Articles | Volume 16, issue 13
https://doi.org/10.5194/bg-16-2693-2019
© Author(s) 2019. 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-16-2693-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
11 Jul 2019
Research article | Highlight paper |
| 11 Jul 2019
| 11 Jul 2019
Dissolved organic matter at the fluvial–marine transition in the Laptev Sea using in situ data and ocean colour remote sensing
Institute for Space Sciences, Department of Earth Sciences, Freie
Universität Berlin, Berlin, Germany
Pier Paul Overduin
Alfred Wegener Institute Helmholtz Centre for Polar and Marine
Research, Potsdam, Germany
Jens Hölemann
Alfred Wegener Institute Helmholtz Centre for Polar and Marine
Research, Bremerhaven, Germany
Martin Hieronymi
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht,
Geesthacht, Germany
Atsushi Matsuoka
Takuvik Joint International Laboratory, Département de Biologie,
Université Laval, Québec City, Canada
Birgit Heim
Alfred Wegener Institute Helmholtz Centre for Polar and Marine
Research, Potsdam, Germany
Jürgen Fischer
Institute for Space Sciences, Department of Earth Sciences, Freie
Universität Berlin, Berlin, Germany
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Nicole Docter, Rene Preusker, Florian Filipitsch, Lena Kritten, Franziska Schmidt, and Jürgen Fischer
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Lena Katharina Jänicke, Rene Preusker, Marco Celesti, Marin Tudoroiu, Jürgen Fischer, Dirk Schüttemeyer, and Matthias Drusch
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Martine Lizotte, Bennet Juhls, Atsushi Matsuoka, Philippe Massicotte, Gaëlle Mével, David Obie James Anikina, Sofia Antonova, Guislain Bécu, Marine Béguin, Simon Bélanger, Thomas Bossé-Demers, Lisa Bröder, Flavienne Bruyant, Gwénaëlle Chaillou, Jérôme Comte, Raoul-Marie Couture, Emmanuel Devred, Gabrièle Deslongchamps, Thibaud Dezutter, Miles Dillon, David Doxaran, Aude Flamand, Frank Fell, Joannie Ferland, Marie-Hélène Forget, Michael Fritz, Thomas J. Gordon, Caroline Guilmette, Andrea Hilborn, Rachel Hussherr, Charlotte Irish, Fabien Joux, Lauren Kipp, Audrey Laberge-Carignan, Hugues Lantuit, Edouard Leymarie, Antonio Mannino, Juliette Maury, Paul Overduin, Laurent Oziel, Colin Stedmon, Crystal Thomas, Lucas Tisserand, Jean-Éric Tremblay, Jorien Vonk, Dustin Whalen, and Marcel Babin
Earth Syst. Sci. Data, 15, 1617–1653, https://doi.org/10.5194/essd-15-1617-2023, https://doi.org/10.5194/essd-15-1617-2023, 2023
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Ngai-Ham Chan, Moritz Langer, Bennet Juhls, Tabea Rettelbach, Paul Overduin, Kimberly Huppert, and Jean Braun
Earth Surf. Dynam., 11, 259–285, https://doi.org/10.5194/esurf-11-259-2023, https://doi.org/10.5194/esurf-11-259-2023, 2023
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Olga Ogneva, Gesine Mollenhauer, Bennet Juhls, Tina Sanders, Juri Palmtag, Matthias Fuchs, Hendrik Grotheer, Paul J. Mann, and Jens Strauss
Biogeosciences, 20, 1423–1441, https://doi.org/10.5194/bg-20-1423-2023, https://doi.org/10.5194/bg-20-1423-2023, 2023
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Femke van Geffen, Birgit Heim, Frederic Brieger, Rongwei Geng, Iuliia A. Shevtsova, Luise Schulte, Simone M. Stuenzi, Nadine Bernhardt, Elena I. Troeva, Luidmila A. Pestryakova, Evgenii S. Zakharov, Bringfried Pflug, Ulrike Herzschuh, and Stefan Kruse
Earth Syst. Sci. Data, 14, 4967–4994, https://doi.org/10.5194/essd-14-4967-2022, https://doi.org/10.5194/essd-14-4967-2022, 2022
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SiDroForest is an attempt to remedy data scarcity regarding vegetation data in the circumpolar region, whilst providing adjusted and labeled data for machine learning and upscaling practices. SiDroForest contains four datasets that include SfM point clouds, individually labeled trees, synthetic tree crowns and labeled Sentinel-2 patches that provide insights into the vegetation composition and forest structure of two important vegetation transition zones in Siberia, Russia.
