Articles | Volume 23, issue 11
https://doi.org/10.5194/bg-23-3755-2026
© 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-23-3755-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Ideas and perspectives
| 
08 Jun 2026
Ideas and perspectives |
| 08 Jun 2026
| 08 Jun 2026
Ideas and perspectives: Max MACS – constraining the potential global scale of Marine Anoxic Carbon Storage for CO2 removal
Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
Earth Science Department, University of California Santa Barbara, Santa Barbara, California, USA
Nitai Amiel
Rewind Earth LTD, Tel Aviv, Israel
Dror L. Angel
Rewind Earth LTD, Tel Aviv, Israel
Department of Maritime Civilizations, University of Haifa, Haifa, Israel
James P. Barry
Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, California, USA
Thomas M. Blattmann
Asian School of the Environment, Nanyang Technological University, Singapore
Laura Boicenco
National Institute for Marine Research and Development “Grigore Antipa” (NIMRD), Constanta, Romania
Antoine Crémière
Geo-Ocean, Univ. Brest, CNRS, Ifremer, UMR6538, 29280 Plouzané, France
Natalya Evans
Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
Nora Gallarotti
Department of Earth and Planetary Sciences, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
Sebastian Haas
Puro.earth, Tammasaarenkatu 1, 00180 Helsinki, Finland
Jan-Hendrik Hehemann
MARUM, University of Bremen, Bremen, Germany
Peter Krost
Coastal Research and Management, Kiel, Germany
Pranay Lal
Deep Carbon, C-4a Qutub Industrial Area, New Delhi 110016, India
David Lordkipanidze
Georgian National Museum, 0105 Tbilisi, Georgia
Georgian State University, 0105 Tbilisi, Georgia
Tiia Luostarinen
Puro.earth, Tammasaarenkatu 1, 00180 Helsinki, Finland
Aaron M. Martinez
Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
Allison J. Matzelle
Carboniferous Inc., Houston, Texas, USA
Selma Menabit
Romanian Natl. Institute of Marine Geology and Geoecology – GeoEcoMar, Str. Dimitrie Onciul 23-25, Bucharest, Romania
Mihaela Muresan
Romanian Natl. Institute of Marine Geology and Geoecology – GeoEcoMar, Str. Dimitrie Onciul 23-25, Bucharest, Romania
Andreas Neumann
Institute of Carbon Cycles, Helmholtz-Zentrum HEREON, Geesthacht, Germany
Jean-Daniel Paris
Laboratoire des Sciences du Climat et de l'Environnement, Université Paris-Saclay, Gif-sur-Yvette, France
Climate and Atmosphere Research Centre (CARE-C), The Cyprus Institute, Nicosia, 2121, Cyprus
Christopher R. Pearce
National Oceanography Centre, Southampton, UK
Nick Reynard
Department of Earth Science, University of Cambridge, Cambridge, England
Daniel L. Sanchez
Department of Environmental Science, Policy, and Mgmt., University of California Berkeley, Berkeley, California, USA
Carbon Direct LLC, New York, New York, USA
Florence Schubotz
MARUM, University of Bremen, Bremen, Germany
Violeta Slabakova
Institute of Oceanology, Bulgarian Academy of Sciences, Varna, Bulgaria
Adrian Stanica
Romanian Natl. Institute of Marine Geology and Geoecology – GeoEcoMar, Str. Dimitrie Onciul 23-25, Bucharest, Romania
Elena Stoica
National Institute for Marine Research and Development “Grigore Antipa” (NIMRD), Constanta, Romania
Andrew K. Sweetman
Scottish Association for Marine Science, Oban, Argyll, Scotland
Tina Treude
Department of Earth, Planetary, and Space Sciences, University of California Los Angeles, Los Angeles, California, USA
Yoana G. Voynova
Institute of Carbon Cycles, Helmholtz-Zentrum HEREON, Geesthacht, Germany
Nikolaos D. Zarokanellos
