Articles | Volume 21, issue 17
https://doi.org/10.5194/bg-21-4037-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-21-4037-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Sep 2024
Research article |
| 13 Sep 2024
| 13 Sep 2024
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Centre for Earth and Observation Science, University of Manitoba, Manitoba, Canada
Marcos Lemes
Centre for Earth and Observation Science, University of Manitoba, Manitoba, Canada
Thomas Juul-Pedersen
Pinngortitaleriffik, Greenland Institute of Natural Resources, Nuuk, Greenland
Mikael Kristian Sejr
Institut for Ecoscience, Aarhus University, Aarhus, Denmark
Johnna Marchiano Holding
Arctic Research Centre, Aarhus University, Aarhus, Denmark
Institut for Ecoscience, Aarhus University, Aarhus, Denmark
Søren Rysgaard
Arctic Research Centre, Aarhus University, Aarhus, Denmark
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Fleur Rooijakkers, Ebbe Poulsen, Eugenio Ruiz-Castillo, and Søren Rysgaard
The Cryosphere, 19, 2881–2894, https://doi.org/10.5194/tc-19-2881-2025, https://doi.org/10.5194/tc-19-2881-2025, 2025
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Glacier melting contributes to global sea level rise, largely due to interactions between the ocean and glacier fronts. Understanding these interactions is crucial. This study explores these processes in a fjord in understudied East Greenland, using a drone to collect data near the glacier. Based on our measurements, we hypothesise that glacier meltwater refreezes in cold Polar Water, forming ice crystals that float to the surface and melt when exposed to warmer ocean temperatures.
Christian Lønborg, Cátia Carreira, Gwenaël Abril, Susana Agustí, Valentina Amaral, Agneta Andersson, Javier Arístegui, Punyasloke Bhadury, Mariana B. Bif, Alberto V. Borges, Steven Bouillon, Maria Ll. Calleja, Luiz C. Cotovicz Jr., Stefano Cozzi, Maryló Doval, Carlos M. Duarte, Bradley Eyre, Cédric G. Fichot, E. Elena García-Martín, Alexandra Garzon-Garcia, Michele Giani, Rafael Gonçalves-Araujo, Renee Gruber, Dennis A. Hansell, Fuminori Hashihama, Ding He, Johnna M. Holding, William R. Hunter, J. Severino P. Ibánhez, Valeria Ibello, Shan Jiang, Guebuem Kim, Katja Klun, Piotr Kowalczuk, Atsushi Kubo, Choon-Weng Lee, Cláudia B. Lopes, Federica Maggioni, Paolo Magni, Celia Marrase, Patrick Martin, S. Leigh McCallister, Roisin McCallum, Patricia M. Medeiros, Xosé Anxelu G. Morán, Frank E. Muller-Karger, Allison Myers-Pigg, Marit Norli, Joanne M. Oakes, Helena Osterholz, Hyekyung Park, Maria Lund Paulsen, Judith A. Rosentreter, Jeff D. Ross, Digna Rueda-Roa, Chiara Santinelli, Yuan Shen, Eva Teira, Tinkara Tinta, Guenther Uher, Masahide Wakita, Nicholas Ward, Kenta Watanabe, Yu Xin, Youhei Yamashita, Liyang Yang, Jacob Yeo, Huamao Yuan, Qiang Zheng, and Xosé Antón Álvarez-Salgado
Earth Syst. Sci. Data, 16, 1107–1119, https://doi.org/10.5194/essd-16-1107-2024, https://doi.org/10.5194/essd-16-1107-2024, 2024
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In this paper, we present the first edition of a global database compiling previously published and unpublished measurements of dissolved organic matter (DOM) collected in coastal waters (CoastDOM v1). Overall, the CoastDOM v1 dataset will be useful to identify global spatial and temporal patterns and to facilitate reuse in studies aimed at better characterizing local biogeochemical processes and identifying a baseline for modelling future changes in coastal waters.
Eva Friis Møller, Asbjørn Christensen, Janus Larsen, Kenneth D. Mankoff, Mads Hvid Ribergaard, Mikael Sejr, Philip Wallhead, and Marie Maar
Ocean Sci., 19, 403–420, https://doi.org/10.5194/os-19-403-2023, https://doi.org/10.5194/os-19-403-2023, 2023
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Melt from the Greenland ice sheet and sea ice both influence light and nutrient availability in the Arctic coastal ocean. We use a 3D coupled hydrodynamic–biogeochemical model to evaluate the relative importance of these processes for timing, distribution, and magnitude of phytoplankton production in Disko Bay, west Greenland. Our study indicates that decreasing sea ice and more freshwater discharge can work synergistically and increase primary productivity of the coastal ocean around Greenland.
Mark J. Hopwood, Dustin Carroll, Thorben Dunse, Andy Hodson, Johnna M. Holding, José L. Iriarte, Sofia Ribeiro, Eric P. Achterberg, Carolina Cantoni, Daniel F. Carlson, Melissa Chierici, Jennifer S. Clarke, Stefano Cozzi, Agneta Fransson, Thomas Juul-Pedersen, Mie H. S. Winding, and Lorenz Meire
The Cryosphere, 14, 1347–1383, https://doi.org/10.5194/tc-14-1347-2020, https://doi.org/10.5194/tc-14-1347-2020, 2020
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Here we compare and contrast results from five well-studied Arctic field sites in order to understand how glaciers affect marine biogeochemistry and marine primary production. The key questions are listed as follows. Where and when does glacial freshwater discharge promote or reduce marine primary production? How does spatio-temporal variability in glacial discharge affect marine primary production? And how far-reaching are the effects of glacial discharge on marine biogeochemistry?
Johnna M. Holding, Stiig Markager, Thomas Juul-Pedersen, Maria L. Paulsen, Eva F. Møller, Lorenz Meire, and Mikael K. Sejr
Biogeosciences, 16, 3777–3792, https://doi.org/10.5194/bg-16-3777-2019, https://doi.org/10.5194/bg-16-3777-2019, 2019
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Phytoplankton sustain important fisheries along the coast of Greenland. However, climate change is causing severe melting of the Greenland Ice Sheet, and continued melting has the potential to alter fjord ecosystems. We investigate how freshwater from the ice sheet is impacting the environment of one fjord in northeast Greenland, causing a low production of phytoplankton. This fjord may be a model for how some fjord ecosystems will be altered following increased melting and glacial retreat.
Nicolas-Xavier Geilfus, Ryan J. Galley, Brent G. T. Else, Karley Campbell, Tim Papakyriakou, Odile Crabeck, Marcos Lemes, Bruno Delille, and Søren Rysgaard
The Cryosphere, 10, 2173–2189, https://doi.org/10.5194/tc-10-2173-2016, https://doi.org/10.5194/tc-10-2173-2016, 2016
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The fate of ikaite precipitation within sea ice is poorly understood. In this study, we estimated ikaite precipitation of up to 167 µmol kg-1 within sea ice, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64–66 μmol kg-1. We estimated that more than half of the total ikaite precipitated was still contained in the ice when sea ice began to melt. The dissolution of the ikaite crystals in the water column kept the seawater pCO2 undersaturated.
Odile Crabeck, Ryan Galley, Bruno Delille, Brent Else, Nicolas-Xavier Geilfus, Marcos Lemes, Mathieu Des Roches, Pierre Francus, Jean-Louis Tison, and Søren Rysgaard
The Cryosphere, 10, 1125–1145, https://doi.org/10.5194/tc-10-1125-2016, https://doi.org/10.5194/tc-10-1125-2016, 2016
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We present a new non-destructive X-ray-computed tomography technique to quantify the air volume fraction and produce separate 3-D images of air-volume inclusions in sea ice. While the internal layers showed air-volume fractions < 2 %, the ice–air interface (top 2 cm) showed values up to 5 %. As a result of the presence of large bubbles and higher air volume fraction measurements in sea ice, we introduce new perspectives on processes regulating gas exchange at the ice–atmosphere interface.
L. Meire, D. H. Søgaard, J. Mortensen, F. J. R. Meysman, K. Soetaert, K. E. Arendt, T. Juul-Pedersen, M. E. Blicher, and S. Rysgaard
Biogeosciences, 12, 2347–2363, https://doi.org/10.5194/bg-12-2347-2015, https://doi.org/10.5194/bg-12-2347-2015, 2015
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The Greenland Ice Sheet releases large amounts of freshwater, which strongly influences the biogeochemistry of the adjacent fjord systems and continental shelves. Here we present seasonal observations of the carbonate system in the surface waters of a west Greenland tidewater outlet glacier fjord. Our data reveal a permanent undersaturation of CO2 in the surface layer of the entire fjord and adjacent shelf, creating a high annual uptake of 65gCm-2yr-1.
