Articles | Volume 18, issue 21
https://doi.org/10.5194/gmd-18-8203-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-18-8203-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Model description paper
| 
05 Nov 2025
Model description paper |
| 05 Nov 2025
| 05 Nov 2025
age_flow_line-1.0: a fast and accurate numerical age model for a pseudo-steady flow tube of an ice sheet
Frédéric Parrenin
CORRESPONDING AUTHOR
Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, IGE, 38000 Grenoble, France
Ailsa Chung
Univ. Grenoble Alpes, IRD, CNRS, INRAE, Grenoble INP, IGE, 38000 Grenoble, France
Carlos Martín
British Antarctic Survey, Cambridge, UK
Related authors
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. MacKie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Vjeran Višnjević, Rodrigo Zamora, and Alexandra Zuhr
The Cryosphere, 19, 4611–4655, https://doi.org/10.5194/tc-19-4611-2025, https://doi.org/10.5194/tc-19-4611-2025, 2025
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The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative working together on these archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica and how this is being used to reconstruct past and to predict future ice and climate behaviour.
Ailsa Chung, Frédéric Parrenin, Robert Mulvaney, Luca Vittuari, Massimo Frezzotti, Antonio Zanutta, David A. Lilien, Marie G. P. Cavitte, and Olaf Eisen
The Cryosphere, 19, 4125–4140, https://doi.org/10.5194/tc-19-4125-2025, https://doi.org/10.5194/tc-19-4125-2025, 2025
Short summary
Short summary
We applied an ice flow model to a flow line from the summit of Dome C to the Beyond EPICA ice core drill site on Little Dome C in Antarctica. Results show that the oldest ice at the drill site may be 1.12 Ma (at an age density of 20 kyr m-1) and originate from around 15 km upstream. We also discuss the nature of the 200–250 m thick basal layer which could be composed of stagnant ice, disturbed ice or even accreted ice (possibly containing debris).
Titouan Tcheng, Elise Fourré, Christophe Leroy-Dos-Santos, Frédéric Parrenin, Emmanuel Le Meur, Frédéric Prié, Olivier Jossoud, Roxanne Jacob, Bénédicte Minster, Olivier Magand, Cécile Agosta, Niels Dutrievoz, Vincent Favier, Léa Baubant, Coralie Lassalle-Bernard, Mathieu Casado, Martin Werner, Alexandre Cauquoin, Laurent Arnaud, Bruno Jourdain, Ghislain Picard, Marie Bouchet, and Amaëlle Landais
EGUsphere, https://doi.org/10.5194/egusphere-2025-2863, https://doi.org/10.5194/egusphere-2025-2863, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
Studying Antarctic ice cores is crucial to assess past climate changes, as they hold historical climate data. This study examines multiple ice cores from three sites in coastal Adélie Land to see if combining cores improves data interpretability. It does at two sites, but at a third, wind-driven snow layer mixing limited benefits. We show that using multiple ice cores from one location can better uncover climate history, especially in areas with less wind disturbance.
Felix Pollak, Frédéric Parrenin, Emilie Capron, Zanna Chase, Lenneke Jong, and Etienne Legrain
EGUsphere, https://doi.org/10.5194/egusphere-2025-2233, https://doi.org/10.5194/egusphere-2025-2233, 2025
Short summary
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The Mid-Pleistocene Transition (MPT) marked a shift towards extended glacial periods and amplitudes, while its underlying mechanisms are still disputed. Here, we present a new conceptual model capable of simulating the global ice volume over the last 2.6 Ma and reconstructing the MPT. We find that a long-lasting, gradual trend in the climate system is most favourable in reconstructing the MPT and that for the last 900 ka, precession was more important for glacial terminations than obliquity.
Frédéric Parrenin, Marie Bouchet, Christo Buizert, Emilie Capron, Ellen Corrick, Russell Drysdale, Kenji Kawamura, Amaëlle Landais, Robert Mulvaney, Ikumi Oyabu, and Sune Olander Rasmussen
Geosci. Model Dev., 17, 8735–8750, https://doi.org/10.5194/gmd-17-8735-2024, https://doi.org/10.5194/gmd-17-8735-2024, 2024
Short summary
Short summary
The Paleochrono-1.1 probabilistic dating model allows users to derive a common and optimized chronology for several paleoclimatic sites from various archives (ice cores, speleothems, marine cores, lake cores, etc.). It combines prior sedimentation scenarios with chronological information such as dated horizons, dated intervals, stratigraphic links and (for ice cores) Δdepth observations. Paleochrono-1.1 is available under an open-source license.
Dominique Raynaud, Qiuzhen Yin, Emilie Capron, Zhipeng Wu, Frédéric Parrenin, André Berger, and Vladimir Lipenkov
Clim. Past, 20, 1269–1282, https://doi.org/10.5194/cp-20-1269-2024, https://doi.org/10.5194/cp-20-1269-2024, 2024
Short summary
Short summary
There is a lack of reconstructions from Antarctic ice cores of the temperature during the summer, a critical season in terms of solar energy received, preventing a good understanding of the link between Antarctic past climate and astronomically induced insolation changes. Here, the variations in total air content in an Antarctic ice core are found to be correlated to local summer temperatures simulated with a climate model. This tracer can be used to reconstruct past local summer temperatures.