SOCIB- Balearic Islands Coastal Ocean Observing and Forecasting System, Palma de Mallorca, Spain
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Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
Biogeosciences, 22, 863–957, https://doi.org/10.5194/bg-22-863-2025, https://doi.org/10.5194/bg-22-863-2025, 2025
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Paleo-oxygen proxies can extend current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
Manuel Vargas-Yáñez, Orens Pasqueron de Fommervault, Emanuela Clementi, Christian Ferrarin, Svitlana Liubertseva, Diego Álvarez-Berastegui, Baptiste Mourre, Salvatore Aronica, Rosa Balbin, Joaquín Ballabrera-Poy, Sana Ben Ismail, Nathaniel Benssousan, Ismail Bessa, Alicia Blanco, Anthony Bosse, Evi Bourma, François Bourrin, Carlo Brandini, Fulvio Capodici, Clara Casals-Baixas, Branko Cermelj, Giuseppe Ciraolo, Pascal Conan, Laurent Coppola, Lorenzo Corgnati, Joaquín del Río, Emilie Diamond Riquier, Lara Diaz-Barroso, Bartolomeo Doronzo, Xavier Durrieu de Madron, Milad Fakhri, Costantine Frangoulis, Claudia Fratianni, Emilio García-Ladona, Jesus García-Lafuente, M. Carmen García-Martínez, Joaquín Garrabou, Josep Gasol, Adam Gauci, Frédéric Gazeau, Gerard Gregory, Abed El Raman Hassoun, Jordi Isern-Fontanet, Dominique Lefevre, Nadia Lo Bue, Guiomar López, Pablo Lorente, Deny Malengros, Ramon Massana, Sinan Mavruk, Stefano Miserocchi, Behzad Mostajir, Laure Mousseau, Francina Moya, Antonio Novellino, Arianna Orasi, Emanuele Organelli, Vicent Ouisse, Tal Ozer, Begoña Pérez-Gómez, Susana Pérez-Rubio, Leonidas Perivoliotis, Georges Petihakis, Anne Petrenko, Sebastien Pinel, Xavier Pitarch, Angela Pomaro, Lucía Quirós-Collazos, Emma Reyes, Simone Sammartino, Anna Sánchez-Vidal, Katrin Schroeder, Stefano Taddei, Elena Tel, Pierre Testor, Marco Torri, Daniela Turk, Laura Ursella, Dimitris Velaoras, Francesca Vidussi, Ivica Vilivić, Enrico Zambiachi, D. Nikolaos Zarokanellos, George Zodiatis, and Vanessa Cardin
EGUsphere, https://doi.org/10.5194/egusphere-2026-2632, https://doi.org/10.5194/egusphere-2026-2632, 2026
This preprint is open for discussion and under review for Ocean Science (OS).
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This work compiles current marine observation capabilities in the Mediterranean Sea, making this information accessible to scientists, organizations, stakeholders, and environmental policymakers. It supports initiatives such as Copernicus Marine Service, EMODNet, the European Ocean Pact, and EU directives. It is intended as a living resource to be updated, identifying strengths and gaps in Mediterranean observation systems.
Florian Volmer Martin Kokoszka, Mireno Borghini, Katrin Schroeder, Jacopo Chiggiato, Joaquín Tintoré, Nikolaos Dimitrios Zarokanellos, Albert Miralles, Patricia Rivera Rodríguez, Manuel Rubio, Miguel Charcos, Benjamín Casas, and Anneke ten Doeschate
Earth Syst. Sci. Data, 18, 2203–2226, https://doi.org/10.5194/essd-18-2203-2026, https://doi.org/10.5194/essd-18-2203-2026, 2026
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We present a unique dataset of underwater measurements collected by an autonomous glider in the western Mediterranean Sea. It reveals how ocean layers mix over seasons and years. Using sensors to detect small scale water movements, we estimated how mechanical energy and heat are transferred in the ocean. These data help scientists better understand ocean circulation and climate effects. All files and methods are openly shared to support future research.