S. Rysgaard, F. Wang, R. J. Galley, R. Grimm, D. Notz, M. Lemes, N.-X. Geilfus, A. Chaulk, A. A. Hare, O. Crabeck, B. G. T. Else, K. Campbell, L. L. Sørensen, J. Sievers, and T. Papakyriakou
The Cryosphere, 8, 1469–1478, https://doi.org/10.5194/tc-8-1469-2014, https://doi.org/10.5194/tc-8-1469-2014, 2014
F. Wang, A. Saiz-Lopez, A. S. Mahajan, J. C. Gómez Martín, D. Armstrong, M. Lemes, T. Hay, and C. Prados-Roman
Atmos. Chem. Phys., 14, 1323–1335, https://doi.org/10.5194/acp-14-1323-2014, https://doi.org/10.5194/acp-14-1323-2014, 2014
Related subject area
Biogeochemistry: Coastal Ocean
Improved understanding of nitrate trends, eutrophication indicators, and risk areas using machine learning
Evaluating ocean alkalinity enhancement as a carbon dioxide removal strategy in the North Sea
Spring–neap tidal cycles modulate the strength of the carbon source at the estuary–coast interface
Spatiotemporal variations in surface marine carbonate system properties across the western Mediterranean Sea using volunteer observing ship data
Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022
Depositional controls and budget of organic carbon burial in fine-grained sediments of the North Sea – the Helgoland Mud Area as a natural laboratory
Effects of submarine groundwater on nutrient concentration and primary production in a deep bay of the Japan Sea
The bacteria–protist link as a main route of dissolved organic matter across contrasting productivity areas on the Patagonian Shelf
Ocean alkalinity enhancement (OAE) does not cause cellular stress in a phytoplankton community of the subtropical Atlantic Ocean
Reviews and syntheses: On increasing hypoxia in eastern boundary upwelling systems – zooplankton under metabolic stress
Zinc stimulation of phytoplankton in a low carbon dioxide, coastal Antarctic environment: evidence for the Zn hypothesis
Technical note: Testing a new approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer for long-term observations
A niche for diverse cable bacteria in continental margin sediments overlain by oxygen-deficient waters
Phytoplankton community succession and biogeochemistry in a bloom simulation experiment at an estuary-ocean interface
Long-term variations in pH in coastal waters along the Korean Peninsula
The effect of carbonate mineral additions on biogeochemical conditions in surface sediments and benthic–pelagic exchange fluxes
Estimation of Metabolic Dynamics of Restored Seagrass Meadows in a Southeast Asia Islet: Insights from Ex Situ Benthic Incubation
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Human Activities Caused Hypoxia Expansion in a Large Eutrophic Estuary: Non-negligible Role of Riverine Suspended Sediments
Photosynthetic electron, carbon and oxygen fluxes within a mosaic of Fe limitation in the California Current Upwelling System
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Estimates of carbon sequestration potential in an expanding Arctic fjord (Hornsund, Svalbard) affected by dark plumes of glacial meltwater
An assessment of ocean alkalinity enhancement using aqueous hydroxides: kinetics, efficiency, and precipitation thresholds
Dissolved nitric oxide in the lower Elbe Estuary and the Port of Hamburg area
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
Investigating the effect of silicate- and calcium-based ocean alkalinity enhancement on diatom silicification
Ocean alkalinity enhancement using sodium carbonate salts does not lead to measurable changes in Fe dynamics in a mesocosm experiment
Quantification and mitigation of bottom-trawling impacts on sedimentary organic carbon stocks in the North Sea
Influence of ocean alkalinity enhancement with olivine or steel slag on a coastal plankton community in Tasmania
Multi-model comparison of trends and controls of near-bed oxygen concentration on the northwest European continental shelf under climate change
Picoplanktonic methane production in eutrophic surface waters
Vertical mixing alleviates autumnal oxygen deficiency in the central North Sea
Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
Above- and belowground plant mercury dynamics in a salt marsh estuary in Massachusetts, USA
Variability and drivers of carbonate chemistry at shellfish aquaculture sites in the Salish Sea, British Columbia
Unusual Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters
Insights into carbonate environmental conditions in the Chukchi Sea
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Iron “ore” nothing: benthic iron fluxes from the oxygen-deficient Santa Barbara Basin enhance phytoplankton productivity in surface waters
Marine anoxia initiates giant sulfur-oxidizing bacterial mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
Uncertainty in the evolution of northwestern North Atlantic circulation leads to diverging biogeochemical projections
Deep S. Banerjee and Jozef Skákala
Biogeosciences, 22, 3769–3784, https://doi.org/10.5194/bg-22-3769-2025, https://doi.org/10.5194/bg-22-3769-2025, 2025
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Nitrate is a crucial nutrient in oceans, whose excess can trigger uncontrolled algae growth that damages marine ecosystems. We used machine learning to generate skilled, gap-free, bi-decadal surface nitrate data from sparse observations, revealing areas on the North-West European Shelf that are more vulnerable to excess algae growth if nutrient pollution occurs. We also looked at bi-decadal trends in coastal nitrate and the impact of winter nitrate on spring phytoplankton blooms.
Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
Biogeosciences, 22, 3699–3719, https://doi.org/10.5194/bg-22-3699-2025, https://doi.org/10.5194/bg-22-3699-2025, 2025
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Ocean alkalinity enhancement (OAE) boosts oceanic CO₂ absorption, offering a climate solution. Using a regional model, we examined OAE in the North Sea, revealing that shallow coastal areas achieve higher CO₂ uptake than offshore where alkalinity is more susceptible to deep-ocean loss. Long-term carbon storage is limited, and pH shifts vary by location. Our findings guide OAE deployment to optimize carbon removal while minimizing ecological effects, supporting global climate mitigation efforts.
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
Biogeosciences, 22, 3375–3396, https://doi.org/10.5194/bg-22-3375-2025, https://doi.org/10.5194/bg-22-3375-2025, 2025
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We found that biogeochemical variability at the land–sea interface (LSI) in two major temperate estuaries is modulated by the 14 d spring–neap tidal cycle, with large effects on dissolved inorganic and organic carbon concentrations and distribution. As this effect increases the strength of the carbon source to the atmosphere by up to 74 % during spring tide, it should be accounted for in regional models, which aim to resolve biogeochemical processing at the LSI.
David Curbelo-Hernández, David González-Santana, Aridane G. González, J. Magdalena Santana-Casiano, and Melchor González-Dávila
Biogeosciences, 22, 3329–3356, https://doi.org/10.5194/bg-22-3329-2025, https://doi.org/10.5194/bg-22-3329-2025, 2025
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This study offers a unique high-resolution dataset (2019–2024) on surface physicochemical properties in the western Mediterranean Sea. It reveals accelerated surface warming, significantly altering CO2 levels and pH. Currently a net CO2 sink, the region may become a CO2 source by 2030 due to weakening in-gassing. The research highlights the value of VOS (volunteer observing ship) lines for monitoring climate impacts and emphasizes the need for ongoing observations to enhance long-term trend accuracy and future projections.
Darren J. Pilcher, Jessica N. Cross, Natalie Monacci, Linquan Mu, Kelly A. Kearney, Albert J. Hermann, and Wei Cheng
Biogeosciences, 22, 3103–3125, https://doi.org/10.5194/bg-22-3103-2025, https://doi.org/10.5194/bg-22-3103-2025, 2025
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The Bering Sea shelf is a highly productive marine ecosystem that is vulnerable to ocean acidification. We use a computational model to simulate the carbon cycle and acidification rates from 1970–2022. The results suggest that bottom water acidification rates are more than twice as great as surface rates. Bottom waters are also naturally more acidic. Thus these waters will pass key thresholds known to negatively impact marine organisms, such as red king crab, much sooner than surface waters.
Daniel Müller, Bo Liu, Walter Geibert, Moritz Holtappels, Lasse Sander, Elda Miramontes, Heidi Taubner, Susann Henkel, Kai-Uwe Hinrichs, Denise Bethke, Ingrid Dohrmann, and Sabine Kasten
Biogeosciences, 22, 2541–2567, https://doi.org/10.5194/bg-22-2541-2025, https://doi.org/10.5194/bg-22-2541-2025, 2025
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Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and porewater data set from the Helgoland Mud Area (HMA), North Sea, to determine which depositional factors control the preservation of OC. The burial efficiency is highest in an area of high sedimentation and terrigenous OC. The HMA covers 0.09 % of the North Sea but accounts for 0.76 % of its OC accumulation, highlighting the importance of the depocentre.
