Articles | Volume 15, issue 17
https://doi.org/10.5194/bg-15-5437-2018
© Author(s) 2018. 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-15-5437-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Sep 2018
Research article |
| 14 Sep 2018
| 14 Sep 2018
Distributions of total and size-fractionated particulate 210Po and 210Pb activities 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
Maxi Castrillejo
Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona,
Bellaterra, 08193, Spain
Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, Zürich, 8093, Switzerland
Montserrat Roca-Martí
Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona,
Bellaterra, 08193, Spain
Pere Masqué
Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona,
Bellaterra, 08193, Spain
School of Science and Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, Western Australia, Australia
Nolwenn Lemaitre
Department of Earth Sciences, Institute of Geochemistry and Petrology, ETH Zurich, Zürich, Switzerland
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
Related authors
Yi Tang, Nolwenn Lemaitre, Maxi Castrillejo, Montserrat Roca-Martí, Pere Masqué, and Gillian Stewart
Biogeosciences, 16, 309–327, https://doi.org/10.5194/bg-16-309-2019, https://doi.org/10.5194/bg-16-309-2019, 2019
Short summary
Short summary
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.
Géraldine Sarthou, Pascale Lherminier, Eric P. Achterberg, Fernando Alonso-Pérez, Eva Bucciarelli, Julia Boutorh, Vincent Bouvier, Edward A. Boyle, Pierre Branellec, Lidia I. Carracedo, Nuria Casacuberta, Maxi Castrillejo, Marie Cheize, Leonardo Contreira Pereira, Daniel Cossa, Nathalie Daniault, Emmanuel De Saint-Léger, Frank Dehairs, Feifei Deng, Floriane Desprez de Gésincourt, Jérémy Devesa, Lorna Foliot, Debany Fonseca-Batista, Morgane Gallinari, Maribel I. García-Ibáñez, Arthur Gourain, Emilie Grossteffan, Michel Hamon, Lars Eric Heimbürger, Gideon M. Henderson, Catherine Jeandel, Catherine Kermabon, François Lacan, Philippe Le Bot, Manon Le Goff, Emilie Le Roy, Alison Lefèbvre, Stéphane Leizour, Nolwenn Lemaitre, Pere Masqué, Olivier Ménage, Jan-Lukas Menzel Barraqueta, Herlé Mercier, Fabien Perault, Fiz F. Pérez, Hélène F. Planquette, Frédéric Planchon, Arnout Roukaerts, Virginie Sanial, Raphaëlle Sauzède, Catherine Schmechtig, Rachel U. Shelley, Gillian Stewart, Jill N. Sutton, Yi Tang, Nadine Tisnérat-Laborde, Manon Tonnard, Paul Tréguer, Pieter van Beek, Cheryl M. Zurbrick, and Patricia Zunino
Biogeosciences, 15, 7097–7109, https://doi.org/10.5194/bg-15-7097-2018, https://doi.org/10.5194/bg-15-7097-2018, 2018
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Brandon Stephens, Montserrat Roca-Martí, Amy Maas, Vinícius Amaral, Samantha Clevenger, Shawnee Traylor, Claudia Benitez-Nelson, Philip Boyd, Ken Buesseler, Craig Carlson, Nicolas Cassar, Margaret Estapa, Andrea Fassbender, Yibin Huang, Phoebe Lam, Olivier Marchal, Susanne Menden-Deuer, Nicola Paul, Alyson Santoro, David Siegel, and David Nicholson
EGUsphere, https://doi.org/10.5194/egusphere-2024-2251, https://doi.org/10.5194/egusphere-2024-2251, 2024
Short summary
Short summary
The ocean’s mesopelagic zone (MZ) plays a crucial role in the global carbon cycle. This study combines new and previously published measurements of organic carbon supply and demand collected in August 2018 for the MZ in the subarctic North Pacific Ocean. Supply was insufficient to meet demand in August, but supply entering into the MZ in the spring of 2018 could have met the August demand. Results suggest observations over seasonal time scales may help to close MZ carbon budgets.
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
Short summary
Short summary
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.
Marion Lagarde, Nolwenn Lemaitre, Hélène Planquette, Mélanie Grenier, Moustafa Belhadj, Pascale Lherminier, and Catherine Jeandel
Biogeosciences, 17, 5539–5561, https://doi.org/10.5194/bg-17-5539-2020, https://doi.org/10.5194/bg-17-5539-2020, 2020
Viena Puigcorbé, Pere Masqué, and Frédéric A. C. Le Moigne
Earth Syst. Sci. Data, 12, 1267–1285, https://doi.org/10.5194/essd-12-1267-2020, https://doi.org/10.5194/essd-12-1267-2020, 2020
Short summary
Short summary
The biological carbon pump is a mechanism by which the oceans capture atmospheric carbon dioxide thanks to microscopic marine algae. Quantifying its strength and efficiency is crucial to understand the global carbon budget and be able to forecast its trends. The radioactive pair 234Th : 238U has been extensively used for that purpose. This is a global compilation of carbon-to-234Th ratios (needed to convert the 234Th fluxes to carbon fluxes) that will contribute to improve our modeling efforts.
Sarah Paradis, Antonio Pusceddu, Pere Masqué, Pere Puig, Davide Moccia, Tommaso Russo, and Claudio Lo Iacono
Biogeosciences, 16, 4307–4320, https://doi.org/10.5194/bg-16-4307-2019, https://doi.org/10.5194/bg-16-4307-2019, 2019
Short summary
Short summary
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.
Arthur Gourain, Hélène Planquette, Marie Cheize, Nolwenn Lemaitre, Jan-Lukas Menzel Barraqueta, Rachel Shelley, Pascale Lherminier, and Géraldine Sarthou
Biogeosciences, 16, 1563–1582, https://doi.org/10.5194/bg-16-1563-2019, https://doi.org/10.5194/bg-16-1563-2019, 2019
Short summary
Short summary
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
Short summary
Short summary
Dinitrogen fixation and primary production were investigated using stable isotope incubation experiments along two transects off the Western Iberian Margin in May 2014 close to the end of the phytoplankton spring bloom. We observed substantial N2 fixation activities (up to 1533 µmol N m-2 d-1) associated with a predominance of unicellular cyanobacteria and non-cyanobacterial diazotrophs, which seemed to be promoted by the presence of bloom-derived organic matter and excess phosphorus.
