 and pH changes observed in the southern Indian Ocean over the last two decades (1998–2019)
Global nutrient cycling by commercially targeted marine fish
Major processes of the dissolved cobalt cycle in the North and equatorial Pacific Ocean
The impact of the South-East Madagascar Bloom on the oceanic CO2 sink
Nitrite regeneration in the oligotrophic Atlantic Ocean
Bridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the ocean
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Acidification of the Nordic Seas
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N2 fixation in the Mediterranean Sea related to the composition of the diazotrophic community and impact of dust under present and future environmental conditions
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Subsurface iron accumulation and rapid aluminum removal in the Mediterranean following African dust deposition
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Anna Belcher, Sian F. Henley, Katharine Hendry, Marianne Wootton, Lisa Friberg, Ursula Dallman, Tong Wang, Christopher Coath, and Clara Manno
Biogeosciences, 20, 3573–3591, https://doi.org/10.5194/bg-20-3573-2023, https://doi.org/10.5194/bg-20-3573-2023, 2023
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The oceans play a crucial role in the uptake of atmospheric carbon dioxide, particularly the Southern Ocean. The biological pumping of carbon from the surface to the deep ocean is key to this. Using sediment trap samples from the Scotia Sea, we examine biogeochemical fluxes of carbon, nitrogen, and biogenic silica and their stable isotope compositions. We find phytoplankton community structure and physically mediated processes are important controls on particulate fluxes to the deep ocean.
Sabine Mecking and Kyla Drushka
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-132, https://doi.org/10.5194/bg-2023-132, 2023
Revised manuscript accepted for BG
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This study investigates whether northeastern North Pacific oxygen changes may be caused by surface density changes in the northwest as water moves along density horizons from the surface into the subsurface ocean. A correlation is found with a lag that matches about the travel time of water from the northwest to the northeast. Salinity is the main driver causing decadal changes in surface density whereas salinity and temperature contribute about equally to long-term declining density trends.
Asmita Singh, Susanne Fietz, Sandy J. Thomalla, Nicolas Sanchez, Murat V. Ardelan, Sébastien Moreau, Hanna M. Kauko, Agneta Fransson, Melissa Chierici, Saumik Samanta, Thato N. Mtshali, Alakendra N. Roychoudhury, and Thomas J. Ryan-Keogh
Biogeosciences, 20, 3073–3091, https://doi.org/10.5194/bg-20-3073-2023, https://doi.org/10.5194/bg-20-3073-2023, 2023
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Despite the scarcity of iron in the Southern Ocean, seasonal blooms occur due to changes in nutrient and light availability. Surprisingly, during an autumn bloom in the Antarctic sea-ice zone, the results from incubation experiments showed no significant photophysiological response of phytoplankton to iron addition. This suggests that ambient iron concentrations were sufficient, challenging the notion of iron deficiency in the Southern Ocean through extended iron-replete post-bloom conditions.
Benoît Pasquier, Mark Holzer, Matthew A. Chamberlain, Richard J. Matear, Nathaniel L. Bindoff, and François W. Primeau
Biogeosciences, 20, 2985–3009, https://doi.org/10.5194/bg-20-2985-2023, https://doi.org/10.5194/bg-20-2985-2023, 2023
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Modeling the ocean's carbon and oxygen cycles accurately is challenging. Parameter optimization improves the fit to observed tracers but can introduce artifacts in the biological pump. Organic-matter production and subsurface remineralization rates adjust to compensate for circulation biases, changing the pathways and timescales with which nutrients return to the surface. Circulation biases can thus strongly alter the system’s response to ecological change, even when parameters are optimized.
Priyanka Banerjee
Biogeosciences, 20, 2613–2643, https://doi.org/10.5194/bg-20-2613-2023, https://doi.org/10.5194/bg-20-2613-2023, 2023
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This study shows that atmospheric deposition is the most important source of iron to the upper northern Indian Ocean for phytoplankton growth. This is followed by iron from continental-shelf sediment. Phytoplankton increase following iron addition is possible only with high background levels of nitrate. Vertical mixing is the most important physical process supplying iron to the upper ocean in this region throughout the year. The importance of ocean currents in supplying iron varies seasonally.
Iris Kriest, Julia Getzlaff, Angela Landolfi, Volkmar Sauerland, Markus Schartau, and Andreas Oschlies
Biogeosciences, 20, 2645–2669, https://doi.org/10.5194/bg-20-2645-2023, https://doi.org/10.5194/bg-20-2645-2023, 2023
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John C. Tracey, Andrew R. Babbin, Elizabeth Wallace, Xin Sun, Katherine L. DuRussel, Claudia Frey, Donald E. Martocello III, Tyler Tamasi, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 20, 2499–2523, https://doi.org/10.5194/bg-20-2499-2023, https://doi.org/10.5194/bg-20-2499-2023, 2023
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Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-76, https://doi.org/10.5194/bg-2023-76, 2023
Revised manuscript accepted for BG
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The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit on these autonomous measurements platforms. By applying the Argo correction routines to float-pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Amanda Gerotto, Hongrui Zhang, Renata Hanae Nagai, Heather M. Stoll, Rubens César Lopes Figueira, Chuanlian Liu, and Iván Hernández-Almeida
Biogeosciences, 20, 1725–1739, https://doi.org/10.5194/bg-20-1725-2023, https://doi.org/10.5194/bg-20-1725-2023, 2023
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Based on the analysis of the response of coccolithophores’ morphological attributes in a laboratory dissolution experiment and surface sediment samples from the South China Sea, we proposed that the thickness shape (ks) factor of fossil coccoliths together with the normalized ks variation, which is the ratio of the standard deviation of ks (σ) over the mean ks (σ/ks), is a robust and novel proxy to reconstruct past changes in deep ocean carbon chemistry.