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
Biogeosciences, 22, 2383–2402, https://doi.org/10.5194/bg-22-2383-2025, https://doi.org/10.5194/bg-22-2383-2025, 2025
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Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
M. Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
Biogeosciences, 22, 2309–2325, https://doi.org/10.5194/bg-22-2309-2025, https://doi.org/10.5194/bg-22-2309-2025, 2025
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This study explores how microbial dynamics influence the dissolved organic matter (DOM) pool in the Patagonian Shelf. Despite high phytoplankton biomass, selective grazing on fast-growing bacteria led to DOM accumulation, likely due to reduced DOM-consuming bacteria and added egestion compounds. Experiments showed that bacteria not only acted as a carbon sink through mineralization but also transferred assimilated carbon dioxide (CO2) to higher trophic levels.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
Biogeosciences, 22, 1865–1886, https://doi.org/10.5194/bg-22-1865-2025, https://doi.org/10.5194/bg-22-1865-2025, 2025
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We studied the potential effects of increasing ocean alkalinity on a natural plankton community in subtropical waters of the Atlantic near Gran Canaria, Spain. Alkalinity is the capacity of water to resist acidification, and plankton are usually microscopic plants (phytoplankton) and animals (zooplankton), often less than 2.5 cm in length. This study suggests that increasing ocean alkalinity did not have a significant negative impact on the plankton community studied.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
Biogeosciences, 22, 1839–1852, https://doi.org/10.5194/bg-22-1839-2025, https://doi.org/10.5194/bg-22-1839-2025, 2025
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Evidence shows that due to global warming, zooplankton inhabiting the coastal upwelling zone are exposed to increasing hypoxia affecting their physiology, metabolism, and population dynamics. The adaptive responses of zooplankton to cope with mild/severe hypoxia may depend on trade-offs with other metabolic/energy demands, implying less energy for growth, feeding, and reproduction, with ecological consequences for the zooplankton population and the marine food web.
Riss M. Kell, Adam V. Subhas, Nicole L. Schanke, Lauren E. Lees, Rebecca J. Chmiel, Deepa Rao, Margaret M. Brisbin, Dawn M. Moran, Matthew R. McIlvin, Francesco Bolinesi, Olga Mangoni, Raffaella Casotti, Cecilia Balestra, Tristan Horner, Robert B. Dunbar, Andrew E. Allen, Giacomo R. DiTullio, and Mak A. Saito
EGUsphere, https://doi.org/10.1101/2023.11.05.565706, https://doi.org/10.1101/2023.11.05.565706, 2025
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Photosynthetic productivity is strongly influenced by water column nutrient availability. Despite the importance of zinc, definitive evidence for oceanic zinc limitation of photosynthesis has been scarce. We applied multiple biogeochemical measurements to a field site in Terra Nova Bay, Antarctica, to demonstrate that the phytoplankton community was experiencing zinc limitation. This field evidence paves the way for future experimental studies to consider Zn as a limiting oceanic micronutrient.
Sören Iwe, Oliver Schmale, and Bernd Schneider
Biogeosciences, 22, 1767–1779, https://doi.org/10.5194/bg-22-1767-2025, https://doi.org/10.5194/bg-22-1767-2025, 2025
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We present a novel method for quantifying N2 fixation by cyanobacteria, which is crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOSs), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring that it can complement current methods and contribute valuable data for better understanding N2 fixation in the Baltic Sea.
Caroline P. Slomp, Martijn Hermans, Niels A. G. M. van Helmond, Silke Severmann, James McManus, Marit R. van Erk, and Sairah Malkin
EGUsphere, https://doi.org/10.5194/egusphere-2025-817, https://doi.org/10.5194/egusphere-2025-817, 2025
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Cable bacteria couple oxidation of sulfide at depth in sediments with reduction of oxygen, nitrate or nitrite near the sediment surface, thereby preventing release of toxic hydrogen sulfide to the overlying water. We show evidence for a diversity of cable bacteria in sediments from hypoxic and anoxic basins along the continental margin of California and Mexico. Cable bacteria activity in this setting is likely periodic and dependent on the supply of organic matter and/or oxygen.
Jenna Alyson Lee, Joseph H. Vineis, Mathieu A. Poupon, Laure Resplandy, and Bess B. Ward
EGUsphere, https://doi.org/10.5194/egusphere-2025-871, https://doi.org/10.5194/egusphere-2025-871, 2025
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Concurrent sampling of environmental parameters, productivity rates, photopigments, and DNA were used to analyze a 24–L estuarine diatom bloom microcosm. Biogeochemical data and an ecological model indicated that the bloom was terminated by grazing. Comparisons to previous studies revealed (1) additional community and diversity complexity using 18S amplicon vs. traditional pigment–based analyses, and (2) a potential global productivity–diversity relationship using 18S and carbon transport rates.
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong Hwa Oh, Sang Heon Lee, and DongJoo Joung
Biogeosciences, 22, 675–690, https://doi.org/10.5194/bg-22-675-2025, https://doi.org/10.5194/bg-22-675-2025, 2025
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Long-term pH variation in coastal waters along the Korean Peninsula was assessed for the first time, and it exhibited no significant pH change over an 11-year period. This contrasts with the ongoing pH decline in open oceans and other coastal areas. Analysis of environmental data showed that pH is mainly controlled by dissolved oxygen in bottom waters. This suggests that ocean warming could cause a pH decline in Korean coastal waters, affecting many fish and seaweed aquaculture operations.
Kadir Biçe, Tristen Myers Stewart, George G. Waldbusser, and Christof Meile
Biogeosciences, 22, 641–657, https://doi.org/10.5194/bg-22-641-2025, https://doi.org/10.5194/bg-22-641-2025, 2025
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We studied the effect of addition of carbonate minerals on coastal sediments. We carried out laboratory experiments to quantify the dissolution kinetics and integrated these observations into a numerical model that describes biogeochemical cycling in surficial sediments. Using the model, we demonstrate the buffering effect of the mineral additions and their duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
Mariche Bandibas Natividad, Jian-Jhih Chen, Hsin-Yu Chou, Lan-Feng Fan, Yi-Le Shen, and Wen-Chen Chou
EGUsphere, https://doi.org/10.5194/egusphere-2024-4000, https://doi.org/10.5194/egusphere-2024-4000, 2025
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Seagrass restoration serves as a nature-based solution for CO2 removal. We examined the organic carbon and carbonate dynamics of restored seagrasses (SG) and bare sediments (BS) using ex situ core incubations. SG exhibited higher net ecosystem metabolism compared to BS, while no significant difference was observed in net ecosystem calcification. Consequently, SG demonstrated a significantly enhanced overall capacity for carbon uptake.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
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Ocean alkalinity enhancement (OAE) is a promising negative emission technology that results in the net sequestration of atmospheric carbon. In this paper, we assess the potential impact of OAE on phytoplankton through an analysis of prior studies and the effects of simulated OAE on photosynthetic competence. Our findings suggest that there may be little if any significant impact on most phytoplankton studied to date if OAE is conducted in well-flushed, nearshore environments.
Yue Nan, Zheng Chen, Bin Wang, Bo Liang, and Jiatang Hu
EGUsphere, https://doi.org/10.5194/egusphere-2024-4013, https://doi.org/10.5194/egusphere-2024-4013, 2025
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Human activities are changing the coastal water environment, but the role of suspended sediments in oxygen loss is not well understood. We used a model to compare dissolved oxygen levels and related factors in the 1990s and 2010s in the Pearl River Estuary. Reduced suspended sediments and increased pollution have expanded low-oxygen areas by 1.5 times. It highlights that declining suspended sediments increase hypoxia in estuaries, especially with rising nutrients, which need urgent attention.
Yayla Sezginer, Kate Schuler, Emily Speciale, Adrian Marchetti, Claire Till, Ralph Till, and Philippe Tortell
EGUsphere, https://doi.org/10.5194/egusphere-2024-3812, https://doi.org/10.5194/egusphere-2024-3812, 2025
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We recorded three metrics of photosynthesis in the California Current. Real-time observations of microalgae physiology and productivity revealed signs of iron limitation where the continental shelf rapidly dropped off. Iron limitation influenced how efficiently light was absorbed and used for carbon fixation but did not appear to affect net photosynthetic oxygen production. Our results offer useful insights towards efforts to model carbon fixation rates from microalgae optical properties.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
Biogeosciences, 21, 5707–5724, https://doi.org/10.5194/bg-21-5707-2024, https://doi.org/10.5194/bg-21-5707-2024, 2024
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This study exposed a natural community to two non-CO2-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO2, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.
