Articles | Volume 23, issue 4
https://doi.org/10.5194/bg-23-1459-2026
© Author(s) 2026. 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-23-1459-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Feb 2026
Research article |
| 24 Feb 2026
| 24 Feb 2026
Enhanced methane cycling across the Laptev Sea signaled by time-integrated biomarkers of aerobic methane oxidation
Department of Environmental Science (ACES), Stockholm University, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm, Sweden
Birgit Wild
Department of Environmental Science (ACES), Stockholm University, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm, Sweden
Wei-Li Hong
Bolin Centre for Climate Research, Stockholm, Sweden
Department of Geological Sciences (IGV), Stockholm University, Stockholm, Sweden
Baltic Sea Centre, Stockholm University, Stockholm, Sweden
Henry Holmstrand
Department of Environmental Science (ACES), Stockholm University, Stockholm, Sweden
Francisco J. A. Nascimento
Baltic Sea Centre, Stockholm University, Stockholm, Sweden
Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
Stefano Bonaglia
Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
Denis Kosmach
Laboratory for Arctic Research, V.I. Ilichov Pacific Oceanological Institute (POI), Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia
Igor Semiletov
Laboratory for Arctic Research, V.I. Ilichov Pacific Oceanological Institute (POI), Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia
Laboratory for Integrated Research of the Arctic System “land-shelf”, National Tomsk State Research University (TSU), Tomsk, Russia
Laboratory of Chemical and Biological Research, Sakhalin State University (SakhSU), Yuzhno-Sakhalinsk, Russia
Natalia Shakhova
Laboratory for Integrated Research of the Arctic System “land-shelf”, National Tomsk State Research University (TSU), Tomsk, Russia
Sadovsky Institute of Geosphere Dynamics (IGD) of the Russian Academy of Sciences, Moscow, Russia
Örjan Gustafsson
CORRESPONDING AUTHOR
Department of Environmental Science (ACES), Stockholm University, Stockholm, Sweden
Bolin Centre for Climate Research, Stockholm, Sweden
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EGUsphere, https://doi.org/10.5194/egusphere-2026-411, https://doi.org/10.5194/egusphere-2026-411, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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Methane is a powerful greenhouse gas, but its sources remain uncertain in many regions. The isotope fingerprints of methane are diagnostic of its sources, yet their source end-members are poorly constrained for South Asia. Here we determined the methane isotope signal for major sources in South Asia and found these to differ from global averages. Improved regional-specific isotope source fingerprints will help to improve top-down assessments of methane budgets and climate mitigation strategies.
Nils Ekeroth, Mikhail Kononets, Stefano Bonaglia, Volker Brüchert, Elizabeth K. Robertson, Anders Tengberg, and Per O. J. Hall
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Sean Clarke, Henry Holmstrand, Krishnakant Budhavant, Manoj Remani, Sophie Haslett, Katerina Rodiouchkina, Ellen Kooijman, and Örjan Gustafsson
EGUsphere, https://doi.org/10.5194/egusphere-2025-5334, https://doi.org/10.5194/egusphere-2025-5334, 2025
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Krishnakant Budhavant, Mohanan Remani Manoj, Hari Ram Chandrika Rajendran Nair, Samuel Mwaniki Gaita, Henry Holmstrand, Abdus Salam, Ahmed Muslim, Sreedharan Krishnakumari Satheesh, and Örjan Gustafsson
Atmos. Chem. Phys., 24, 11911–11925, https://doi.org/10.5194/acp-24-11911-2024, https://doi.org/10.5194/acp-24-11911-2024, 2024
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The South Asian Pollution Experiment 2018 used access to three strategically located receptor observatories. Observational constraints revealed opposing trends in the mass absorption cross sections of black carbon (BC MAC) and brown carbon (BrC MAC) during long-range transport. Models estimating the climate effects of BC aerosols may have underestimated the ambient BC MAC over distant receptor areas, leading to discrepancies in aerosol absorption predicted by observation-constrained models.
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Earth Syst. Sci. Data, 16, 3419–3431, https://doi.org/10.5194/essd-16-3419-2024, https://doi.org/10.5194/essd-16-3419-2024, 2024
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A comprehensive study conducted in 2021 examined the distributions of dissolved nutrients and carbon in the western Spitsbergen fjords during the high-melting season. Significant spatial variability was observed in the water column and pore water concentrations of constituents, highlighting the unique biogeochemical characteristics of each fjord and their potential impact on ecosystem functioning and oceanographic processes.