Marie Bouchet, Amaëlle Landais, Antoine Grisart, Frédéric Parrenin, Frédéric Prié, Roxanne Jacob, Elise Fourré, Emilie Capron, Dominique Raynaud, Vladimir Ya Lipenkov, Marie-France Loutre, Thomas Extier, Anders Svensson, Etienne Legrain, Patricia Martinerie, Markus Leuenberger, Wei Jiang, Florian Ritterbusch, Zheng-Tian Lu, and Guo-Min Yang
Clim. Past, 19, 2257–2286, https://doi.org/10.5194/cp-19-2257-2023, https://doi.org/10.5194/cp-19-2257-2023, 2023
Short summary
Short summary
A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with improved accuracy. Precise ice core timescales are key to studying the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To construct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.
Zhuo Wang, Ailsa Chung, Daniel Steinhage, Frédéric Parrenin, Johannes Freitag, and Olaf Eisen
The Cryosphere, 17, 4297–4314, https://doi.org/10.5194/tc-17-4297-2023, https://doi.org/10.5194/tc-17-4297-2023, 2023
Short summary
Short summary
We combine radar-based observed internal layer stratigraphy of the ice sheet with a 1-D ice flow model in the Dome Fuji region. This results in maps of age and age density of the basal ice, the basal thermal conditions, and reconstructed accumulation rates. Based on modeled age we then identify four potential candidates for ice which is potentially 1.5 Myr old. Our map of basal thermal conditions indicates that melting prevails over the presence of stagnant ice in the study area.
Ailsa Chung, Frédéric Parrenin, Daniel Steinhage, Robert Mulvaney, Carlos Martín, Marie G. P. Cavitte, David A. Lilien, Veit Helm, Drew Taylor, Prasad Gogineni, Catherine Ritz, Massimo Frezzotti, Charles O'Neill, Heinrich Miller, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, https://doi.org/10.5194/tc-17-3461-2023, 2023
Short summary
Short summary
We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.
Robert Mulvaney, Eric W. Wolff, Mackenzie M. Grieman, Helene H. Hoffmann, Jack D. Humby, Christoph Nehrbass-Ahles, Rachael H. Rhodes, Isobel F. Rowell, Frédéric Parrenin, Loïc Schmidely, Hubertus Fischer, Thomas F. Stocker, Marcus Christl, Raimund Muscheler, Amaelle Landais, and Frédéric Prié
Clim. Past, 19, 851–864, https://doi.org/10.5194/cp-19-851-2023, https://doi.org/10.5194/cp-19-851-2023, 2023
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We present an age scale for a new ice core drilled at Skytrain Ice Rise, an ice rise facing the Ronne Ice Shelf in Antarctica. Various measurements in the ice and air phases are used to match the ice core to other Antarctic cores that have already been dated, and a new age scale is constructed. The 651 m ice core includes ice that is confidently dated to 117 000–126 000 years ago, in the last interglacial. Older ice is found deeper down, but there are flow disturbances in the deeper ice.
Ikumi Oyabu, Kenji Kawamura, Shuji Fujita, Ryo Inoue, Hideaki Motoyama, Kotaro Fukui, Motohiro Hirabayashi, Yu Hoshina, Naoyuki Kurita, Fumio Nakazawa, Hiroshi Ohno, Konosuke Sugiura, Toshitaka Suzuki, Shun Tsutaki, Ayako Abe-Ouchi, Masashi Niwano, Frédéric Parrenin, Fuyuki Saito, and Masakazu Yoshimori
Clim. Past, 19, 293–321, https://doi.org/10.5194/cp-19-293-2023, https://doi.org/10.5194/cp-19-293-2023, 2023
Short summary
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We reconstructed accumulation rate around Dome Fuji, Antarctica, over the last 5000 years from 15 shallow ice cores and seven snow pits. We found a long-term decreasing trend in the preindustrial period, which may be associated with secular surface cooling and sea ice expansion. Centennial-scale variations were also found, which may partly be related to combinations of volcanic, solar and greenhouse gas forcings. The most rapid and intense increases of accumulation rate occurred since 1850 CE.
David A. Lilien, Daniel Steinhage, Drew Taylor, Frédéric Parrenin, Catherine Ritz, Robert Mulvaney, Carlos Martín, Jie-Bang Yan, Charles O'Neill, Massimo Frezzotti, Heinrich Miller, Prasad Gogineni, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 15, 1881–1888, https://doi.org/10.5194/tc-15-1881-2021, https://doi.org/10.5194/tc-15-1881-2021, 2021
Short summary
Short summary
We collected radar data between EDC, an ice core spanning ~800 000 years, and BELDC, the site chosen for a new
oldest icecore at nearby Little Dome C. These data allow us to identify 50 % older internal horizons than previously traced in the area. We fit a model to the ages of those horizons at BELDC to determine the age of deep ice there. We find that there is likely to be 1.5 Myr old ice ~265 m above the bed, with sufficient resolution to preserve desired climatic information.
Jinhwa Shin, Christoph Nehrbass-Ahles, Roberto Grilli, Jai Chowdhry Beeman, Frédéric Parrenin, Grégory Teste, Amaelle Landais, Loïc Schmidely, Lucas Silva, Jochen Schmitt, Bernhard Bereiter, Thomas F. Stocker, Hubertus Fischer, and Jérôme Chappellaz
Clim. Past, 16, 2203–2219, https://doi.org/10.5194/cp-16-2203-2020, https://doi.org/10.5194/cp-16-2203-2020, 2020
Short summary
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We reconstruct atmospheric CO2 from the EPICA Dome C ice core during Marine Isotope Stage 6 (185–135 ka) to understand carbon mechanisms under the different boundary conditions of the climate system. The amplitude of CO2 is highly determined by the Northern Hemisphere stadial duration. Carbon dioxide maxima show different lags with respect to the corresponding abrupt CH4 jumps, the latter reflecting rapid warming in the Northern Hemisphere.