Andreas Neumann, Justus E. E. van Beusekom, Alexander Bratek, Jana Friedrich, Jürgen Möbius, Tina Sanders, Hendrik Wolschke, and Kirstin Dähnke
Biogeosciences, 23, 1103–1116, https://doi.org/10.5194/bg-23-1103-2026, https://doi.org/10.5194/bg-23-1103-2026, 2026
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The North-Western shelf of the Black Sea is substantially influenced by the discharge of nutrients from River Danube. We have sampled the sediment there and measured particulate carbon and nitrogen to reconstruct the variability of nitrogen sources to the NW shelf. Our results demonstrate that the balance of riverine nitrogen input and marine nitrogen fixation is sensitive to climate changes. Nitrogen from human activities is detectable in NW shelf sediment since the 12th century.
Constantina Rousogenous, Christof Petri, Pierre-Yves Quéhé, Thomas Laemmel, Joshua L. Laughner, Maximilien Desservettaz, Michael Pikridas, Michel Ramonet, Efstratios Bourtsoukidis, Matthias Buschmann, Justus Notholt, Thorsten Warneke, Jean-Daniel Paris, Jean Sciare, and Mihalis Vrekoussis
Atmos. Meas. Tech., 19, 565–581, https://doi.org/10.5194/amt-19-565-2026, https://doi.org/10.5194/amt-19-565-2026, 2026
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The Eastern Mediterranean and Middle East is a greenhouse gas emission hotspot but lacks atmospheric monitoring. Our study introduces the first Total Carbon Column Observing Network site in this region, in Cyprus, providing high-precision columnar measurement of key greenhouse gases. This new dataset enhances global climate monitoring efforts, supports the validation of satellites, will help assess regional emission trends, filling a critical observational gap in this climate-sensitive region.
Inga Hellige, Aman Akeerath Mundanatt, Jana C. Massing, and Jan-Hendrik Hehemann
Biogeosciences, 23, 387–398, https://doi.org/10.5194/bg-23-387-2026, https://doi.org/10.5194/bg-23-387-2026, 2026
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Coastal plant habitats such as mangroves, seagrass meadows and saltmarshes store carbon. While these plants absorb carbon dioxide and trap carbon in sediments via their roots, we also discovered that carbon from algae is transported into these systems and preserved in the soil. By analyzing sugars from plants and algae, we show that restoring these ecosystems helps lock away both local and distant carbon, offering powerful benefits for climate and biodiversity.
Christian Ferrarin, Debora Bellafiore, Alejandro Paladio Hernandez, Irina Dinu, and Adrian Stanica
Ocean Sci., 21, 3291–3310, https://doi.org/10.5194/os-21-3291-2025, https://doi.org/10.5194/os-21-3291-2025, 2025
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This paper investigates the hydrodynamic processes among the interconnected water bodies (river branches, lagoons, and the coastal sea) that together form the Danube Delta river-sea continuum. To achieve this, we implemented the SHYFEM (System of HydrodYnamic Finite Element Modules) model across the entire Danube Delta. The model was applied to investigate the distribution of water among river branches, coastal dynamics in front of the delta, the renewal capacity of the lagoons, and the potential impacts of lagoon-sea reconnection solutions.
Julia Meyer, Yoana G. Voynova, Bryce Van Dam, Lara Luitjens, Dagmar Daehne, and Helmuth Thomas
Biogeosciences, 22, 6255–6273, https://doi.org/10.5194/bg-22-6255-2025, https://doi.org/10.5194/bg-22-6255-2025, 2025
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The study highlights the inter-seasonal variability of the carbonate dynamics of the East Frisian Wadden Sea, the world's largest intertidal area. During spring, increased biological activity leads to lower CO2 and nitrate levels, while total alkalinity (TA) rises slightly. In summer, TA increases, enhancing the ocean's ability to absorb CO2. Our research emphasizes the vital role of these intertidal regions in regulating carbon, contributing to a better understanding of carbon storage.
Lina Eyouni, Zoi Kokkini, Nikolaos D. Zarokanellos, and Burton H. Jones
Ocean Sci., 21, 2345–2366, https://doi.org/10.5194/os-21-2345-2025, https://doi.org/10.5194/os-21-2345-2025, 2025
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This study examines how multiple processes in the northern Red Sea form Red Sea Outflow Water and affect biogeochemical fluxes. Using glider data, wind and air–sea flux reanalysis, and satellite observations, it highlights seasonal evolution. Eddy-driven upwelling exposes cool water to heat loss and evaporation, fueling primary productivity. Circulation patterns block inflows, extend cooling, and subduct water into the ocean interior, influencing regional dynamics.