Riss M. Kell, Rebecca J. Chmiel, Deepa Rao, Dawn M. Moran, Matthew R. McIlvin, Tristan J. Horner, Nicole L. Schanke, Ichiko Sugiyama, Robert B. Dunbar, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 21, 5685–5706, https://doi.org/10.5194/bg-21-5685-2024, https://doi.org/10.5194/bg-21-5685-2024, 2024
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Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.
Luisa Chiara Meiritz, Tim Rixen, Anja Karin van der Plas, Tarron Lamont, and Niko Lahajnar
Biogeosciences, 21, 5261–5276, https://doi.org/10.5194/bg-21-5261-2024, https://doi.org/10.5194/bg-21-5261-2024, 2024
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Moored and drifting sediment trap experiments in the northern (nBUS) and southern (sBUS) Benguela Upwelling System showed that active carbon fluxes by vertically migrating zooplankton were about 3 times higher in the sBUS than in the nBUS. Despite these large variabilities, the mean passive particulate organic carbon (POC) fluxes were almost equal in the two subsystems. The more intense near-bottom oxygen minimum layer seems to lead to higher POC fluxes and accumulation rates in the nBUS.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica M. Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
Biogeosciences, 21, 4975–5004, https://doi.org/10.5194/bg-21-4975-2024, https://doi.org/10.5194/bg-21-4975-2024, 2024
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Oxygen-depleted ocean waters have increased worldwide. In order to improve our understanding of the impacts of this oxygen loss on marine life it is essential that we develop reliable indicators that track the negative impacts of low oxygen. We review various indicators of low-oxygen stress for marine animals including their use, research needs, and application to confront the challenges of ocean oxygen loss.
Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
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Phytoplankton growth in the Southern Ocean (SO) is often limited by low iron (Fe) concentrations. Sea surface warming impacts Fe availability and can affect phytoplankton growth. We used shipboard Fe clean incubations to test how changes in Fe and temperature affect SO phytoplankton. Their abundances usually increased with Fe addition and temperature increase, with Fe being the major factor. These findings imply potential shifts in ecosystem structure, impacting food webs and elemental cycling.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
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Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
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Ocean alkalinity enhancement (OAE) is an emerging marine CO2 removal method, but its environmental effects are insufficiently understood. The OAE Pelagic Impact Intercomparison Project (OAEPIIP) provides funding for a standardized and globally replicated microcosm experiment to study the effects of OAE on plankton communities. Here, we provide a detailed manual for the OAEPIIP experiment. We expect OAEPIIP to help build scientific consensus on the effects of OAE on plankton.
Marlena Szeligowska, Déborah Benkort, Anna Przyborska, Mateusz Moskalik, Bernabé Moreno, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk
Biogeosciences, 21, 3617–3639, https://doi.org/10.5194/bg-21-3617-2024, https://doi.org/10.5194/bg-21-3617-2024, 2024
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The European Arctic is experiencing rapid regional warming, causing glaciers that terminate in the sea to retreat onto land. Due to this process, the area of a well-studied fjord, Hornsund, has increased by around 100 km2 (40%) since 1976. Combining satellite and in situ data with a mathematical model, we estimated that, despite some negative consequences of glacial meltwater release, such emerging coastal waters could mitigate climate change by increasing carbon uptake and storage by sediments.
Mallory C. Ringham, Nathan Hirtle, Cody Shaw, Xi Lu, Julian Herndon, Brendan R. Carter, and Matthew D. Eisaman
Biogeosciences, 21, 3551–3570, https://doi.org/10.5194/bg-21-3551-2024, https://doi.org/10.5194/bg-21-3551-2024, 2024
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Ocean alkalinity enhancement leverages the large surface area and carbon storage capacity of the oceans to store atmospheric CO2 as dissolved bicarbonate. We monitored CO2 uptake in seawater treated with NaOH to establish operational boundaries for carbon removal experiments. Results show that CO2 equilibration occurred on the order of weeks to months, was consistent with values expected from equilibration calculations, and was limited by mineral precipitation at high pH and CaCO3 saturation.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
Biogeosciences, 21, 3425–3440, https://doi.org/10.5194/bg-21-3425-2024, https://doi.org/10.5194/bg-21-3425-2024, 2024
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Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. Dissolved NO was supersaturated in the Elbe Estuary, indicating that it is a source of atmospheric NO. The observed distribution of dissolved NO most likely resulted from nitrification.
Weiyi Tang, Jeff Talbott, Timothy Jones, and Bess B. Ward
Biogeosciences, 21, 3239–3250, https://doi.org/10.5194/bg-21-3239-2024, https://doi.org/10.5194/bg-21-3239-2024, 2024
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Wastewater treatment plants (WWTPs) are known to be hotspots of greenhouse gas emissions. However, the impact of WWTPs on the emission of the greenhouse gas N2O in downstream aquatic environments is less constrained. We found spatially and temporally variable but overall higher N2O concentrations and fluxes in waters downstream of WWTPs, pointing to the need for efficient N2O removal in addition to the treatment of nitrogen in WWTPs.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
Biogeosciences, 21, 2955–2971, https://doi.org/10.5194/bg-21-2955-2024, https://doi.org/10.5194/bg-21-2955-2024, 2024
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We measured nutrients and dissolved organic matter for 1 year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen compared to silicon and phosphorus. Our data help to explain how eutrophication persists in this system.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
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Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo-Pirotta, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
Biogeosciences, 21, 2705–2715, https://doi.org/10.5194/bg-21-2705-2024, https://doi.org/10.5194/bg-21-2705-2024, 2024
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In a recent experiment off the coast of Gran Canaria (Spain), scientists explored a method called ocean alkalinization enhancement (OAE), where carbonate minerals were added to seawater. This process changed the levels of certain ions in the water, affecting its pH and buffering capacity. The researchers were particularly interested in how this could impact the levels of essential trace metals in the water.
Lucas Porz, Wenyan Zhang, Nils Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
Biogeosciences, 21, 2547–2570, https://doi.org/10.5194/bg-21-2547-2024, https://doi.org/10.5194/bg-21-2547-2024, 2024
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Seafloor sediments store a large amount of carbon, helping to naturally regulate Earth's climate. If disturbed, some sediment particles can turn into CO2, but this effect is not well understood. Using computer simulations, we found that bottom-contacting fishing gears release about 1 million tons of CO2 per year in the North Sea, one of the most heavily fished regions globally. We show how protecting certain areas could reduce these emissions while also benefitting seafloor-living animals.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
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Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
Biogeosciences, 21, 2143–2158, https://doi.org/10.5194/bg-21-2143-2024, https://doi.org/10.5194/bg-21-2143-2024, 2024
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This work shows that, under a high-emission scenario, oxygen concentration in deep water of parts of the North Sea and Celtic Sea can become critically low (hypoxia) towards the end of this century. The extent and frequency of hypoxia depends on the intensity of climate change projected by different climate models. This is the result of a complex combination of factors like warming, increase in stratification, changes in the currents and changes in biological processes.
Sandy E. Tenorio and Laura Farías
Biogeosciences, 21, 2029–2050, https://doi.org/10.5194/bg-21-2029-2024, https://doi.org/10.5194/bg-21-2029-2024, 2024
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Time series studies show that CH4 is highly dynamic on the coastal ocean surface and planktonic communities are linked to CH4 accumulation, as found in coastal upwelling off Chile. We have identified the crucial role of picoplankton (> 3 µm) in CH4 recycling, especially with the addition of methylated substrates (trimethylamine and methylphosphonic acid) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding CH4 emission estimates.
Charlotte A. J. Williams, Tom Hull, Jan Kaiser, Claire Mahaffey, Naomi Greenwood, Matthew Toberman, and Matthew R. Palmer
Biogeosciences, 21, 1961–1971, https://doi.org/10.5194/bg-21-1961-2024, https://doi.org/10.5194/bg-21-1961-2024, 2024
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Oxygen (O2) is a key indicator of ocean health. The risk of O2 loss in the productive coastal/continental slope regions is increasing. Autonomous underwater vehicles equipped with O2 optodes provide lots of data but have problems resolving strong vertical O2 changes. Here we show how to overcome this and calculate how much O2 is supplied to the low-O2 bottom waters via mixing. Bursts in mixing supply nearly all of the O2 to bottom waters in autumn, stopping them reaching ecologically low levels.