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. MacKie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Vjeran Višnjević, Rodrigo Zamora, and Alexandra Zuhr
The Cryosphere, 19, 4611–4655, https://doi.org/10.5194/tc-19-4611-2025, https://doi.org/10.5194/tc-19-4611-2025, 2025
Short summary
Short summary
The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative working together on these archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica and how this is being used to reconstruct past and to predict future ice and climate behaviour.
Álvaro Arenas-Pingarrón, Alex M. Brisbourne, Carlos Martín, Hugh F. J. Corr, Carl Robinson, Tom A. Jordan, and Paul V. Brennan
The Cryosphere, 19, 4657–4670, https://doi.org/10.5194/tc-19-4657-2025, https://doi.org/10.5194/tc-19-4657-2025, 2025
Short summary
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Synthetic Aperture Radar (SAR) imaging is essential for deep englacial observations. Each pixel is formed by averaging the radar echoes within an antenna beamwidth, but the echo diversity is lost after the average. We improve the SAR interpretation if three sub-images are formed with different sub-beamwidths: each is coloured in red, green, or blue, and they are overlapped, creating a coloured image. Interpreters will better identify the slopes of internal layers, crevasses, and layer roughness.
Ailsa Chung, Frédéric Parrenin, Robert Mulvaney, Luca Vittuari, Massimo Frezzotti, Antonio Zanutta, David A. Lilien, Marie G. P. Cavitte, and Olaf Eisen
The Cryosphere, 19, 4125–4140, https://doi.org/10.5194/tc-19-4125-2025, https://doi.org/10.5194/tc-19-4125-2025, 2025
Short summary
Short summary
We applied an ice flow model to a flow line from the summit of Dome C to the Beyond EPICA ice core drill site on Little Dome C in Antarctica. Results show that the oldest ice at the drill site may be 1.12 Ma (at an age density of 20 kyr m-1) and originate from around 15 km upstream. We also discuss the nature of the 200–250 m thick basal layer which could be composed of stagnant ice, disturbed ice or even accreted ice (possibly containing debris).
Amy Constance Faith King, Thomas Keith Bauska, Amaelle Landais, Carlos Martin, and Eric William Wolff
EGUsphere, https://doi.org/10.5194/egusphere-2025-3305, https://doi.org/10.5194/egusphere-2025-3305, 2025
This preprint is open for discussion and under review for Climate of the Past (CP).
Short summary
Short summary
We show how measurements of nitrogen isotopes in Antarctic ice core records can be used to show dramatic thinning of an ice sheet during ice mass changes in the Holocene. Combining such measurements with proxies for ice sheet elevation could be a powerful tool for constraining the history of ice dynamics at sites which are sensitive to rapid changes, and could contribute to constraining ice sheet models.
Titouan Tcheng, Elise Fourré, Christophe Leroy-Dos-Santos, Frédéric Parrenin, Emmanuel Le Meur, Frédéric Prié, Olivier Jossoud, Roxanne Jacob, Bénédicte Minster, Olivier Magand, Cécile Agosta, Niels Dutrievoz, Vincent Favier, Léa Baubant, Coralie Lassalle-Bernard, Mathieu Casado, Martin Werner, Alexandre Cauquoin, Laurent Arnaud, Bruno Jourdain, Ghislain Picard, Marie Bouchet, and Amaëlle Landais
EGUsphere, https://doi.org/10.5194/egusphere-2025-2863, https://doi.org/10.5194/egusphere-2025-2863, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
Studying Antarctic ice cores is crucial to assess past climate changes, as they hold historical climate data. This study examines multiple ice cores from three sites in coastal Adélie Land to see if combining cores improves data interpretability. It does at two sites, but at a third, wind-driven snow layer mixing limited benefits. We show that using multiple ice cores from one location can better uncover climate history, especially in areas with less wind disturbance.
Ole Zeising, Álvaro Arenas-Pingarrón, Alex M. Brisbourne, and Carlos Martín
The Cryosphere, 19, 2355–2363, https://doi.org/10.5194/tc-19-2355-2025, https://doi.org/10.5194/tc-19-2355-2025, 2025
Short summary
Short summary
Ice crystal orientation influences how glacier ice deforms. Radar polarimetry is commonly used to study the bulk ice crystal orientation, but the often used coherence method only provides information of the shallow ice in fast-flowing areas. This study shows that reducing the bandwidth of high-bandwidth radar data significantly enhances the depth limit of the coherence method. This improvement helps us to better understand ice dynamics in fast-flowing ice streams.
Vikram Goel, Carlos Martin, Kenichi Matsuoka, Bhanu Pratap, Geir Moholdt, Rahul Dey, Chavarukonam M. Laluraj, and Meloth Thamban
EGUsphere, https://doi.org/10.5194/egusphere-2025-2037, https://doi.org/10.5194/egusphere-2025-2037, 2025
Short summary
Short summary
We identified an ideal site in coastal East Antarctica for extracting ice core that contain detailed climate records dating back 20,000 years. We surveyed two ice rises combining radar measurements with ice flow modeling to assess their suitability. One site emerged as optimal, offering well-preserved climate history with high temporal resolution. An ice core record from this site could help us understand historical interactions between sea ice, winds, and precipitation patterns in the region.