Mauricio Arboleda-Zapata, Michael Angelopoulos, Pier Paul Overduin, Guido Grosse, Benjamin M. Jones, and Jens Tronicke
The Cryosphere, 16, 4423–4445, https://doi.org/10.5194/tc-16-4423-2022, https://doi.org/10.5194/tc-16-4423-2022, 2022
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We demonstrate how we can reliably estimate the thawed–frozen permafrost interface with its associated uncertainties in subsea permafrost environments using 2D electrical resistivity tomography (ERT) data. In addition, we show how further analyses considering 1D inversion and sensitivity assessments can help quantify and better understand 2D ERT inversion results. Our results illustrate the capabilities of the ERT method to get insights into the development of the subsea permafrost.
Ulrike Herzschuh, Chenzhi Li, Thomas Böhmer, Alexander K. Postl, Birgit Heim, Andrei A. Andreev, Xianyong Cao, Mareike Wieczorek, and Jian Ni
Earth Syst. Sci. Data, 14, 3213–3227, https://doi.org/10.5194/essd-14-3213-2022, https://doi.org/10.5194/essd-14-3213-2022, 2022
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Pollen preserved in environmental archives such as lake sediments and bogs are extensively used for reconstructions of past vegetation and climate. Here we present LegacyPollen 1.0, a dataset of 2831 fossil pollen records from all over the globe that were collected from publicly available databases. We harmonized the names of the pollen taxa so that all datasets can be jointly investigated. LegacyPollen 1.0 is available as an open-access dataset.
Matthias Fuchs, Juri Palmtag, Bennet Juhls, Pier Paul Overduin, Guido Grosse, Ahmed Abdelwahab, Michael Bedington, Tina Sanders, Olga Ogneva, Irina V. Fedorova, Nikita S. Zimov, Paul J. Mann, and Jens Strauss
Earth Syst. Sci. Data, 14, 2279–2301, https://doi.org/10.5194/essd-14-2279-2022, https://doi.org/10.5194/essd-14-2279-2022, 2022
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We created digital, high-resolution bathymetry data sets for the Lena Delta and Kolyma Gulf regions in northeastern Siberia. Based on nautical charts, we digitized depth points and isobath lines, which serve as an input for a 50 m bathymetry model. The benefit of this data set is the accurate mapping of near-shore areas as well as the offshore continuation of the main deep river channels. This will improve the estimation of river outflow and the nutrient flux output into the coastal zone.
Charlotte Haugk, Loeka L. Jongejans, Kai Mangelsdorf, Matthias Fuchs, Olga Ogneva, Juri Palmtag, Gesine Mollenhauer, Paul J. Mann, P. Paul Overduin, Guido Grosse, Tina Sanders, Robyn E. Tuerena, Lutz Schirrmeister, Sebastian Wetterich, Alexander Kizyakov, Cornelia Karger, and Jens Strauss
Biogeosciences, 19, 2079–2094, https://doi.org/10.5194/bg-19-2079-2022, https://doi.org/10.5194/bg-19-2079-2022, 2022
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Stiig Wilkenskjeld, Frederieke Miesner, Paul P. Overduin, Matteo Puglini, and Victor Brovkin
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Thawing permafrost releases carbon to the atmosphere, enhancing global warming. Part of the permafrost soils have been flooded by rising sea levels since the last ice age, becoming subsea permafrost (SSPF). The SSPF is less studied than the part on land. In this study we use a global model to obtain rates of thawing of SSPF under different future climate scenarios until the year 3000. After the year 2100 the scenarios strongly diverge, closely connected to the eventual disappearance of sea ice.
Thomas Krumpen, Luisa von Albedyll, Helge F. Goessling, Stefan Hendricks, Bennet Juhls, Gunnar Spreen, Sascha Willmes, H. Jakob Belter, Klaus Dethloff, Christian Haas, Lars Kaleschke, Christian Katlein, Xiangshan Tian-Kunze, Robert Ricker, Philip Rostosky, Janna Rückert, Suman Singha, and Julia Sokolova
The Cryosphere, 15, 3897–3920, https://doi.org/10.5194/tc-15-3897-2021, https://doi.org/10.5194/tc-15-3897-2021, 2021
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We use satellite data records collected along the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) drift to categorize ice conditions that shaped and characterized the floe and surroundings during the expedition. A comparison with previous years is made whenever possible. The aim of this analysis is to provide a basis and reference for subsequent research in the six main research areas of atmosphere, ocean, sea ice, biogeochemistry, remote sensing and ecology.
