Articles | Volume 11, issue 6
https://doi.org/10.5194/tc-11-2427-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/tc-11-2427-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| Highlight paper
| 
02 Nov 2017
Research article | Highlight paper |
| 02 Nov 2017
Is there 1.5-million-year-old ice near Dome C, Antarctica?
Frédéric Parrenin
CORRESPONDING AUTHOR
Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
Marie G. P. Cavitte
Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
Donald D. Blankenship
Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
Jérôme Chappellaz
Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
Hubertus Fischer
Climate and Environmental Physics, Physics Institute & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Olivier Gagliardini
Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
Valérie Masson-Delmotte
Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ/IPSL – UMR8212, Gif-Sur-Yvette, France
Olivier Passalacqua
Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
Catherine Ritz
Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
Jason Roberts
Australian Antarctic Division, Kingston, 7050 Tasmania, Australia
Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, 7001 Tasmania, Australia
Martin J. Siegert
Grantham Institute and Department of Earth Science and Engineering, Imperial College London, London, UK
Duncan A. Young
Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
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We combine the observed internal layer stratigraphy with 1D ice flow model in the Dome Fuji (DF) region. From the modelling results we map the age of ice, the basal thermal condition and accumulation rate. We identify four potential candidates for old ice based on age and age density of ice. Map of basal thermal condition implies melting prevails over stagnant ice here. We interpolate the age of basal ice of 1345.8 ka, melt rate of 0.11 mm/a and accumulation rate of 0.022 m/a at DF.
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
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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
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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
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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
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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
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Anders Svensson, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Thomas Blunier, Sune O. Rasmussen, Bo M. Vinther, Paul Vallelonga, Emilie Capron, Vasileios Gkinis, Eliza Cook, Helle Astrid Kjær, Raimund Muscheler, Sepp Kipfstuhl, Frank Wilhelms, Thomas F. Stocker, Hubertus Fischer, Florian Adolphi, Tobias Erhardt, Michael Sigl, Amaelle Landais, Frédéric Parrenin, Christo Buizert, Joseph R. McConnell, Mirko Severi, Robert Mulvaney, and Matthias Bigler
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We identify signatures of large bipolar volcanic eruptions in Greenland and Antarctic ice cores during the last glacial period, which allows for a precise temporal alignment of the ice cores. Thereby the exact timing of unexplained, abrupt climatic changes occurring during the last glacial period can be determined in a global context. The study thus provides a step towards a full understanding of elements of the climate system that may also play an important role in the future.
Jai Chowdhry Beeman, Léa Gest, Frédéric Parrenin, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
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As the Dome C region is a key area for oldest-ice research, we need to better constrain the geothermal flux (GF) so that past basal melt rates are well constrained. Our inverse heat model significantly reduces the confidence intervals of the GF regional field around Dome C, which ranges from 48 to 60 mW m−2. Radar echoes need to be interpreted knowing the time lag of the climate signal to reach the bed. Several old-ice targets are confirmed and a new one is suggested, in which the GF is very low.
Léa Gest, Frédéric Parrenin, Jai Chowdhry Beeman, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-71, https://doi.org/10.5194/cp-2017-71, 2017
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In this manuscript, we place the atmospheric CO2 and Antarctic temperature records onto a common age scale during the last deglaciation. Moreover, we evaluate the phase relationship between those two records in order to discuss possible climatic and carbon cycle scenarios. Indeed, this phase relationship is central to determine the role of the former in past (and therefore future) climatic variations. This scientific problem was even discussed by some policy makers (e.g., in the USA senate).
Olivier Passalacqua, Olivier Gagliardini, Frédéric Parrenin, Joe Todd, Fabien Gillet-Chaulet, and Catherine Ritz
Geosci. Model Dev., 9, 2301–2313, https://doi.org/10.5194/gmd-9-2301-2016, https://doi.org/10.5194/gmd-9-2301-2016, 2016
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In ice-flow modelling, computing in 3-D requires a lot of resources, but 2-D models lack physical likelihood when the flow is diverging. That is why 2-D models accounting for the divergence, so-called 2.5-D models, are an interesting trade-off. However, the applicability of these 2.5-D models has never been systematically examined. We show that these models are ineffective in the case of highly diverging flows, but also for varying temperature, which was not suspected.
Shin'ya Nakano, Kazue Suzuki, Kenji Kawamura, Frédéric Parrenin, and Tomoyuki Higuchi
Nonlin. Processes Geophys., 23, 31–44, https://doi.org/10.5194/npg-23-31-2016, https://doi.org/10.5194/npg-23-31-2016, 2016
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This paper proposes a technique for dating an ice core. The proposed technique employs a hybrid method combining the sequential Monte Carlo method and the Markov chain Monte Carlo method, which is referred to as the particle Markov chain Monte Carlo method. The sequential Monte Carlo method, which is also known as the particle filter, is widely used for nonlinear time-series analysis. This paper demonstrates the usefulness of the approach in time-series analysis for dating an ice core.
S. Fujita, F. Parrenin, M. Severi, H. Motoyama, and E. W. Wolff
Clim. Past, 11, 1395–1416, https://doi.org/10.5194/cp-11-1395-2015, https://doi.org/10.5194/cp-11-1395-2015, 2015
B. Lemieux-Dudon, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, M. Guillevic, P. Kindler, F. Parrenin, and P. Martinerie
Clim. Past, 11, 959–978, https://doi.org/10.5194/cp-11-959-2015, https://doi.org/10.5194/cp-11-959-2015, 2015
F. Parrenin, L. Bazin, E. Capron, A. Landais, B. Lemieux-Dudon, and V. Masson-Delmotte
Geosci. Model Dev., 8, 1473–1492, https://doi.org/10.5194/gmd-8-1473-2015, https://doi.org/10.5194/gmd-8-1473-2015, 2015
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This manuscript describes a probabilistic model which aims at optimizing the chronology of ice cores by combining different sources of information.