Takamitsu Ito, Hernan E. Garcia, Zhankun Wang, Shoshiro Minobe, Matthew C. Long, Just Cebrian, James Reagan, Tim Boyer, Christopher Paver, Courtney Bouchard, Yohei Takano, Seth Bushinsky, Ahron Cervania, and Curtis A. Deutsch
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-72, https://doi.org/10.5194/bg-2023-72, 2023
Revised manuscript accepted for BG
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This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainties comes from the statistical gap-fill methods. Outputs from earth system models are used to generate synthetic observations where oxygen data is extracted from the model output at the location and time of historical oceangraphic cruises. Reconstructed oxygen trend is approximately two thirds of the true trend.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences, 20, 1671–1690, https://doi.org/10.5194/bg-20-1671-2023, https://doi.org/10.5194/bg-20-1671-2023, 2023
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We present a new method for reconstructing ocean carbon using climate models and temperature and salinity observations. To test this method, we reconstruct modelled carbon using synthetic observations consistent with current sampling programmes. Sensitivity tests show skill in reconstructing carbon trends and variability within the upper 2000 m. Our results indicate that this method can be used for a new global estimate for ocean carbon content.
Alexandre Mignot, Hervé Claustre, Gianpiero Cossarini, Fabrizio D'Ortenzio, Elodie Gutknecht, Julien Lamouroux, Paolo Lazzari, Coralie Perruche, Stefano Salon, Raphaëlle Sauzède, Vincent Taillandier, and Anna Teruzzi
Biogeosciences, 20, 1405–1422, https://doi.org/10.5194/bg-20-1405-2023, https://doi.org/10.5194/bg-20-1405-2023, 2023
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Numerical models of ocean biogeochemistry are becoming a major tool to detect and predict the impact of climate change on marine resources and monitor ocean health. Here, we demonstrate the use of the global array of BGC-Argo floats for the assessment of biogeochemical models. We first detail the handling of the BGC-Argo data set for model assessment purposes. We then present 23 assessment metrics to quantify the consistency of BGC model simulations with respect to BGC-Argo data.
Alban Planchat, Lester Kwiatkowski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschön, Tomas Lovato, Roland Séférian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jörg Schwinger, Jerry Tjiputra, John P. Dunne, and Charles Stock
Biogeosciences, 20, 1195–1257, https://doi.org/10.5194/bg-20-1195-2023, https://doi.org/10.5194/bg-20-1195-2023, 2023
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Ocean alkalinity is critical to the uptake of atmospheric carbon and acidification in surface waters. We review the representation of alkalinity and the associated calcium carbonate cycle in Earth system models. While many parameterizations remain present in the latest generation of models, there is a general improvement in the simulated alkalinity distribution. This improvement is related to an increase in the export of biotic calcium carbonate, which closer resembles observations.
Jérôme Pinti, Tim DeVries, Tommy Norin, Camila Serra-Pompei, Roland Proud, David A. Siegel, Thomas Kiørboe, Colleen M. Petrik, Ken H. Andersen, Andrew S. Brierley, and André W. Visser
Biogeosciences, 20, 997–1009, https://doi.org/10.5194/bg-20-997-2023, https://doi.org/10.5194/bg-20-997-2023, 2023
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Large numbers of marine organisms such as zooplankton and fish perform daily vertical migration between the surface (at night) and the depths (in the daytime). This fascinating migration is important for the carbon cycle, as these organisms actively bring carbon to depths where it is stored away from the atmosphere for a long time. Here, we quantify the contributions of different animals to this carbon drawdown and storage and show that fish are important to the biological carbon pump.
Alastair J. M. Lough, Alessandro Tagliabue, Clément Demasy, Joseph A. Resing, Travis Mellett, Neil J. Wyatt, and Maeve C. Lohan
Biogeosciences, 20, 405–420, https://doi.org/10.5194/bg-20-405-2023, https://doi.org/10.5194/bg-20-405-2023, 2023
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Iron is a key nutrient for ocean primary productivity. Hydrothermal vents are a source of iron to the oceans, but the size of this source is poorly understood. This study examines the variability in iron inputs between hydrothermal vents in different geological settings. The vents studied release different amounts of Fe, resulting in plumes with similar dissolved iron concentrations but different particulate concentrations. This will help to refine modelling of iron-limited ocean productivity.
Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
Biogeosciences, 20, 325–347, https://doi.org/10.5194/bg-20-325-2023, https://doi.org/10.5194/bg-20-325-2023, 2023
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The primary nitrite maximum is a ubiquitous upper ocean feature where nitrite accumulates, but we still do not understand its formation and the co-occurring microbial processes involved. Using correlative methods and rates measurements, we found strong spatial patterns between environmental conditions and depths of the nitrite maxima, but not the maximum concentrations. Nitrification was the dominant source of nitrite, with occasional high nitrite production from phytoplankton near the coast.
Natacha Le Grix, Jakob Zscheischler, Keith B. Rodgers, Ryohei Yamaguchi, and Thomas L. Frölicher
Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth system models. The models share similar drivers in the low latitudes but disagree in the high latitudes due to divergent factors limiting phytoplankton production.
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022, https://doi.org/10.5194/bg-19-5689-2022, 2022
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Marine heat waves (MHWs) are a frequent event in the northeast Pacific, with a large impact on the region's ecosystems. Large phytoplankton in the North Pacific Transition Zone are greatly affected by decreased nutrients, with less of an impact in the Alaskan Gyre. For small phytoplankton, MHWs increase the spring small phytoplankton population in both regions thanks to reduced light limitation. In both zones, this results in a significant decrease in the ratio of large to small phytoplankton.
Margot C. F. Debyser, Laetitia Pichevin, Robyn E. Tuerena, Paul A. Dodd, Antonia Doncila, and Raja S. Ganeshram
Biogeosciences, 19, 5499–5520, https://doi.org/10.5194/bg-19-5499-2022, https://doi.org/10.5194/bg-19-5499-2022, 2022
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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We use a microbial ecosystem model to quantitatively explain the mechanisms controlling observed relative abundances and nitrification rates of ammonia- and nitrite-oxidizing microorganisms in the ocean. We also estimate how much global carbon fixation can be associated with chemoautotrophic nitrification. Our results improve our understanding of the controls on nitrification, laying the groundwork for more accurate predictions in global climate models.