Lydia Stolpmann, Caroline Coch, Anne Morgenstern, Julia Boike, Michael Fritz, Ulrike Herzschuh, Kathleen Stoof-Leichsenring, Yury Dvornikov, Birgit Heim, Josefine Lenz, Amy Larsen, Katey Walter Anthony, Benjamin Jones, Karen Frey, and Guido Grosse
Biogeosciences, 18, 3917–3936, https://doi.org/10.5194/bg-18-3917-2021, https://doi.org/10.5194/bg-18-3917-2021, 2021
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Our new database summarizes DOC concentrations of 2167 water samples from 1833 lakes in permafrost regions across the Arctic to provide insights into linkages between DOC and environment. We found increasing lake DOC concentration with decreasing permafrost extent and higher DOC concentrations in boreal permafrost sites compared to tundra sites. Our study shows that DOC concentration depends on the environmental properties of a lake, especially permafrost extent, ecoregion, and vegetation.
Jens A. Hölemann, Bennet Juhls, Dorothea Bauch, Markus Janout, Boris P. Koch, and Birgit Heim
Biogeosciences, 18, 3637–3655, https://doi.org/10.5194/bg-18-3637-2021, https://doi.org/10.5194/bg-18-3637-2021, 2021
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The Arctic Ocean receives large amounts of river water rich in terrestrial dissolved organic matter (tDOM), which is an important component of the Arctic carbon cycle. Our analysis shows that mixing of three major freshwater sources is the main factor that regulates the distribution of tDOM concentrations in the Siberian shelf seas. In this context, the formation and melting of the land-fast ice in the Laptev Sea and the peak spring discharge of the Lena River are of particular importance.
Iuliia Shevtsova, Ulrike Herzschuh, Birgit Heim, Luise Schulte, Simone Stünzi, Luidmila A. Pestryakova, Evgeniy S. Zakharov, and Stefan Kruse
Biogeosciences, 18, 3343–3366, https://doi.org/10.5194/bg-18-3343-2021, https://doi.org/10.5194/bg-18-3343-2021, 2021
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In the light of climate changes in subarctic regions, notable general increase in above-ground biomass for the past 15 years (2000 to 2017) was estimated along a tundra–taiga gradient of central Chukotka (Russian Far East). The greatest increase occurred in the northern taiga in the areas of larch closed-canopy forest expansion with Cajander larch as a main contributor. For the estimations, we used field data (taxa-separated plant biomass, 2018) and upscaled it based on Landsat satellite data.
Philippe Massicotte, Rainer M. W. Amon, David Antoine, Philippe Archambault, Sergio Balzano, Simon Bélanger, Ronald Benner, Dominique Boeuf, Annick Bricaud, Flavienne Bruyant, Gwenaëlle Chaillou, Malik Chami, Bruno Charrière, Jing Chen, Hervé Claustre, Pierre Coupel, Nicole Delsaut, David Doxaran, Jens Ehn, Cédric Fichot, Marie-Hélène Forget, Pingqing Fu, Jonathan Gagnon, Nicole Garcia, Beat Gasser, Jean-François Ghiglione, Gaby Gorsky, Michel Gosselin, Priscillia Gourvil, Yves Gratton, Pascal Guillot, Hermann J. Heipieper, Serge Heussner, Stanford B. Hooker, Yannick Huot, Christian Jeanthon, Wade Jeffrey, Fabien Joux, Kimitaka Kawamura, Bruno Lansard, Edouard Leymarie, Heike Link, Connie Lovejoy, Claudie Marec, Dominique Marie, Johannie Martin, Jacobo Martín, Guillaume Massé, Atsushi Matsuoka, Vanessa McKague, Alexandre Mignot, William L. Miller, Juan-Carlos Miquel, Alfonso Mucci, Kaori Ono, Eva Ortega-Retuerta, Christos Panagiotopoulos, Tim Papakyriakou, Marc Picheral, Louis Prieur, Patrick Raimbault, Joséphine Ras, Rick A. Reynolds, André Rochon, Jean-François Rontani, Catherine Schmechtig, Sabine Schmidt, Richard Sempéré, Yuan Shen, Guisheng Song, Dariusz Stramski, Eri Tachibana, Alexandre Thirouard, Imma Tolosa, Jean-Éric Tremblay, Mickael Vaïtilingom, Daniel Vaulot, Frédéric Vaultier, John K. Volkman, Huixiang Xie, Guangming Zheng, and Marcel Babin
Earth Syst. Sci. Data, 13, 1561–1592, https://doi.org/10.5194/essd-13-1561-2021, https://doi.org/10.5194/essd-13-1561-2021, 2021
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The MALINA oceanographic expedition was conducted in the Mackenzie River and the Beaufort Sea systems. The sampling was performed across seven shelf–basin transects to capture the meridional gradient between the estuary and the open ocean. The main goal of this research program was to better understand how processes such as primary production are influencing the fate of organic matter originating from the surrounding terrestrial landscape during its transition toward the Arctic Ocean.