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.
Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
Biogeosciences, 22, 863–957, https://doi.org/10.5194/bg-22-863-2025, https://doi.org/10.5194/bg-22-863-2025, 2025
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Paleo-oxygen proxies can extend current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
Xuefeng Peng, David J. Yousavich, Annie Bourbonnais, Frank Wenzhöfer, Felix Janssen, Tina Treude, and David L. Valentine
Biogeosciences, 21, 3041–3052, https://doi.org/10.5194/bg-21-3041-2024, https://doi.org/10.5194/bg-21-3041-2024, 2024
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Biologically available (fixed) nitrogen (N) is a limiting nutrient for life in the ocean. Under low-oxygen conditions, fixed N is either removed via denitrification or retained via dissimilatory nitrate reduction to ammonia (DNRA). Using in situ incubations in the Santa Barbara Basin, which undergoes seasonal anoxia, we found that benthic denitrification was the dominant nitrate reduction process, while nitrate availability and organic carbon content control the relative importance of DNRA.
Sophie Wittig, Antoine Berchet, Isabelle Pison, Marielle Saunois, and Jean-Daniel Paris
Atmos. Chem. Phys., 24, 6359–6373, https://doi.org/10.5194/acp-24-6359-2024, https://doi.org/10.5194/acp-24-6359-2024, 2024
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The aim of this work is to analyse how accurately a methane bomb event could be detected with the current and a hypothetically extended stationary observation network in the Arctic. For this, we incorporate synthetically modelled possible future CH4 concentrations based on plausible emission scenarios into an inverse modelling framework. We analyse how well the increase is detected in different Arctic regions and evaluate the impact of additional observation sites in this respect.
Yunsong Liu, Jean-Daniel Paris, Gregoire Broquet, Violeta Bescós Roy, Tania Meixus Fernandez, Rasmus Andersen, Andrés Russu Berlanga, Emil Christensen, Yann Courtois, Sebastian Dominok, Corentin Dussenne, Travis Eckert, Andrew Finlayson, Aurora Fernández de la Fuente, Catlin Gunn, Ram Hashmonay, Juliano Grigoleto Hayashi, Jonathan Helmore, Soeren Honsel, Fabrizio Innocenti, Matti Irjala, Torgrim Log, Cristina Lopez, Francisco Cortés Martínez, Jonathan Martinez, Adrien Massardier, Helle Gottschalk Nygaard, Paula Agregan Reboredo, Elodie Rousset, Axel Scherello, Matthias Ulbricht, Damien Weidmann, Oliver Williams, Nigel Yarrow, Murès Zarea, Robert Ziegler, Jean Sciare, Mihalis Vrekoussis, and Philippe Bousquet
Atmos. Meas. Tech., 17, 1633–1649, https://doi.org/10.5194/amt-17-1633-2024, https://doi.org/10.5194/amt-17-1633-2024, 2024
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We investigated the performance of 10 methane emission quantification techniques in a blind controlled-release experiment at an inerted natural gas compressor station. We reported their respective strengths, weaknesses, and potential complementarity depending on the emission rates and atmospheric conditions. Additionally, we assess the dependence of emission quantification performance on key parameters such as wind speed, deployment constraints, and measurement duration.
Pramod Kumar, Christopher Caldow, Grégoire Broquet, Adil Shah, Olivier Laurent, Camille Yver-Kwok, Sebastien Ars, Sara Defratyka, Susan Warao Gichuki, Luc Lienhardt, Mathis Lozano, Jean-Daniel Paris, Felix Vogel, Caroline Bouchet, Elisa Allegrini, Robert Kelly, Catherine Juery, and Philippe Ciais
Atmos. Meas. Tech., 17, 1229–1250, https://doi.org/10.5194/amt-17-1229-2024, https://doi.org/10.5194/amt-17-1229-2024, 2024
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This study presents a series of mobile measurement campaigns to monitor the CH4 emissions from an active landfill. These measurements are processed using a Gaussian plume model and atmospheric inversion techniques to quantify the landfill CH4 emissions. The methane emission estimates range between ~0.4 and ~7 t CH4 per day, and their variations are analyzed. The robustness of the estimates is assessed depending on the distance of the measurements from the potential sources in the landfill.