Felix Pollak, Frédéric Parrenin, Emilie Capron, Zanna Chase, Lenneke Jong, and Etienne Legrain
EGUsphere, https://doi.org/10.5194/egusphere-2025-2233, https://doi.org/10.5194/egusphere-2025-2233, 2025
Short summary
Short summary
The Mid-Pleistocene Transition (MPT) marked a shift towards extended glacial periods and amplitudes, while its underlying mechanisms are still disputed. Here, we present a new conceptual model capable of simulating the global ice volume over the last 2.6 Ma and reconstructing the MPT. We find that a long-lasting, gradual trend in the climate system is most favourable in reconstructing the MPT and that for the last 900 ka, precession was more important for glacial terminations than obliquity.
Frédéric Parrenin, Marie Bouchet, Christo Buizert, Emilie Capron, Ellen Corrick, Russell Drysdale, Kenji Kawamura, Amaëlle Landais, Robert Mulvaney, Ikumi Oyabu, and Sune Olander Rasmussen
Geosci. Model Dev., 17, 8735–8750, https://doi.org/10.5194/gmd-17-8735-2024, https://doi.org/10.5194/gmd-17-8735-2024, 2024
Short summary
Short summary
The Paleochrono-1.1 probabilistic dating model allows users to derive a common and optimized chronology for several paleoclimatic sites from various archives (ice cores, speleothems, marine cores, lake cores, etc.). It combines prior sedimentation scenarios with chronological information such as dated horizons, dated intervals, stratigraphic links and (for ice cores) Δdepth observations. Paleochrono-1.1 is available under an open-source license.
Dominique Raynaud, Qiuzhen Yin, Emilie Capron, Zhipeng Wu, Frédéric Parrenin, André Berger, and Vladimir Lipenkov
Clim. Past, 20, 1269–1282, https://doi.org/10.5194/cp-20-1269-2024, https://doi.org/10.5194/cp-20-1269-2024, 2024
Short summary
Short summary
There is a lack of reconstructions from Antarctic ice cores of the temperature during the summer, a critical season in terms of solar energy received, preventing a good understanding of the link between Antarctic past climate and astronomically induced insolation changes. Here, the variations in total air content in an Antarctic ice core are found to be correlated to local summer temperatures simulated with a climate model. This tracer can be used to reconstruct past local summer temperatures.
Marie Bouchet, Amaëlle Landais, Antoine Grisart, Frédéric Parrenin, Frédéric Prié, Roxanne Jacob, Elise Fourré, Emilie Capron, Dominique Raynaud, Vladimir Ya Lipenkov, Marie-France Loutre, Thomas Extier, Anders Svensson, Etienne Legrain, Patricia Martinerie, Markus Leuenberger, Wei Jiang, Florian Ritterbusch, Zheng-Tian Lu, and Guo-Min Yang
Clim. Past, 19, 2257–2286, https://doi.org/10.5194/cp-19-2257-2023, https://doi.org/10.5194/cp-19-2257-2023, 2023
Short summary
Short summary
A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with improved accuracy. Precise ice core timescales are key to studying the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To construct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.
Zhuo Wang, Ailsa Chung, Daniel Steinhage, Frédéric Parrenin, Johannes Freitag, and Olaf Eisen
The Cryosphere, 17, 4297–4314, https://doi.org/10.5194/tc-17-4297-2023, https://doi.org/10.5194/tc-17-4297-2023, 2023
Short summary
Short summary
We combine radar-based observed internal layer stratigraphy of the ice sheet with a 1-D ice flow model in the Dome Fuji region. This results in maps of age and age density of the basal ice, the basal thermal conditions, and reconstructed accumulation rates. Based on modeled age we then identify four potential candidates for ice which is potentially 1.5 Myr old. Our map of basal thermal conditions indicates that melting prevails over the presence of stagnant ice in the study area.
Ailsa Chung, Frédéric Parrenin, Daniel Steinhage, Robert Mulvaney, Carlos Martín, Marie G. P. Cavitte, David A. Lilien, Veit Helm, Drew Taylor, Prasad Gogineni, Catherine Ritz, Massimo Frezzotti, Charles O'Neill, Heinrich Miller, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, https://doi.org/10.5194/tc-17-3461-2023, 2023
Short summary
Short summary
We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.
Isobel Rowell, Carlos Martin, Robert Mulvaney, Helena Pryer, Dieter Tetzner, Emily Doyle, Hara Madhav Talasila, Jilu Li, and Eric Wolff
Clim. Past, 19, 1699–1714, https://doi.org/10.5194/cp-19-1699-2023, https://doi.org/10.5194/cp-19-1699-2023, 2023
Short summary
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We present an age scale for a new type of ice core from a vulnerable region in West Antarctic, which is lacking in longer-term (greater than a few centuries) ice core records. The Sherman Island core extends to greater than 1 kyr. We provide modelling evidence for the potential of a 10 kyr long core. We show that this new type of ice core can be robustly dated and that climate records from this core will be a significant addition to existing regional climate records.
Robert Mulvaney, Eric W. Wolff, Mackenzie M. Grieman, Helene H. Hoffmann, Jack D. Humby, Christoph Nehrbass-Ahles, Rachael H. Rhodes, Isobel F. Rowell, Frédéric Parrenin, Loïc Schmidely, Hubertus Fischer, Thomas F. Stocker, Marcus Christl, Raimund Muscheler, Amaelle Landais, and Frédéric Prié
Clim. Past, 19, 851–864, https://doi.org/10.5194/cp-19-851-2023, https://doi.org/10.5194/cp-19-851-2023, 2023
Short summary
Short summary
We present an age scale for a new ice core drilled at Skytrain Ice Rise, an ice rise facing the Ronne Ice Shelf in Antarctica. Various measurements in the ice and air phases are used to match the ice core to other Antarctic cores that have already been dated, and a new age scale is constructed. The 651 m ice core includes ice that is confidently dated to 117 000–126 000 years ago, in the last interglacial. Older ice is found deeper down, but there are flow disturbances in the deeper ice.