Ines Spangenberg, Pier Paul Overduin, Ellen Damm, Ingeborg Bussmann, Hanno Meyer, Susanne Liebner, Michael Angelopoulos, Boris K. Biskaborn, Mikhail N. Grigoriev, and Guido Grosse
The Cryosphere, 15, 1607–1625, https://doi.org/10.5194/tc-15-1607-2021, https://doi.org/10.5194/tc-15-1607-2021, 2021
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Thermokarst lakes are common on ice-rich permafrost. Many studies have shown that they are sources of methane to the atmosphere. Although they are usually covered by ice, little is known about what happens to methane in winter. We studied how much methane is contained in the ice of a thermokarst lake, a thermokarst lagoon and offshore. Methane concentrations differed strongly, depending on water body type. Microbes can also oxidize methane in ice and lower the concentrations during winter.
Rebecca Rolph, Pier Paul Overduin, Thomas Ravens, Hugues Lantuit, and Moritz Langer
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2021-28, https://doi.org/10.5194/gmd-2021-28, 2021
Revised manuscript not accepted
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Declining sea ice, larger waves, and increasing air temperatures are contributing to a rapidly eroding Arctic coastline. We simulate water levels using wind speed and direction, which are used with wave height, wave period, and sea surface temperature to drive an erosion model of a partially frozen cliff and beach. This provides a first step to include Arctic erosion in larger-scale earth system models. Simulated cumulative retreat rates agree within the same order of magnitude as observations.
Ingeborg Bussmann, Irina Fedorova, Bennet Juhls, Pier Paul Overduin, and Matthias Winkel
Biogeosciences, 18, 2047–2061, https://doi.org/10.5194/bg-18-2047-2021, https://doi.org/10.5194/bg-18-2047-2021, 2021
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Arctic rivers, lakes, and bays are affected by a warming climate. We measured the amount and consumption of methane in waters from Siberia under ice cover and in open water. In the lake, methane concentrations under ice cover were much higher than in summer, and methane consumption was highest. The ice cover leads to higher methane concentration under ice. In a warmer Arctic, there will be more time with open water when methane is consumed by bacteria, and less methane will escape into the air.
Florian Tornow, Carlos Domenech, Howard W. Barker, René Preusker, and Jürgen Fischer
Atmos. Meas. Tech., 13, 3909–3922, https://doi.org/10.5194/amt-13-3909-2020, https://doi.org/10.5194/amt-13-3909-2020, 2020
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Clouds reflect sunlight unevenly, which makes it difficult to quantify the portion reflected back to space via satellite observation. To improve quantification, we propose a new statistical model that incorporates more satellite-inferred cloud and atmospheric properties than state-of-the-art models. We use concepts from radiative transfer theory that we statistically optimize to fit observations. The new model often explains past satellite observations better and predicts reflection plausibly.
H. Jakob Belter, Thomas Krumpen, Stefan Hendricks, Jens Hoelemann, Markus A. Janout, Robert Ricker, and Christian Haas
The Cryosphere, 14, 2189–2203, https://doi.org/10.5194/tc-14-2189-2020, https://doi.org/10.5194/tc-14-2189-2020, 2020
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The validation of satellite sea ice thickness (SIT) climate data records with newly acquired moored sonar SIT data shows that satellite products provide modal rather than mean SIT in the Laptev Sea region. This tendency of satellite-based SIT products to underestimate mean SIT needs to be considered for investigations of sea ice volume transports. Validation of satellite SIT in the first-year-ice-dominated Laptev Sea will support algorithm development for more reliable SIT records in the Arctic.
Thomas Krumpen, Florent Birrien, Frank Kauker, Thomas Rackow, Luisa von Albedyll, Michael Angelopoulos, H. Jakob Belter, Vladimir Bessonov, Ellen Damm, Klaus Dethloff, Jari Haapala, Christian Haas, Carolynn Harris, Stefan Hendricks, Jens Hoelemann, Mario Hoppmann, Lars Kaleschke, Michael Karcher, Nikolai Kolabutin, Ruibo Lei, Josefine Lenz, Anne Morgenstern, Marcel Nicolaus, Uwe Nixdorf, Tomash Petrovsky, Benjamin Rabe, Lasse Rabenstein, Markus Rex, Robert Ricker, Jan Rohde, Egor Shimanchuk, Suman Singha, Vasily Smolyanitsky, Vladimir Sokolov, Tim Stanton, Anna Timofeeva, Michel Tsamados, and Daniel Watkins
The Cryosphere, 14, 2173–2187, https://doi.org/10.5194/tc-14-2173-2020, https://doi.org/10.5194/tc-14-2173-2020, 2020
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In October 2019 the research vessel Polarstern was moored to an ice floe in order to travel with it on the 1-year-long MOSAiC journey through the Arctic. Here we provide historical context of the floe's evolution and initial state for upcoming studies. We show that the ice encountered on site was exceptionally thin and was formed on the shallow Siberian shelf. The analyses presented provide the initial state for the analysis and interpretation of upcoming biogeochemical and ecological studies.