Yi Tang, Nolwenn Lemaitre, Maxi Castrillejo, Montserrat Roca-Martí, Pere Masqué, and Gillian Stewart
Biogeosciences, 16, 309–327, https://doi.org/10.5194/bg-16-309-2019, https://doi.org/10.5194/bg-16-309-2019, 2019
Short summary
Short summary
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.
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
Short summary
Short summary
To better use Pa / Th to reconstruct deep water ventilation rate, we assessed controls on 230Th and 231Pa in the northern North Atlantic. With extended optimum multi-parameter analysis and CFC-based water-mass age, we found the imprint of young overflow water on Th and Pa and enhanced scavenging near the seafloor. A significantly higher advective loss of Pa to the south relative to Th in the Atlantic was estimated, supporting the use of Pa / Th for assessing basin-scale meridional transport.
Géraldine Sarthou, Pascale Lherminier, Eric P. Achterberg, Fernando Alonso-Pérez, Eva Bucciarelli, Julia Boutorh, Vincent Bouvier, Edward A. Boyle, Pierre Branellec, Lidia I. Carracedo, Nuria Casacuberta, Maxi Castrillejo, Marie Cheize, Leonardo Contreira Pereira, Daniel Cossa, Nathalie Daniault, Emmanuel De Saint-Léger, Frank Dehairs, Feifei Deng, Floriane Desprez de Gésincourt, Jérémy Devesa, Lorna Foliot, Debany Fonseca-Batista, Morgane Gallinari, Maribel I. García-Ibáñez, Arthur Gourain, Emilie Grossteffan, Michel Hamon, Lars Eric Heimbürger, Gideon M. Henderson, Catherine Jeandel, Catherine Kermabon, François Lacan, Philippe Le Bot, Manon Le Goff, Emilie Le Roy, Alison Lefèbvre, Stéphane Leizour, Nolwenn Lemaitre, Pere Masqué, Olivier Ménage, Jan-Lukas Menzel Barraqueta, Herlé Mercier, Fabien Perault, Fiz F. Pérez, Hélène F. Planquette, Frédéric Planchon, Arnout Roukaerts, Virginie Sanial, Raphaëlle Sauzède, Catherine Schmechtig, Rachel U. Shelley, Gillian Stewart, Jill N. Sutton, Yi Tang, Nadine Tisnérat-Laborde, Manon Tonnard, Paul Tréguer, Pieter van Beek, Cheryl M. Zurbrick, and Patricia Zunino
Biogeosciences, 15, 7097–7109, https://doi.org/10.5194/bg-15-7097-2018, https://doi.org/10.5194/bg-15-7097-2018, 2018
Short summary
Short summary
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.
Ariane Arias-Ortiz, Pere Masqué, Jordi Garcia-Orellana, Oscar Serrano, Inés Mazarrasa, Núria Marbà, Catherine E. Lovelock, Paul S. Lavery, and Carlos M. Duarte
Biogeosciences, 15, 6791–6818, https://doi.org/10.5194/bg-15-6791-2018, https://doi.org/10.5194/bg-15-6791-2018, 2018
Short summary
Short summary
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
Short summary
Short summary
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
Biogeosciences, 15, 5545–5564, https://doi.org/10.5194/bg-15-5545-2018, https://doi.org/10.5194/bg-15-5545-2018, 2018
Short summary
Short summary
The investigation of water mass transport pathways and timescales is important to understand the global ocean circulation. Following earlier studies, we use artificial radionuclides introduced to the oceans in the 1950s to investigate the water transport in the subpolar North Atlantic (SPNA). For the first time, we combine measurements of the long-lived iodine-129 and uranium-236 to confirm earlier findings/hypotheses and to better understand shallow and deep ventilation processes in the SPNA.
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
Short summary
Short summary
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
Related subject area
Biogeochemistry: Open Ocean
Sedimentary organic matter signature hints at the phytoplankton-driven biological carbon pump in the central Arabian Sea
Hydrological cycle amplification imposes spatial patterns on the climate change response of ocean pH and carbonate chemistry
Assessing the tropical Atlantic biogeochemical processes in the Norwegian Earth System Model
Evolution of oxygen and stratification and their relationship in the North Pacific Ocean in CMIP6 Earth system models
Evaluation of CMIP6 model performance in simulating historical biogeochemistry across the southern South China Sea
Drivers of decadal trends in the ocean carbon sink in the past, present, and future in Earth system models
Anthropogenic carbon storage and its decadal changes in the Atlantic between 1990–2020
Ocean alkalinity enhancement impacts: regrowth of marine microalgae in alkaline mineral concentrations simulating the initial concentrations after ship-based dispersions
Climatic controls on metabolic constraints in the ocean
Effects of grain size and seawater salinity on magnesium hydroxide dissolution and secondary calcium carbonate precipitation kinetics: implications for ocean alkalinity enhancement
Short-term response of Emiliania huxleyi growth and morphology to abrupt salinity stress
Assessing the impact of CO2-equilibrated ocean alkalinity enhancement on microbial metabolic rates in an oligotrophic system
Ocean Acidification trends and Carbonate System dynamics in the North Atlantic Subpolar Gyre during 2009–2019
Phosphomonoesterase and phosphodiesterase activities in the eastern Mediterranean in two contrasting seasonal situations
Net primary production annual maxima in the North Atlantic projected to shift in the 21st century
Testing the influence of light on nitrite cycling in the eastern tropical North Pacific
Loss of nitrogen via anaerobic ammonium oxidation (anammox) in the California Current system during the late Quaternary
Technical note: Assessment of float pH data quality control methods – a case study in the subpolar northwest Atlantic Ocean
Linking northeastern North Pacific oxygen changes to upstream surface outcrop variations
Underestimation of multi-decadal global O2 loss due to an optimal interpolation method
Reviews and syntheses: expanding the global coverage of gross primary production and net community production measurements using Biogeochemical-Argo floats
Characteristics of surface physical and biogeochemical parameters within mesoscale eddies in the Southern Ocean
Seasonal dynamics and annual budget of dissolved inorganic carbon in the northwestern Mediterranean deep-convection region
The fingerprint of climate variability on the surface ocean cycling of iron and its isotopes
Reconstructing the ocean's mesopelagic zone carbon budget: sensitivity and estimation of parameters associated with prokaryotic remineralization
Seasonal cycles of biogeochemical fluxes in the Scotia Sea, Southern Ocean: a stable isotope approach
Absence of photophysiological response to iron addition in autumn phytoplankton in the Antarctic sea-ice zone
Optimal parameters for the ocean's nutrient, carbon, and oxygen cycles compensate for circulation biases but replumb the biological pump
Importance of multiple sources of iron for the upper-ocean biogeochemistry over the northern Indian Ocean
Exploring the role of different data types and timescales in the quality of marine biogeochemical model calibration
All about nitrite: exploring nitrite sources and sinks in the eastern tropical North Pacific oxygen minimum zone
Fossil coccolith morphological attributes as a new proxy for deep ocean carbonate chemistry
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
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)
Controlling factors on the global distribution of a representative marine non-cyanobacterial diazotroph phylotype (Gamma A)
Summer trends and drivers of sea surface fCO2 and pH changes observed in the southern Indian Ocean over the last two decades (1998–2019)
Global nutrient cycling by commercially targeted marine fish
Medhavi Pandey, Haimanti Biswas, Daniel Birgel, Nicole Burdanowitz, and Birgit Gaye
Biogeosciences, 21, 4681–4698, https://doi.org/10.5194/bg-21-4681-2024, https://doi.org/10.5194/bg-21-4681-2024, 2024
Short summary
Short summary
We analysed sea surface temperature (SST) proxy and plankton biomarkers in sediments that accumulate sinking material signatures from surface waters in the central Arabian Sea (21°–11° N, 64° E), a tropical basin impacted by monsoons. We saw a north–south SST gradient, and the biological proxies showed more organic matter from larger algae in the north. Smaller algae and zooplankton were more numerous in the south. These trends were related to ocean–atmospheric processes and oxygen availability.