Zuozhu Wen, Thomas J. Browning, Rongbo Dai, Wenwei Wu, Weiying Li, Xiaohua Hu, Wenfang Lin, Lifang Wang, Xin Liu, Zhimian Cao, Haizheng Hong, and Dalin Shi
Biogeosciences, 19, 5237–5250, https://doi.org/10.5194/bg-19-5237-2022, https://doi.org/10.5194/bg-19-5237-2022, 2022
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Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
Claudia Eisenring, Sophy E. Oliver, Samar Khatiwala, and Gregory F. de Souza
Biogeosciences, 19, 5079–5106, https://doi.org/10.5194/bg-19-5079-2022, https://doi.org/10.5194/bg-19-5079-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Yoshikazu Sasai, Sherwood Lan Smith, Eko Siswanto, Hideharu Sasaki, and Masami Nonaka
Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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We have investigated the adaptive response of phytoplankton growth to changing light, nutrients, and temperature over the North Pacific using two physical-biological models. We compare modeled chlorophyll and primary production from an inflexible control model (InFlexPFT), which assumes fixed carbon (C):nitrogen (N):chlorophyll (Chl) ratios, to a recently developed flexible phytoplankton functional type model (FlexPFT), which incorporates photoacclimation and variable C:N:Chl ratios.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Nolwenn Lemaitre, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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This study quantifies the role of commercially targeted fish biomass in the cycling of three important nutrients (N, P, and Fe), relative to nutrients otherwise available in water and to nutrients required by primary producers, and the impact of fishing. We use a model of commercially targeted fish biomass constrained by fish catch and stock assessment data to assess the contributions of fish at the global scale, at the time of the global peak catch and prior to industrial fishing.
Rebecca Chmiel, Nathan Lanning, Allison Laubach, Jong-Mi Lee, Jessica Fitzsimmons, Mariko Hatta, William Jenkins, Phoebe Lam, Matthew McIlvin, Alessandro Tagliabue, and Mak Saito
Biogeosciences, 19, 2365–2395, https://doi.org/10.5194/bg-19-2365-2022, https://doi.org/10.5194/bg-19-2365-2022, 2022
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Dissolved cobalt is present in trace amounts in seawater and is a necessary nutrient for marine microbes. On a transect from the Alaskan coast to Tahiti, we measured seawater concentrations of dissolved cobalt. Here, we describe several interesting features of the Pacific cobalt cycle including cobalt sources along the Alaskan coast and Hawaiian vents, deep-ocean particle formation, cobalt activity in low-oxygen regions, and how our samples compare to a global biogeochemical model’s predictions.
Nicolas Metzl, Claire Lo Monaco, Coraline Leseurre, Céline Ridame, Jonathan Fin, Claude Mignon, Marion Gehlen, and Thi Tuyet Trang Chau
Biogeosciences, 19, 1451–1468, https://doi.org/10.5194/bg-19-1451-2022, https://doi.org/10.5194/bg-19-1451-2022, 2022
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During an oceanographic cruise conducted in January 2020 in the south-western Indian Ocean, we observed very low CO2 concentrations associated with a strong phytoplankton bloom that occurred south-east of Madagascar. This biological event led to a strong regional CO2 ocean sink not previously observed.
Darren R. Clark, Andrew P. Rees, Charissa M. Ferrera, Lisa Al-Moosawi, Paul J. Somerfield, Carolyn Harris, Graham D. Quartly, Stephen Goult, Glen Tarran, and Gennadi Lessin
Biogeosciences, 19, 1355–1376, https://doi.org/10.5194/bg-19-1355-2022, https://doi.org/10.5194/bg-19-1355-2022, 2022
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Measurements of microbial processes were made in the sunlit open ocean during a research cruise (AMT19) between the UK and Chile. These help us to understand how microbial communities maintain the function of remote ecosystems. We find that the nitrogen cycling microbes which produce nitrite respond to changes in the environment. Our insights will aid the development of models that aim to replicate and ultimately project how marine environments may respond to ongoing climate change.
Martí Galí, Marcus Falls, Hervé Claustre, Olivier Aumont, and Raffaele Bernardello
Biogeosciences, 19, 1245–1275, https://doi.org/10.5194/bg-19-1245-2022, https://doi.org/10.5194/bg-19-1245-2022, 2022
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Part of the organic matter produced by plankton in the upper ocean is exported to the deep ocean. This process, known as the biological carbon pump, is key for the regulation of atmospheric carbon dioxide and global climate. However, the dynamics of organic particles below the upper ocean layer are not well understood. Here we compared the measurements acquired by autonomous robots in the top 1000 m of the ocean to a numerical model, which can help improve future climate projections.
Marie Barbieux, Julia Uitz, Alexandre Mignot, Collin Roesler, Hervé Claustre, Bernard Gentili, Vincent Taillandier, Fabrizio D'Ortenzio, Hubert Loisel, Antoine Poteau, Edouard Leymarie, Christophe Penkerc'h, Catherine Schmechtig, and Annick Bricaud
Biogeosciences, 19, 1165–1194, https://doi.org/10.5194/bg-19-1165-2022, https://doi.org/10.5194/bg-19-1165-2022, 2022
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This study assesses marine biological production in two Mediterranean systems representative of vast desert-like (oligotrophic) areas encountered in the global ocean. We use a novel approach based on non-intrusive high-frequency in situ measurements by two profiling robots, the BioGeoChemical-Argo (BGC-Argo) floats. Our results indicate substantial yet variable production rates and contribution to the whole water column of the subsurface layer, typically considered steady and non-productive.
