Articles | Volume 22, issue 4
https://doi.org/10.5194/os-22-2595-2026
© 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/os-22-2595-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
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27 Aug 2026
Research article | Highlight paper |
| 27 Aug 2026
| 27 Aug 2026
Water masses in the Atlantic Ocean: water mass ages and ventilation
Mian Liu
CORRESPONDING AUTHOR
School of Environmental Science and Engineering, Xiamen University of Technology, Xiamen, 361021, China
GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry, Chemical Oceanography, Wischhofstraße 1–3, 24148 Kiel, Germany
Toste Tanhua
GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry, Chemical Oceanography, Wischhofstraße 1–3, 24148 Kiel, Germany
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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
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2026-496, https://doi.org/10.5194/essd-2026-496, 2026
Preprint under review for ESSD
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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. GLODAPv3 is the third version release of GLODAP. The data that are included have been subjected to extensive quality control, including systematic evaluation of systematic cruise differences. This version contains data from 1181 hydrographic cruises covering the world's oceans from 1972 to 2023.
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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CARIMED (CARbon, tracers, and ancillary data In the MEDiterranean Sea) is a high-quality, FAIR (Findability, Accessibility, Interoperability, and Reusability) dataset integrating hydrographic, biogeochemical, and transient tracer data from 46 research cruises (1976–2018) across the Mediterranean Sea. The data underwent rigorous, basin-adapted quality control to remove systematic biases, unifying four decades of fragmented data, delivering two complementary products: the aggregated original cruise data product and the bias-adjusted data synthesis product.
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.
William A. Nesbitt, Alfonso O. Mucci, Toste Tanhua, Yves Gélinas, Jean-Éric Tremblay, Gwénaëlle Chaillou, Ludovic Pascal, Caroline Fradette, Lennart Gerke, Samuel W. Stevens, Mathilde Jutras, Marjolaine Blais, Martine Lizotte, Michel Starr, and Douglas W. R. Wallace
Earth Syst. Sci. Data, 18, 3609–3634, https://doi.org/10.5194/essd-18-3609-2026, https://doi.org/10.5194/essd-18-3609-2026, 2026
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Over the past few decades, the St. Lawrence Estuary and Gulf have shown clear trends in oxygen depletion and acidification. This data description paper brings together twenty years of measurements from the St. Lawrence Estuary, Gulf of St. Lawrence, and Saguenay Fjord, carefully performing quality control procedures on data, and makes them publicly available. The resulting dataset supports future research, monitoring, and environmental management in this sensitive marine system.
Lennart Gerke, Toste Tanhua, William A. Nesbitt, Samuel W. Stevens, and Douglas W. R. Wallace
Ocean Sci., 22, 1391–1407, https://doi.org/10.5194/os-22-1391-2026, https://doi.org/10.5194/os-22-1391-2026, 2026
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Transient tracer data, measured for the first time in 2022 in the Gulf of St. Lawrence, reveal older deep waters in the east than the west, contrary to expected estuarine circulation, indicating increased influence of older, warmer, less oxygenated North Atlantic Central Water over younger, oxygen-rich Labrador Current Water. While consistent with previous reports of increasing NACW contribution, our results contradict claims of a complete shift to NACW by 2021, showing that LCW still persists.