Mindaugas Žilius, Rūta Barisevičiūtė, Stefano Bonaglia, Isabell Klawonn, Elise Lorre, Tobia Politi, Irma Vybernaite-Lubiene, Maren Voss, and Paul Bukaveckas
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This study analyzes the mechanisms driving nitrate retention and elimination within a large estuarine system. Simultaneous measurements of pelagic and benthic processes provide insight into how nitrates are transformed. Finally, our findings are consistent with the paradigm that eutrophication favors a shift from benthic to pelagic-dominated processes.
Leonard Kirago, Örjan Gustafsson, Samuel Mwaniki Gaita, Sophie L. Haslett, Michael J. Gatari, Maria Elena Popa, Thomas Röckmann, Christoph Zellweger, Martin Steinbacher, Jörg Klausen, Christian Félix, David Njiru, and August Andersson
Atmos. Chem. Phys., 23, 14349–14357, https://doi.org/10.5194/acp-23-14349-2023, https://doi.org/10.5194/acp-23-14349-2023, 2023
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This study provides ground-observational evidence that supports earlier suggestions that savanna fires are the main emitters and modulators of carbon monoxide gas in Africa. Using isotope-based techniques, the study has shown that about two-thirds of this gas is emitted from savanna fires, while for urban areas, in this case Nairobi, primary sources approach 100 %. The latter has implications for air quality policy, suggesting primary emissions such as traffic should be targeted.
Christoph Heinze, Thorsten Blenckner, Peter Brown, Friederike Fröb, Anne Morée, Adrian L. New, Cara Nissen, Stefanie Rynders, Isabel Seguro, Yevgeny Aksenov, Yuri Artioli, Timothée Bourgeois, Friedrich Burger, Jonathan Buzan, B. B. Cael, Veli Çağlar Yumruktepe, Melissa Chierici, Christopher Danek, Ulf Dieckmann, Agneta Fransson, Thomas Frölicher, Giovanni Galli, Marion Gehlen, Aridane G. González, Melchor Gonzalez-Davila, Nicolas Gruber, Örjan Gustafsson, Judith Hauck, Mikko Heino, Stephanie Henson, Jenny Hieronymus, I. Emma Huertas, Fatma Jebri, Aurich Jeltsch-Thömmes, Fortunat Joos, Jaideep Joshi, Stephen Kelly, Nandini Menon, Precious Mongwe, Laurent Oziel, Sólveig Ólafsdottir, Julien Palmieri, Fiz F. Pérez, Rajamohanan Pillai Ranith, Juliano Ramanantsoa, Tilla Roy, Dagmara Rusiecka, J. Magdalena Santana Casiano, Yeray Santana-Falcón, Jörg Schwinger, Roland Séférian, Miriam Seifert, Anna Shchiptsova, Bablu Sinha, Christopher Somes, Reiner Steinfeldt, Dandan Tao, Jerry Tjiputra, Adam Ulfsbo, Christoph Völker, Tsuyoshi Wakamatsu, and Ying Ye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-182, https://doi.org/10.5194/bg-2023-182, 2023
Revised manuscript not accepted
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Jannik Martens, Evgeny Romankevich, Igor Semiletov, Birgit Wild, Bart van Dongen, Jorien Vonk, Tommaso Tesi, Natalia Shakhova, Oleg V. Dudarev, Denis Kosmach, Alexander Vetrov, Leopold Lobkovsky, Nikolay Belyaev, Robie W. Macdonald, Anna J. Pieńkowski, Timothy I. Eglinton, Negar Haghipour, Salve Dahle, Michael L. Carroll, Emmelie K. L. Åström, Jacqueline M. Grebmeier, Lee W. Cooper, Göran Possnert, and Örjan Gustafsson
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Short summary
Thawing subsea permafrost in the East Siberian Arctic Seas releases methane, a potent greenhouse gas. Using molecular fossils in sediments, we traced aerobic methane oxidation as a proxy of enhanced methane cycling across the Laptev Sea, including in regions once thought low in emissions. This approach captures long-term patterns of methane cycling over years-decades , overcoming limits of short-term seawater measurements and highlights the importance of the Laptev Sea in Arctic methane cycling.
Thawing subsea permafrost in the East Siberian Arctic Seas releases methane, a potent greenhouse...
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