Sabine Schmidt and Ibrahima Iris Diallo
Biogeosciences, 21, 1785–1800, https://doi.org/10.5194/bg-21-1785-2024, https://doi.org/10.5194/bg-21-1785-2024, 2024
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Along the French coast facing the Bay of Biscay, the large Gironde and Loire estuaries suffer from hypoxia. This prompted a study of the small Charente estuary located between them. This work reveals a minimum oxygen zone in the Charente estuary, which extends for about 25 km. Temperature is the main factor controlling the hypoxia. This calls for the monitoring of small turbid macrotidal estuaries that are vulnerable to hypoxia, a risk expected to increase with global warming.
Simone R. Alin, Jan A. Newton, Richard A. Feely, Samantha Siedlecki, and Dana Greeley
Biogeosciences, 21, 1639–1673, https://doi.org/10.5194/bg-21-1639-2024, https://doi.org/10.5194/bg-21-1639-2024, 2024
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We provide a new multi-stressor data product that allows us to characterize the seasonality of temperature, O2, and CO2 in the southern Salish Sea and delivers insights into the impacts of major marine heatwave and precipitation anomalies on regional ocean acidification and hypoxia. We also describe the present-day frequencies of temperature, O2, and ocean acidification conditions that cross thresholds of sensitive regional species that are economically or ecologically important.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera, Manuel Castillo, Aida Alvera-Azcárate, Mónica Alvarado, Gabriel Soto, Cécile Pujol, Camila Schwerter, Sara Arenas-Uribe, Pilar Navarro, Guido Mancilla-Gutiérrez, Robinson Altamirano, Javiera San Martín, and Camila Soto-Riquelme
Biogeosciences, 21, 1433–1459, https://doi.org/10.5194/bg-21-1433-2024, https://doi.org/10.5194/bg-21-1433-2024, 2024
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The Patagonian fjords comprise a world region where low-oxygen water and hypoxia conditions are observed. An in situ dataset was used to quantify the mechanism involved in the presence of these conditions in northern Patagonian fjords. Water mass analysis confirmed the contribution of Equatorial Subsurface Water in the advection of the low-oxygen water, and hypoxic conditions occurred when the community respiration rate exceeded the gross primary production.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
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The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Eleanor Simpson, Debby Ianson, Karen E. Kohfeld, Ana C. Franco, Paul A. Covert, Marty Davelaar, and Yves Perreault
Biogeosciences, 21, 1323–1353, https://doi.org/10.5194/bg-21-1323-2024, https://doi.org/10.5194/bg-21-1323-2024, 2024
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Shellfish aquaculture operates in nearshore areas where data on ocean acidification parameters are limited. We show daily and seasonal variability in pH and saturation states of calcium carbonate at nearshore aquaculture sites in British Columbia, Canada, and determine the contributing drivers of this variability. We find that nearshore locations have greater variability than open waters and that the uptake of carbon by phytoplankton is the major driver of pH and saturation state variability.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy Jr., Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences, 21, 1235–1257, https://doi.org/10.5194/bg-21-1235-2024, https://doi.org/10.5194/bg-21-1235-2024, 2024
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The coastal ocean in the northeastern USA provides many services, including fisheries and habitats for threatened species. In summer 2019, a bloom occurred of a large unusual phytoplankton, the diatom Hemiaulus, with nitrogen-fixing symbionts. This led to vast changes in productivity and grazing rates in the ecosystem. This work shows that the emergence of one species can have profound effects on ecosystem function. Such changes may become more prevalent as the ocean warms due to climate change.
Claudine Hauri, Brita Irving, Sam Dupont, Rémi Pagés, Donna D. W. Hauser, and Seth L. Danielson
Biogeosciences, 21, 1135–1159, https://doi.org/10.5194/bg-21-1135-2024, https://doi.org/10.5194/bg-21-1135-2024, 2024
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Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. We present pH and pCO2 time series (2016–2020) from the Chukchi Ecosystem Observatory and analyze the drivers of the current conditions to get a better understanding of how climate change and ocean acidification could affect the ecological niches of organisms.
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
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Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
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The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
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Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
Krysten Rutherford, Katja Fennel, Lina Garcia Suarez, and Jasmin G. John
Biogeosciences, 21, 301–314, https://doi.org/10.5194/bg-21-301-2024, https://doi.org/10.5194/bg-21-301-2024, 2024
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We downscaled two mid-century (~2075) ocean model projections to a high-resolution regional ocean model of the northwest North Atlantic (NA) shelf. In one projection, the NA shelf break current practically disappears; in the other it remains almost unchanged. This leads to a wide range of possible future shelf properties. More accurate projections of coastal circulation features would narrow the range of possible outcomes of biogeochemical projections for shelf regions.
Cited articles
Anderson, L. G., Andersson, P. S., Björk, G., Peter Jones, E., Jutterström, S., and Wåhlström, I.: Source and formation of the upper halocline of the Arctic Ocean, J. Geophys. Res.-Ocean., 118, 410–421, https://doi.org/10.1029/2012JC008291, 2013. a, b
Ardyna, M., Mundy, C. J., Mayot, N., Matthes, L. C., Oziel, L., Horvat, C., Leu, E., Assmy, P., Hill, V., Matrai, P. A., Gale, M., Melnikov, I. A., and Arrigo, K. R.: Under-Ice Phytoplankton Blooms: Shedding Light on the “Invisible” Part of Arctic Primary Production, Front. Mar. Sci., 7, 608032, https://doi.org/10.3389/fmars.2020.608032, 2020. a, b
Arrigo, K. R. and van Dijken, G. L.: Continued increases in Arctic Ocean primary production, Prog. Oceanogr., 136, 60–70, https://doi.org/10/f7mdc6, 2015. a
Arrigo, K. R., Perovich, D. K., Pickart, R. S., Brown, Z. W., Van Dijken, G. L., Lowry, K. E., Mills, M. M., Palmer, M. A., Balch, W. M., Bahr, F., Bates, N. R., Benitez-Nelson, C., Bowler, B., Brownlee, E., Ehn, J. K., Frey, K. E., Garley, R., Laney, S. R., Lubelczyk, L., Mathis, J., Matsuoka, A., Mitchell, B. G., Moore, G. W. K., Ortega-Retuerta, E., Pal, S., Polashenski, C. M., Reynolds, R. A., Schieber, B., Sosik, H. M., Stephens, M., and Swift, J. H.: Massive Phytoplankton Blooms Under Arctic Sea Ice, Science, 336, 1408–1408, https://doi.org/10.1126/science.1215065, 2012. a
Bakker, D. C. E., Alin, S. R., Bates, N., Becker, M., Feely, R. A., Gkritzalis, T., Jones, S. D., Kozyr, A., Lauvset, S. K., Metzl, N., Munro, D. R., Nakaoka, S.-I., Nojiri, Y., O'Brien, K. M., Olsen, A., Pierrot, D., Rehder, G., Steinhoff, T., Sutton, A. J., Sweeney, C., Tilbrook, B., Wada, C., Wanninkhof, R., Akl, J., Barbero, L., Beatty, C. M., Berghoff, C. F., Bittig, H. C., Bott, R., Burger, E. F., Cai, W.-J., Castaño-Primo, R., Corredor, J. E., Cronin, M., De Carlo, E. H., DeGrandpre, M. D., Dietrich, C., Drennan, W. M., Emerson, S. R., Enochs, I. C., Enyo, K., Epherra, L., Evans, W., Fiedler, B., Fontela, M., Frangoulis, C., Gehrung, M., Giannoudi, L., Glockzin, M., Hales, B., Howden, S. D., Ibánhez, J. S. P., Kamb, L., Körtzinger, A., Lefèvre, N., Lo Monaco, C., Lutz, V. A., Macovei, V. A., Maenner Jones, S., Manalang, D., Manzello, D. P., Metzl, N., Mickett, J., Millero, F. J., Monacci, N. M., Morell, J. M., Musielewicz, S., Neill, C., Newberger, T., Newton, J., Noakes, S., Ólafsdóttir, S. R., Ono, T., Osborne, J., Padín, X. A., Paulsen, M., Perivoliotis, L., Petersen, W., Petihakis, G., Plueddemann, A. J., Rodriguez, C., Rutgersson, A., Sabine, C. L., Salisbury, J. E., Schlitzer, R., Skjelvan, I., Stamataki, N., Sullivan, K. F., Sutherland, S. C., T'Jampens, M., Tadokoro, K., Tanhua, T., Telszewski, M., Theetaert, H., Tomlinson, M., Vandemark, D., Velo, A., Voynova, Y. G., Weller, R. A., Whitehead, C., and Wimart-Rousseau, C.: Surface Ocean CO2 Atlas Database Version 2023 (SOCATv2023) (NCEI Accession 0278913) [data set], https://doi.org/10.25921/R7XA-BT92, 2023. a, b