Allison Hogikyan and Laure Resplandy
Biogeosciences, 21, 4621–4636, https://doi.org/10.5194/bg-21-4621-2024, https://doi.org/10.5194/bg-21-4621-2024, 2024
Short summary
Short summary
Rising atmospheric CO2 influences ocean carbon chemistry, leading to ocean acidification. Global warming introduces spatial patterns in the intensity of ocean acidification. We show that the most prominent spatial patterns are controlled by warming-driven changes in rainfall and evaporation, not by the direct effect of warming on carbon chemistry and pH. These evaporation and rainfall patterns oppose acidification in saltier parts of the ocean and enhance acidification in fresher regions.
Shunya Koseki, Lander R. Crespo, Jerry Tjiputra, Filippa Fransner, Noel S. Keenlyside, and David Rivas
Biogeosciences, 21, 4149–4168, https://doi.org/10.5194/bg-21-4149-2024, https://doi.org/10.5194/bg-21-4149-2024, 2024
Short summary
Short summary
We investigated how the physical biases of an Earth system model influence the marine biogeochemical processes in the tropical Atlantic. With four different configurations of the model, we have shown that the versions with better SST reproduction tend to better represent the primary production and air–sea CO2 flux in terms of climatology, seasonal cycle, and response to climate variability.
Lyuba Novi, Annalisa Bracco, Takamitsu Ito, and Yohei Takano
Biogeosciences, 21, 3985–4005, https://doi.org/10.5194/bg-21-3985-2024, https://doi.org/10.5194/bg-21-3985-2024, 2024
Short summary
Short summary
We explored the relationship between oxygen and stratification in the North Pacific Ocean using a combination of data mining and machine learning. We used isopycnic potential vorticity (IPV) as an indicator to quantify ocean ventilation and analyzed its predictability, a strong O2–IPV connection, and predictability for IPV in the tropical Pacific. This opens new routes for monitoring ocean O2 through few observational sites co-located with more abundant IPV measurements in the tropical Pacific.
Winfred Marshal, Jing Xiang Chung, Nur Hidayah Roseli, Roswati Md Amin, and Mohd Fadzil Bin Mohd Akhir
Biogeosciences, 21, 4007–4035, https://doi.org/10.5194/bg-21-4007-2024, https://doi.org/10.5194/bg-21-4007-2024, 2024
Short summary
Short summary
This study stands out for thoroughly examining CMIP6 ESMs' ability to simulate biogeochemical variables in the southern South China Sea, an economically important region. It assesses variables like chlorophyll, phytoplankton, nitrate, and oxygen on annual and seasonal scales. While global assessments exist, this study addresses a gap by objectively ranking 13 CMIP6 ocean biogeochemistry models' performance at a regional level, focusing on replicating specific observed biogeochemical variables.
Jens Terhaar
Biogeosciences, 21, 3903–3926, https://doi.org/10.5194/bg-21-3903-2024, https://doi.org/10.5194/bg-21-3903-2024, 2024
Short summary
Short summary
Despite the ocean’s importance in the carbon cycle and hence the climate, observing the ocean carbon sink remains challenging. Here, I use an ensemble of 12 models to understand drivers of decadal trends of the past, present, and future ocean carbon sink. I show that 80 % of the decadal trends in the multi-model mean ocean carbon sink can be explained by changes in decadal trends in atmospheric CO2. The remaining 20 % are due to internal climate variability and ocean heat uptake.
Reiner Steinfeldt, Monika Rhein, and Dagmar Kieke
Biogeosciences, 21, 3839–3867, https://doi.org/10.5194/bg-21-3839-2024, https://doi.org/10.5194/bg-21-3839-2024, 2024
Short summary
Short summary
We calculate the amount of anthropogenic carbon (Cant) in the Atlantic for the years 1990, 2000, 2010 and 2020. Cant is the carbon that is taken up by the ocean as a result of humanmade CO2 emissions. To determine the amount of Cant, we apply a technique that is based on the observations of other humanmade gases (e.g., chlorofluorocarbons). Regionally, changes in ocean ventilation have an impact on the storage of Cant. Overall, the increase in Cant is driven by the rising CO2 in the atmosphere.
Stephanie Delacroix, Tor Jensen Nystuen, August E. Dessen Tobiesen, Andrew L. King, and Erik Höglund
Biogeosciences, 21, 3677–3690, https://doi.org/10.5194/bg-21-3677-2024, https://doi.org/10.5194/bg-21-3677-2024, 2024
Short summary
Short summary
The addition of alkaline minerals into the ocean might reduce excessive anthropogenic CO2 emissions. Magnesium hydroxide can be added in large amounts because of its low seawater solubility without reaching harmful pH levels. The toxicity effect results of magnesium hydroxide, by simulating the expected concentrations from a ship's dispersion scenario, demonstrated low impacts on both sensitive and local assemblages of marine microalgae when compared to calcium hydroxide.