Stanford B. Hooker, Atsushi Matsuoka, Raphael M. Kudela, Youhei Yamashita, Koji Suzuki, and Henry F. Houskeeper
Biogeosciences, 17, 475–497, https://doi.org/10.5194/bg-17-475-2020, https://doi.org/10.5194/bg-17-475-2020, 2020
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A Kd(λ) and aCDOM(440) data set spanned oceanic, coastal, and inland waters. The algorithmic approach, based on Kd end-member pairs, can be used globally. End-members with the largest spectral span had an accuracy of 1.2–2.4 % (RMSE). Validation was influenced by subjective
nonconservativewater masses. The influence of subcategories was confirmed with an objective cluster analysis.
Philippe Massicotte, Rémi Amiraux, Marie-Pier Amyot, Philippe Archambault, Mathieu Ardyna, Laurent Arnaud, Lise Artigue, Cyril Aubry, Pierre Ayotte, Guislain Bécu, Simon Bélanger, Ronald Benner, Henry C. Bittig, Annick Bricaud, Éric Brossier, Flavienne Bruyant, Laurent Chauvaud, Debra Christiansen-Stowe, Hervé Claustre, Véronique Cornet-Barthaux, Pierre Coupel, Christine Cox, Aurelie Delaforge, Thibaud Dezutter, Céline Dimier, Florent Domine, Francis Dufour, Christiane Dufresne, Dany Dumont, Jens Ehn, Brent Else, Joannie Ferland, Marie-Hélène Forget, Louis Fortier, Martí Galí, Virginie Galindo, Morgane Gallinari, Nicole Garcia, Catherine Gérikas Ribeiro, Margaux Gourdal, Priscilla Gourvil, Clemence Goyens, Pierre-Luc Grondin, Pascal Guillot, Caroline Guilmette, Marie-Noëlle Houssais, Fabien Joux, Léo Lacour, Thomas Lacour, Augustin Lafond, José Lagunas, Catherine Lalande, Julien Laliberté, Simon Lambert-Girard, Jade Larivière, Johann Lavaud, Anita LeBaron, Karine Leblanc, Florence Le Gall, Justine Legras, Mélanie Lemire, Maurice Levasseur, Edouard Leymarie, Aude Leynaert, Adriana Lopes dos Santos, Antonio Lourenço, David Mah, Claudie Marec, Dominique Marie, Nicolas Martin, Constance Marty, Sabine Marty, Guillaume Massé, Atsushi Matsuoka, Lisa Matthes, Brivaela Moriceau, Pierre-Emmanuel Muller, Christopher-John Mundy, Griet Neukermans, Laurent Oziel, Christos Panagiotopoulos, Jean-Jacques Pangrazi, Ghislain Picard, Marc Picheral, France Pinczon du Sel, Nicole Pogorzelec, Ian Probert, Bernard Quéguiner, Patrick Raimbault, Joséphine Ras, Eric Rehm, Erin Reimer, Jean-François Rontani, Søren Rysgaard, Blanche Saint-Béat, Makoto Sampei, Julie Sansoulet, Catherine Schmechtig, Sabine Schmidt, Richard Sempéré, Caroline Sévigny, Yuan Shen, Margot Tragin, Jean-Éric Tremblay, Daniel Vaulot, Gauthier Verin, Frédéric Vivier, Anda Vladoiu, Jeremy Whitehead, and Marcel Babin
Earth Syst. Sci. Data, 12, 151–176, https://doi.org/10.5194/essd-12-151-2020, https://doi.org/10.5194/essd-12-151-2020, 2020
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The Green Edge initiative was developed to understand the processes controlling the primary productivity and the fate of organic matter produced during the Arctic spring bloom (PSB). In this article, we present an overview of an extensive and comprehensive dataset acquired during two expeditions conducted in 2015 and 2016 on landfast ice southeast of Qikiqtarjuaq Island in Baffin Bay.
Caroline Coch, Bennet Juhls, Scott F. Lamoureux, Melissa J. Lafrenière, Michael Fritz, Birgit Heim, and Hugues Lantuit
Biogeosciences, 16, 4535–4553, https://doi.org/10.5194/bg-16-4535-2019, https://doi.org/10.5194/bg-16-4535-2019, 2019
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Climate change affects Arctic ecosystems. This includes thawing of permafrost (ground below 0 °C) and an increase in rainfall. Both have substantial impacts on the chemical composition of river water. We compared the composition of small rivers in the low and high Arctic with the large Arctic rivers. In comparison, dissolved organic matter in the small rivers is more susceptible to degradation; thus, it could potentially increase carbon dioxide emissions. Rainfall events have a similar effect.