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.
Louise C. V. Rewrie, Burkard Baschek, Justus E. E. van Beusekom, Arne Körtzinger, Gregor Ollesch, and Yoana G. Voynova
Biogeosciences, 20, 4931–4947, https://doi.org/10.5194/bg-20-4931-2023, https://doi.org/10.5194/bg-20-4931-2023, 2023
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After heavy pollution in the 1980s, a long-term inorganic carbon increase in the Elbe Estuary (1997–2020) was fueled by phytoplankton and organic carbon production in the upper estuary, associated with improved water quality. A recent drought (2014–2020) modulated the trend, extending the water residence time and the dry summer season into May. The drought enhanced production of inorganic carbon in the estuary but significantly decreased the annual inorganic carbon export to coastal waters.
Sebastian J. E. Krause, Jiarui Liu, David J. Yousavich, DeMarcus Robinson, David W. Hoyt, Qianhui Qin, Frank Wenzhöfer, Felix Janssen, David L. Valentine, and Tina Treude
Biogeosciences, 20, 4377–4390, https://doi.org/10.5194/bg-20-4377-2023, https://doi.org/10.5194/bg-20-4377-2023, 2023
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Methane is a potent greenhouse gas, and hence it is important to understand its sources and sinks in the environment. Here we present new data from organic-rich surface sediments below an oxygen minimum zone off the coast of California (Santa Barbara Basin) demonstrating the simultaneous microbial production and consumption of methane, which appears to be an important process preventing the build-up of methane in these sediments and the emission into the water column and atmosphere.
Mona Norbisrath, Andreas Neumann, Kirstin Dähnke, Tina Sanders, Andreas Schöl, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 20, 4307–4321, https://doi.org/10.5194/bg-20-4307-2023, https://doi.org/10.5194/bg-20-4307-2023, 2023
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Total alkalinity (TA) is the oceanic capacity to store CO2. Estuaries can be a TA source. Anaerobic metabolic pathways like denitrification (reduction of NO3− to N2) generate TA and are a major nitrogen (N) sink. Another important N sink is anammox that transforms NH4+ with NO2− into N2 without TA generation. By combining TA and N2 production, we identified a TA source, denitrification, occurring in the water column and suggest anammox as the dominant N2 producer in the bottom layer of the Ems.
Baptiste Mourre, Emma Reyes, Pablo Lorente, Alex Santana, Jaime Hernández-Lasheras, Ismael Hernández-Carrasco, Maximo García-Jove, and Nikolaos D. Zarokanellos
State Planet, 1-osr7, 15, https://doi.org/10.5194/sp-1-osr7-15-2023, https://doi.org/10.5194/sp-1-osr7-15-2023, 2023
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We characterize the signature of an intense storm-induced coastal upwelling along the north-western coast of the Balearic Islands in 2021 using a high-resolution operational prediction model. The upwelling, with a duration of 3 d and a spatial offshore extension of 20 km, led to cross-shore surface temperature differences of up to 6 °C. It was the most intense event of the past 9 years in terms of the impact on temperature and the second-most intense event in terms of cross-shore transports.
Sara M. Defratyka, James L. France, Rebecca E. Fisher, Dave Lowry, Julianne M. Fernandez, Semra Bakkaloglu, Camille Yver-Kwok, Jean-Daniel Paris, Philippe Bousquet, Tim Arnold, Chris Rennick, Jon Helmore, Nigel Yarrow, and Euan G. Nisbet
EGUsphere, https://doi.org/10.5194/egusphere-2023-1490, https://doi.org/10.5194/egusphere-2023-1490, 2023
Preprint archived
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We are focused on verification of δ13CH4 measurements in near-source conditions and we have provided an insight into the impact of chosen calculation methods for determined isotopic signatures. Our study offers a step forward for establishing an unified, robust, and reliable analytical technique to determine δ13CH4 of methane sources. Our recommended analytical approach reduces biases and uncertainties coming from measurement conditions, data clustering and various available fitting methods.
