Articles | Volume 18, issue 9
https://doi.org/10.5194/essd-18-6207-2026
© 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/essd-18-6207-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Data description article
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31 Aug 2026
Data description article | Highlight paper |
| 31 Aug 2026
| 31 Aug 2026
Nitrous oxide and methane concentrations and air-sea fluxes in undersampled areas of the Mediterranean basin
Mercedes de la Paz
CORRESPONDING AUTHOR
Instituto de Investigaciones Marinas (IIM‐CSIC), Vigo, Spain
Susana Flecha
Instituto de Ciencias Marinas de Andalucía (ICMAN-CSIC), Puerto Real, Cádiz, Spain
Fatima Zohra Bouthir
Institut National de Recherche Halieutique (INRH), Casablanca, Morocco
Milad Fahkri
National Centre for Marine Sciences, National Council for Scientific Research in Lebanon (CNRS-L), Beirut, Lebanon
Abed El Rahman Hassoun
National Centre for Marine Sciences, National Council for Scientific Research in Lebanon (CNRS-L), Beirut, Lebanon
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Valeria Ibello
Middle East Technical University, Institute of Marine Sciences, Mersin, Türkiye
Korhan Özkan
Middle East Technical University, Institute of Marine Sciences, Mersin, Türkiye
Fiz F. Pérez
Instituto de Investigaciones Marinas (IIM‐CSIC), Vigo, Spain
Adil Chair
Institut National de Recherche Halieutique (INRH), Casablanca, Morocco
Iris E. Hendriks
Climate Change Research Group. Mediterranean Institute for Advanced Studies (IMEDEA-CSIC), Esporles, Spain
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Ocean acidification threatens marine ecosystems and the climate and is commonly assessed through ocean pH measurements. This study provides a new twenty-year dataset of pH measurements from the North Atlantic, derived from the correction and reevaluation of both historical and recent pH measurements affected by methodological bias. This revised dataset enables a more accurate reassessment of pH trends and carbon variables under novel and updated methodological standards.
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Nitrous oxide (N2O), a potent greenhouse gas, is understudied in coastal zones. We present N2O concentrations and air–sea fluxes from the Balearic coast (2018–2023). Concentrations varied slightly across sites, with areas acting as weak sources or being near equilibrium. Temperature was the main driver of seasonal changes. These findings improve our understanding of coastal N2O emissions.
Nico Lange, Siv K. Lauvset, Brendan R. Carter, Matthew P. Humphreys, Ryan J. Woosley, Are Olsen, Henry C. Bittig, Alex Kozyr, Marta Álvarez, Kumiko Azetsu-Scott, Susan Becker, Peter J. Brown, Leticia Cotrim da Cunha, Larissa Dias, Mario Hoppema, Masao Ishii, Emil Jeansson, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Carsten Schirnick, Reiner Steinfeldt, Adam Ulfsbo, Anton Velo, and Toste Tanhua
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Marta Álvarez, Maribel I. García-Ibáñez, Nico Lange, Alex Kozyr, Antón Velo, Toste Tanhua, Giuseppe Civitarese, Carolina Cantoni, Malek Belgacem, Katrin Schroeder, Rubén Acerbi, Laurent Coppola, Thibaut Wagener, Noelia M. Fajar, Susana Flecha, Michele Giani, Louisa Giannoudi, Elisa F. Guallart, Abed El Rahman Hassoun, Emma I. Huertas, Valeria Ibello, Mehdia A. Keraghel, Férial Louanchi, Anna Luchetta, Fiz F. Pérez, Carsten Schirnick, Ekaterini Souvermezoglou, Lidia Urbini, Montserrat Vidal, and Patrizia Ziveri
Earth Syst. Sci. Data, 18, 4915–4941, https://doi.org/10.5194/essd-18-4915-2026, https://doi.org/10.5194/essd-18-4915-2026, 2026
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Rémy Asselot, Virginie Thierry, Lidia I. Carracedo, Herle Mercier, Anton Velo, Raphaël Bajon, and Fiz F. Pérez
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Matthew P. Humphreys, Siv K. Lauvset, Nico Lange, Henry C. Bittig, Brendan R. Carter, Mario Hoppema, Akihiko Murata, Are Olsen, Toste Tanhua, Adam Ulfsbo, Antón Velo, Ryan J. Woosley, Kumiko Azetsu-Scott, Jens D. Müller, and Fiz F. Pérez
EGUsphere, https://doi.org/10.5194/egusphere-2026-3063, https://doi.org/10.5194/egusphere-2026-3063, 2026
This preprint is open for discussion and under review for Ocean Science (OS).