Filippa Fransner, Friederike Fröb, Jerry Tjiputra, Nadine Goris, Siv K. Lauvset, Ingunn Skjelvan, Emil Jeansson, Abdirahman Omar, Melissa Chierici, Elizabeth Jones, Agneta Fransson, Sólveig R. Ólafsdóttir, Truls Johannessen, and Are Olsen
Biogeosciences, 19, 979–1012, https://doi.org/10.5194/bg-19-979-2022, https://doi.org/10.5194/bg-19-979-2022, 2022
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Ocean acidification, a direct consequence of the CO2 release by human activities, is a serious threat to marine ecosystems. In this study, we conduct a detailed investigation of the acidification of the Nordic Seas, from 1850 to 2100, by using a large set of samples taken during research cruises together with numerical model simulations. We estimate the effects of changes in different environmental factors on the rate of acidification and its potential effects on cold-water corals.
Guorong Zhong, Xuegang Li, Jinming Song, Baoxiao Qu, Fan Wang, Yanjun Wang, Bin Zhang, Xiaoxia Sun, Wuchang Zhang, Zhenyan Wang, Jun Ma, Huamao Yuan, and Liqin Duan
Biogeosciences, 19, 845–859, https://doi.org/10.5194/bg-19-845-2022, https://doi.org/10.5194/bg-19-845-2022, 2022
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A predictor selection algorithm was constructed to decrease the predicting error in the surface ocean partial pressure of CO2 (pCO2) mapping by finding better combinations of pCO2 predictors in different regions. Compared with previous research using the same combination of predictors in all regions, using different predictors selected by the algorithm in different regions can effectively decrease pCO2 predicting errors.
Shantelle Smith, Katye E. Altieri, Mhlangabezi Mdutyana, David R. Walker, Ruan G. Parrott, Sedick Gallie, Kurt A. M. Spence, Jessica M. Burger, and Sarah E. Fawcett
Biogeosciences, 19, 715–741, https://doi.org/10.5194/bg-19-715-2022, https://doi.org/10.5194/bg-19-715-2022, 2022
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Ammonium is a crucial yet poorly understood component of the Southern Ocean nitrogen cycle. We attribute our finding of consistently high ammonium concentrations in the winter mixed layer to limited ammonium consumption and sustained ammonium production, conditions under which the Southern Ocean becomes a source of carbon dioxide to the atmosphere. From similar data collected over an annual cycle, we propose a seasonal cycle for ammonium in shallow polar waters – a first for the Southern Ocean.
Jannes Koelling, Dariia Atamanchuk, Johannes Karstensen, Patricia Handmann, and Douglas W. R. Wallace
Biogeosciences, 19, 437–454, https://doi.org/10.5194/bg-19-437-2022, https://doi.org/10.5194/bg-19-437-2022, 2022
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In this study, we investigate oxygen variability in the deep western boundary current in the Labrador Sea from multiyear moored records. We estimate that about half of the oxygen taken up in the interior Labrador Sea by air–sea gas exchange during deep water formation is exported southward the same year. Our results underline the complexity of the oxygen uptake and export in the Labrador Sea and highlight the important role this region plays in supplying oxygen to the deep ocean.
Céline Ridame, Julie Dinasquet, Søren Hallstrøm, Estelle Bigeard, Lasse Riemann, France Van Wambeke, Matthieu Bressac, Elvira Pulido-Villena, Vincent Taillandier, Fréderic Gazeau, Antonio Tovar-Sanchez, Anne-Claire Baudoux, and Cécile Guieu
Biogeosciences, 19, 415–435, https://doi.org/10.5194/bg-19-415-2022, https://doi.org/10.5194/bg-19-415-2022, 2022
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We show that in the Mediterranean Sea spatial variability in N2 fixation is related to the diazotrophic community composition reflecting different nutrient requirements among species. Nutrient supply by Saharan dust is of great importance to diazotrophs, as shown by the strong stimulation of N2 fixation after a simulated dust event under present and future climate conditions; the magnitude of stimulation depends on the degree of limitation related to the diazotrophic community composition.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
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A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Gerhard Fischer, Oscar E. Romero, Johannes Karstensen, Karl-Heinz Baumann, Nasrollah Moradi, Morten Iversen, Götz Ruhland, Marco Klann, and Arne Körtzinger
Biogeosciences, 18, 6479–6500, https://doi.org/10.5194/bg-18-6479-2021, https://doi.org/10.5194/bg-18-6479-2021, 2021
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Low-oxygen eddies in the eastern subtropical North Atlantic can form an oasis for phytoplankton growth. Here we report on particle flux dynamics at the oligotrophic Cape Verde Ocean Observatory. We observed consistent flux patterns during the passages of low-oxygen eddies. We found distinct flux peaks in late winter, clearly exceeding background fluxes. Our findings suggest that the low-oxygen eddies sequester higher organic carbon than expected for oligotrophic settings.
Matthieu Bressac, Thibaut Wagener, Nathalie Leblond, Antonio Tovar-Sánchez, Céline Ridame, Vincent Taillandier, Samuel Albani, Sophie Guasco, Aurélie Dufour, Stéphanie H. M. Jacquet, François Dulac, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 6435–6453, https://doi.org/10.5194/bg-18-6435-2021, https://doi.org/10.5194/bg-18-6435-2021, 2021
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Phytoplankton growth is limited by the availability of iron in about 50 % of the ocean. Atmospheric deposition of desert dust represents a key source of iron. Here, we present direct observations of dust deposition in the Mediterranean Sea. A key finding is that the input of iron from dust primarily occurred in the deep ocean, while previous studies mainly focused on the ocean surface. This new insight will enable us to better represent controls on global marine productivity in models.