Nils Madenach, Cintia Carbajal Henken, René Preusker, Odran Sourdeval, and Jürgen Fischer
Atmos. Chem. Phys., 19, 13535–13546, https://doi.org/10.5194/acp-19-13535-2019, https://doi.org/10.5194/acp-19-13535-2019, 2019
Julia Mitzscherling, Fabian Horn, Maria Winterfeld, Linda Mahler, Jens Kallmeyer, Pier P. Overduin, Lutz Schirrmeister, Matthias Winkel, Mikhail N. Grigoriev, Dirk Wagner, and Susanne Liebner
Biogeosciences, 16, 3941–3958, https://doi.org/10.5194/bg-16-3941-2019, https://doi.org/10.5194/bg-16-3941-2019, 2019
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Permafrost temperatures increased substantially at a global scale, potentially altering microbial assemblages involved in carbon mobilization before permafrost thaws. We used Arctic Shelf submarine permafrost as a natural laboratory to investigate the microbial response to long-term permafrost warming. Our work shows that millennia after permafrost warming by > 10 °C, microbial community composition and population size reflect the paleoenvironment rather than a direct effect through warming.
Jordis S. Tradowsky, Gregory E. Bodeker, Richard R. Querel, Peter J. H. Builtjes, and Jürgen Fischer
Earth Syst. Sci. Data, 10, 2195–2211, https://doi.org/10.5194/essd-10-2195-2018, https://doi.org/10.5194/essd-10-2195-2018, 2018
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A best-estimate data set of the temperature profile above the atmospheric measurement facility at Lauder, New Zealand, has been developed. This site atmospheric state best estimate (SASBE) combines atmospheric measurements made at two locations and includes an estimate of uncertainty on every data point. The SASBE enhances the value of measurements made by a reference-quality climate observing network and may be used for a variety of purposes in research and education.
Sophia Walther, Luis Guanter, Birgit Heim, Martin Jung, Gregory Duveiller, Aleksandra Wolanin, and Torsten Sachs
Biogeosciences, 15, 6221–6256, https://doi.org/10.5194/bg-15-6221-2018, https://doi.org/10.5194/bg-15-6221-2018, 2018
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We explored the timing of the peak of the short annual growing season in tundra ecosystems as indicated by an extensive suite of satellite indicators of vegetation productivity. Delayed peak greenness compared to peak photosynthesis is consistently found across years and land-cover classes. Plants also experience growth after optimal conditions for assimilation regarding light and temperature have passed. Our results have implications for the modelling of the circumpolar carbon balance.
Vincent Le Fouest, Atsushi Matsuoka, Manfredi Manizza, Mona Shernetsky, Bruno Tremblay, and Marcel Babin
Biogeosciences, 15, 1335–1346, https://doi.org/10.5194/bg-15-1335-2018, https://doi.org/10.5194/bg-15-1335-2018, 2018
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Climate warming could enhance the load of terrigenous dissolved organic carbon (tDOC) of Arctic rivers. We show that tDOC concentrations simulated by an ocean–biogeochemical model in the Canadian Beaufort Sea compare favorably with their satellite counterparts. Over spring–summer, riverine tDOC contributes to 35 % of primary production and an equivalent of ~ 10 % of tDOC is exported westwards with the potential for fueling the biological production of the eastern Alaskan nearshore waters.
Julia Boike, Inge Juszak, Stephan Lange, Sarah Chadburn, Eleanor Burke, Pier Paul Overduin, Kurt Roth, Olaf Ippisch, Niko Bornemann, Lielle Stern, Isabelle Gouttevin, Ernst Hauber, and Sebastian Westermann
Earth Syst. Sci. Data, 10, 355–390, https://doi.org/10.5194/essd-10-355-2018, https://doi.org/10.5194/essd-10-355-2018, 2018
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A 20-year data record from the Bayelva site at Ny-Ålesund, Svalbard, is presented on meteorology, energy balance components, surface and subsurface observations. This paper presents the data set, instrumentation, calibration, processing and data quality control. The data show that mean annual, summer and winter soil temperature data from shallow to deeper depths have been warming over the period of record, indicating the degradation and loss of permafrost at this site.