Ikumi Oyabu, Kenji Kawamura, Shuji Fujita, Ryo Inoue, Hideaki Motoyama, Kotaro Fukui, Motohiro Hirabayashi, Yu Hoshina, Naoyuki Kurita, Fumio Nakazawa, Hiroshi Ohno, Konosuke Sugiura, Toshitaka Suzuki, Shun Tsutaki, Ayako Abe-Ouchi, Masashi Niwano, Frédéric Parrenin, Fuyuki Saito, and Masakazu Yoshimori
Clim. Past, 19, 293–321, https://doi.org/10.5194/cp-19-293-2023, https://doi.org/10.5194/cp-19-293-2023, 2023
Short summary
Short summary
We reconstructed accumulation rate around Dome Fuji, Antarctica, over the last 5000 years from 15 shallow ice cores and seven snow pits. We found a long-term decreasing trend in the preindustrial period, which may be associated with secular surface cooling and sea ice expansion. Centennial-scale variations were also found, which may partly be related to combinations of volcanic, solar and greenhouse gas forcings. The most rapid and intense increases of accumulation rate occurred since 1850 CE.
M. Reza Ershadi, Reinhard Drews, Carlos Martín, Olaf Eisen, Catherine Ritz, Hugh Corr, Julia Christmann, Ole Zeising, Angelika Humbert, and Robert Mulvaney
The Cryosphere, 16, 1719–1739, https://doi.org/10.5194/tc-16-1719-2022, https://doi.org/10.5194/tc-16-1719-2022, 2022
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Radio waves transmitted through ice split up and inform us about the ice sheet interior and orientation of single ice crystals. This can be used to infer how ice flows and improve projections on how it will evolve in the future. Here we used an inverse approach and developed a new algorithm to infer ice properties from observed radar data. We applied this technique to the radar data obtained at two EPICA drilling sites, where ice cores were used to validate our results.
Tun Jan Young, Carlos Martín, Poul Christoffersen, Dustin M. Schroeder, Slawek M. Tulaczyk, and Eliza J. Dawson
The Cryosphere, 15, 4117–4133, https://doi.org/10.5194/tc-15-4117-2021, https://doi.org/10.5194/tc-15-4117-2021, 2021
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Short summary
If the molecules that make up ice are oriented in specific ways, the ice becomes softer and enhances flow. We use radar to measure the orientation of ice molecules in the top 1400 m of the Western Antarctic Ice Sheet Divide. Our results match those from an ice core extracted 10 years ago and conclude that the ice flow has not changed direction for the last 6700 years. Our methods are straightforward and accurate and can be applied in places across ice sheets unsuitable for ice coring.
David A. Lilien, Daniel Steinhage, Drew Taylor, Frédéric Parrenin, Catherine Ritz, Robert Mulvaney, Carlos Martín, Jie-Bang Yan, Charles O'Neill, Massimo Frezzotti, Heinrich Miller, Prasad Gogineni, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 15, 1881–1888, https://doi.org/10.5194/tc-15-1881-2021, https://doi.org/10.5194/tc-15-1881-2021, 2021
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We collected radar data between EDC, an ice core spanning ~800 000 years, and BELDC, the site chosen for a new
oldest icecore at nearby Little Dome C. These data allow us to identify 50 % older internal horizons than previously traced in the area. We fit a model to the ages of those horizons at BELDC to determine the age of deep ice there. We find that there is likely to be 1.5 Myr old ice ~265 m above the bed, with sufficient resolution to preserve desired climatic information.
Jinhwa Shin, Christoph Nehrbass-Ahles, Roberto Grilli, Jai Chowdhry Beeman, Frédéric Parrenin, Grégory Teste, Amaelle Landais, Loïc Schmidely, Lucas Silva, Jochen Schmitt, Bernhard Bereiter, Thomas F. Stocker, Hubertus Fischer, and Jérôme Chappellaz
Clim. Past, 16, 2203–2219, https://doi.org/10.5194/cp-16-2203-2020, https://doi.org/10.5194/cp-16-2203-2020, 2020
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We reconstruct atmospheric CO2 from the EPICA Dome C ice core during Marine Isotope Stage 6 (185–135 ka) to understand carbon mechanisms under the different boundary conditions of the climate system. The amplitude of CO2 is highly determined by the Northern Hemisphere stadial duration. Carbon dioxide maxima show different lags with respect to the corresponding abrupt CH4 jumps, the latter reflecting rapid warming in the Northern Hemisphere.
Cited articles
Born, A. and Robinson, A.: Modeling the Greenland englacial stratigraphy, The Cryosphere, 15, 4539–4556, https://doi.org/10.5194/tc-15-4539-2021, 2021.
Bouchet, M., Landais, A., Grisart, A., Parrenin, F., Prié, F., Jacob, R., Fourré, E., Capron, E., Raynaud, D., Lipenkov, V. Y., Loutre, M.-F., Extier, T., Svensson, A., Legrain, E., Martinerie, P., Leuenberger, M., Jiang, W., Ritterbusch, F., Lu, Z.-T., and Yang, G.-M.: The Antarctic Ice Core Chronology 2023 (AICC2023) chronological framework and associated timescale for the European Project for Ice Coring in Antarctica (EPICA) Dome C ice core, Clim. Past, 19, 2257–2286, https://doi.org/10.5194/cp-19-2257-2023, 2023.