Léo Berline, Andrea Michelangelo Doglioli, Anne Petrenko, Stéphanie Barrillon, Boris Espinasse, Frederic A. C. Le Moigne, François Simon-Bot, Melilotus Thyssen, and François Carlotti
Biogeosciences, 18, 6377–6392, https://doi.org/10.5194/bg-18-6377-2021, https://doi.org/10.5194/bg-18-6377-2021, 2021
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While the Ionian Sea is considered a nutrient-depleted and low-phytoplankton biomass area, it is a crossroad for water mass circulation. In the central Ionian Sea, we observed a strong contrast in particle distribution across a ~100 km long transect. Using remote sensing and Lagrangian simulations, we suggest that this contrast finds its origin in the long-distance transport of particles from the north, west and east of the Ionian Sea, where phytoplankton production was more intense.
Anna Teruzzi, Giorgio Bolzon, Laura Feudale, and Gianpiero Cossarini
Biogeosciences, 18, 6147–6166, https://doi.org/10.5194/bg-18-6147-2021, https://doi.org/10.5194/bg-18-6147-2021, 2021
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During summer, maxima of phytoplankton chlorophyll concentration (DCM) occur in the subsurface of the Mediterranean Sea and can play a relevant role in carbon sequestration into the ocean interior. A numerical model based on in situ and satellite observations provides insights into the range of DCM conditions across the relatively small Mediterranean Sea and shows a western DCM that is 25 % shallower and with a higher phytoplankton chlorophyll concentration than in the eastern Mediterranean.
Elvira Pulido-Villena, Karine Desboeufs, Kahina Djaoudi, France Van Wambeke, Stéphanie Barrillon, Andrea Doglioli, Anne Petrenko, Vincent Taillandier, Franck Fu, Tiphanie Gaillard, Sophie Guasco, Sandra Nunige, Sylvain Triquet, and Cécile Guieu
Biogeosciences, 18, 5871–5889, https://doi.org/10.5194/bg-18-5871-2021, https://doi.org/10.5194/bg-18-5871-2021, 2021
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We report on phosphorus dynamics in the surface layer of the Mediterranean Sea. Highly sensitive phosphate measurements revealed vertical gradients above the phosphacline. The relative contribution of diapycnal fluxes to total external supply of phosphate to the mixed layer decreased towards the east, where atmospheric deposition dominated. Taken together, external sources of phosphate contributed little to total supply, which was mainly sustained by enzymatic hydrolysis of organic phosphorus.
Zouhair Lachkar, Michael Mehari, Muchamad Al Azhar, Marina Lévy, and Shafer Smith
Biogeosciences, 18, 5831–5849, https://doi.org/10.5194/bg-18-5831-2021, https://doi.org/10.5194/bg-18-5831-2021, 2021
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This study documents and quantifies a significant recent oxygen decline in the upper layers of the Arabian Sea and explores its drivers. Using a modeling approach we show that the fast local warming of sea surface is the main factor causing this oxygen drop. Concomitant summer monsoon intensification contributes to this trend, although to a lesser extent. These changes exacerbate oxygen depletion in the subsurface, threatening marine habitats and altering the local biogeochemistry.
Cited articles
Acker, J. G. and Leptoukh, G.: Online Analysis Enhances Use of NASA Earth
Science Data, Eos Trans. AGU, 88, 14–17, 2007.
Behrenfeld, M. J. and Falkowski, P. G.: Photosynthetic rates derived from satellite-based chlorophyll concentration,
Limnol. Oceanogr., 42, 1–20, https://doi.org/10.4319/lo.1997.42.1.0001, 1997.
Bhat, S. G., Krishnaswamy, S., Lal, D., Rama, and Moore, W. S.: 234Th/238U
ratios in the ocean, Earth Planet. Sc. Lett., 5, 483–491,
1968.
Broecker, W. S., Kaufman, A., and Trier, R. M.: The residence time of thorium in surface sea water and its implications
regarding the rate of reactive pollutants, Earth Planet. Sc. Lett., 20, 35–44, https://doi.org/10.1016/0012-821X(73)90137-4, 1973.
Buesseler, K. O.: The decoupling of production and particulate export in the
surface ocean, Global Biogeochem. Cy., 12, 297–310, https://doi.org/10.1029/97GB03366,
1998.
Buesseler, K. O., Bacon, M. P., Kirk Cochran, J., and Livingston, H. D.:
Carbon and nitrogen export during the JGOFS North Atlantic Bloom experiment
estimated from 234Th:238U disequilibria, Deep-Sea Res. Pt. I, 39, 1115–1137, 1992.
Cherrier, J., Burnett, W. C., and LaRock, P. A.: Uptake of polonium and
sulfur by bacteria, Geomicrobiol. J., 13, 103–115,
https://doi.org/10.1080/01490459509378009, 1995.
Chuang, C., Santschi, P. H., Ho, Y., Conte, M. H., Guo, L., Schumann, D.,
Ayranov, M., and Li, Y.: Role of biopolymers as major carrier phases of Th,
Pa, Pb, Po, and Be radionuclides in settling particles from the Atlantic
Ocean, Mar. Chem., 157, 131–143, 2013.
Cochran, J. K.: Uranium-Series Disequilibrium – Application to Earth,
Marine, and Environmental Sciences, The oceanic chemistry of the uranium and
thorium-series nuclides, Oxford University Press, 334–395, 1992.
Djogic, R., Sipos, L., and Branica, M.: Characterization of uranium(VI) in
seawater, Limnol. Oceanogr., 31, 1122–1131,
https://doi.org/10.4319/lo.1986.31.5.1122, 1986.
Ducklow, H., Steinberg, D., and Buesseler, K.: Upper Ocean Carbon Export and
the Biological Pump, Oceanography, 14, 50–58, https://doi.org/10.5670/oceanog.2001.06, 2001.
Durkin, C. A., Van Mooy, B. A. S., Dyhrman, S. T., and Buesseler, K. O.:
Sinking phytoplankton associated with carbon flux in the Atlantic Ocean,
Limnol. Oceanogr., 61, 1172–1187, https://doi.org/10.1002/lno.10253, 2016.