Ralf Bennartz, Heidrun Höschen, Bruno Picard, Marc Schröder, Martin Stengel, Oliver Sus, Bojan Bojkov, Stefano Casadio, Hannes Diedrich, Salomon Eliasson, Frank Fell, Jürgen Fischer, Rainer Hollmann, Rene Preusker, and Ulrika Willén
Atmos. Meas. Tech., 10, 1387–1402, https://doi.org/10.5194/amt-10-1387-2017, https://doi.org/10.5194/amt-10-1387-2017, 2017
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The microwave radiometers (MWR) on board ERS-1, ERS-2, and Envisat provide a continuous time series of brightness temperature observations between 1991 and 2012. Here we report on a new total column water vapour (TCWV) and wet tropospheric correction (WTC) dataset that builds on this time series. The dataset is publicly available under doi:10.5676/DWD_EMIR/V001.
Lutz Schirrmeister, Georg Schwamborn, Pier Paul Overduin, Jens Strauss, Margret C. Fuchs, Mikhail Grigoriev, Irina Yakshina, Janet Rethemeyer, Elisabeth Dietze, and Sebastian Wetterich
Biogeosciences, 14, 1261–1283, https://doi.org/10.5194/bg-14-1261-2017, https://doi.org/10.5194/bg-14-1261-2017, 2017
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We investigate late Pleistocene permafrost at the Buor Khaya Peninsula (Laptev Sea, Siberia) for cryolithological, geochemical, and geochronological parameters. The sequences were composed of ice-oversaturated silts and fine-grained sands with 0.2 to 24 wt% of organic matter. The deposition was between 54.1 and 9.7 kyr BP. Due to coastal erosion, the biogeochemical signature of the deposits represents the terrestrial end-member, and is related to organic matter deposited in the marine realm.
Heike Hildegard Zimmermann, Elena Raschke, Laura Saskia Epp, Kathleen Rosmarie Stoof-Leichsenring, Georg Schwamborn, Lutz Schirrmeister, Pier Paul Overduin, and Ulrike Herzschuh
Biogeosciences, 14, 575–596, https://doi.org/10.5194/bg-14-575-2017, https://doi.org/10.5194/bg-14-575-2017, 2017
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Organic matter stored in permafrost will start decomposing due to climate warming. To better understand its composition in ice-rich Yedoma, we analyzed ancient sedimentary DNA, pollen and non-pollen palynomorphs throughout an 18.9 m long permafrost core. The combination of both proxies allow an interpretation both of regional floristic changes and of the local environmental conditions at the time of deposition.
Pier Paul Overduin, Sebastian Wetterich, Frank Günther, Mikhail N. Grigoriev, Guido Grosse, Lutz Schirrmeister, Hans-Wolfgang Hubberten, and Aleksandr Makarov
The Cryosphere, 10, 1449–1462, https://doi.org/10.5194/tc-10-1449-2016, https://doi.org/10.5194/tc-10-1449-2016, 2016
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How fast does permafrost warm up and thaw after it is covered by the sea? Ice-rich permafrost in the Laptev Sea, Siberia, is rapidly eroded by warm air and waves. We used a floating electrical technique to measure the depth of permafrost thaw below the sea, and compared it to 60 years of coastline retreat and permafrost depths from drilling 30 years ago. Thaw is rapid right after flooding of the land and slows over time. The depth of permafrost is related to how fast the coast retreats.
H. Diedrich, R. Preusker, R. Lindstrot, and J. Fischer
Atmos. Meas. Tech., 8, 823–836, https://doi.org/10.5194/amt-8-823-2015, https://doi.org/10.5194/amt-8-823-2015, 2015
P. Coupel, A. Matsuoka, D. Ruiz-Pino, M. Gosselin, D. Marie, J.-É. Tremblay, and M. Babin
Biogeosciences, 12, 991–1006, https://doi.org/10.5194/bg-12-991-2015, https://doi.org/10.5194/bg-12-991-2015, 2015
F. Günther, P. P. Overduin, I. A. Yakshina, T. Opel, A. V. Baranskaya, and M. N. Grigoriev
The Cryosphere, 9, 151–178, https://doi.org/10.5194/tc-9-151-2015, https://doi.org/10.5194/tc-9-151-2015, 2015
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Coastal erosion rates at Muostakh Island (eastern Siberian Arctic) have doubled, based on remotely sensed observations of land loss, and therefore the island will disappear prematurely. Based on analyses of seasonal variability of permafrost thaw, thermo-erosion increases by 1.2m per year when summer temperatures rise by 1°C. Due to rapid permafrost thaw, the land surface is subsiding up to 11cm per year, based on comparison of elevation changes and active layer thaw depth.