Precious Mongwe, Matthew Long, Takamitsu Ito, Curtis Deutsch, and Yeray Santana-Falcón
Biogeosciences, 21, 3477–3490, https://doi.org/10.5194/bg-21-3477-2024, https://doi.org/10.5194/bg-21-3477-2024, 2024
Short summary
Short summary
We use a collection of measurements that capture the physiological sensitivity of organisms to temperature and oxygen and a CESM1 large ensemble to investigate how natural climate variations and climate warming will impact the ability of marine heterotrophic marine organisms to support habitats in the future. We find that warming and dissolved oxygen loss over the next several decades will reduce the volume of ocean habitats and will increase organisms' vulnerability to extremes.
Charly A. Moras, Tyler Cyronak, Lennart T. Bach, Renaud Joannes-Boyau, and Kai G. Schulz
Biogeosciences, 21, 3463–3475, https://doi.org/10.5194/bg-21-3463-2024, https://doi.org/10.5194/bg-21-3463-2024, 2024
Short summary
Short summary
We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain sizes dissolved faster but calcium carbonate precipitated earlier, suggesting that medium grain sizes are optimal for kinetics.
Rosie M. Sheward, Christina Gebühr, Jörg Bollmann, and Jens O. Herrle
Biogeosciences, 21, 3121–3141, https://doi.org/10.5194/bg-21-3121-2024, https://doi.org/10.5194/bg-21-3121-2024, 2024
Short summary
Short summary
How quickly do marine microorganisms respond to salinity stress? Our experiments with the calcifying marine plankton Emiliania huxleyi show that growth and cell morphology responded to salinity stress within as little as 24–48 hours, demonstrating that morphology and calcification are sensitive to salinity over a range of timescales. Our results have implications for understanding the short-term role of E. huxleyi in biogeochemical cycles and in size-based paleoproxies for salinity.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, Joaquín Ortiz, Stephen D. Archer, Andrea Ludwig, and Ulf Riebesell
Biogeosciences, 21, 2859–2876, https://doi.org/10.5194/bg-21-2859-2024, https://doi.org/10.5194/bg-21-2859-2024, 2024
Short summary
Short summary
Our planet is facing a climate crisis. Scientists are working on innovative solutions that will aid in capturing the hard to abate emissions before it is too late. Exciting research reveals that ocean alkalinity enhancement, a key climate change mitigation strategy, does not harm phytoplankton, the cornerstone of marine ecosystems. Through meticulous study, we may have uncovered a positive relationship: up to a specific limit, enhancing ocean alkalinity boosts photosynthesis by certain species.
David Curbelo-Hernández, Fiz F. Pérez, Melchor González-Dávila, Sergey V. Gladyshev, Aridane G. González, David González-Santana, Antón Velo, Alexey Sokov, and J. Magdalena Santana-Casiano
EGUsphere, https://doi.org/10.5194/egusphere-2024-1388, https://doi.org/10.5194/egusphere-2024-1388, 2024
Short summary
Short summary
The study evaluated CO2-carbonate system dynamics in the North Atlantic Subpolar Gyre from 2009 to 2019. Significant ocean acidification, largely due to rising anthropogenic CO2 levels, was found. Cooling, freshening, and enhanced convective processes intensified this trend, affecting calcite and aragonite saturation. The findings contribute to a deeper understanding of Ocean Acidification and improve our knowledge about its impact on marine ecosystems.
France Van Wambeke, Pascal Conan, Mireille Pujo-Pay, Vincent Taillandier, Olivier Crispi, Alexandra Pavlidou, Sandra Nunige, Morgane Didry, Christophe Salmeron, and Elvira Pulido-Villena
Biogeosciences, 21, 2621–2640, https://doi.org/10.5194/bg-21-2621-2024, https://doi.org/10.5194/bg-21-2621-2024, 2024
Short summary
Short summary
Phosphomonoesterase (PME) and phosphodiesterase (PDE) activities over the epipelagic zone are described in the eastern Mediterranean Sea in winter and autumn. The types of concentration kinetics obtained for PDE (saturation at 50 µM, high Km, high turnover times) compared to those of PME (saturation at 1 µM, low Km, low turnover times) are discussed in regard to the possible inequal distribution of PDE and PME in the size continuum of organic material and accessibility to phosphodiesters.
Jenny Hieronymus, Magnus Hieronymus, Matthias Gröger, Jörg Schwinger, Raffaele Bernadello, Etienne Tourigny, Valentina Sicardi, Itzel Ruvalcaba Baroni, and Klaus Wyser
Biogeosciences, 21, 2189–2206, https://doi.org/10.5194/bg-21-2189-2024, https://doi.org/10.5194/bg-21-2189-2024, 2024
Short summary
Short summary
The timing of the net primary production annual maxima in the North Atlantic in the period 1750–2100 is investigated using two Earth system models and the high-emissions scenario SSP5-8.5. It is found that, for most of the region, the annual maxima occur progressively earlier, with the most change occurring after the year 2000. Shifts in the seasonality of the primary production may impact the entire ecosystem, which highlights the need for long-term monitoring campaigns in this area.
Nicole M. Travis, Colette L. Kelly, and Karen L. Casciotti
Biogeosciences, 21, 1985–2004, https://doi.org/10.5194/bg-21-1985-2024, https://doi.org/10.5194/bg-21-1985-2024, 2024
Short summary
Short summary
We conducted experimental manipulations of light level on microbial communities from the primary nitrite maximum. Overall, while individual microbial processes have different directions and magnitudes in their response to increasing light, the net community response is a decline in nitrite production with increasing light. We conclude that while increased light may decrease net nitrite production, high-light conditions alone do not exclude nitrification from occurring in the surface ocean.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
Short summary
Short summary
The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences, 21, 1191–1211, https://doi.org/10.5194/bg-21-1191-2024, https://doi.org/10.5194/bg-21-1191-2024, 2024
Short summary
Short summary
The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit these autonomous measurements platforms. By applying the Argo correction routines to float pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Sabine Mecking and Kyla Drushka
Biogeosciences, 21, 1117–1133, https://doi.org/10.5194/bg-21-1117-2024, https://doi.org/10.5194/bg-21-1117-2024, 2024
Short summary
Short summary
This study investigates whether northeastern North Pacific oxygen changes may be caused by surface density changes in the northwest as water moves along density horizons from the surface into the subsurface ocean. A correlation is found with a lag that about matches the travel time of water from the northwest to the northeast. Salinity is the main driver causing decadal changes in surface density, whereas salinity and temperature contribute about equally to long-term declining density trends.