Gesa Schulz, Tina Sanders, Yoana G. Voynova, Hermann W. Bange, and Kirstin Dähnke
Biogeosciences, 20, 3229–3247, https://doi.org/10.5194/bg-20-3229-2023, https://doi.org/10.5194/bg-20-3229-2023, 2023
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Nitrous oxide (N2O) is an important greenhouse gas. However, N2O emissions from estuaries underlie significant uncertainties due to limited data availability and high spatiotemporal variability. We found the Elbe Estuary (Germany) to be a year-round source of N2O, with the highest emissions in winter along with high nitrogen loads. However, in spring and summer, N2O emissions did not decrease alongside lower nitrogen loads because organic matter fueled in situ N2O production along the estuary.
Sophie Wittig, Antoine Berchet, Isabelle Pison, Marielle Saunois, Joël Thanwerdas, Adrien Martinez, Jean-Daniel Paris, Toshinobu Machida, Motoki Sasakawa, Douglas E. J. Worthy, Xin Lan, Rona L. Thompson, Espen Sollum, and Mikhail Arshinov
Atmos. Chem. Phys., 23, 6457–6485, https://doi.org/10.5194/acp-23-6457-2023, https://doi.org/10.5194/acp-23-6457-2023, 2023
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Here, an inverse modelling approach is applied to estimate CH4 sources and sinks in the Arctic from 2008 to 2019. We study the magnitude, seasonal patterns and trends from different sources during recent years. We also assess how the current observation network helps to constrain fluxes. We find that constraints are only significant for North America and, to a lesser extent, West Siberia, where the observation network is relatively dense. We find no clear trend over the period of inversion.
Clément Narbaud, Jean-Daniel Paris, Sophie Wittig, Antoine Berchet, Marielle Saunois, Philippe Nédélec, Boris D. Belan, Mikhail Y. Arshinov, Sergei B. Belan, Denis Davydov, Alexander Fofonov, and Artem Kozlov
Atmos. Chem. Phys., 23, 2293–2314, https://doi.org/10.5194/acp-23-2293-2023, https://doi.org/10.5194/acp-23-2293-2023, 2023
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We measured CH4 and CO2 from aircraft over the Russian Arctic. Analyzing our data with the Lagrangian model FLEXPART, we find a sharp east–west gradient in atmospheric composition. Western Siberia is influenced by strong wetland CH4 emissions, deep CO2 gradient from biospheric uptake, and long-range transport from Europe and North America. Eastern flights document less variability. Over the Arctic Ocean, we find a small influence from marine CH4 emissions compatible with reasonable inventories.
Kirstin Dähnke, Tina Sanders, Yoana Voynova, and Scott D. Wankel
Biogeosciences, 19, 5879–5891, https://doi.org/10.5194/bg-19-5879-2022, https://doi.org/10.5194/bg-19-5879-2022, 2022
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Nitrogen is an important macronutrient that fuels algal production in rivers and coastal regions. We investigated the production and removal of nitrogen-bearing compounds in the freshwater section of the tidal Elbe Estuary and found that particles in the water column are key for the production and removal of water column nitrate. Using a stable isotope approach, we pinpointed regions where additional removal of nitrate or input from sediments plays an important role in estuarine biogeochemistry.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
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We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
Yunsong Liu, Jean-Daniel Paris, Mihalis Vrekoussis, Panayiota Antoniou, Christos Constantinides, Maximilien Desservettaz, Christos Keleshis, Olivier Laurent, Andreas Leonidou, Carole Philippon, Panagiotis Vouterakos, Pierre-Yves Quéhé, Philippe Bousquet, and Jean Sciare
Atmos. Meas. Tech., 15, 4431–4442, https://doi.org/10.5194/amt-15-4431-2022, https://doi.org/10.5194/amt-15-4431-2022, 2022
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This paper details laboratory-based and field developments of a cost-effective and compacted UAV CO2 sensor system to address the challenge of measuring CO2 with sufficient precision and acquisition frequency. We assess its performance extensively through laboratory and field tests and provide a case study in an urban area (Nicosia, Cyprus). We therefore expect that this portable system will be widely used for measuring CO2 emission and distribution in natural or urban environments.