I. Fedorova, A. Chetverova, D. Bolshiyanov, A. Makarov, J. Boike, B. Heim, A. Morgenstern, P. P. Overduin, C. Wegner, V. Kashina, A. Eulenburg, E. Dobrotina, and I. Sidorina
Biogeosciences, 12, 345–363, https://doi.org/10.5194/bg-12-345-2015, https://doi.org/10.5194/bg-12-345-2015, 2015
B. Heim, E. Abramova, R. Doerffer, F. Günther, J. Hölemann, A. Kraberg, H. Lantuit, A. Loginova, F. Martynov, P. P. Overduin, and C. Wegner
Biogeosciences, 11, 4191–4210, https://doi.org/10.5194/bg-11-4191-2014, https://doi.org/10.5194/bg-11-4191-2014, 2014
A. Matsuoka, M. Babin, D. Doxaran, S. B. Hooker, B. G. Mitchell, S. Bélanger, and A. Bricaud
Biogeosciences, 11, 3131–3147, https://doi.org/10.5194/bg-11-3131-2014, https://doi.org/10.5194/bg-11-3131-2014, 2014
A. C. Kraberg, E. Druzhkova, B. Heim, M. J. G. Loeder, and K. H. Wiltshire
Biogeosciences, 10, 7263–7277, https://doi.org/10.5194/bg-10-7263-2013, https://doi.org/10.5194/bg-10-7263-2013, 2013
S. Bélanger, S. A. Cizmeli, J. Ehn, A. Matsuoka, D. Doxaran, S. Hooker, and M. Babin
Biogeosciences, 10, 6433–6452, https://doi.org/10.5194/bg-10-6433-2013, https://doi.org/10.5194/bg-10-6433-2013, 2013
D. Antoine, S. B. Hooker, S. Bélanger, A. Matsuoka, and M. Babin
Biogeosciences, 10, 4493–4509, https://doi.org/10.5194/bg-10-4493-2013, https://doi.org/10.5194/bg-10-4493-2013, 2013
M. Ardyna, M. Babin, M. Gosselin, E. Devred, S. Bélanger, A. Matsuoka, and J.-É. Tremblay
Biogeosciences, 10, 4383–4404, https://doi.org/10.5194/bg-10-4383-2013, https://doi.org/10.5194/bg-10-4383-2013, 2013
F. Günther, P. P. Overduin, A. V. Sandakov, G. Grosse, and M. N. Grigoriev
Biogeosciences, 10, 4297–4318, https://doi.org/10.5194/bg-10-4297-2013, https://doi.org/10.5194/bg-10-4297-2013, 2013
L. Rabenstein, T. Krumpen, S. Hendricks, C. Koeberle, C. Haas, and J. A. Hoelemann
The Cryosphere, 7, 947–959, https://doi.org/10.5194/tc-7-947-2013, https://doi.org/10.5194/tc-7-947-2013, 2013
J. Para, B. Charrière, A. Matsuoka, W. L. Miller, J. F. Rontani, and R. Sempéré
Biogeosciences, 10, 2761–2774, https://doi.org/10.5194/bg-10-2761-2013, https://doi.org/10.5194/bg-10-2761-2013, 2013
T. Krumpen, M. Janout, K. I. Hodges, R. Gerdes, F. Girard-Ardhuin, J. A. Hölemann, and S. Willmes
The Cryosphere, 7, 349–363, https://doi.org/10.5194/tc-7-349-2013, https://doi.org/10.5194/tc-7-349-2013, 2013
C. Wegner, D. Bauch, J. A. Hölemann, M. A. Janout, B. Heim, A. Novikhin, H. Kassens, and L. Timokhov
Biogeosciences, 10, 1117–1129, https://doi.org/10.5194/bg-10-1117-2013, https://doi.org/10.5194/bg-10-1117-2013, 2013
A. Matsuoka, S. B. Hooker, A. Bricaud, B. Gentili, and M. Babin
Biogeosciences, 10, 917–927, https://doi.org/10.5194/bg-10-917-2013, https://doi.org/10.5194/bg-10-917-2013, 2013
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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
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
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
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
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
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.
Esdoorn Willcox, Marcos Lemes, Thomas Juul-Pedersen, Mikael Kristian Sejr, Johnna Marchiano Holding, and Søren Rysgaard
Biogeosciences, 21, 4037–4050, https://doi.org/10.5194/bg-21-4037-2024, https://doi.org/10.5194/bg-21-4037-2024, 2024
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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.
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.
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Short summary
In this article, we present the variability and characteristics of dissolved organic matter at the fluvial–marine transition in the Laptev Sea from a unique dataset collected during 11 Arctic expeditions. We develop a new relationship between dissolved organic carbon (DOC) and coloured dissolved organic matter absorption, which is used to estimate surface water DOC concentration from space. We believe that our findings help current efforts to monitor ongoing changes in the Arctic carbon cycle.
In this article, we present the variability and characteristics of dissolved organic matter at...
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