Bashmachnikov, I. L., Kozlov, I. E., Petrenko, L. A., Glok, N. I., and Wekerle, C.: Eddies in the North Greenland Sea and Fram Strait From Satellite Altimetry, SAR and High-Resolution Model Data, J. Geophys. Res.-Ocean., 125, e2019JC015832, https://doi.org/10.1029/2019JC015832, 2020. a
Bates, N. R., Mathis, J. T., and Cooper, L. W.: Ocean acidification and biologically induced seasonality of carbonate mineral saturation states in the western Arctic Ocean, J. Geophys. Res., 114, C11007, https://doi.org/10.1029/2008jc004862, 2009. a, b
Bauch, D., Hölemann, J., Willmes, S., Gröger, M., Novikhin, A., Nikulina, A., Kassens, H., and Timokhov, L.: Changes in distribution of brine waters on the Laptev Sea shelf in 2007, J. Geophys. Res., 115, C11008, https://doi.org/10.1029/2010JC006249, 2010. a
Bignami, F. and Hopkins, T.: The water mass characteristics of the Northeast Water Polynya: Polar Sea data 1992–1993, J. Mar. Syst., 10, 139–156, https://doi.org/10.1016/S0924-7963(96)00079-6, 1997. a
Bodur, Y. V., Renaud, P. E., Lins, L., Da Costa Monteiro, L., Ambrose, W. G., Felden, J., Krumpen, T., Wenzhöfer, F., Włodarska-Kowalczuk, M., and Braeckman, U.: Weakened pelagic-benthic coupling on an Arctic outflow shelf (Northeast Greenland) suggested by benthic ecosystem changes, Elem. Sci. Anth., 12, 00005, https://doi.org/10.1525/elementa.2023.00005, 2024. a, b
Broecker, W. S.: Thermohaline Circulation, the Achilles Heel of Our Climate System: Will Man-Made CO2 Upset the Current Balance?, Science, 278, 1582–1588, https://doi.org/10.1126/science.278.5343.1582, 1997. a
Budéus, G. and Schneider, W.: On the hydrography of the Northeast Water Polynya, J. Geophys. Res., 100, 4287, https://doi.org/10.1029/94jc02024, 1995. a
Budéus, G., Schneider, W., and Kattner, G.: Distribution and exchange of water masses in the Northeast Water polynya (Greenland Sea), J. Mar. Syst., 10, 123–138, https://doi.org/10.1016/s0924-7963(96)00074-7, 1997. a
Carmack, E. and Wassmann, P.: Food webs and physical–biological coupling on pan-Arctic shelves: Unifying concepts and comprehensive perspectives, Prog. Oceanogr., 71, 446–477, https://doi.org/10.1016/j.pocean.2006.10.004, 2006. a
Chang, B. X. and Devol, A. H.: Seasonal and spatial patterns of sedimentary denitrification rates in the Chukchi sea, Deep-Sea Res. Pt. II, 56, 1339–1350, https://doi.org/10.1016/j.dsr2.2008.10.024, 2009. a
Cooper, L. W., McClelland, J. W., Holmes, R. M., Raymond, P. A., Gibson, J. J., Guay, C. K., and Peterson, B. J.: Flow-weighted values of runoff tracers (δ18O, DOC, Ba, alkalinity) from the six largest Arctic rivers, Geophys. Res. Lett., 35, L18606, https://doi.org/10.1029/2008gl035007, 2008. a
De Steur, L., Sumata, H., Divine, D. V., Granskog, M. A., and Pavlova, O.: Upper ocean warming and sea ice reduction in the East Greenland Current from 2003 to 2019, Commun. Earth Environ., 4, 261, https://doi.org/10.1038/s43247-023-00913-3, 2023. a
Dickson, A. and Millero, F.: A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep-Sea Res. Pt. A, 34, 1733–1743, https://doi.org/10.1016/0198-0149(87)90021-5, 1987. a
Dickson, A. G.: Standard potential of the reaction: AgCl(s) + iH,(g) = Ag(s) + HCl(aq), and and the standard acidity constant of the ion HSOh in synthetic sea water from 273.15 to 318.15 K, J. Chem. Thermodyn., 22, 113–127, https://doi.org/10.1016/0021-9614(90)90074-Z, 1990. a
Duke, P. J., Else, B. G. T., Jones, S. F., Marriot, S., Ahmed, M. M. M., Nandan, V., Butterworth, B., Gonski, S. F., Dewey, R., Sastri, A., Miller, L. A., Simpson, K. G., and Thomas, H.: Seasonal marine carbon system processes in an Arctic coastal landfast sea ice environment observed with an innovative underwater sensor platform, Elementa, 9, 00103, https://doi.org/10.1525/elementa.2021.00103, 2021. a
Ericson, Y., Fransson, A., Chierici, M., Jones, E. M., Skjelvan, I., Omar, A., Olsen, A., and Becker, M.: Rapid fCO2 rise in the northern Barents Sea and Nansen Basin, Prog. Oceanogr., 217, 103079, https://doi.org/10.1016/j.pocean.2023.103079, 2023. a
Farmer, J. R., Hönisch, B., Haynes, L. L., Kroon, D., Jung, S., Ford, H. L., Raymo, M. E., Jaume-Seguí, M., Bell, D. B., Goldstein, S. L., Pena, L. D., Yehudai, M., and Kim, J.: Deep Atlantic Ocean carbon storage and the rise of 100,000-year glacial cycles, Nat. Geosci., 12, 355–360, https://doi.org/10.1038/s41561-019-0334-6, 2019. a
Fay, A. R., Gregor, L., Landschützer, P., McKinley, G. A., Gruber, N., Gehlen, M., Iida, Y., Laruelle, G. G., Rödenbeck, C., Roobaert, A., and Zeng, J.: SeaFlux: harmonization of air–sea CO2 fluxes from surface pCO2 data products using a standardized approach, Earth Syst. Sci. Data, 13, 4693–4710, https://doi.org/10.5194/essd-13-4693-2021, 2021. a
Fransson, A., Chierici, M., Granskog, M. A., Dodd, P. A., and Stedmon, C. A.: Impacts of glacial and sea-ice meltwater, primary production, and ocean CO2 uptake on ocean acidification state of waters by the 79 North Glacier and northeast Greenland shelf, Front. Mar. Sci., 10, 1155126, https://doi.org/10.3389/fmars.2023.1155126, 2023. a, b
Gascard, J.-C., Watson, A. J., Messias, M.-J., Olsson, K. A., Johannessen, T., and Simonsen, K.: Long-lived vortices as a mode of deep ventilation in the Greenland Sea, Nature, 416, 525–527, https://doi.org/10.1038/416525a, 2002. a
Good, S., Fiedler, E., Mao, C., Martin, M. J., Maycock, A., Reid, R., Roberts-Jones, J., Searle, T., Waters, J., While, J., and Worsfold, M.: The Current Configuration of the OSTIA System for Operational Production of Foundation Sea Surface Temperature and Ice Concentration Analyses, Remote Sens., 12, 720, https://doi.org/10.3390/rs12040720, 2020. a
Henson, H. C., Holding, J. M., Meire, L., Rysgaard, S., Stedmon, C. A., Stuart-Lee, A., Bendtsen, J., and Sejr, M.: Coastal freshening drives acidification state in Greenland fjords, Sci. Total Environ., 855, 158962, https://doi.org/10.1016/j.scitotenv.2022.158962, 2023. a, b
Henson, H. C., Sejr, M. K., Meire, L., Sørensen, L. L., Winding, M. H., and Holding, J. M.: Resolving heterogeneity in CO2 uptake potential in the Greenland coastal ocean, ESS Open Archive, https://doi.org/10.22541/essoar.171052503.36306724/v1, 2024. a, b
Holding, J. M., Markager, S., Juul-Pedersen, T., Paulsen, M. L., Møller, E. F., Meire, L., and Sejr, M. K.: Seasonal and spatial patterns of primary production in a high-latitude fjord affected by Greenland Ice Sheet run-off, Biogeosciences, 16, 3777–3792, https://doi.org/10.5194/bg-16-3777-2019, 2019. a
Hunt, G. L., Drinkwater, K. F., Arrigo, K., Berge, J., Daly, K. L., Danielson, S., Daase, M., Hop, H., Isla, E., Karnovsky, N., Laidre, K., Mueter, F. J., Murphy, E. J., Renaud, P. E., Smith, W. O., Trathan, P., Turner, J., and Wolf-Gladrow, D.: Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems, Prog. Oceanogr., 149, 40–81, https://doi.org/10.1016/j.pocean.2016.10.004, 2016. a
Jakobsson, M., Mayer, L. A., Bringensparr, C., Castro, C. F., Mohammad, R., Johnson, P., Ketter, T., Accettella, D., Amblas, D., An, L., Arndt, J. E., Canals, M., Casamor, J. L., Chauché, N., Coakley, B., Danielson, S., Demarte, M., Dickson, M.-L., Dorschel, B., Dowdeswell, J. A., Dreutter, S., Fremand, A. C., Gallant, D., Hall, J. K., Hehemann, L., Hodnesdal, H., Hong, J., Ivaldi, R., Kane, E., Klaucke, I., Krawczyk, D. W., Kristoffersen, Y., Kuipers, B. R., Millan, R., Masetti, G., Morlighem, M., Noormets, R., Prescott, M. M., Rebesco, M., Rignot, E., Semiletov, I., Tate, A. J., Travaglini, P., Velicogna, I., Weatherall, P., Weinrebe, W., Willis, J. K., Wood, M., Zarayskaya, Y., Zhang, T., Zimmermann, M., and Zinglersen, K. B.: The International Bathymetric Chart of the Arctic Ocean Version 4.0, Sci. Data, 7, 176, https://doi.org/10.1038/s41597-020-0520-9, 2020. a
Jones, E., Anderson, L., Jutterström, S., and Swift, J.: Sources and distribution of fresh water in the East Greenland Current, Prog. Oceanogr., 78, 37–44, https://doi.org/10.1016/j.pocean.2007.06.003, 2008.