Boris D. Belan, Gerard Ancellet, Irina S. Andreeva, Pavel N. Antokhin, Viktoria G. Arshinova, Mikhail Y. Arshinov, Yurii S. Balin, Vladimir E. Barsuk, Sergei B. Belan, Dmitry G. Chernov, Denis K. Davydov, Alexander V. Fofonov, Georgii A. Ivlev, Sergei N. Kotel'nikov, Alexander S. Kozlov, Artem V. Kozlov, Katharine Law, Andrey V. Mikhal'chishin, Igor A. Moseikin, Sergei V. Nasonov, Philippe Nédélec, Olesya V. Okhlopkova, Sergei E. Ol'kin, Mikhail V. Panchenko, Jean-Daniel Paris, Iogannes E. Penner, Igor V. Ptashnik, Tatyana M. Rasskazchikova, Irina K. Reznikova, Oleg A. Romanovskii, Alexander S. Safatov, Denis E. Savkin, Denis V. Simonenkov, Tatyana K. Sklyadneva, Gennadii N. Tolmachev, Semyon V. Yakovlev, and Polina N. Zenkova
Atmos. Meas. Tech., 15, 3941–3967, https://doi.org/10.5194/amt-15-3941-2022, https://doi.org/10.5194/amt-15-3941-2022, 2022
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The change of the global climate is most pronounced in the Arctic, where the air temperature increases faster than the global average. This is associated with an increase in the concentration of greenhouse gases in the atmosphere. It is important to study how the air composition in the Arctic changes in the changing climate. Thus this integrated experiment was carried out to measure the composition of the troposphere in the Russian sector of the Arctic from on board the aircraft laboratory.
Gesa Schulz, Tina Sanders, Justus E. E. van Beusekom, Yoana G. Voynova, Andreas Schöl, and Kirstin Dähnke
Biogeosciences, 19, 2007–2024, https://doi.org/10.5194/bg-19-2007-2022, https://doi.org/10.5194/bg-19-2007-2022, 2022
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Estuaries can significantly alter nutrient loads before reaching coastal waters. Our study of the heavily managed Ems estuary (Northern Germany) reveals three zones of nitrogen turnover along the estuary with water-column denitrification in the most upstream hyper-turbid part, nitrate production in the middle reaches and mixing/nitrate uptake in the North Sea. Suspended particulate matter was the overarching control on nitrogen cycling in the hyper-turbid estuary.
Hanna K. Lappalainen, Tuukka Petäjä, Timo Vihma, Jouni Räisänen, Alexander Baklanov, Sergey Chalov, Igor Esau, Ekaterina Ezhova, Matti Leppäranta, Dmitry Pozdnyakov, Jukka Pumpanen, Meinrat O. Andreae, Mikhail Arshinov, Eija Asmi, Jianhui Bai, Igor Bashmachnikov, Boris Belan, Federico Bianchi, Boris Biskaborn, Michael Boy, Jaana Bäck, Bin Cheng, Natalia Chubarova, Jonathan Duplissy, Egor Dyukarev, Konstantinos Eleftheriadis, Martin Forsius, Martin Heimann, Sirkku Juhola, Vladimir Konovalov, Igor Konovalov, Pavel Konstantinov, Kajar Köster, Elena Lapshina, Anna Lintunen, Alexander Mahura, Risto Makkonen, Svetlana Malkhazova, Ivan Mammarella, Stefano Mammola, Stephany Buenrostro Mazon, Outi Meinander, Eugene Mikhailov, Victoria Miles, Stanislav Myslenkov, Dmitry Orlov, Jean-Daniel Paris, Roberta Pirazzini, Olga Popovicheva, Jouni Pulliainen, Kimmo Rautiainen, Torsten Sachs, Vladimir Shevchenko, Andrey Skorokhod, Andreas Stohl, Elli Suhonen, Erik S. Thomson, Marina Tsidilina, Veli-Pekka Tynkkynen, Petteri Uotila, Aki Virkkula, Nadezhda Voropay, Tobias Wolf, Sayaka Yasunaka, Jiahua Zhang, Yubao Qiu, Aijun Ding, Huadong Guo, Valery Bondur, Nikolay Kasimov, Sergej Zilitinkevich, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 4413–4469, https://doi.org/10.5194/acp-22-4413-2022, https://doi.org/10.5194/acp-22-4413-2022, 2022
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We summarize results during the last 5 years in the northern Eurasian region, especially from Russia, and introduce recent observations of the air quality in the urban environments in China. Although the scientific knowledge in these regions has increased, there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures and integrative data analyses, hindering a comprehensive system analysis.