Takamitsu Ito, Hernan E. Garcia, Zhankun Wang, Shoshiro Minobe, Matthew C. Long, Just Cebrian, James Reagan, Tim Boyer, Christopher Paver, Courtney Bouchard, Yohei Takano, Seth Bushinsky, Ahron Cervania, and Curtis A. Deutsch
Biogeosciences, 21, 747–759, https://doi.org/10.5194/bg-21-747-2024, https://doi.org/10.5194/bg-21-747-2024, 2024
Short summary
Short summary
This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainty comes from the statistical gap-filling methods. Outputs from Earth system models are used to generate synthetic observations where oxygen data are extracted from the model output at the location and time of historical oceanographic cruises. Reconstructed oxygen trend is approximately two-thirds of the true trend.
Robert W. Izett, Katja Fennel, Adam C. Stoer, and David P. Nicholson
Biogeosciences, 21, 13–47, https://doi.org/10.5194/bg-21-13-2024, https://doi.org/10.5194/bg-21-13-2024, 2024
Short summary
Short summary
This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array.
Qian Liu, Yingjie Liu, and Xiaofeng Li
Biogeosciences, 20, 4857–4874, https://doi.org/10.5194/bg-20-4857-2023, https://doi.org/10.5194/bg-20-4857-2023, 2023
Short summary
Short summary
In the Southern Ocean, abundant eddies behave opposite to our expectations. That is, anticyclonic (cyclonic) eddies are cold (warm). By investigating the variations of physical and biochemical parameters in eddies, we find that abnormal eddies have unique and significant effects on modulating the parameters. This study fills a gap in understanding the effects of abnormal eddies on physical and biochemical parameters in the Southern Ocean.
Caroline Ulses, Claude Estournel, Patrick Marsaleix, Karline Soetaert, Marine Fourrier, Laurent Coppola, Dominique Lefèvre, Franck Touratier, Catherine Goyet, Véronique Guglielmi, Fayçal Kessouri, Pierre Testor, and Xavier Durrieu de Madron
Biogeosciences, 20, 4683–4710, https://doi.org/10.5194/bg-20-4683-2023, https://doi.org/10.5194/bg-20-4683-2023, 2023
Short summary
Short summary
Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles in the Mediterranean Sea, considered to be a hotspot of biodiversity and climate change. In this study, we investigate the seasonal and annual budget of dissolved inorganic carbon in the deep-convection area of the northwestern Mediterranean Sea.
Daniela König and Alessandro Tagliabue
Biogeosciences, 20, 4197–4212, https://doi.org/10.5194/bg-20-4197-2023, https://doi.org/10.5194/bg-20-4197-2023, 2023
Short summary
Short summary
Using model simulations, we show that natural and anthropogenic changes in the global climate leave a distinct fingerprint in the isotopic signatures of iron in the surface ocean. We find that these climate effects on iron isotopes are often caused by the redistribution of iron from different external sources to the ocean, due to changes in ocean currents, and by changes in algal growth, which take up iron. Thus, isotopes may help detect climate-induced changes in iron supply and algal uptake.
Chloé Baumas, Robin Fuchs, Marc Garel, Jean-Christophe Poggiale, Laurent Memery, Frédéric A. C. Le Moigne, and Christian Tamburini
Biogeosciences, 20, 4165–4182, https://doi.org/10.5194/bg-20-4165-2023, https://doi.org/10.5194/bg-20-4165-2023, 2023
Short summary
Short summary
Through the sink of particles in the ocean, carbon (C) is exported and sequestered when reaching 1000 m. Attempts to quantify C exported vs. C consumed by heterotrophs have increased. Yet most of the conducted estimations have led to C demands several times higher than C export. The choice of parameters greatly impacts the results. As theses parameters are overlooked, non-accurate values are often used. In this study we show that C budgets can be well balanced when using appropriate values.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
Global biogeochemical ocean models are often subjectively assessed and tuned against observations. We applied different strategies to calibrate a global model against observations. Although the calibrated models show similar tracer distributions at the surface, they differ in global biogeochemical fluxes, especially in global particle flux. Simulated global volume of oxygen minimum zones varies strongly with calibration strategy and over time, rendering its temporal extrapolation difficult.
John C. Tracey, Andrew R. Babbin, Elizabeth Wallace, Xin Sun, Katherine L. DuRussel, Claudia Frey, Donald E. Martocello III, Tyler Tamasi, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 20, 2499–2523, https://doi.org/10.5194/bg-20-2499-2023, https://doi.org/10.5194/bg-20-2499-2023, 2023
Short summary
Short summary
Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic.
Amanda Gerotto, Hongrui Zhang, Renata Hanae Nagai, Heather M. Stoll, Rubens César Lopes Figueira, Chuanlian Liu, and Iván Hernández-Almeida
Biogeosciences, 20, 1725–1739, https://doi.org/10.5194/bg-20-1725-2023, https://doi.org/10.5194/bg-20-1725-2023, 2023
Short summary
Short summary
Based on the analysis of the response of coccolithophores’ morphological attributes in a laboratory dissolution experiment and surface sediment samples from the South China Sea, we proposed that the thickness shape (ks) factor of fossil coccoliths together with the normalized ks variation, which is the ratio of the standard deviation of ks (σ) over the mean ks (σ/ks), is a robust and novel proxy to reconstruct past changes in deep ocean carbon chemistry.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences, 20, 1671–1690, https://doi.org/10.5194/bg-20-1671-2023, https://doi.org/10.5194/bg-20-1671-2023, 2023
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Amacher, J., Neuer, S., and Lomas, M.: DNA-based molecular fingerprinting of
eukaryotic protists and cyanobacteria contributing to sinking particle flux
at the Bermuda Atlantic time-series study, Deep-Sea Res. Pt. II, 93, 71–83, https://doi.org/10.1016/j.dsr2.2013.01.001,
2013.
Bacon, M. P.: 210Pb and 210Po results from F.S.
“Meteor” cruise 32 in the North Atlantic, PANGAEA, https://doi.org/10.1594/PANGAEA.604014, 1977.
Bacon, M. P., Spencer, D. W., and Brewer, P. G.:
210Pb ∕ 226Ra and
210Po ∕ 210Pb disequilibria in seawater and suspended
particulate matter, Earth Planet. Sc. Lett., 32, 277–296, https://doi.org/10.1016/0012-821X(76)90068-6, 1976.