Jones, E. M., Chierici, M., Menze, S., Fransson, A., Ingvaldsen, R. B., and Lødemel, H. H.: Ocean acidification state variability of the Atlantic Arctic Ocean around northern Svalbard, Prog. Oceanogr., 199, 102708, https://doi.org/10.1016/j.pocean.2021.102708, 2021. a, b, c
Martin, J., Dumont, D., and Tremblay, J.-É.: Contribution of subsurface chlorophyll maxima to primary production in the coastal Beaufort Sea (Canadian Arctic): A model assessment: CONTRIBUTION OF SCM IN BEAUFORT SEA, J. Geophys. Res.-Ocean., 118, 5873–5886, https://doi.org/10.1002/2013JC008843, 2013. a
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicx, R. M.: Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897–907, https://doi.org/10.4319/lo.1973.18.6.0897, 1973. a
Meteorological Office UK: ESA SST CCI and C3S reprocessed sea surface temperature analyses, E.U. Copernicus Marine Service Information (CMEMS), Marine Data Store (MDS), https://doi.org/10.48670/moi-00169, 2019. a
Michel, C., Hamilton, J., Hansen, E., Barber, D., Reigstad, M., Iacozza, J., Seuthe, L., and Niemi, A.: Arctic Ocean outflow shelves in the changing Arctic: A review and perspectives, Prog. Oceanogr., 139, 66–88, https://doi.org/10.1016/j.pocean.2015.08.007, 2015. a
Moon, T. A., Fisher, M., Harden, L., Shimonoko, H., and Stafford, T.: QGreenland (v2.0.0), Zenodo, https://doi.org/10.5281/zenodo.6369184, 2022. a
Mundy, C. J., Gosselin, M., Ehn, J., Gratton, Y., Rossnagel, A., Barber, D. G., Martin, J., Tremblay, J.-É., Palmer, M., Arrigo, K. R., Darnis, G., Fortier, L., Else, B., and Papakyriakou, T.: Contribution of under-ice primary production to an ice-edge upwelling phytoplankton bloom in the Canadian Beaufort Sea, Geophys. Res. Lett., 36, 2009GL038837, https://doi.org/10.1029/2009GL038837, 2009. a, b
Nakaoka, S.-I., Aoki, S., Nakazawa, T., Hashida, G., Morimoto, S., Yamanouchi, T., and Yoshikawa-Inoue, H.: Temporal and spatial variations of oceanic pCO2 and air–sea CO2 flux in the Greenland Sea and the Barents Sea, Tellus B, 58, 148, https://doi.org/10.1111/j.1600-0889.2006.00178.x, 2006. a
Nitishinsky, M., Anderson, L. G., and Hölemann, J. A.: Inorganic carbon and nutrient fluxes on the Arctic Shelf, Cont. Shelf Res., 27, 1584–1599, https://doi.org/10.1016/j.csr.2007.01.019, 2007. a
Nondal, G., Bellerby, R. G. J., Olsen, A., Johannessen, T., and Olafsson, J.: Optimal evaluation of the surface ocean CO2 system in the northern North Atlantic using data from voluntary observing ships, Limnol. Oceanogr.-Method., 7, 109–118, https://doi.org/10.4319/lom.2009.7.109, 2009. a, b, c
Olafsson, J., Olafsdottir, S. R., Takahashi, T., Danielsen, M., and Arnarson, T. S.: Enhancement of the North Atlantic CO2 sink by Arctic Waters, Biogeosciences, 18, 1689–1701, https://doi.org/10.5194/bg-18-1689-2021, 2021. a
Olsen, A.: Nordic Seas total alkalinity data in CARINA, Earth Syst. Sci. Data, 1, 77–86, https://doi.org/10.5194/essd-1-77-2009, 2009. a, b, c
Olsen, A., Brown, K. R., Chierici, M., Johannessen, T., and Neill, C.: Sea-surface CO2 fugacity in the subpolar North Atlantic, Biogeosciences, 5, 535–547, https://doi.org/10.5194/bg-5-535-2008, 2008. a
Overland, J., Dunlea, E., Box, J. E., Corell, R., Forsius, M., Kattsov, V., Olsen, M. S., Pawlak, J., Reiersen, L.-O., and Wang, M.: The urgency of Arctic change, Polar Sci., 21, 6–13, https://doi.org/10.1016/j.polar.2018.11.008, 2019. a
Polyakov, I. V., Pnyushkov, A. V., Alkire, M. B., Ashik, I. M., Baumann, T. M., Carmack, E. C., Goszczko, I., Guthrie, J., Ivanov, V. V., Kanzow, T., Krishfield, R., Kwok, R., Sundfjord, A., Morison, J., Rember, R., and Yulin, A.: Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean, Science, 356, 285–291, https://doi.org/10.1126/science.aai8204, 2017. a
Polyakov, I. V., Rippeth, T. P., Fer, I., Alkire, M. B., Baumann, T. M., Carmack, E. C., Ingvaldsen, R., Ivanov, V. V., Janout, M., Lind, S., Padman, L., Pnyushkov, A. V., and Rember, R.: Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean, J. Clim., 33, 8107–8123, https://doi.org/10.1175/JCLI-D-19-0976.1, 2020. a
Qu, B., Gabric, A. J., Zhu, J.-N., Lin, D.-R., Qian, F., and Zhao, M.: Correlation between sea surface temperature and wind speed in Greenland Sea and their relationships with NAO variability, Water Sci. Eng., 5, 304–315, https://doi.org/10.3882/j.issn.1674-2370.2012.03.006, 2012. a
Rajasakaren, B., Jeansson, E., Olsen, A., Tanhua, T., Johannessen, T., and Smethie, W.: Trends in anthropogenic carbon in the Arctic Ocean, Prog. Oceanogr., 178, 102177, https://doi.org/10.1016/j.pocean.2019.102177, 2019. a
Richter-Menge, J., Overland, J. E., Mathis, J. T., Osborne, E., Brown, R., Mudryk, L., Luojus, K., and Helfrich, S.: Arctic Report Card 2017, Tech. rep., https://doi.org/10.25923/8ntk-7817, 2017. a
Rudels, B., Björk, G., Nilsson, J., Winsor, P., Lake, I., and Nohr, C.: The interaction between waters from the Arctic Ocean and the Nordic Seas north of Fram Strait and along the East Greenland Current: results from the Arctic Ocean-02 Oden expedition, J. Mar. Syst., 55, 1–30, https://doi.org/10.1016/j.jmarsys.2004.06.008, 2005. a
Rysgaard, S., Vang, T., Stjernholm, M., Rasmussen, B., Windelin, A., and Kiilsholm, S.: Physical Conditions, Carbon Transport, and Climate Change Impacts in a Northeast Greenland Fjord, Arct. Antarct. Alp. Res., 35, 301–312, https://doi.org/10.1657/1523-0430(2003)035[0301:PCCTAC]2.0.CO;2, 2003. a
Rysgaard, S., Bendtsen, J., Pedersen, L. T., Ramløv, H., and Glud, R. N.: Increased CO2 uptake due to sea ice growth and decay in the Nordic Seas, J. Geophys. Res., 114, C09011, https://doi.org/10.1029/2008JC005088, 2009. a
Sejr, M., Krause-Jensen, D., Rysgaard, S., Sørensen, L., Christensen, P., and Glud, R.: Air–sea flux of CO 2 in arctic coastal waters influenced by glacial melt water and sea ice, Tellus B, 63, 815–822, https://doi.org/10.1111/j.1600-0889.2011.00540.x, 2011. a
Serreze, M. C. and Barry, R. G.: Processes and impacts of Arctic amplification: A research synthesis, Glob. Planet.Change, 77, 85–96, https://doi.org/10.1016/j.gloplacha.2011.03.004, 2011. a