F. Parrenin, S. Fujita, A. Abe-Ouchi, K. Kawamura, V. Masson-Delmotte, H. Motoyama, F. Saito, M. Severi, B. Stenni, R. Uemura, and E. Wolff
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-377-2015, https://doi.org/10.5194/cpd-11-377-2015, 2015
Revised manuscript has not been submitted
H. Fischer, J. Severinghaus, E. Brook, E. Wolff, M. Albert, O. Alemany, R. Arthern, C. Bentley, D. Blankenship, J. Chappellaz, T. Creyts, D. Dahl-Jensen, M. Dinn, M. Frezzotti, S. Fujita, H. Gallee, R. Hindmarsh, D. Hudspeth, G. Jugie, K. Kawamura, V. Lipenkov, H. Miller, R. Mulvaney, F. Parrenin, F. Pattyn, C. Ritz, J. Schwander, D. Steinhage, T. van Ommen, and F. Wilhelms
Clim. Past, 9, 2489–2505, https://doi.org/10.5194/cp-9-2489-2013, https://doi.org/10.5194/cp-9-2489-2013, 2013
L. Bazin, A. Landais, B. Lemieux-Dudon, H. Toyé Mahamadou Kele, D. Veres, F. Parrenin, P. Martinerie, C. Ritz, E. Capron, V. Lipenkov, M.-F. Loutre, D. Raynaud, B. Vinther, A. Svensson, S. O. Rasmussen, M. Severi, T. Blunier, M. Leuenberger, H. Fischer, V. Masson-Delmotte, J. Chappellaz, and E. Wolff
Clim. Past, 9, 1715–1731, https://doi.org/10.5194/cp-9-1715-2013, https://doi.org/10.5194/cp-9-1715-2013, 2013
D. Veres, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, B. Lemieux-Dudon, F. Parrenin, P. Martinerie, E. Blayo, T. Blunier, E. Capron, J. Chappellaz, S. O. Rasmussen, M. Severi, A. Svensson, B. Vinther, and E. W. Wolff
Clim. Past, 9, 1733–1748, https://doi.org/10.5194/cp-9-1733-2013, https://doi.org/10.5194/cp-9-1733-2013, 2013
E. Capron, A. Landais, D. Buiron, A. Cauquoin, J. Chappellaz, M. Debret, J. Jouzel, M. Leuenberger, P. Martinerie, V. Masson-Delmotte, R. Mulvaney, F. Parrenin, and F. Prié
Clim. Past, 9, 983–999, https://doi.org/10.5194/cp-9-983-2013, https://doi.org/10.5194/cp-9-983-2013, 2013
A. Svensson, M. Bigler, T. Blunier, H. B. Clausen, D. Dahl-Jensen, H. Fischer, S. Fujita, K. Goto-Azuma, S. J. Johnsen, K. Kawamura, S. Kipfstuhl, M. Kohno, F. Parrenin, T. Popp, S. O. Rasmussen, J. Schwander, I. Seierstad, M. Severi, J. P. Steffensen, R. Udisti, R. Uemura, P. Vallelonga, B. M. Vinther, A. Wegner, F. Wilhelms, and M. Winstrup
Clim. Past, 9, 749–766, https://doi.org/10.5194/cp-9-749-2013, https://doi.org/10.5194/cp-9-749-2013, 2013
F. Parrenin and D. Paillard
Clim. Past, 8, 2031–2037, https://doi.org/10.5194/cp-8-2031-2012, https://doi.org/10.5194/cp-8-2031-2012, 2012
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
EGUsphere, https://doi.org/10.5194/egusphere-2023-1081, https://doi.org/10.5194/egusphere-2023-1081, 2023
This preprint is open for discussion and under review for Climate of the Past (CP).
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A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with an improved accuracy. Precise ice core timescales are key to study the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To consruct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.
Michaela Mühl, Jochen Schmitt, Barbara Seth, James E. Lee, Jon S. Edwards, Edward J. Brook, Thomas Blunier, and Hubertus Fischer
Clim. Past, 19, 999–1025, https://doi.org/10.5194/cp-19-999-2023, https://doi.org/10.5194/cp-19-999-2023, 2023
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Our ice core measurements show that methane, ethane, and propane concentrations are significantly elevated above their past atmospheric background for Greenland ice samples containing mineral dust. The underlying co-production process happens during the classical discrete wet extraction of air from the ice sample and affects previous reconstructions of the inter-polar difference of methane as well as methane stable isotope records derived from dust-rich Greenland ice.
Marie G. P. Cavitte, Hugues Goosse, Kenichi Matsuoka, Sarah Wauthy, Vikram Goel, Rahul Dey, Bhanu Pratap, Brice Van Liefferinge, Thamban Meloth, and Jean-Louis Tison
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-65, https://doi.org/10.5194/tc-2023-65, 2023
Preprint under review for TC
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Piers Maxwell Forster, Christopher J. Smith, Tristram Walsh, William F. Lamb, Matthew D. Palmer, Karina von Schuckmann, Blair Trewin, Myles Allen, Robbie Andrew, Arlene Birt, Alex Borger, Tim Boyer, Jiddu A. Broersma, Lijing Cheng, Frank Dentener, Pierre Friedlingstein, Nathan Gillett, José M. Gutiérrez, Johannes Gütschow, Mathias Hauser, Bradley Hall, Masayoshi Ishii, Stuart Jenkins, Robin Lamboll, Xin Lan, June-Yi Lee, Colin Morice, Christopher Kadow, John Kennedy, Rachel Killick, Jan Minx, Vaishali Naik, Glen Peters, Anna Pirani, Julia Pongratz, Aurélien Ribes, Joeri Rogelj, Debbie Rosen, Carl-Friedrich Schleussner, Sonia Seneviratne, Sophie Szopa, Peter Thorne, Robert Rohde, Maisa Rojas Corradi, Dominik Schumacher, Russell Vose, Kirsten Zickfeld, Xuebin Zhang, Valérie Masson-Delmotte, and Panmao Zhai
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2023-166, https://doi.org/10.5194/essd-2023-166, 2023
Preprint under review for ESSD
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This is a critical decade for climate action but there is no annual tracking of the level of human-induced warming. We build from the Intergovernmental Panel on Climate Change assessment reports that are authoritative but published infrequently to create a set of key global climate indicators that can be tracked through time. Our hope is that this becomes an important annual publications that policymakers, media, scientists and the public can refer to.
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
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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.
James W. Marschalek, Edward Gasson, Tina van de Flierdt, Claus-Dieter Hillenbrand, Martin J. Siegert, and Liam Holder
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-8, https://doi.org/10.5194/gmd-2023-8, 2023
Preprint under review for GMD
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Ice sheet models can help predict how Antarctica’s ice sheets respond to environmental change; such models benefit from comparison to geological data. Here, we use ice sheet model results, plus other data, to predict the erosion of Antarctic debris and trace its transport to where it is deposited on the ocean floor. This allows the results of ice sheet modelling to be directly and quantitively compared to real-world data, helping to reduce uncertainty regarding Antarctic sea level contribution.