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The Global Ocean Data Analysis Project (GLODAP) collects oceanographic datasets from research cruises that are needed to study the marine carbon cycle. The datasets are quality controlled and adjusted where necessary to ensure consistency between cruises, and published as a global data product. Here, we present a new method for calculating the consistency adjustments called ‘furthest-first inversion’ which has been developed for the newest version of the data product.
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
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Raphaël Bajon, Lidia I. Carracedo, Herlé Mercier, Rémy Asselot, and Fiz F. Pérez
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Earth Syst. Sci. Data, 18, 1405–1462, https://doi.org/10.5194/essd-18-1405-2026, https://doi.org/10.5194/essd-18-1405-2026, 2026
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Fiz F. Pérez, Marta López-Mozos, Marcos Fontela, Maribel I. García-Ibáñez, Noelia Fajar, Xosé Antonio Padín, Mónica Castaño-Carrera, Mercedes de la Paz, Lidia I. Carracedo, Marta Álvarez, Herlé Mercier, Pascale Lherminier, and Antón Velo
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Ocean acidification threatens marine ecosystems and the climate and is commonly assessed through ocean pH measurements. This study provides a new twenty-year dataset of pH measurements from the North Atlantic, derived from the correction and reevaluation of both historical and recent pH measurements affected by methodological bias. This revised dataset enables a more accurate reassessment of pH trends and carbon variables under novel and updated methodological standards.
Susana Flecha, Mercedes de la Paz, Fiz Fernández Pérez, Núria Marbà, Carlos Morell, Eva Alou-Font, Joaquín Tintoré, and Iris E. Hendriks
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Nitrous oxide (N2O), a potent greenhouse gas, is understudied in coastal zones. We present N2O concentrations and air–sea fluxes from the Balearic coast (2018–2023). Concentrations varied slightly across sites, with areas acting as weak sources or being near equilibrium. Temperature was the main driver of seasonal changes. These findings improve our understanding of coastal N2O emissions.
David Curbelo-Hernández, Fiz F. Pérez, Melchor González-Dávila, Sergey V. Gladyshev, Aridane G. González, David González-Santana, Antón Velo, Alexey Sokov, and J. Magdalena Santana-Casiano
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The study evaluated CO2–carbonate system dynamics in the North Atlantic subpolar gyre during 2009–2019. Significant ocean acidification, largely due to rising anthropogenic CO2 levels, was found. Cooling, freshening, and enhanced convective processes intensified this trend, affecting calcite and aragonite saturation. The findings contribute to a deeper understanding of ocean acidification and improve our knowledge about its impact on marine ecosystems.
Herlé Mercier, Damien Desbruyères, Pascale Lherminier, Antón Velo, Lidia Carracedo, Marcos Fontela, and Fiz F. Pérez
Ocean Sci., 20, 779–797, https://doi.org/10.5194/os-20-779-2024, https://doi.org/10.5194/os-20-779-2024, 2024
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Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Marta Álvarez, Kumiko Azetsu-Scott, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
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GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2023 is the fifth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1108 hydrographic cruises covering the world's oceans from 1972 to 2021.
Nico Lange, Björn Fiedler, Marta Álvarez, Alice Benoit-Cattin, Heather Benway, Pier Luigi Buttigieg, Laurent Coppola, Kim Currie, Susana Flecha, Dana S. Gerlach, Makio Honda, I. Emma Huertas, Siv K. Lauvset, Frank Muller-Karger, Arne Körtzinger, Kevin M. O'Brien, Sólveig R. Ólafsdóttir, Fernando C. Pacheco, Digna Rueda-Roa, Ingunn Skjelvan, Masahide Wakita, Angelicque White, and Toste Tanhua
Earth Syst. Sci. Data, 16, 1901–1931, https://doi.org/10.5194/essd-16-1901-2024, https://doi.org/10.5194/essd-16-1901-2024, 2024
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The Synthesis Product for Ocean Time Series (SPOTS) is a novel achievement expanding and complementing the biogeochemical data landscape by providing consistent and high-quality biogeochemical time-series data from 12 ship-based fixed time-series programs. SPOTS covers multiple unique marine environments and time-series ranges, including data from 1983 to 2021. All in all, it facilitates a variety of applications that benefit from the collective value of biogeochemical time-series observations.
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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For assessing the consequences of human-induced climate change for the marine realm, it is necessary to not only look at gradual changes but also at abrupt changes of environmental conditions. We summarise abrupt changes in ocean warming, acidification, and oxygen concentration as the key environmental factors for ecosystems. Taking these abrupt changes into account requires greenhouse gas emissions to be reduced to a larger extent than previously thought to limit respective damage.