Buchardt, S. L.: Basal melting and Eemian ice along the main ice ridge in northern Greenland, PhD thesis, University of Copenhagen, Copenhagen, 199 pp., https://nbi.ku.dk/english/theses/phd-theses/susanne-l-buchardt/PhD_Buchardt.pdf (last access: 29 October 2025), 2009.
Buchardt, S. L. and Dahl-Jensen, D.: Estimating the basal melt rate at NorthGRIP using a Monte Carlo technique, Ann. Glaciol., 45, 137–142, https://doi.org/10.3189/172756407782282435, 2007.
Cavitte, M. G. P., Blankenship, D. D., Young, D. A., Schroeder, D. M., Parrenin, F., Lemeur, E., Macgregor, J. A., and Siegert, M. J.: Deep radiostratigraphy of the East Antarctic plateau: connecting the Dome C and Vostok ice core sites, J. Glaciol., 62, 323–334, https://doi.org/10.1017/jog.2016.11, 2016.
Cavitte, M. G. P., Parrenin, F., Ritz, C., Young, D. A., Van Liefferinge, B., Blankenship, D. D., Frezzotti, M., and Roberts, J. L.: Accumulation patterns around Dome C, East Antarctica, in the last 73 kyr, The Cryosphere, 12, 1401–1414, https://doi.org/10.5194/tc-12-1401-2018, 2018.
Chung, A., Parrenin, F., Steinhage, D., Mulvaney, R., Martín, C., Cavitte, M. G. P., Lilien, D. A., Helm, V., Taylor, D., Gogineni, P., Ritz, C., Frezzotti, M., O'Neill, C., Miller, H., Dahl-Jensen, D., and Eisen, O.: Stagnant ice and age modelling in the Dome C region, Antarctica, The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, 2023.
Chung, A., Parrenin, F., Mulvaney, R., Vittuari, L., Frezzotti, M., Zanutta, A., Lilien, D. A., Cavitte, M. G. P., and Eisen, O.: Age, thinning and spatial origin of the Beyond EPICA ice from a 2.5D ice flow model, The Cryosphere, 19, 4125–4140, https://doi.org/10.5194/tc-19-4125-2025, 2025.
Fyke, J., Sergienko, O., Löfverström, M., Price, S., and Lenaerts, J. T. M.: An Overview of Interactions and Feedbacks Between Ice Sheets and the Earth System, Rev. Geophys., 56, 361–408, https://doi.org/10.1029/2018RG000600, 2018.
Gerber, T. A., Hvidberg, C. S., Rasmussen, S. O., Franke, S., Sinnl, G., Grinsted, A., Jansen, D., and Dahl-Jensen, D.: Upstream flow effects revealed in the EastGRIP ice core using Monte Carlo inversion of a two-dimensional ice-flow model, The Cryosphere, 15, 3655–3679, https://doi.org/10.5194/tc-15-3655-2021, 2021.
Hindmarsh, R. C. A., Vieli, G. J.-M. C. L., and Parrenin, F.: A large-scale numerical model for computing isochrone geometry, Ann. Glaciol., 50, 130–140, https://doi.org/10.3189/172756409789097450, 2009.
Huybrechts, P., Rybak, O., Pattyn, F., Ruth, U., and Steinhage, D.: Ice thinning, upstream advection, and non-climatic biases for the upper 89 % of the EDML ice core from a nested model of the Antarctic ice sheet, Clim. Past, 3, 577–589, https://doi.org/10.5194/cp-3-577-2007, 2007.
IPCC: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate, edited by: Pörtner, H.-O., Roberts, D. C., Masson-Delmotte, V., Zhai, P., Tignor, M., Poloczanska, E., Mintenbeck, K., Alegría, A., Nicolai, M., Okem, A., Petzold, J., Rama, B., and Weyer, N. M., Cambridge University Press, Cambridge, UK and New York, NY, USA, 755 pp., https://doi.org/10.1017/9781009157964, 2019.
Johnsen, S. J. and Dansgaard, W.: On flow model dating of stable isotope records from Greenland ice cores, in: The Last Deglaciation: Absolute and Radiocarbon Chronologies, edited by: Bard, E. and Broecker, W. S., Springer Verlag, Berlin, Heidelberg, 13–24, ISBN 978-3-642-76061-7, 1992.
Jouzel, J., Masson-Delmotte, V., Cattani, O., Dreyfus, G., Falourd, S., Hoffmann, G., Minster, B., Nouet, J., Barnola, J. M., Chappellaz, J., Fischer, H., Gallet, J. C., Johnsen, S., Leuenberger, M., Loulergue, L., Luethi, D., Oerter, H., Parrenin, F., Raisbeck, G., Raynaud, D., Schilt, A., Schwander, J., Selmo, E., Souchez, R., Spahni, R., Stauffer, B., Steffensen, J. P., Stenni, B., Stocker, T. F., Tison, J. L., Werner, M., and Wolff, E. W.: Orbital and Millennial Antarctic Climate Variability over the Past 800,000 Years, Science, 317, 793–796, https://doi.org/10.1126/science.1141038, 2007.
Koutnik, M. R., Fudge, T. J., Conway, H., Waddington, E. D., Neumann, T. A., Cuffey, K. M., Buizert, C., and Taylor, K. C.: Holocene accumulation and ice flow near the West Antarctic Ice Sheet Divide ice core site, J. Geophys Res.-Earth, 121, 907–924, https://doi.org/10.1002/2015JF003668, 2016.
Lambert, F., Bigler, M., Steffensen, J. P., Hutterli, M., and Fischer, H.: Centennial mineral dust variability in high-resolution ice core data from Dome C, Antarctica, Clim. Past, 8, 609–623, https://doi.org/10.5194/cp-8-609-2012, 2012.