Zhuo Wang, Ailsa Chung, Daniel Steinhage, Frédéric Parrenin, Johannes Freitag, and Olaf Eisen
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-35, https://doi.org/10.5194/tc-2023-35, 2023
Preprint under review for TC
Short summary
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We combine the observed internal layer stratigraphy with 1D ice flow model in the Dome Fuji (DF) region. From the modelling results we map the age of ice, the basal thermal condition and accumulation rate. We identify four potential candidates for old ice based on age and age density of ice. Map of basal thermal condition implies melting prevails over stagnant ice here. We interpolate the age of basal ice of 1345.8 ka, melt rate of 0.11 mm/a and accumulation rate of 0.022 m/a at DF.
Sune Olander Rasmussen, Dorthe Dahl-Jensen, Hubertus Fischer, Katrin Fuhrer, Steffen Bo Hansen, Margareta Hansson, Christine Schøtt Hvidberg, Ulf Jonsell, Sepp Kipfstuhl, Urs Ruth, Jakob Schwander, Marie-Louise Siggaard-Andersen, Giulia Sinnl, Jørgen Peder Steffensen, Anders M. Svensson, and Bo Vinther
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-361, https://doi.org/10.5194/essd-2022-361, 2023
Revised manuscript accepted for ESSD
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Time scales are essential for interpreting palaeoclimate data. The data series presented here were used for annual-layer identification when constructing the time scales named the Greenland Ice-Core Chronology 2005 (GICC05) and the revised version GICC21. Hopefully, these high-resolution data sets will be useful also for other purposes.
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
EGUsphere, https://doi.org/10.5194/egusphere-2023-157, https://doi.org/10.5194/egusphere-2023-157, 2023
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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 site on Little Dome C, the maximum age of the ice is around 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.
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
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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.
Susanne Preunkert, Pascal Bohleber, Michel Legrand, Hubertus Fischer, Adrien Gilbert, Tobias Erhardt, Roland Purtschert, Lars Zipf, Astrid Waldner, and Joseph R. McConnell
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-259, https://doi.org/10.5194/tc-2022-259, 2023
Revised manuscript under review for TC
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Being close to European pollution source regions makes ice cores from Alpine glaciers important to reconstruct past anthropogenic changes over Europe. Three ice cores covering the 20th century were extracted at the same place at the Col du Dôme (4250 masl, French Alps) in 1994, 2004, and 2012. Combining chemical profiles, bomb test markers and 210Pb profiles, used as footprints of crevasses, allowed to highlight changes over time of the depth-age characteristics at an Alpine drill site.
Lars Mächler, Daniel Baggenstos, Florian Krauss, Jochen Schmitt, Bernhard Bereiter, Remo Walther, Christoph Reinhard, Béla Tuzson, Lukas Emmenegger, and Hubertus Fischer
Atmos. Meas. Tech., 16, 355–372, https://doi.org/10.5194/amt-16-355-2023, https://doi.org/10.5194/amt-16-355-2023, 2023
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We present a new method to extract the gases from ice cores and measure their greenhouse gas composition. The ice is sublimated continuously with a near-infrared laser, releasing the gases, which are then analyzed on a laser absorption spectrometer. The main advantage over previous efforts is a low effective resolution of 1–2 cm. This capability is crucial for the analysis of highly thinned ice, as expected from ongoing drilling efforts to extend ice core history further back in time.
Sarah S. Thompson, Bernd Kulessa, Adrian Luckman, Jacqueline A. Halpin, Jamin S. Greenbaum, Tyler Pelle, Feras Habbal, Jingxue Guo, Lenneke M. Jong, Jason L. Roberts, Bo Sun, and Donald D. Blankenship
The Cryosphere, 17, 157–174, https://doi.org/10.5194/tc-17-157-2023, https://doi.org/10.5194/tc-17-157-2023, 2023
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We use satellite imagery and ice penetrating radar to investigate the stability of the Shackleton system in East Antarctica. We find significant changes in surface structures across the system and observe a significant increase in ice flow speed (up to 50 %) on the floating part of Scott Glacier. We conclude that knowledge remains woefully insufficient to explain recent observed changes in the grounded and floating regions of the system.
Benoit S. Lecavalier, Lev Tarasov, Greg Balco, Perry Spector, Claus-Dieter Hillenbrand, Christo Buizert, Catherine Ritz, Marion Leduc-Leballeur, Robert Mulvaney, Pippa L. Whitehouse, Michael J. Bentley, and Jonathan Bamber
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-398, https://doi.org/10.5194/essd-2022-398, 2022
Revised manuscript under review for ESSD
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The Antarctic ice sheet evolution constraint database version 2 (AntICE2) consists of a large variety of observations that constrain the evolution of the Antarctic ice sheet over the last glacial cycle. This includes observations of past ice sheet extent, past ice thickness, past relative sea level, borehole temperature profiles, and present-day bedrock displacement rates. The database is intended to improve our understanding of past Antarctic changes and for ice sheet model calibrations.
Aymeric P. M. Servettaz, Anaïs J. Orsi, Mark A. J. Curran, Andrew D. Moy, Amaelle Landais, Joseph R. McConnell, Trevor J. Popp, Emmanuel Le Meur, Xavier Faïn, and Jérôme Chappelaz
Clim. Past Discuss., https://doi.org/10.5194/cp-2022-91, https://doi.org/10.5194/cp-2022-91, 2022
Revised manuscript accepted for CP
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The temperature of the past 2000 years is still poorly known in vast parts of the East Antarctic plateau. In this study, we present temperature reconstructions based on water and gases stables isotopes from the Aurora Basin North ice core. Spatial and temporal significance of each proxy differs, and we can identify some cold periods in the snow temperature, consistent with Southern Annular Mode variability, which could not be determined with water isotopes only.