Joelle Habib, Caroline Ulses, Claude Estournel, Milad Fakhri, Patrick Marsaleix, Mireille Pujo-Pay, Marine Fourrier, Laurent Coppola, Alexandre Mignot, Laurent Mortier, and Pascal Conan
Biogeosciences, 20, 3203–3228, https://doi.org/10.5194/bg-20-3203-2023, https://doi.org/10.5194/bg-20-3203-2023, 2023
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The Rhodes Gyre, eastern Mediterranean Sea, is the main Levantine Intermediate Water formation site. In this study, we use a 3D physical–biogeochemical model to investigate the seasonal and interannual variability of organic carbon dynamics in the gyre. Our results show its autotrophic nature and its high interannual variability, with enhanced primary production, downward exports, and onward exports to the surrounding regions during years marked by intense heat losses and deep mixed layers.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Simone Alin, Marta Álvarez, Kumiko Azetsu-Scott, Leticia Barbero, Susan Becker, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Richard A. Feely, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Li-Qing Jiang, Steve D. Jones, Claire Lo Monaco, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Benjamin Pfeil, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Bronte Tilbrook, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 14, 5543–5572, https://doi.org/10.5194/essd-14-5543-2022, https://doi.org/10.5194/essd-14-5543-2022, 2022
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GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2022 is the fourth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1085 hydrographic cruises covering the world's oceans from 1972 to 2021.
Georges Baaklini, Roy El Hourany, Milad Fakhri, Julien Brajard, Leila Issa, Gina Fifani, and Laurent Mortier
Ocean Sci., 18, 1491–1505, https://doi.org/10.5194/os-18-1491-2022, https://doi.org/10.5194/os-18-1491-2022, 2022
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We use machine learning to analyze the long-term variation of the surface currents in the Levantine Sea, located in the eastern Mediterranean Sea. We decompose the circulation into groups based on their physical characteristics and analyze their spatial and temporal variability. We show that most structures of the Levantine Sea are becoming more energetic over time, despite those of the western area remaining the most dominant due to their complex bathymetry and strong currents.
Iris E. Hendriks, Anna Escolano-Moltó, Susana Flecha, Raquel Vaquer-Sunyer, Marlene Wesselmann, and Núria Marbà
Biogeosciences, 19, 4619–4637, https://doi.org/10.5194/bg-19-4619-2022, https://doi.org/10.5194/bg-19-4619-2022, 2022
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Seagrasses are marine plants with the capacity to act as carbon sinks due to their high primary productivity, using carbon for growth. This capacity can play a key role in climate change mitigation. We compiled and published data showing that two Mediterranean seagrass species have different metabolic rates, while the study method influences the rates of the measurements. Most communities act as carbon sinks, while the western basin might be more productive than the eastern Mediterranean.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Marta Álvarez, Susan Becker, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Richard A. Feely, Steven van Heuven, Mario Hoppema, Masao Ishii, Emil Jeansson, Sara Jutterström, Steve D. Jones, Maren K. Karlsen, Claire Lo Monaco, Patrick Michaelis, Akihiko Murata, Fiz F. Pérez, Benjamin Pfeil, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Bronte Tilbrook, Anton Velo, Rik Wanninkhof, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 13, 5565–5589, https://doi.org/10.5194/essd-13-5565-2021, https://doi.org/10.5194/essd-13-5565-2021, 2021
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GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2021 is the third update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality control, including systematic evaluation of measurement biases. This version contains data from 989 hydrographic cruises covering the world's oceans from 1972 to 2020.
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Editorial statement
This data paper presents a particularly valuable dataset on two major greenhouse gases, nitrous oxide (N₂O) and methane (CH₄), whose oceanic sources, sinks, and contributions to the global greenhouse-gas budget remain subject to substantial uncertainties. The compilation of N₂O and CH₄ concentrations and associated air–sea fluxes across undersampled regions of the Mediterranean basin fills an important observational gap.
This data paper presents a particularly valuable dataset on two major greenhouse gases, nitrous...
Short summary
This study provides monthly year-long dataset of nitrous oxide and methane concentrations and their air-sea exchange in understudied coastal areas of the Mediterranean Sea. By using standardized methods across multiple sites, it reveals marked seasonal and regional differences, with methane showing highly variable bursts linked to local sources. The dataset addresses major observational gaps and offers a reliable foundation for future environmental evaluation in this sensitive region.
This study provides monthly year-long dataset of nitrous oxide and methane concentrations and...
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