Li-Qing Jiang, Amanda Fay, Jens Daniel Müller, Luke Gregor, Alizée Roobaert, Lydia Keppler, Dustin Carroll, Siv K. Lauvset, Tim DeVries, Judith Hauck, Christian Rödenbeck, Nicolas Metzl, Andrea J. Fassbender, Jean-Pierre Gattuso, Peter Landschützer, Rik Wanninkhof, Christopher Sabine, Simone R. Alin, Mario Hoppema, Are Olsen, Matthew P. Humphreys, Kunal Chakraborty, Ana C. Franco, Kumiko Azetsu-Scott, Dorothee C. E. Bakker, Leticia Barbero, Nicholas R. Bates, Nicole Besemer, Henry C. Bittig, Albert E. Boyd, Daniel Broullón, Wei-Jun Cai, Brendan R. Carter, Thi-Tuyet-Trang Chau, Chen-Tung Arthur Chen, Frédéric Cyr, John E. Dore, Ian Enochs, Richard A. Feely, Hernan E. Garcia, Marion Gehlen, Prasanna Kanti Ghoshal, Lucas Gloege, Melchor González-Dávila, Nicolas Gruber, Debby Ianson, Yosuke Iida, Masao Ishii, Apurva Padamnabh Joshi, Esther Kennedy, Alex Kozyr, Nico Lange, Claire Lo Monaco, Derek P. Manzello, Galen A. McKinley, Natalie M. Monacci, Xose A. Padin, Ana M. Palacio-Castro, Fiz F. Pérez, J. Magdalena Santana-Casiano, Jonathan Sharp, Adrienne Sutton, Jim Swift, Toste Tanhua, Maciej Telszewski, Jens Terhaar, Ruben van Hooidonk, Anton Velo, Andrew J. Watson, Angelicque E. White, Zelun Wu, Liang Xue, Hyelim Yoo, Jiye Zeng, and Guorong Zhong
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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This review article provides an overview of 68 existing ocean carbonate chemistry data products and data product sets, encompassing a broad range of types, including compilations of cruise datasets, gap-filled observational products, model simulations, and more. It is designed to help researchers identify and access the data products that best support their scientific objectives, thereby facilitating progress in understanding the ocean's changing carbonate chemistry.
Anne-Marie Wefing, Annabel Payne, Marcel Scheiwiller, Christof Vockenhuber, Marcus Christl, Toste Tanhua, and Núria Casacuberta
Ocean Sci., 21, 3311–3340, https://doi.org/10.5194/os-21-3311-2025, https://doi.org/10.5194/os-21-3311-2025, 2025
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Here we used the anthropogenic radionuclides I-129 and U-236 as tracers for Atlantic Water circulation in the Arctic Ocean. New data collected in 2021 allowed to assess the distribution of Atlantic Water and mixing with Pacific-origin water in the surface layer in that year. By using historical tracer data from 2011 to 2021, we looked into temporal changes of the circulation and found slightly older waters in the central Arctic Ocean in 2021 compared to 2015.
William A. Nesbitt, Samuel W. Stevens, Alfonso O. Mucci, Lennart Gerke, Toste Tanhua, Gwénaëlle Chaillou, and Douglas W. R. Wallace
Ocean Sci., 21, 2179–2195, https://doi.org/10.5194/os-21-2179-2025, https://doi.org/10.5194/os-21-2179-2025, 2025
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We combine two decades of oxygen data with new carbon observations and a tracer-informed model to quantify oxygen loss and carbon buildup in the deep waters of the Gulf and Lower St. Lawrence Estuary. We then test a novel idea: reoxygenating these waters with the oxygen produced as a by-product from green-hydrogen production. Our results suggest this could significantly reduce hypoxia, though full recovery would require larger inputs.
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
Earth Syst. Sci. Data, 16, 2047–2072, https://doi.org/10.5194/essd-16-2047-2024, https://doi.org/10.5194/essd-16-2047-2024, 2024
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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.