Alice C. Frémand, Peter Fretwell, Julien Bodart, Hamish D. Pritchard, Alan Aitken, Jonathan L. Bamber, Robin Bell, Cesido Bianchi, Robert G. Bingham, Donald D. Blankenship, Gino Casassa, Ginny Catania, Knut Christianson, Howard Conway, Hugh F. J. Corr, Xiangbin Cui, Daniel Damaske, Volkmar Damm, Reinhard Drews, Graeme Eagles, Olaf Eisen, Hannes Eisermann, Fausto Ferraccioli, Elena Field, René Forsberg, Steven Franke, Shuji Fujita, Yonggyu Gim, Vikram Goel, Siva Prasad Gogineni, Jamin Greenbaum, Benjamin Hills, Richard C. A. Hindmarsh, Per Holmlund, Nicholas Holschuh, John W. Holt, Angelika Humbert, Robert W. Jacobel, Daniela Jansen, Adrian Jenkins, Wilfried Jokat, Tom Jordan, Edward King, Jack Kohler, William Krabill, Kirsty Langley, Joohan Lee, German Leitchenkov, Carlton Leuschen, Bruce Luyendyk, Joseph MacGregor, Emma MacKie, Kenichi Matsuoka, Mathieu Morlinghem, Jeremie Mouginot, Frank O. Nitsche, Yoshifumi Nogi, Ole A. Nost, John Paden, Frank Pattyn, Sergey V. Popov, Mette Riger-Kusk, Eric Rignot, David M. Rippin, Andres Rivera, Jason Roberts, Neil Ross, Antonia Ruppel, Dustin M. Schroeder, Martin J. Siegert, Andrew M. Smith, Daniel Steinhage, Michael Studinger, Bo Sun, Ignazio Tabacco, Kirsty Tinto, Stefano Urbini, David Vaughan, Brian C. Welch, Douglas S. Wilson, Duncan A. Young, and Achille Zirizzotti
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-355, https://doi.org/10.5194/essd-2022-355, 2022
Revised manuscript accepted for ESSD
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This paper presents the release of over 60 years of ice thickness, bed and surface elevation data acquired over Antarctica by the international community. These data are a crucial component of the Antarctic Bedmap initiative which aims to produce a new map and datasets of Antarctic ice thickness and bed topography for the international glaciology and geophysical community.
Antoine Grisart, Mathieu Casado, Vasileios Gkinis, Bo Vinther, Philippe Naveau, Mathieu Vrac, Thomas Laepple, Bénédicte Minster, Frederic Prié, Barbara Stenni, Elise Fourré, Hans Christian Steen-Larsen, Jean Jouzel, Martin Werner, Katy Pol, Valérie Masson-Delmotte, Maria Hoerhold, Trevor Popp, and Amaelle Landais
Clim. Past, 18, 2289–2301, https://doi.org/10.5194/cp-18-2289-2022, https://doi.org/10.5194/cp-18-2289-2022, 2022
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This paper presents a compilation of high-resolution (11 cm) water isotopic records, including published and new measurements, for the last 800 000 years from the EPICA Dome C ice core, Antarctica. Using this new combined water isotopes (δ18O and δD) dataset, we study the variability and possible influence of diffusion at the multi-decadal to multi-centennial scale. We observe a stronger variability at the onset of the interglacial interval corresponding to a warm period.
Lenneke M. Jong, Christopher T. Plummer, Jason L. Roberts, Andrew D. Moy, Mark A. J. Curran, Tessa R. Vance, Joel B. Pedro, Chelsea A. Long, Meredith Nation, Paul A. Mayewski, and Tas D. van Ommen
Earth Syst. Sci. Data, 14, 3313–3328, https://doi.org/10.5194/essd-14-3313-2022, https://doi.org/10.5194/essd-14-3313-2022, 2022
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Ice core records from Law Dome in East Antarctica, collected over the the last 3 decades, provide high-resolution data for studies of the climate of Antarctica, Australia and the Southern and Indo-Pacific oceans. Here, we present a set of annually dated records from Law Dome covering the last 2000 years. This dataset provides an update and extensions both forward and back in time of previously published subsets of the data, bringing them together into a coherent set with improved dating.
Eric W. Wolff, Hubertus Fischer, Tas van Ommen, and David A. Hodell
Clim. Past, 18, 1563–1577, https://doi.org/10.5194/cp-18-1563-2022, https://doi.org/10.5194/cp-18-1563-2022, 2022
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Projects are underway to drill ice cores in Antarctica reaching 1.5 Myr back in time. Dating such cores will be challenging. One method is to match records from the new core against datasets from existing marine sediment cores. Here we explore the options for doing this and assess how well the ice and marine records match over the existing 800 000-year time period. We are able to recommend a strategy for using marine data to place an age scale on the new ice cores.
Benoît Urruty, Emily A. Hill, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gael Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-104, https://doi.org/10.5194/tc-2022-104, 2022
Preprint under review for TC
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Retreat of the Antarctic grounding lines could destabilise large parts of the ice sheet. We use three ice sheet models to show that the present-day locations of Antarctic grounding lines are stable with respect to a small perturbation away from their current position. This suggests that self-sustained retreat of grounding lines, due to an internal instability, has not begun. Instead, the currently observed retreat is likely due to external forcing alone.
Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gael Durand, Fabien Gillet-Chaulet, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-105, https://doi.org/10.5194/tc-2022-105, 2022
Revised manuscript accepted for TC
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We use an ice sheet model to test where current climate conditions in Antarctica might lead. We find that, depending on model parameters, present-day ocean and atmosphere conditions might commit a collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not yet irreversible as shown in our accompanying study.
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.
Xavier Faïn, Rachael H. Rhodes, Philip Place, Vasilii V. Petrenko, Kévin Fourteau, Nathan Chellman, Edward Crosier, Joseph R. McConnell, Edward J. Brook, Thomas Blunier, Michel Legrand, and Jérôme Chappellaz
Clim. Past, 18, 631–647, https://doi.org/10.5194/cp-18-631-2022, https://doi.org/10.5194/cp-18-631-2022, 2022
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Carbon monoxide (CO) is a regulated pollutant and one of the key components determining the oxidizing capacity of the atmosphere. In this study, we analyzed five ice cores from Greenland at high resolution for CO concentrations by coupling laser spectrometry with continuous melting. By combining these new datasets, we produced an upper-bound estimate of past atmospheric CO abundance since preindustrial times for the Northern Hemisphere high latitudes, covering the period from 1700 to 1957 CE.