Shiklomanov, A., Déry, S., Tretiakov, M., Yang, D., Magritsky, D., Georgiadi, A., and Tang, W.: River freshwater flux to the arctic ocean, in: Arctic hydrology, permafrost and ecosystems, edited by: Yang, D. and Kane, D. L., 703–738, Springer International Publishing, Cham, ISBN 978-3-030-50930-9, 2021. a
Smethie, J. W. M. and Fine, R. A.: Rates of North Atlantic Deep Water formation calculated from chlorofluorocarbon inventories, Deep-Sea Res. Pt. I, 48, 189–215, https://doi.org/10.1016/S0967-0637(00)00048-0, 2001. a
Stroh, J., Kirillov, S., Panteleev, G., Francis, O., Yaremchuk, M., Bloshkina, E., and Lebedev, N.: Changes in Arctic Ocean Climate Evinced through Analysis of IPY 2007–2008 Oceanographic Observations, in: Arctic Studies – A Proxy for Climate Change, edited by: Kanao, M., Kakinami, Y., and Toyokuni, G., IntechOpen, ISBN 978-1-78984-099-5, 978-1-78984-100-8, https://doi.org/10.5772/intechopen.80926, 2019. a
Sumata, H., De Steur, L., Gerland, S., Divine, D. V., and Pavlova, O.: Unprecedented decline of Arctic sea ice outflow in 2018, Nature Communications, 13, 1747, https://doi.org/10.1038/s41467-022-29470-7, 2022. a, b
Takahashi, T., Sutherland, S., Chipman, D., Goddard, J., Ho, C., Newberger, T., Sweeney, C., and Munro, D.: Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, and temporal changes at selected locations, Mar. Chem., 164, 95–125, https://doi.org/10.1016/j.marchem.2014.06.004, 2014. a
Tuerena, R. E., Mahaffey, C., Henley, S. F., De La Vega, C., Norman, L., Brand, T., Sanders, T., Debyser, M., Dähnke, K., Braun, J., and März, C.: Nutrient pathways and their susceptibility to past and future change in the Eurasian Arctic Ocean, Ambio, 51, 355–369, https://doi.org/10.1007/s13280-021-01673-0, 2022. a, b
van Heuven, S., Pierrot, D., Rae, J., Lewis, E., and Wallace, D.: CO2SYS v 1.1, MATLAB program developed for CO2 system calculations, ORNL/CDIAC-105b. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge [code], Tennessee, https://news-oceanacidification-icc.org/2011/10/11/co2sys-for-matlab-updated-to-v1-1/ (last access: 6 September 2024), 2011. a
von Appen, W.-J., Waite, A. M., Bergmann, M., Bienhold, C., Boebel, O., Bracher, A., Cisewski, B., Hagemann, J., Hoppema, M., Iversen, M. H., Konrad, C., Krumpen, T., Lochthofen, N., Metfies, K., Niehoff, B., Nöthig, E.-M., Purser, A., Salter, I., Schaber, M., Scholz, D., Soltwedel, T., Torres-Valdes, S., Wekerle, C., Wenzhöfer, F., Wietz, M., and Boetius, A.: Sea-ice derived meltwater stratification slows the biological carbon pump: results from continuous observations, Nat. Commun., 12, 7309, https://doi.org/10.1038/s41467-021-26943-z, 2021. a, b
Wadhams, P., Holfort, J., Hansen, E., and Wilkinson, J. P.: A deep convective chimney in the winter greenland sea, Geophys. Res. Lett., 29, 1434, https://doi.org/10.1029/2001GL014306, 2002. a
Wallace, D., Behrens, W., Hopkins, T., Kinder, C., Deming, J., Smith, W., Top, Z., and Walsh, I.: Collaborative research on the Northeast Water Polynya: NEWP92 hydrographic data report, USCGC Polar Sea cruise, July 15–August 15, 1992, Tech. Rep. BNL–61923, 102497, https://doi.org/10.2172/102497, 1995a. a, b
Wallace, D. W. R., Minnett, P. J., and Hopkins, T. S.: Nutrients, oxygen, and inferred new production in the Northeast Water Polynya, 1992, J. Geophys. Res., 100, 4323, https://doi.org/10.1029/94JC02203, 1995b. a
Willcox, E. W., Bendtsen, J., Mortensen, J., Mohn, C., Lemes, M., Pedersen, T.-J., Holding, J., Møller, E. F., Sejr, M. K., Seidenkrantz, M.-S., and Rysgaard, S.: An Updated View of the Water Masses on the Northeast Greenland Shelf and Their Link to the Laptev Sea and Lena River, J. Geophys. Res.-Ocean., 128, e2022JC019052, https://doi.org/10.1029/2022JC019052, 2023. a, b, c, d
Willcox, E., Rysgaard, S., Sejr, M. K., Juul-Pedersen, T., Lemes, M., Holding, J.: Additional bottle chemistry values (ta, tco2, stable water isotopes, nutrients) for the NEG2017 cruises on the Northeast Greenland Shelf, August–September 2017, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.968792, 2024a. a
Willcox, E., Rysgaard, S., Sejr, M. K., Juul-Pedersen, T., Lemes, M., Holding, J.: Additional bottle chemistry values (ta, tco2, stable water isotopes, nutrients) for the NorthGreen2017 cruise on the Northeast Greenland Shelf, August–September 2017, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.968793, 2024b. a
Yager, P. L., Wallace, D. W. R., Johnson, K. M., Smith, W. O., Minnett, P. J., and Deming, J. W.: The Northeast Water Polynya as an atmospheric CO 2 sink: A seasonal rectification hypothesis, J. Geophys. Res., 100, 4389, https://doi.org/10.1029/94JC01962, 1995. a, b, c
Yasunaka, S., Siswanto, E., Olsen, A., Hoppema, M., Watanabe, E., Fransson, A., Chierici, M., Murata, A., Lauvset, S. K., Wanninkhof, R., Takahashi, T., Kosugi, N., Omar, A. M., van Heuven, S., and Mathis, J. T.: Arctic Ocean CO2 uptake: an improved multiyear estimate of the air–sea CO2 flux incorporating chlorophyll a concentrations, Biogeosciences, 15, 1643–1661, https://doi.org/10.5194/bg-15-1643-2018, 2018. a
Zeebe, R. E. and Wolf-Gladrow, D. A.: CO2 in seawater: equilibrium, kinetics, isotopes, no. 65 in Elsevier oceanography series, Elsevier, Amsterdam, New York, ISBN: 978-0-444-50579-8, 978-0-444-50946-8, 2001. a
Zhuang, Y., Jin, H., Cai, W.-J., Li, H., Jin, M., Qi, D., and Chen, J.: Freshening leads to a three-decade trend of declining nutrients in the western Arctic Ocean, Environ. Res. Lett., 16, 054047, https://doi.org/10.1088/1748-9326/abf58b, 2021. a
Zhuang, Y., Jin, H., Cai, W.-J., Li, H., Qi, D., and Chen, J.: Extreme Nitrate Deficits in the Western Arctic Ocean: Origin, Decadal Changes, and Implications for Denitrification on a Polar Marginal Shelf, Global Biogeochem. Cy., 36, e2022GB007304, https://doi.org/10.1029/2022GB007304, 2022. a
Short summary
In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO2. Historically, the region has always been thought to take up CO2 from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.
In this work, we measured the chemistry of seawater from samples obtained from different depths...
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