Bacon, M. P., Brewer, P. G., Spencer, D. W., Murray, J. W., and Goddard, J.:
Lead-210, polonium-210, manganese and iron in the Cariaco Trench, Deep-Sea
Res. Pt. A, 27, 119–135, https://doi.org/10.1016/0198-0149(80)90091-6, 1980a.
Bacon, M. P., Spencer, D. W., and Brewer, P. G.: Lead-210 and Polonium-210 as
Marine Geochemical Tracers: Review and Discussion of Results from the
Labrador Sea, Natural radiation environment III, edited by: Gesell, T. F. and
Lowder, W. M., 1, 473–501, 1980b.
Bacon, M. P., Belastock, R. A., Tecotzky, M., Turekian, K. K., and Spencer,
D. W.: Lead-210 and polonium-210 in ocean water profiles of the continental
shelf and slope south of New England, Cont. Shelf Res., 8, 841–853, https://doi.org/10.1016/0278-4343(88)90079-9, 1988.
Benetti, M., Reverdin, G., Lique, C., Yashayaev, I., Holliday, N. P., Tynan,
E., Torres-Valdes, S., Lherminier, P., Tréguer, P., and Sarthou, G.:
Composition of freshwater in the spring of 2014 on the southern Labrador
shelf and slope, J. Geophys. Res.-Oceans, 122, 1102–1121, https://doi.org/10.1002/2016JC012244, 2017.
Bishop, J. K. B., Edmond, J. M., Ketten, D. R., Bacon, M. P., and Silker, W.
B.: The chemistry, biology, and vertical flux of particulate matter from the
upper 400 m of the equatorial Atlantic Ocean, Deep-Sea Res., 24, 511–548, https://doi.org/10.1016/0146-6291(78)90010-3,
1977.
BODC, Lowry, R. K., Machin, P., and Cramer, R. N.: Compilation of the results
of EU-project BOFS, PANGAEA, https://doi.org/10.1594/PANGAEA.859221, 2016.
Boyer, T., Conkright, M. E., and Levitus, S.: Seasonal variability of
dissolved oxygen, percent oxygen saturation, and apparent oxygen utilization
in the Atlantic and Pacific Oceans, Deep-Sea Res. Pt. I, 46, 1593–1613, https://doi.org/10.1016/S0967-0637(99)00021-7,
1999.
Carmack, E., Barber, D., Christensen, J., Macdonald, R., Rudels, B., and
Sakshaug, E.: Climate variability and physical forcing of the food webs and
the carbon budget on panarctic shelves, Prog. Oceanogr., 71, 145–181, https://doi.org/10.1016/j.pocean.2006.10.005, 2006.
Ceballos-Romero, E., Le Moigne, F. A. C., Henson, S., Marsay, C. M., Sanders,
R. J., García-Tenorio, R., and Villa-Alfageme, M.: Influence of bloom
dynamics on Particle Export Efficiency in the North Atlantic: a comparative
study of radioanalytical techniques and sediment traps, Mar. Chem., 186,
198–210, https://doi.org/10.1016/j.marchem.2016.10.001, 2016.
Clegg, S. L. and Whitfield, M.: A generalised model for the scavenging of
trace metals in the open ocean: I. Particle cycling, Deep-Sea Res. Pt. A, 37,
809–832, https://doi.org/10.1016/0198-0149(90)90008-J, 1990.
Clegg, S. L. and Whitfield, M.: A generalied model for the scavenging of
trace metals in the open ocean – II. Thorium scavenging, Deep-Sea Res. Pt.
A, 38, 91–120, https://doi.org/10.1016/0198-0149(91)90056-L, 1991.
Cochran, J. K. and Masqué, P.: Short-lived U/Th Series Radionuclides in
the Ocean: Tracers for Scavenging Rates, Export Fluxes and Particle Dynamics,
Reviews in Mineralogy and Geochemistry, 52, 461–492, https://doi.org/10.2113/0520461, 2003.
Cochran, J. K., Bacon, M. P., Krishnaswami, S., and Turekian, K. K.:
210Po and 210Pb distributions in the central and eastern
Indian Ocean, Earth Planet. Sc. Lett., 65, 433–452, https://doi.org/10.1016/0012-821X(83)90180-2, 1983.
Cooper, L.: Factors affecting the distribution of silicate in the North
Atlantic Ocean and the formation of North Atlantic deep water, J. Mar. Biol.
Assoc. UK, 30, 511–526, https://doi.org/10.1017/S0025315400012947, 1952.
Coppola, L., Prieur, L., Taupier-Letage, I., Estournel, C., Testor, P.,
Lefevre, D., Belamari, S., LeReste, S., and Taillandier, V.: Observation of
oxygen ventilation into deep waters through targeted deployment of multiple
Argo-O2 floats in the north-western Mediterranean Sea in 2013, J.
Geophys. Res.-Oceans, 122, 6325–6341, https://doi.org/10.1002/2016JC012594, 2017.
Dugdale, R. C. and Goering, J. J.: uptake of new and regenrated forms of
nitrogen in primary production, Limnol. Oceanogr., 12, 196–206, https://doi.org/10.4319/lo.1967.12.2.0196, 1967.
Duteil, O., Koeve, W., Oschlies, A., Bianchi, D., Galbraith, E., Kriest, I.,
and Matear, R.: A novel estimate of ocean oxygen utilisation points to a
reduced rate of respiration in the ocean interior, Biogeosciences, 10,
7723–7738, https://doi.org/10.5194/bg-10-7723-2013, 2013.
Fleer, A. P. and Bacon, M. P.: Determination of 210Pb and
210Po in seawater and marine particulate matter, Nuclear
Instruments and Methods in Physics Research, 223, 243–249, https://doi.org/10.1016/0167-5087(84)90655-0, 1984.
Flynn, W. W.: The determination of low levels of polonium-210 in
environmental materials, Anal. Chim. Ac., 43, 221–227, https://doi.org/10.1016/S0003-2670(00)89210-7, 1968.
Fowler, S. W. and Knauer, G. A.: Role of large particles in the transport of
elements and organic compounds through the oceanic water column, Prog.
Oceanogr., 16, 147–194, https://doi.org/10.1016/0079-6611(86)90032-7, 1986.