Tobias Erhardt, Matthias Bigler, Urs Federer, Gideon Gfeller, Daiana Leuenberger, Olivia Stowasser, Regine Röthlisberger, Simon Schüpbach, Urs Ruth, Birthe Twarloh, Anna Wegner, Kumiko Goto-Azuma, Takayuki Kuramoto, Helle A. Kjær, Paul T. Vallelonga, Marie-Louise Siggaard-Andersen, Margareta E. Hansson, Ailsa K. Benton, Louise G. Fleet, Rob Mulvaney, Elizabeth R. Thomas, Nerilie Abram, Thomas F. Stocker, and Hubertus Fischer
Earth Syst. Sci. Data, 14, 1215–1231, https://doi.org/10.5194/essd-14-1215-2022, https://doi.org/10.5194/essd-14-1215-2022, 2022
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The datasets presented alongside this manuscript contain high-resolution concentration measurements of chemical impurities in deep ice cores, NGRIP and NEEM, from the Greenland ice sheet. The impurities originate from the deposition of aerosols to the surface of the ice sheet and are influenced by source, transport and deposition processes. Together, these records contain detailed, multi-parameter records of past climate variability over the last glacial period.
Jiamei Lin, Anders Svensson, Christine S. Hvidberg, Johannes Lohmann, Steffen Kristiansen, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Sune Olander Rasmussen, Eliza Cook, Helle Astrid Kjær, Bo M. Vinther, Hubertus Fischer, Thomas Stocker, Michael Sigl, Matthias Bigler, Mirko Severi, Rita Traversi, and Robert Mulvaney
Clim. Past, 18, 485–506, https://doi.org/10.5194/cp-18-485-2022, https://doi.org/10.5194/cp-18-485-2022, 2022
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We employ acidity records from Greenland and Antarctic ice cores to estimate the emission strength, frequency and climatic forcing for large volcanic eruptions from the last half of the last glacial period. A total of 25 volcanic eruptions are found to be larger than any eruption in the last 2500 years, and we identify more eruptions than obtained from geological evidence. Towards the end of the glacial period, there is a notable increase in volcanic activity observed for Greenland.
Marie G. P. Cavitte, Duncan A. Young, Robert Mulvaney, Catherine Ritz, Jamin S. Greenbaum, Gregory Ng, Scott D. Kempf, Enrica Quartini, Gail R. Muldoon, John Paden, Massimo Frezzotti, Jason L. Roberts, Carly R. Tozer, Dustin M. Schroeder, and Donald D. Blankenship
Earth Syst. Sci. Data, 13, 4759–4777, https://doi.org/10.5194/essd-13-4759-2021, https://doi.org/10.5194/essd-13-4759-2021, 2021
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We present a data set consisting of ice-penetrating-radar internal stratigraphy: 26 internal reflecting horizons that cover the greater Dome C area, East Antarctica, the most extensive IRH data set to date in the region. This data set uses radar surveys collected over the span of 10 years, starting with an airborne international collaboration in 2008 to explore the region, up to the detailed ground-based surveys in support of the European Beyond EPICA – Oldest Ice (BE-OI) project.
Yaowen Zheng, Lenneke M. Jong, Steven J. Phipps, Jason L. Roberts, Andrew D. Moy, Mark A. J. Curran, and Tas D. van Ommen
Clim. Past, 17, 1973–1987, https://doi.org/10.5194/cp-17-1973-2021, https://doi.org/10.5194/cp-17-1973-2021, 2021
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South West Western Australia has experienced a prolonged drought in recent decades. The causes of this drought are unclear. We use an ice core from East Antarctica to reconstruct changes in rainfall over the past 2000 years. We find that the current drought is unusual, with only two other droughts of similar severity having occurred during this period. Climate modelling shows that greenhouse gas emissions during the industrial era are likely to have contributed to the recent drying trend.
Johannes Sutter, Hubertus Fischer, and Olaf Eisen
The Cryosphere, 15, 3839–3860, https://doi.org/10.5194/tc-15-3839-2021, https://doi.org/10.5194/tc-15-3839-2021, 2021
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Projections of global sea-level changes in a warming world require ice-sheet models. We expand the calibration of these models by making use of the internal architecture of the Antarctic ice sheet, which is formed by its evolution over many millennia. We propose that using our novel approach to constrain ice sheet models, we will be able to both sharpen our understanding of past and future sea-level changes and identify weaknesses in the parameterisation of current continental-scale models.
Steven J. Phipps, Jason L. Roberts, and Matt A. King
Geosci. Model Dev., 14, 5107–5124, https://doi.org/10.5194/gmd-14-5107-2021, https://doi.org/10.5194/gmd-14-5107-2021, 2021
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Simplified schemes, known as parameterisations, are sometimes used to describe physical processes within numerical models. However, the values of the parameters are uncertain. This introduces uncertainty into the model outputs. We develop a simple approach to identify plausible ranges for model parameters. Using a model of the Antarctic Ice Sheet, we find that the value of one parameter can depend on the values of others. We conclude that a single optimal set of parameter values does not exist.
Loïc Schmidely, Christoph Nehrbass-Ahles, Jochen Schmitt, Juhyeong Han, Lucas Silva, Jinwha Shin, Fortunat Joos, Jérôme Chappellaz, Hubertus Fischer, and Thomas F. Stocker
Clim. Past, 17, 1627–1643, https://doi.org/10.5194/cp-17-1627-2021, https://doi.org/10.5194/cp-17-1627-2021, 2021
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Using ancient gas trapped in polar glaciers, we reconstructed the atmospheric concentrations of methane and nitrous oxide over the penultimate deglaciation to study their response to major climate changes. We show this deglaciation to be characterized by modes of methane and nitrous oxide variability that are also found during the last deglaciation and glacial cycle.
Lisa Craw, Adam Treverrow, Sheng Fan, Mark Peternell, Sue Cook, Felicity McCormack, and Jason Roberts
The Cryosphere, 15, 2235–2250, https://doi.org/10.5194/tc-15-2235-2021, https://doi.org/10.5194/tc-15-2235-2021, 2021
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Ice sheet and ice shelf models rely on data from experiments to accurately represent the way ice moves. Performing experiments at the temperatures and stresses that are generally present in nature takes a long time, and so there are few of these datasets. Here, we test the method of speeding up an experiment by running it initially at a higher temperature, before dropping to a lower target temperature to generate the relevant data. We show that this method can reduce experiment time by 55 %.
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.