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.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Luke Gregor, Judith Hauck, Corinne Le Quéré, Ingrid T. Luijkx, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Ramdane Alkama, Almut Arneth, Vivek K. Arora, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Henry C. Bittig, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Wiley Evans, Stefanie Falk, Richard A. Feely, Thomas Gasser, Marion Gehlen, Thanos Gkritzalis, Lucas Gloege, Giacomo Grassi, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Atul K. Jain, Annika Jersild, Koji Kadono, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Peter Landschützer, Nathalie Lefèvre, Keith Lindsay, Junjie Liu, Zhu Liu, Gregg Marland, Nicolas Mayot, Matthew J. McGrath, Nicolas Metzl, Natalie M. Monacci, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin O'Brien, Tsuneo Ono, Paul I. Palmer, Naiqing Pan, Denis Pierrot, Katie Pocock, Benjamin Poulter, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Carmen Rodriguez, Thais M. Rosan, Jörg Schwinger, Roland Séférian, Jamie D. Shutler, Ingunn Skjelvan, Tobias Steinhoff, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Toste Tanhua, Pieter P. Tans, Xiangjun Tian, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Anthony P. Walker, Rik Wanninkhof, Chris Whitehead, Anna Willstrand Wranne, Rebecca Wright, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng
Earth Syst. Sci. Data, 14, 4811–4900, https://doi.org/10.5194/essd-14-4811-2022, https://doi.org/10.5194/essd-14-4811-2022, 2022
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The Global Carbon Budget 2022 describes the datasets and methodology used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, the land ecosystems, and the ocean. These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Rainer Kiko, Marc Picheral, David Antoine, Marcel Babin, Léo Berline, Tristan Biard, Emmanuel Boss, Peter Brandt, Francois Carlotti, Svenja Christiansen, Laurent Coppola, Leandro de la Cruz, Emilie Diamond-Riquier, Xavier Durrieu de Madron, Amanda Elineau, Gabriel Gorsky, Lionel Guidi, Helena Hauss, Jean-Olivier Irisson, Lee Karp-Boss, Johannes Karstensen, Dong-gyun Kim, Rachel M. Lekanoff, Fabien Lombard, Rubens M. Lopes, Claudie Marec, Andrew M. P. McDonnell, Daniela Niemeyer, Margaux Noyon, Stephanie H. O'Daly, Mark D. Ohman, Jessica L. Pretty, Andreas Rogge, Sarah Searson, Masashi Shibata, Yuji Tanaka, Toste Tanhua, Jan Taucher, Emilia Trudnowska, Jessica S. Turner, Anya Waite, and Lars Stemmann
Earth Syst. Sci. Data, 14, 4315–4337, https://doi.org/10.5194/essd-14-4315-2022, https://doi.org/10.5194/essd-14-4315-2022, 2022
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The term
marine particlescomprises detrital aggregates; fecal pellets; bacterioplankton, phytoplankton and zooplankton; and even fish. Here, we present a global dataset that contains 8805 vertical particle size distribution profiles obtained with Underwater Vision Profiler 5 (UVP5) camera systems. These data are valuable to the scientific community, as they can be used to constrain important biogeochemical processes in the ocean, such as the flux of carbon to the deep sea.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido R. van der Werf, Nicolas Vuichard, Chisato Wada, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, and Jiye Zeng
Earth Syst. Sci. Data, 14, 1917–2005, https://doi.org/10.5194/essd-14-1917-2022, https://doi.org/10.5194/essd-14-1917-2022, 2022
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The Global Carbon Budget 2021 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
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
Atlantic water masses are particularly interesting, not only regionally, but also for the global ocean, due to the vital status of the Atlantic Meridional Overturning Circulation in the global climate. This study presents quantitative assessments of water mass age characteristics and ventilation time scales through an analysis using the transient tracers chlorofluorocarbon‑12 (CFC‑12), sulfur hexafluoride (SF6), and argon‑39 (39Ar). The age analysis reveals significant basin‑scale asymmetries, with western basins exhibiting younger ages compared to eastern counterparts. This integrated age framework provides novel insights into water mass ventilation dynamics and their biogeochemical implications through quantitative characterization of temporal‑spatial age distributions across different oceanographic provinces.
Atlantic water masses are particularly interesting, not only regionally, but also for the global...
Short summary
We measured the age of Atlantic waters using man-made gases and a radioactive isotope. Age increases with depth: young surface waters are about 30 years old, deep Antarctic water reaches 100 years, and the oldest bottom water is roughly 120 years. The western Atlantic is younger and better ventilated than the east. These patterns help estimate deep-sea oxygen use and are key for climate models and marine ecosystems.
We measured the age of Atlantic waters using man-made gases and a radioactive isotope. Age...