Lhomme, N., Clarke, G. K. C., and Ritz, C.: Global budget of water isotopes inferred from polar ice sheets, Geophys. Res. Lett., 32, https://doi.org/10.1029/2005GL023774, 2005a.
Lhomme, N., Clarke, G. K., and Marshall, S. J.: Tracer transport in the Greenland Ice Sheet: constraints on ice cores and glacial history, Quaternary Sci. Rev., 24, 173–194, https://doi.org/10.1016/j.quascirev.2004.08.020, 2005b.
Lliboutry, L.: A critical review of analytical approximate solutions for steady state velocities and temperature in cold ice sheets, Z. Gletscherkd. Glazialgeol., 15, 135–148, 1979.
Loulergue, L., Schilt, A., Spahni, R., Masson-Delmotte, V., Blunier, T., Lemieux, B., Barnola, J.-M., Raynaud, D., Stocker, T. F., and Chappellaz, J.: Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years, Nature, 453, 383–386, https://doi.org/10.1038/nature06950, 2008.
Lüthi, D., Floch, M. L., Bereiter, B., Blunier, T., Barnola, J.-M., Siegenthaler, U., Raynaud, D., Jouzel, J., Fischer, H., Kawamura, K., and Stocker, T. F.: High-resolution carbon dioxide concentration record 650,000–800,000 years before present, Nature, 453, 379–382, https://doi.org/10.1038/nature06949, 2008.
MacGregor, J. A., Fahnestock, M. A., Catania, G. A., Paden, J. D., Prasad Gogineni, S., Young, S. K., Rybarski, S. C., Mabrey, A. N., Wagman, B. M., and Morlighem, M.: Radiostratigraphy and age structure of the Greenland Ice Sheet, J. Geophys. Res.-Earth, 120, 2014JF003215, https://doi.org/10.1002/2014JF003215, 2015.
Martín, C. and Gudmundsson, G. H.: Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides, The Cryosphere, 6, 1221–1229, https://doi.org/10.5194/tc-6-1221-2012, 2012.
NorthGRIP project members: High-resolution record of Northern Hemisphere climate extending into the last interglacial period, Nature, 431, 147–151, https://doi.org/10.1038/nature02805, 2004.
Obase, T., Abe-Ouchi, A., Saito, F., Tsutaki, S., Fujita, S., Kawamura, K., and Motoyama, H.: A one-dimensional temperature and age modeling study for selecting the drill site of the oldest ice core near Dome Fuji, Antarctica, The Cryosphere, 17, 2543–2562, https://doi.org/10.5194/tc-17-2543-2023, 2023.
Oerlemans, J. and Van Der Veen, C. J.: Ice Sheets and Climate, Springer Netherlands, Dordrecht, https://doi.org/10.1007/978-94-009-6325-2, 1984.
Oyabu, I., Kawamura, K., Buizert, C., Parrenin, F., Orsi, A., Kitamura, K., Aoki, S., and Nakazawa, T.: The Dome Fuji ice core DF2021 chronology (0–207 kyr BP), Quaternary Sci. Rev., 294, 107754, https://doi.org/10.1016/j.quascirev.2022.107754, 2022.
Parrenin, F.: Sur l'âge de la glace et des bulles d'air dans les calottes polaires, Université Joseph Fourier, Grenoble, France, https://hal.science/tel-01219813/ (last access: 29 October 2025), 2013.
Parrenin, F.: age_flow_line: A numerical age model along a flow line of an ice sheet, Github [code], https://github.com/parrenin/age_flow_line (last access: 1 November 2024), 2024.
Parrenin, F.: parrenin/age_flow_line: Version of age_flow_line as accepted in GMD, Zenodo [code], https://doi.org/10.5281/ZENODO.16920689, 2025.
Parrenin, F. and Hindmarsh, R.: Influence of a non-uniform velocity field on isochrone geometry along a steady flowline of an ice sheet, J. Glaciol., 53, 612–622, https://doi.org/10.3189/002214307784409298, 2007.
Parrenin, F., Jouzel, J., Waelbroeck, C., Ritz, C., and Barnola, J.-M.: Dating the Vostok ice core by an inverse method, J. Geophys. Res.-Atmos., 106, 31837–31851, https://doi.org/10.1029/2001JD900245, 2001.
Parrenin, F., Rémy, F., Ritz, C., Siegert, M. J., and Jouzel, J.: New modeling of the Vostok ice flow line and implication for the glaciological chronology of the Vostok ice core, J. Geophys. Res.-Atmos., 109, https://doi.org/10.1029/2004JD004561, 2004.
Parrenin, F., Hindmarsh, R. C. A., and Rémy, F.: Analytical solutions for the effect of topography, accumulation rate and lateral flow divergence on isochrone layer geometry, J. Glaciol., 52, 191–202, https://doi.org/10.3189/172756506781828728, 2006.
Parrenin, F., Dreyfus, G., Durand, G., Fujita, S., Gagliardini, O., Gillet, F., Jouzel, J., Kawamura, K., Lhomme, N., Masson-Delmotte, V., Ritz, C., Schwander, J., Shoji, H., Uemura, R., Watanabe, O., and Yoshida, N.: 1-D-ice flow modelling at EPICA Dome C and Dome Fuji, East Antarctica, Clim. Past, 3, 243–259, https://doi.org/10.5194/cp-3-243-2007, 2007.