Marcel Haeberli, Daniel Baggenstos, Jochen Schmitt, Markus Grimmer, Adrien Michel, Thomas Kellerhals, and Hubertus Fischer
Clim. Past, 17, 843–867, https://doi.org/10.5194/cp-17-843-2021, https://doi.org/10.5194/cp-17-843-2021, 2021
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Using the temperature-dependent solubility of noble gases in ocean water, we reconstruct global mean ocean temperature (MOT) over the last 700 kyr using noble gas ratios in air enclosed in polar ice cores. Our record shows that glacial MOT was about 3 °C cooler compared to the Holocene. Interglacials before 450 kyr ago were characterized by about 1.5 °C lower MOT than the Holocene. In addition, some interglacials show transient maxima in ocean temperature related to changes in ocean circulation.
Lucas H. Beem, Duncan A. Young, Jamin S. Greenbaum, Donald D. Blankenship, Marie G. P. Cavitte, Jingxue Guo, and Sun Bo
The Cryosphere, 15, 1719–1730, https://doi.org/10.5194/tc-15-1719-2021, https://doi.org/10.5194/tc-15-1719-2021, 2021
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Radar observation collected above Titan Dome of the East Antarctic Ice Sheet is used to describe ice geometry and test a hypothesis that ice beneath the dome is older than 1 million years. An important climate transition occurred between 1.25 million and 700 thousand years ago, and if ice old enough to study this period can be removed as an ice core, new insights into climate dynamics are expected. The new observations suggest the ice is too young – more likely 300 to 800 thousand years old.
Christian Vincent, Diego Cusicanqui, Bruno Jourdain, Olivier Laarman, Delphine Six, Adrien Gilbert, Andrea Walpersdorf, Antoine Rabatel, Luc Piard, Florent Gimbert, Olivier Gagliardini, Vincent Peyaud, Laurent Arnaud, Emmanuel Thibert, Fanny Brun, and Ugo Nanni
The Cryosphere, 15, 1259–1276, https://doi.org/10.5194/tc-15-1259-2021, https://doi.org/10.5194/tc-15-1259-2021, 2021
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In situ glacier point mass balance data are crucial to assess climate change in different regions of the world. Unfortunately, these data are rare because huge efforts are required to conduct in situ measurements on glaciers. Here, we propose a new approach from remote sensing observations. The method has been tested on the Argentière and Mer de Glace glaciers (France). It should be possible to apply this method to high-spatial-resolution satellite images and on numerous glaciers in the world.
Hugues Goosse, Quentin Dalaiden, Marie G. P. Cavitte, and Liping Zhang
Clim. Past, 17, 111–131, https://doi.org/10.5194/cp-17-111-2021, https://doi.org/10.5194/cp-17-111-2021, 2021
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Polynyas are ice-free oceanic areas within the sea ice pack. Small polynyas are regularly observed in the Southern Ocean, but large open-ocean polynyas have been rare over the past decades. Using records from available ice cores in Antarctica, we reconstruct past polynya activity and confirm that those events have also been rare over the past centuries, but the information provided by existing data is not sufficient to precisely characterize the timing of past polynya opening.
Felipe Napoleoni, Stewart S. R. Jamieson, Neil Ross, Michael J. Bentley, Andrés Rivera, Andrew M. Smith, Martin J. Siegert, Guy J. G. Paxman, Guisella Gacitúa, José A. Uribe, Rodrigo Zamora, Alex M. Brisbourne, and David G. Vaughan
The Cryosphere, 14, 4507–4524, https://doi.org/10.5194/tc-14-4507-2020, https://doi.org/10.5194/tc-14-4507-2020, 2020
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Subglacial water is important for ice sheet dynamics and stability. Despite this, there is a lack of detailed subglacial-water characterisation in West Antarctica (WA). We report 33 new subglacial lakes. Additionally, a new digital elevation model of basal topography was built and used to simulate the subglacial hydrological network in WA. The simulated subglacial hydrological catchments of Pine Island and Thwaites glaciers do not match precisely with their ice surface catchments.
Anna L. Flack, Anthony S. Kiem, Tessa R. Vance, Carly R. Tozer, and Jason L. Roberts
Hydrol. Earth Syst. Sci., 24, 5699–5712, https://doi.org/10.5194/hess-24-5699-2020, https://doi.org/10.5194/hess-24-5699-2020, 2020
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Palaeoclimate information was analysed for eastern Australia to determine when (and where) there was agreement about the timing of wet and dry epochs in the pre-instrumental period (1000–1899). The results show that instrumental records (~1900–present) underestimate the full range of rainfall variability that has occurred. When coupled with projected impacts of climate change and growing demands, these results highlight major challenges for water resource management and infrastructure.
Bernhard Bereiter, Béla Tuzson, Philipp Scheidegger, André Kupferschmid, Herbert Looser, Lars Mächler, Daniel Baggenstos, Jochen Schmitt, Hubertus Fischer, and Lukas Emmenegger
Atmos. Meas. Tech., 13, 6391–6406, https://doi.org/10.5194/amt-13-6391-2020, https://doi.org/10.5194/amt-13-6391-2020, 2020
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The record of past greenhouse gas composition from ice cores is crucial for our understanding of global climate change. Deciphering this archive requires highly accurate and spatially resolved analysis of the very small amount of gas that is trapped in the ice. This is achieved with a mid-IR laser absorption spectrometer that provides simultaneous, high-precision measurements of CH4, N2O, CO2, and δ13C(CO2) and which will be coupled to a quantitative sublimation extraction method.
Marie G. P. Cavitte, Quentin Dalaiden, Hugues Goosse, Jan T. M. Lenaerts, and Elizabeth R. Thomas
The Cryosphere, 14, 4083–4102, https://doi.org/10.5194/tc-14-4083-2020, https://doi.org/10.5194/tc-14-4083-2020, 2020
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Surface mass balance (SMB) and surface air temperature (SAT) are correlated at the regional scale for most of Antarctica, SMB and δ18O. Areas with low/no correlation are where wind processes (foehn, katabatic wind warming, and erosion) are sufficiently active to overwhelm the synoptic-scale snow accumulation. Measured in ice cores, the link between SMB, SAT, and δ18O is much weaker. Random noise can be removed by core record averaging but local processes perturb the correlation systematically.
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.