Falkowski, P. G., Barber, R. T., and Smetacek, V.: Biogeochemical Controls
and Feedbacks on Ocean Primary Production, Science, 281, 200–206, 1998.
Fisher, N. S., Burns, K. A., Cherry, R. D., and Heyraud, M.: Accumulation and
cellular distribution of 241Am, 210Po and 210Pb in two marine algae, Mar. Ecol.-Prog. Ser., 11, 233–237, 1983.
Fleer, A. P. and Bacon, M. P.: Determination of 210Pb and 210Po in seawater
and marine particulate matter, Nucl. Instrum. Methods, 223, 243–249, 1984.
Flynn, W. W.: The determination of low levels of polonium-210 in
environmental materials, Anal. Chim. Acta, 43, 221–227, 1968.
Fonseca-Batista, D., Li, X., Riou, V., Michotey, V., Deman, F., Fripiat, F., Guasco, S., Brion, N., Lemaitre, N., Tonnard, M.,
Gallinari, M., Planquette, H., Planchon, F., Sarthou, G., Elskens, M., Chou, L., and Dehairs, F.: Evidence of high N2 fixation
rates in productive waters of the temperate Northeast Atlantic, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-220, in review,
2018.
Friedrich, J. and Rutgers van der Loeff, M. M.: A two-tracer (210Po–234Th)
approach to distinguish organic carbon and biogenic silica export flux in
the Antarctic Circumpolar Current, Deep-Sea Res. Pt. I, 49, 101–120, https://doi.org/10.1016/S0967-0637(01)00045-0, 2002.
García-Ibáñez, M. I., Pérez, F. F., Lherminier, P., Zunino, P., Mercier, H., and Tréguer, P.: Water mass
distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic, Biogeosciences, 15, 2075–2090, https://doi.org/10.5194/bg-15-2075-2018, 2018.
Gourain, A., Planquette, H., Cheize, M., Lemaitre, N., Menzel Barraqueta, J.-L., Shelley, R., Lherminier, P., and Sarthou, G.:
Inputs and processes affecting the distribution of particulate iron in the North Atlantic along the GEOVIDE (GEOTRACES GA01)
section, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-234, in review,
2018.
Guidi, L., Stemmann, L., Legendre, L., Picheral, M., Prieur, L., and Gorsky,
G.: Vertical distribution of aggregates (> 110 µm) and
mesoscale activity in the northeastern Atlantic: Effects on the deep
vertical export of surface carbon, Limnol. Oceanogr., 52, 7–18,
https://doi.org/10.4319/lo.2007.52.1.0007, 2007.
Gustafsson, O. and Andersson, P.: 234Th-derived surface export fuxes of POC from the Northern Barents Sea and the Eurasian
sector of the Central Arctic Ocean, Deep-Sea Res. Pt. I, 68, 1–11, https://doi.org/10.1016/j.dsr.2012.05.014, 2012.
Hayes, C. T., Black, E. E., Andersen, R. A., Baskaran, M., Buesseler, K. O.,
Charette, M. A., Cheng, H., Cochran, J. K., Edwards, R. L., Fitzgerald, P.,
Lam, P. J., Lu, Y., Morris, S. O., Ohnemus, D. C., Pavia, F. J., Stewart, G.,
and Tang, Y.: Flux of particulate elements in the North Atlantic Ocean
constrained by multiple radionuclides, Global Biogeochem. Cy., 32, 1738–1758, https://doi.org/10.1029/2018GB005994, 2018
Honjo, S., Manganini, S. J., Krishfield, R. A., and Francois, R.: Particulate
organic carbon fluxes to the ocean interior and factors controlling the
biological pump: A synthesis of global sediment trap programs since 1983,
Prog. Oceanogr., 76, 217–285, 2008.
Jerlov, N. G.: Optical Oceanography, Elsevier Publishing Company, 1968.
Kemp, A. E. S., Pearce, R. B., Grigorov, I., Rance, J., Lange, C. B.,
Quilty, P., and Salter, I.: Production of giant marine diatoms and their
export at oceanic frontal zones: Implications for Si and C flux from
stratified oceans, Global Biogeochem. Cy., 20,
GB4S04, https://doi.org/10.1029/2006GB002698, 2006.
Kim, G. and Church, T. M.: Seasonal biogeochemical fluxes of 234Th and 210Po
in the Upper Sargasso Sea: Influence from atmospheric iron deposition,
Global Biogeochem. Cy., 15, 651–661, https://doi.org/10.1029/2000GB001313, 2001.
Lemaitre, N., Planchon, F., Planquette, H., Dehairs, F., Fonseca-Batista, D., Roukaerts, A., Deman, F., Tang, Y., Mariez, C., and
Sarthou, G.: High variability of particulate organic carbon export along the North Atlantic GEOTRACES section GA01 as
deduced from 234Th fluxes, Biogeosciences, 15, 6417–6437, https://doi.org/10.5194/bg-15-6417-2018, 2018.
Lévy, M., Iovino, D., Resplandy, L., Klein, P., Madec, G., Tréguier,
A. M., Masson, S., and Takahashi, K.: Large-scale impacts of submesoscale
dynamics on phytoplankton: Local and remote effects, Ocean Modell., 43–44,
77–93, https://doi.org/10.1016/j.ocemod.2011.12.003, 2012.
Masqué, P., Sanchez-Cabeza, J. A., Bruach, J. M., Palacios, E., and
Canals, M.: Balance and residence times of 210Pb and 210Po in surface waters
of the northwestern Mediterranean Sea, Cont. Shelf Res., 22,
2127–2146, https://doi.org/10.1016/S0278-4343(02)00074-2, 2002.
Matsumoto, E.: 234Th/238U radioactive disequilibrium in the surface layer of the ocean, Geochim. Cosmochim. Ac., 39, 205–212,
https://doi.org/10.1016/0016-7037(75)90172-6, 1975.