Parrenin, F., Cavitte, M. G. P., Blankenship, D. D., Chappellaz, J., Fischer, H., Gagliardini, O., Masson-Delmotte, V., Passalacqua, O., Ritz, C., Roberts, J., Siegert, M. J., and Young, D. A.: Is there 1.5-million-year-old ice near Dome C, Antarctica?, The Cryosphere, 11, 2427–2437, https://doi.org/10.5194/tc-11-2427-2017, 2017.
Passalacqua, O., Gagliardini, O., Parrenin, F., Todd, J., Gillet-Chaulet, F., and Ritz, C.: Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome, Geosci. Model Dev., 9, 2301–2313, https://doi.org/10.5194/gmd-9-2301-2016, 2016.
Quiquet, A., Ritz, C., Punge, H. J., and Salas y Mélia, D.: Greenland ice sheet contribution to sea level rise during the last interglacial period: a modelling study driven and constrained by ice core data, Clim. Past, 9, 353–366, https://doi.org/10.5194/cp-9-353-2013, 2013.
Raymond, C. F.: Deformation in the vicinity of ice divides, J. Glaciol., 29, 357–373, 1983.
Reeh, N. and Paterson, W. S. B.: Application of a Flow Model to the Ice-divide Region of Devon Island Ice Cap, Canada, J. Glaciol., 34, 55–63, https://doi.org/10.3189/S0022143000009060, 1988.
Ritz, C.: Un modèle thermo-mécanique d'évolution pour le bassin glaciaire antarctique Vostok-glacier Byrd: sensibilité aux valeurs des paramètres mal connus, Thèse d'état, Univ. J. Fourier, Grenoble, France, https://theses.hal.science/tel-00693923v1/ (last access: 29 October 2025), 1992.
Ritz, C., Rommelaere, V., and Dumas, C.: Modeling the evolution of Antarctic ice sheet over the last 420,000 years: Implications for altitude changes in the Vostok region, J. Geophys. Res., 106, 31943–31964, https://doi.org/10.1029/2001JD900232, 2001.
Rybak, O. and Huybrechts, P.: A comparison of Eulerian and Lagrangian methods for dating in numerical ice-sheet models, Ann. Glaciol., 37, 150–158, https://doi.org/10.3189/172756403781815393, 2003.
Salamatin, A. N., Tsyganova, E. A., Popov, S. V., and Lipenkov, V. Y.: Ice flow line modeling in ice core data interpretation: Vostok Station (East Antarctica), in: Physics of Ice Core Records 2, edited by: Hondoh, T., Hokkaido University Press, Sapporo, http://hdl.handle.net/2115/45448 (last access: 29 October 2025), 2009.
Sutter, J., Fischer, H., Grosfeld, K., Karlsson, N. B., Kleiner, T., Van Liefferinge, B., and Eisen, O.: Modelling the Antarctic Ice Sheet across the mid-Pleistocene transition – implications for Oldest Ice, The Cryosphere, 13, 2023–2041, https://doi.org/10.5194/tc-13-2023-2019, 2019.
Sutter, J., Fischer, H., and Eisen, O.: Investigating the internal structure of the Antarctic ice sheet: the utility of isochrones for spatiotemporal ice-sheet model calibration, The Cryosphere, 15, 3839–3860, https://doi.org/10.5194/tc-15-3839-2021, 2021.
Svensson, A., Andersen, K. K., Bigler, M., Clausen, H. B., Dahl-Jensen, D., Davies, S. M., Johnsen, S. J., Muscheler, R., Parrenin, F., Rasmussen, S. O., Röthlisberger, R., Seierstad, I., Steffensen, J. P., and Vinther, B. M.: A 60 000 year Greenland stratigraphic ice core chronology, Clim. Past, 4, 47–57, https://doi.org/10.5194/cp-4-47-2008, 2008.
Van Liefferinge, B. and Pattyn, F.: Using ice-flow models to evaluate potential sites of million year-old ice in Antarctica, Clim. Past, 9, 2335–2345, https://doi.org/10.5194/cp-9-2335-2013, 2013.
Vaughan, D. G., Comiso, J. C., Allison, I., Carrasco, J., Kaser, G., Kwok, R., Mote, P., Murray, T., Paul, F., Ren, J., Rignot, E., Solomina, O., Steffen, K., and Zhang, T.: Observations: Cryosphere, in: Climate Change 2013: The Physical Science Basis, Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, UK and New York, NY, USA, https://doi.org/10.1017/CBO9781107415324.012, 2013.
Waddington, E. D., Neumann, T. A., Koutnik, M. R., Marshall, H.-P., and Morse, D. L.: Inference of accumulation-rate patterns from deep layers in glaciers and ice sheets, J. Glaciol., 53, 694–712, https://doi.org/10.3189/002214307784409351, 2007.
Wolff, E. W., Mulvaney, R., Grieman, M. M., Hoffmann, H. M., Humby, J., Nehrbass-Ahles, C., Rhodes, R. H., Rowell, I. F., Sime, L. C., Fischer, H., Stocker, T. F., Landais, A., Parrenin, F., Steig, E. J., Dütsch, M., and Golledge, N. R.: The Ronne Ice Shelf survived the last interglacial, Nature, https://doi.org/10.1038/s41586-024-08394-w, 2025.
Short summary
We developed a new numerical age solver for a pseudo-steady flow tube of an ice sheet. Thanks to a new coordinate system which tracks the trajectories and a change of the time variable, our scheme combines the advantages of Eulerian and Lagrangian schemes: no numerical diffusion and no dilution of tracers. Our model is so fast that it is easy to optimize its parameters. Our model is made available to the ice sheet community as an easy to use open-source software coded in python.
We developed a new numerical age solver for a pseudo-steady flow tube of an ice sheet. Thanks to...