Xiangbin Cui, Hafeez Jeofry, Jamin S. Greenbaum, Jingxue Guo, Lin Li, Laura E. Lindzey, Feras A. Habbal, Wei Wei, Duncan A. Young, Neil Ross, Mathieu Morlighem, Lenneke M. Jong, Jason L. Roberts, Donald D. Blankenship, Sun Bo, and Martin J. Siegert
Earth Syst. Sci. Data, 12, 2765–2774, https://doi.org/10.5194/essd-12-2765-2020, https://doi.org/10.5194/essd-12-2765-2020, 2020
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We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica. The DEM covers an area of approximately 900 000 km2 and was built from radio-echo sounding data collected in four campaigns since 2015. Previously, to generate the Bedmap2 topographic product, PEL’s bed was characterised from low-resolution satellite gravity data across an otherwise large (>200 km wide) data-free zone.
Vincent Peyaud, Coline Bouchayer, Olivier Gagliardini, Christian Vincent, Fabien Gillet-Chaulet, Delphine Six, and Olivier Laarman
The Cryosphere, 14, 3979–3994, https://doi.org/10.5194/tc-14-3979-2020, https://doi.org/10.5194/tc-14-3979-2020, 2020
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Alpine glaciers are retreating at an accelerating rate in a warming climate. Numerical models allow us to study and anticipate these changes, but the performance of a model is difficult to evaluate. So we compared an ice flow model with the long dataset of observations obtained between 1979 and 2015 on Mer de Glace (Mont Blanc area). The model accurately reconstructs the past evolution of the glacier. We simulate the future evolution of Mer de Glace; it could retreat by 2 to 6 km by 2050.
Jann Schrod, Dominik Kleinhenz, Maria Hörhold, Tobias Erhardt, Sarah Richter, Frank Wilhelms, Hubertus Fischer, Martin Ebert, Birthe Twarloh, Damiano Della Lunga, Camilla M. Jensen, Joachim Curtius, and Heinz G. Bingemer
Atmos. Chem. Phys., 20, 12459–12482, https://doi.org/10.5194/acp-20-12459-2020, https://doi.org/10.5194/acp-20-12459-2020, 2020
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Ice-nucleating particle (INP) concentrations of the last 6 centuries are presented from an ice core in Greenland. The data are accompanied by physical and chemical aerosol data. INPs are correlated to the dust signal from the ice core and seem to follow the annual input of mineral dust. We find no clear trend in the INP concentration. However, modern-day concentrations are higher and more variable than the concentrations of the past. This might have significant atmospheric implications.
Syed Abdul Salam, Jason L. Roberts, Felicity S. McCormack, Richard Coleman, and Jacqueline A. Halpin
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2020-146, https://doi.org/10.5194/essd-2020-146, 2020
Publication in ESSD not foreseen
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Accurate estimates of englacial temperature and geothermal heat flux are incredibly important
for constraining model simulations of ice dynamics (e.g. viscosity is temperature-dependent) and sliding. However, we currently have few direct measurements of vertical temperature (i.e. only at boreholes/ice domes) and geothermal heat flux in Antarctica. This method derives attenuation rates, that can then be mapped directly to englacial temperatures and geothermal heat flux.
Anders Svensson, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Thomas Blunier, Sune O. Rasmussen, Bo M. Vinther, Paul Vallelonga, Emilie Capron, Vasileios Gkinis, Eliza Cook, Helle Astrid Kjær, Raimund Muscheler, Sepp Kipfstuhl, Frank Wilhelms, Thomas F. Stocker, Hubertus Fischer, Florian Adolphi, Tobias Erhardt, Michael Sigl, Amaelle Landais, Frédéric Parrenin, Christo Buizert, Joseph R. McConnell, Mirko Severi, Robert Mulvaney, and Matthias Bigler
Clim. Past, 16, 1565–1580, https://doi.org/10.5194/cp-16-1565-2020, https://doi.org/10.5194/cp-16-1565-2020, 2020
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We identify signatures of large bipolar volcanic eruptions in Greenland and Antarctic ice cores during the last glacial period, which allows for a precise temporal alignment of the ice cores. Thereby the exact timing of unexplained, abrupt climatic changes occurring during the last glacial period can be determined in a global context. The study thus provides a step towards a full understanding of elements of the climate system that may also play an important role in the future.
Fortunat Joos, Renato Spahni, Benjamin D. Stocker, Sebastian Lienert, Jurek Müller, Hubertus Fischer, Jochen Schmitt, I. Colin Prentice, Bette Otto-Bliesner, and Zhengyu Liu
Biogeosciences, 17, 3511–3543, https://doi.org/10.5194/bg-17-3511-2020, https://doi.org/10.5194/bg-17-3511-2020, 2020
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Results of the first globally resolved simulations of terrestrial carbon and nitrogen (N) cycling and N2O emissions over the past 21 000 years are compared with reconstructed N2O emissions. Modelled and reconstructed emissions increased strongly during past abrupt warming events. This evidence appears consistent with a dynamic response of biological N fixation to increasing N demand by ecosystems, thereby reducing N limitation of plant productivity and supporting a land sink for atmospheric CO2.
Neil Ross, Hugh Corr, and Martin Siegert
The Cryosphere, 14, 2103–2114, https://doi.org/10.5194/tc-14-2103-2020, https://doi.org/10.5194/tc-14-2103-2020, 2020
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Using airborne ice-penetrating radar we investigated the physical properties and structure of the West Antarctic Ice Sheet. Ice deep beneath the Institute Ice Stream has prominent layers with physical properties distinct from those around them and which are heavily folded like geological layers. In turn, these folds influence the present-day flow of the ice sheet, with implications for how computer models are used to simulate ice sheet flow and behaviour in a warming world.
Alexander Robinson, Jorge Alvarez-Solas, Marisa Montoya, Heiko Goelzer, Ralf Greve, and Catherine Ritz
Geosci. Model Dev., 13, 2805–2823, https://doi.org/10.5194/gmd-13-2805-2020, https://doi.org/10.5194/gmd-13-2805-2020, 2020
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Here we describe Yelmo v1.0, an intuitive and state-of-the-art hybrid ice sheet model. The model design and physics are described, and benchmark simulations are provided to validate its performance. Yelmo is a versatile ice sheet model that can be applied to a wide variety of problems.