Menemenlis, D., Campin, J., Heimbach, P., Hill, C., Lee, T., Nguyen, A.,
Schodlock, M., and Zhang, H.: ECCO2: High Resolution Global Ocean and Sea Ice
Data Synthesis, Mercator Ocean Quarterly Newsletter, 31, 13–21, 2008.
Moore, H. E., Poet, S. E., Martell, E. A., and Wilkening, M. H.: Origin of
222Rn and its long-lived daughters in air over Hawaii, J.
Geophys. Res., 79, 5019–5024, https://doi.org/10.1029/JC079i033p05019, 1974.
Moran, S. B., Ellis, K. M., and Smith, J. N.: 234Th/238U disequilibrium in the central Arctic Ocean: implications for particulate
organic carbon export, Deep-Sea Res. Pt. II, 44, 1593–1606, https://doi.org/10.1016/S0967-0645(97)00049-0, 1997.
Murray, J. W., Paul, B., Dunne, J. P., and Chapin, T.: 234Th, 210Pb, 210Po
and stable Pb in the central equatorial Pacific: Tracers for particle
cycling, Deep-Sea Res. Pt. I, 52,
2109–2139, 2005.
Owens, S. A., Pike, S., and Buesseler, K. O.: Thorium-234 as a tracer of
particle dynamics and upper ocean export in the Atlantic Ocean, Deep-Sea
Res. Pt. II, 116, 42–59, https://doi.org/10.1016/j.dsr2.2014.11.010, 2015.
Quigley, M. S., Santschi, P. H., Hung, C., Guo, L., and Honeyman, B. D.:
Importance of acid polysaccharides for 234Th complexation to marine organic
matter, Limnol. Oceanogr., 47, 367–377, https://doi.org/10.4319/lo.2002.47.2.0367,
2002.
Richardson, T. L. and Jackson, G. A.: Small Phytoplankton and Carbon Export
from the Surface Ocean, Science, 315, 838–840, https://doi.org/10.1126/science.1133471,
2007.
Rigaud, S., Puigcorbé, V., Camara-Mor, P., Casacuberta, N.,
Roca-Martí, M., Garcia-Orellana, J., Benitez-Nelson, C. R., Masqué,
P., and Church, T.: A methods assessment and recommendations for improving
calculations and reducing uncertainties in the determination of 210Po and
210Pb activities in seawater, Limnol. Oceanogr.-Meth., 11,
561–571, https://doi.org/10.4319/lom.2013.11.561, 2013.
Rigaud, S., Stewart, G., Baskaran, M., Marsan, D., and Church, T.: 210Po and
210Pb distribution, dissolved-particulate exchange rates, and particulate
export along the North Atlantic US GEOTRACES GA03 section, Deep-Sea Res.
Pt. II, 116, 60–78, https://doi.org/10.1016/j.dsr2.2014.11.003, 2015.
Rivière, P. and Pondaven, P.: Phytoplankton size classes competitions at
sub-mesoscale in a frontal oceanic region, J. Marine Syst., 60,
345–364, https://doi.org/10.1016/j.jmarsys.2006.02.005, 2006.
Roca-Martí, M., Puigcorbé, V., Rutgers van der Loeff, M. M.,
Katlein, C., Fernández-Méndez, M., Peeken, I., and Masqué, P.:
Carbon export fluxes and export efficiency in the central Arctic during the
record sea-ice minimum in 2012: a joint 234Th/238U and 210Po/210Pb study,
J. Geophys. Res.-Oceans, 121, 5030–5049,
https://doi.org/10.1002/2016JC011816, 2016.
Rutgers van der Loeff, M. M., Friedrich, J., and Bathmann, U. V.: Carbon
export during the Spring Bloom at the Antarctic Polar Front, determined with
the natural tracer 234Th, Deep-Sea Res. Pt. II, 44, 457–478,
https://doi.org/10.1016/S0967-0645(96)00067-7, 1997.
Sabine, C. L.: The Oceanic Sink for Anthropogenic CO2, Science, 305,
367–371, https://doi.org/10.1126/science.1097403, 2004.
Sarin, M. M., Kim, G., and Church, T. M.: 210Po and 210Pb in the
South-equatorial Atlantic: distribution and disequilibrium in the upper 500
m, Deep-Sea Res. Pt. II, 46, 907–917, 1999.
Savoye, N., Benitez-Nelson, C., Burd, A. B., Cochran, J. K., Charette, M.,
Buesseler, K. O., Jackson, G. A., Roy-Barman, M., Schmidt, S., and Elskens,
M.: 234Th sorption and export models in the water column: A review, Mar. Chem., 100, 234–249, 2006.
Shelley, R. U., Roca-Martí, M., Castrillejo, M., Sanial, V.,
Masqué, P., Landing, W. M., van Beek, P., Planquette, H., and Sarthou,
G.: Quantification of trace element atmospheric deposition fluxes to the
Atlantic Ocean (> 40∘ N; GEOVIDE, GEOTRACES GA01)
during spring 2014, Deep-Sea Res. Pt. I,
119, 34–49, https://doi.org/10.1016/j.dsr.2016.11.010, 2017.
Shimmield, G. B., Ritchie, G. D., and Fileman, T. W.: The impact of marginal
ice zone processes on the distribution of 210Pb, 210Po and 234Th and
implications for new production in the Bellingshausen Sea, Antarctica, Deep-Sea Res. Pt. II, 42, 1313–1335, https://doi.org/10.1016/0967-0645(95)00071-W, 1995.
Stewart, G., Cochran, J. K., Miquel, J. C., Masqué, P., Szlosek, J.,
Rodriguez y Baena, A. M., Fowler, S. W., Gasser, B., and Hirschberg, D. J.:
Comparing POC export from 234Th/238U and 210Po/210Pb disequilibria with
estimates from sediment traps in the northwest Mediterranean, Deep-Sea
Res. Pt. I, 54, 1549–1570,
https://doi.org/10.1016/j.dsr.2007.06.005, 2007.