Friedrich, J.: Polonium-210 and Lead-210 activities measured on 17 water
bottle profiles and 50 surface water samples during POLARSTERN cruise
ARK-XXII/2, PANGAEA, https://doi.org/10.1594/PANGAEA.763937, 2011.
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.
Friedrich, J., Robert, M., and Stimac, I.: Polonium-210 and Lead-210
activities measured on 9 water bottle profiles during POLARSTERN cruise
ANT-XXIV/3, PANGAEA, https://doi.org/10.1594/PANGAEA.763970, 2011.
García-Ibáñez, M. I., Pardo, P. C., Carracedo, L. I., Mercier,
H., Lherminier, P., Ríos, A. F., and Pérez, F. F.: Structure,
transports and transformations of the water masses in the Atlantic Subpolar
Gyre, Prog. Oceanogr., 135, 18–36, https://doi.org/10.1016/j.pocean.2015.03.009, 2015.
GEOTRACES Planning Group: GEOTRACES Science Plan, Baltimore, Maryland, available at: http://www.geotraces.org/libraries/documents/Science_plan.pdf (last access: 7 September 2018), 2006.
Gourain, A., Planquette, H., Cheize, M., Menzel-Barraqueta, J. L., Boutorh,
J., Shelley, R. U., Pereira-Contreira, L., Lemaitre, N., Lacan, F.,
Lherminier, P., and Sarthou, G.: Particualte trace metals along the GEOVIDE
section, Biogeosciences Discuss., in preparation, 2018.
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., in review,
2018.
He, J., Yu, W., Lin, W., Men, W., and Chen, L.: Particulate organic carbon
export fluxes on Chukchi Shelf, western Arctic Ocean, derived from
210Po/210Pb disequilibrium, Chin. J. Oceanol. Limn., 33, 741–747, https://doi.org/10.1007/s00343-015-3357-x, 2015.
Heyraud, M., Fowler, S. W., Beasley, T. M., and Cherry, R. D.: Polonium-210
in euphausiids: A detailed study, Mar. Biol., 34, 127–136, https://doi.org/10.1007/BF00390754, 1976.
Hong, G.-H., Park, S.-K., Baskaran, M., Kim, S.-H., Chung, C.-S., and Lee,
S.-H.: Lead-210 and polonium-210 in the winter well-mixed turbid waters in
the mouth of the Yellow Sea, Cont. Shelf Res., 19, 1049–1064, https://doi.org/10.1016/S0278-4343(99)00011-4, 1999.
Honjo, S., Spencer, D. W., and Gardner, W. D.: A sediment trap
intercomparison experiment in the Panama Basin, 1979, Deep-Sea Res. Pt. A,
39, 333–358, https://doi.org/10.1016/0198-0149(92)90112-7, 1992.
Hu, W., Chen, M., Yang, W., Zhang, R., Qiu, Y., and Zheng, M.: Enhanced
particle scavenging in deep water of the Aleutian Basin revealed by
210Po- 210Pb disequilibria, J. Geophys. Res.-Oceans, 119,
3235–3248, https://doi.org/10.1002/2014JC009819, 2014.
Ito, T., Follows, M. J., and Boyle, E. A.: Is AOU a good measure of
respiration in the oceans?, Geophys. Res. Lett., 31, 1–4, https://doi.org/10.1029/2004GL020900, 2004.
Keeling, R. F., Stephens, B. B., Najjar, R. G., Doney, S. C., Archer, D., and
Heimann, M.: Seasonal variations in the atmospheric
O2 ∕ N2 ratio in relation to the kinetics of air-sea gas
exchange, Global Biogeochem. Cy., 12, 141–163, https://doi.org/10.1029/97GB02339, 1998.
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.
Lam, P. J., Ohnemus, D. C., and Auro, M. E.: Size-fractionated major particle
composition and concentrations from the US GEOTRACES North Atlantic Zonal
Transect, Deep-Sea Res. Pt. II, 116, 303–320, https://doi.org/10.1016/j.dsr2.2014.11.020, 2015.
Lomas, M. W. and Moran, S. B.: Evidence for aggregation and export of
cyanobacteria and nano-eukaryotes from the Sargasso Sea euphotic zone,
Biogeosciences, 8, 203–216, https://doi.org/10.5194/bg-8-203-2011, 2011.
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.
Menzel Barraqueta, J.-L., Schlosser, C., Planquette, H., Gourain, A., Cheize,
M., Boutorh, J., Shelley, R., Pereira Contreira, L., Gledhill, M., Hopwood,
M. J., Lherminier, P., Sarthou, G., and Achterberg, E. P.: Aluminium in the
North Atlantic Ocean and the Labrador Sea (GEOTRACES GA01 section): roles of
continental inputs and biogenic particle removal, Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2018-39, in review, 2018.
Mercier, H., Lherminier, P., Sarafanov, A., Gaillard, F., Daniault, N.,
Desbruyeres, D., Falina, A., Ferron, B., Gourcuff, C., Huck, T., and Thierry,
V.: Variability of the meridional overturning circulation at the
Greenland–Portugal OVIDE section from 1993 to 2010, Prog. Oceanogr., 132,
250–261, https://doi.org/10.1016/j.pocean.2013.11.001, 2015.
Moore, R. M. and Smith, J. N.: Disequilibria between 226Ra,
210Pb and 210Po in the Arctic Ocean and the implications
for chemical modification of the Pacific water inflow, Earth Planet. Sc.
Lett., 77, 285–292, https://doi.org/10.1007/978-94-011-3686-0_15, 1986.
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, https://doi.org/10.1016/j.dsr.2005.06.016,
2005.
Nozaki, Y. and Tsunogai, S.: 226Ra, 210Pb and
210Po disequilibria in the Western North Pacific, Earth Planet. Sc.
Lett., 32, 313–321, https://doi.org/10.1016/0012-821X(76)90071-6, 1976.
Nozaki, Y., Dobashi, F., Kato, Y., and Yamamoto, Y.: Distribution of Ra
isotopes and the 210Pb and 210Po balance in surface
seawaters of the mid Northern Hemisphere, Deep-Sea Res. Pt. I, 45,
1263–1284, https://doi.org/10.1016/S0967-0637(98)00016-8, 1998.
Opsahl, S., Benner, R., and Amon, R. M. W.: Major flux of terrigenous
dissolved organic matter through the Arctic Ocean, Limnol. Oceanogr., 44,
2017–2023, https://doi.org/10.4319/lo.1999.44.8.2017, 1999.