Dirk Dienhart, John N. Crowley, Efstratios Bourtsoukidis, Achim Edtbauer, Philipp G. Eger, Lisa Ernle, Hartwig Harder, Bettina Hottmann, Monica Martinez, Uwe Parchatka, Jean-Daniel Paris, Eva Y. Pfannerstill, Roland Rohloff, Jan Schuladen, Christof Stönner, Ivan Tadic, Sebastian Tauer, Nijing Wang, Jonathan Williams, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 21, 17373–17388, https://doi.org/10.5194/acp-21-17373-2021, https://doi.org/10.5194/acp-21-17373-2021, 2021
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We present the first ship-based in situ measurements of formaldehyde (HCHO), hydroxyl radicals (OH) and the OH reactivity around the Arabian Peninsula. Regression analysis of the HCHO production rate and the related OH chemistry revealed the regional HCHO yield αeff, which represents the different chemical regimes encountered. Highest values were found for the Arabian Gulf (also known as the Persian Gulf), which highlights this region as a hotspot of photochemical air pollution.
Jean-Daniel Paris, Aurélie Riandet, Efstratios Bourtsoukidis, Marc Delmotte, Antoine Berchet, Jonathan Williams, Lisa Ernle, Ivan Tadic, Hartwig Harder, and Jos Lelieveld
Atmos. Chem. Phys., 21, 12443–12462, https://doi.org/10.5194/acp-21-12443-2021, https://doi.org/10.5194/acp-21-12443-2021, 2021
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We measured atmospheric methane and CO2 by ship in the Middle East. We probe the origin of methane with a combination of light alkane measurements and modeling. We find strong influence from nearby oil and gas production over the Arabian Gulf. Comparing our data to inventories indicates that inventories overestimate sources from the upstream gas industry but underestimate emissions from oil extraction and processing. The Red Sea was under a complex mixture of sources due to human activity.
Sara M. Defratyka, Jean-Daniel Paris, Camille Yver-Kwok, Daniel Loeb, James France, Jon Helmore, Nigel Yarrow, Valérie Gros, and Philippe Bousquet
Atmos. Meas. Tech., 14, 5049–5069, https://doi.org/10.5194/amt-14-5049-2021, https://doi.org/10.5194/amt-14-5049-2021, 2021
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We consider the possibility of using the CRDS Picarro G2201-i instrument, originally designed for isotopic CH4 and CO2, for measurements of ethane : methane in near-source conditions. The work involved laboratory tests, a controlled release experiment and mobile measurements. We show the potential of determining ethane : methane with 50 ppb ethane uncertainty. The instrument can correctly estimate the ratio in CH4 enhancements of 1 ppm and more, as can be found at strongly emitting sites.
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Short summary
In addition to reducing emissions, vast quantities of CO2 will need to be removed from the atmosphere to meet climate goals. One strategy known as Marine Anoxic Carbon Storage (MACS) would bury plant carbon for thousands of years in parts in the ocean that lack oxygen, where carbon preservation can be highly efficient. We evaluate the environmental and other impacts of hypothetical large-scale MACS deployment from an interdisciplinary, international perspective and present a research roadmap.
In addition to reducing emissions, vast quantities of CO2 will need to be removed from the...
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