Stewart, G. M. and Fisher, N. S.: Bioaccumulation of polonium-210 in marine
copepods, Limnol. Oceanogr., 48, 2011–2019,
https://doi.org/10.4319/lo.2003.48.5.2011, 2003a.
Stewart, G. M. and Fisher, N. S.: Experimental studies on the accumulation
of polonium-210 by marine phytoplankton, Limnol. Oceanogr., 48,
1193–1201, https://doi.org/10.4319/lo.2003.48.3.1193, 2003b.
Stewart, G. M., Bradley Moran, S., and Lomas, M. W.: Seasonal POC fluxes at
BATS estimated from 210Po deficits, Deep-Sea Res. Pt. I, 57, 113–124, https://doi.org/10.1016/j.dsr.2009.09.007, 2010.
Subha Anand, S., Rengarajan, R., Shenoy, D., Gauns, M., and Naqvi, S. W. A.:
POC export fluxes in the Arabian Sea and the Bay of Bengal: A simultaneous
234Th/238U and 210Po/210Pb study, Mar. Chem., 198, 70–87,
https://doi.org/10.1016/j.marchem.2017.11.005, 2017.
Tang, Y., Stewart, G., Lam, P. J., Rigaud, S., and Church, T.: The influence
of particle concentration and composition on the fractionation of 210Po and
210Pb along the North Atlantic GEOTRACES transect GA03, Deep-Sea Res.
Pt. I, 128, 42–54,
https://doi.org/10.1016/j.dsr.2017.09.001, 2017.
Tang, Y., Castrillejo, M., Roca-Martí, M., Masqué, P., Lemaitre, N., and Stewart, G.: Distributions of total and size-fractionated
particulate 210Po and 210Pb activities along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise, Biogeosciences, 15, 5437–5453, https://doi.org/10.5194/bg-15-5437-2018, 2018.
Turekian, K. K., Nozaki, Y., and Benninger, L. K.: Geochemistry of
Atmospheric Radon and Radon Products, Annu. Rev. Earth Pl.
Sc., 5, 227–255, https://doi.org/10.1146/annurev.ea.05.050177.001303, 1977.
Verdeny, E., Masqué, P., Maiti, K., Garcia-Orellana, J., Bruach, J. M.,
Mahaffey, C., and Benitez-Nelson, C. R.: Particle export within cyclonic
Hawaiian lee eddies derived from 210Pb–210Po disequilibrium, Deep-Sea
Res. Pt. II, 55, 1461–1472,
https://doi.org/10.1016/j.dsr2.2008.02.009, 2008.
Verdeny, E., Masqué, P., Garcia-Orellana, J., Hanfland, C., Kirk
Cochran, J., and Stewart, G. M.: POC export from ocean surface waters by
means of 234Th/238U and 210Po/210Pb disequilibria: A review of the use of
two radiotracer pairs, Deep-Sea Res. Pt. II, 56, 1502–1518,
https://doi.org/10.1016/j.dsr2.2008.12.018, 2009.
Villa-Alfageme, M., Soto, F. C., Ceballos, E., Giering, S. L. C., Le Moigne,
F. A. C., Henson, S., Mas, J. L., and Sanders, R. J.: Geographical, seasonal,
and depth variation in sinking particle speeds in the North Atlantic,
Geophys. Res. Lett., 43, 8609–8616, https://doi.org/10.1002/2016GL069233, 2016.
Waite, A. M., Stemmann, L., Guidi, L., Calil, P. H. R., Hogg, A. M. C.,
Feng, M., Thompson, P. A., Picheral, M., and Gorsky, G.: The wineglass effect
shapes particle export to the deep ocean in mesoscale eddies, Geophys.
Res. Lett., 43, 9791–9800, https://doi.org/10.1002/2015GL066463, 2016.
Wei, C.-L., Lin, S.-Y., Sheu, D. D.-D., Chou, W.-C., Yi, M.-C., Santschi, P. H., and Wen, L.-S.: Particle-reactive radionuclides
(234Th, 210Pb, 210) as tracers for the estimation of export production in the South China Sea, Biogeosciences, 8, 3793–3808, https://doi.org/10.5194/bg-8-3793-2011, 2011.
Wei, C.-L., Yi, M.-C., Lin, S.-Y., Wen, L.-S., and Lee, W.-H.: Seasonal distributions and fluxes of 210Pb and 210Po in
the northern South China Sea, Biogeosciences, 11, 6813–6826, https://doi.org/10.5194/bg-11-6813-2014, 2014.
Weller, R. A. and Plueddemann, A. J.: Observations of the vertical structure
of the oceanic boundary layer, J. Geophys. Res.-Oceans, 101,
8789–8806, https://doi.org/10.1029/96JC00206, 1996.
Yang, W., Guo, L., Chuang, C., Schumann, D., Ayranov, M., and Santschi, P.
H.: Adsorption characteristics of 210Pb, 210Po and 7Be onto micro-particle
surfaces and the effects of macromolecular organic compounds, Geochim.
Cosmochim. Ac., 107 47–64, 2013.
Zunino, P., Lherminier, P., Mercier, H., Daniault, N., García-Ibáñez, M. I., and Pérez, F. F.: The GEOVIDE cruise in May–June 2014
reveals an intense Meridional Overturning Circulation over a cold and fresh subpolar North Atlantic, Biogeosciences, 14, 5323–5342,
https://doi.org/10.5194/bg-14-5323-2017, 2017.
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Oceanographers try to understand the ocean’s role in the global carbon cycle. Trace levels of natural radionuclides can inform this connection and their half-lives provide an estimate of the timing of processes. We used the 210Po and 210Pb pair to examine the export of carbon from the surface ocean to depth along the GEOVIDE GEOTRACES cruise track. We found that the flux was regionally variable, that upwelling was an important regional factor, and that both large and small particles drove flux.
Oceanographers try to understand the ocean’s role in the global carbon cycle. Trace levels of...
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