Peck, G. and Smith, J. D.: Uranium decay series radionuclides in the Western
Equatorial Pacific Ocean and their use in estimating POC fluxes, edited by:
Fernandez, J.-M. and Fichez, R., Paris, 459–469, 2002.
Puigcorbé, V., Benitez-Nelson, C. R., Masqué, P., Verdeny, E., White,
A. E., Popp, B. N., Prahl, F. G., and Lam, P. J.: Small phytoplankton drive
high summertime carbon and nutrient export in the Gulf of California and
Eastern Tropical North Pacific, Global Biogeochem. Cy., 29, 1309–1332, https://doi.org/10.1002/2015GB005134, 2015.
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.
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.
Roca-Martí, M., Puigcorbe, V., Friedrich, J., Rutgers van der Loeff, M.
M., Rabe, B., Korhonen, M., Canara-Mor, P., Garcia-Orellana, J., and
Masqué, P.: Distribution of 210Pb and 210Po in the
Arctic water column during 2007 sea-ice minimun: particle export in the
ice-covered basins, Deep-Sea Res. Pt. I, in review, 2018.
Sarin, M. M., Krishnaswami, S., Ramesh, R., and Somayajulu, B. L. K.:
238U decay series nuclides in the northeastern Arabian Sea:
Scavenging rates and cycling processes, Cont. Shelf Res., 14, 251–265, https://doi.org/10.1016/0278-4343(94)90015-9, 1994.
Sarin, M. M., Kim, G., and Church, T. M.: 210Po and 210Pb
in the South-equatorial Atlantic, Deep-Sea Res. Pt. II, 46, 907–917, https://doi.org/10.1016/S0967-0645(99)00008-9, 1999.
Sarthou, G., Lherminier, P., Achterberg, E. P., Alonso-Pérez, F.,
Bucciarelli, E., Boutorh, J., Bouvier, V., Boyle, E. A., Branellec, P.,
Carracedo, L. I., Casacuberta, N., Castrillejo, M., Cheize, M., Contreira
Pereira, L., Cossa, D., Daniault, N., De Saint-Léger, E., Dehairs, F.,
Deng, F., Desprez de Gésincourt, F., Devesa, J., Foliot, L.,
Fonseca-Batista, D., Gallinari, M., García-Ibáñez, M. I.,
Gourain, A., Grossteffan, E., Hamon, M., Heimbürger, L. E., Henderson, G.
M., Jeandel, C., Kermabon, C., Lacan, F., Le Bot, P., Le Goff, M., Le Roy,
E., Lefèbvre, A., Leizour, S., Lemaitre, N., Masqué, P., Ménage,
O., Menzel Barraqueta, J.-L., Mercier, H., Perault, F., Pérez, F. F.,
Planquette, H. F., Planchon, F., Roukaerts, A., Sanial, V., Sauzède, R.,
Shelley, R. U., Stewart, G., Sutton, J. N., Tang, Y., Tisnérat-Laborde,
N., Tonnard, M., Tréguer, P., van Beek, P., Zurbrick, C. M., and Zunino,
P.: Introduction to the French GEOTRACES North Atlantic Transect (GA01):
GEOVIDE cruise, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-312,
in review, 2018.
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.
Smetacek, V., de Baar, H. J. W., Bathmann, U., Lochte, K., and Rutgers van
der Loeff, M. M.: Export production by 234Th, including
210Po and 210Pb measured on water bottle samples during
POLARSTERN cruise ANT-X/6, PANGAEA, https://doi.org/10.1594/PANGAEA.89432, 1997.
Stanley, R. H. R., Doney, S. C., Jenkins, W. J., and Lott, III, D. E.:
Apparent oxygen utilization rates calculated from tritium and helium-3
profiles at the Bermuda Atlantic Time-series Study site, Biogeosciences, 9,
1969–1983, https://doi.org/10.5194/bg-9-1969-2012, 2012.
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., Fowler, S. W., and Fisher, N. S.: Chapter 8 The
Bioaccumulation of U- and Th-Series Radionuclides in Marine Organisms,
Radioactivity in the Environment, Elsevier, Vol. 13, 269–305, https://doi.org/10.1016/S1569-4860(07)00008-3, 2008.
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., Lemaitre, N., Castrillejo, M., Roca-Martí, M., Masqué, P.,
and Stewart, G.: The export flux of particulate organic carbon derived from
210Po ∕ 210Pb disequilibria along the North Atlantic
GEOTRACES GA01 (GEOVIDE) transect, Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2018-309, in review, 2018.
Tateda, Y., Carvalho, F. P., Fowler, S. W., and Miquel, J.-C.: Fractionation
of 210Po and 210Pb in coastal waters of the NW
Mediterranean continental margin, Cont. Shelf Res., 23, 295–316, https://doi.org/10.1016/s0278-4343(02)00167-x, 2003.
Tonnard, M., Planquette, H., Bowie, A. R., van der Merwe, P., Gallinari, M.,
Desprez de Gésincourt, F., Germain, Y., Gourain, A., Benetti, M.,
Reverdin, G., Tréguer, P., Boutorh, J., Cheize, M., Menzel Barraqueta,
J.-L., Pereira-Contreira, L., Shelley, R., Lherminier, P., and Sarthou, G.:
Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE
section (GEOTRACES section GA01), Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2018-147, in review, 2018.
Towler, P.: Radionuclides measured on water bottle samples during FRANKLIN
cruise FR05/92, PANGAEA, https://doi.org/10.1594/PANGAEA.104707, 2003.
Towler, P.: Radionuclides measured on water bottle samples during FRANKLIN
cruise FR08/93, PANGAEA, https://doi.org/10.1594/PANGAEA.808075, 2013.
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.
Walsh, I. D. and Gardner, W. D.: A comparison of aggregate profiles with
sediment trap fluxes, Deep-Sea Res. Pt. A, 39, 1817–1834, https://doi.org/10.1016/0198-0149(92)90001-A, 1992.
Wei, C., Lin, S., Wen, L., and Sheu, D. D. D.: Geochemical behavior of
210Pb and 210Po in the nearshore waters off western
Taiwan, Mar. Pollut. Bull., 64, 214–220, https://doi.org/10.1016/j.marpolbul.2011.11.031, 2012.
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.
Short summary
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.
We measured two natural radio-isotopes, 210Po and 210Pb, in the dissolved and particulate phase...
Altmetrics
Final-revised paper
Preprint