Roberto Grilli, François Darchambeau, Jérôme Chappellaz, Ange Mugisha, Jack Triest, and Augusta Umutoni
Geosci. Instrum. Method. Data Syst., 9, 141–151, https://doi.org/10.5194/gi-9-141-2020, https://doi.org/10.5194/gi-9-141-2020, 2020
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We report the results from the deployment of a newly developed in situ sensor for dissolved gas measurements. Its adaptation to high gas concentrations and dissolved gas pressures was proven. The campaign leads to a first continuous profile of methane on the first 150 m and allowed us to compare the data with previous measurements. The fast response of the instrument makes this technique a good candidate for regular monitoring of those type of lakes, for anticipating disastrous gas eruptions.
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Alexey A. Ekaykin, Jérôme Chappellaz, and Vladimir Lipenkov
Clim. Past, 16, 503–522, https://doi.org/10.5194/cp-16-503-2020, https://doi.org/10.5194/cp-16-503-2020, 2020
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We quantify how the greenhouse gas records of East Antarctic ice cores (which are the oldest ice cores) might differ from the actual atmosphere history. It is required to properly interpret ice core data. For this, we measured the methane of five new East Antarctic ice core sections using a high-resolution technique. We found that in these very old ice cores, one can retrieve concentration variations occurring in only a few centuries, allowing climatologists to study climate's fast dynamics.
Hubertus Fischer, Jochen Schmitt, Michael Bock, Barbara Seth, Fortunat Joos, Renato Spahni, Sebastian Lienert, Gianna Battaglia, Benjamin D. Stocker, Adrian Schilt, and Edward J. Brook
Biogeosciences, 16, 3997–4021, https://doi.org/10.5194/bg-16-3997-2019, https://doi.org/10.5194/bg-16-3997-2019, 2019
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N2O concentrations were subject to strong variations accompanying glacial–interglacial but also rapid climate changes over the last 21 kyr. The sources of these N2O changes can be identified by measuring the isotopic composition of N2O in ice cores and using the distinct isotopic composition of terrestrial and marine N2O. We show that both marine and terrestrial sources increased from the last glacial to the Holocene but that only terrestrial emissions responded quickly to rapid climate changes.
Pär Jansson, Jack Triest, Roberto Grilli, Bénédicte Ferré, Anna Silyakova, Jürgen Mienert, and Jérôme Chappellaz
Ocean Sci., 15, 1055–1069, https://doi.org/10.5194/os-15-1055-2019, https://doi.org/10.5194/os-15-1055-2019, 2019
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Methane seepage from the seafloor west of Svalbard was investigated with a fast-response membrane inlet laser spectrometer. The acquired data were in good agreement with traditional sparse discrete water sampling, subsequent gas chromatography, and with a new 2-D model based on echo-sounder data. However, the acquired high-resolution data revealed unprecedented details of the methane distribution, which highlights the need for high-resolution measurements for future climate studies.
Johannes Sutter, Hubertus Fischer, Klaus Grosfeld, Nanna B. Karlsson, Thomas Kleiner, Brice Van Liefferinge, and Olaf Eisen
The Cryosphere, 13, 2023–2041, https://doi.org/10.5194/tc-13-2023-2019, https://doi.org/10.5194/tc-13-2023-2019, 2019
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The Antarctic Ice Sheet may have played an important role in moderating the transition between warm and cold climate epochs over the last million years. We find that the Antarctic Ice Sheet grew considerably about 0.9 Myr ago, a time when ice-age–warm-age cycles changed from a
40 000 to a 100 000 year periodicity. Our findings also suggest that ice as old as 1.5 Myr still exists at the bottom of the East Antarctic Ice Sheet despite the major climate reorganisations in the past.
Sébastien Le clec'h, Aurélien Quiquet, Sylvie Charbit, Christophe Dumas, Masa Kageyama, and Catherine Ritz
Geosci. Model Dev., 12, 2481–2499, https://doi.org/10.5194/gmd-12-2481-2019, https://doi.org/10.5194/gmd-12-2481-2019, 2019
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To provide reliable projections of the ice-sheet contribution to future sea-level rise, ice sheet models must be able to simulate the observed ice sheet present-day state. Using a low computational iterative minimisation procedure, based on the adjustment of the basal drag coefficient, we rapidly minimise the errors between the simulated and the observed Greenland ice thickness and ice velocity, and we succeed in stabilising the simulated Greenland ice sheet state under present-day conditions.
Loic Lechevallier, Roberto Grilli, Erik Kerstel, Daniele Romanini, and Jérôme Chappellaz
Atmos. Meas. Tech., 12, 3101–3109, https://doi.org/10.5194/amt-12-3101-2019, https://doi.org/10.5194/amt-12-3101-2019, 2019
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In this work we describe a highly sensitive optical spectrometer for simultaneous measurement of methane, ethane, and the isotopic composition of methane. The coupling of the spectrometer with a dissolved gas extraction system will provide a suitable tool for understanding the origins of the dissolved hydrocarbons and discriminate between the different sources (e.g., biogenic vs. thermogenic).
Lionel Favier, Nicolas C. Jourdain, Adrian Jenkins, Nacho Merino, Gaël Durand, Olivier Gagliardini, Fabien Gillet-Chaulet, and Pierre Mathiot
Geosci. Model Dev., 12, 2255–2283, https://doi.org/10.5194/gmd-12-2255-2019, https://doi.org/10.5194/gmd-12-2255-2019, 2019
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The melting at the base of floating ice shelves is the main driver of the Antarctic ice sheet current retreat. Here, we use an ideal set-up to assess a wide range of melting parameterisations depending on oceanic properties with regard to a new ocean–ice-sheet coupled model, published here for the first time. A parameterisation that depends quadratically on thermal forcing in both a local and a non-local way yields the best results and needs to be further assessed with more realistic set-ups.
Jai Chowdhry Beeman, Léa Gest, Frédéric Parrenin, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past, 15, 913–926, https://doi.org/10.5194/cp-15-913-2019, https://doi.org/10.5194/cp-15-913-2019, 2019
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Atmospheric CO2 was likely an important amplifier of global-scale orbitally-driven warming during the last deglaciation. However, the mechanisms responsible for the rise in CO2, and the coherent rise in Antarctic isotopic temperature records, are under debate. Using a stochastic method, we detect variable lags between coherent changes in Antarctic temperature and CO2. This implies that the climate mechanisms linking the two records changed or experienced modulations during the deglaciation.
Tobias Erhardt, Emilie Capron, Sune Olander Rasmussen, Simon Schüpbach, Matthias Bigler, Florian Adolphi, and Hubertus Fischer
Clim. Past, 15, 811–825, https://doi.org/10.5194/cp-15-811-2019, https://doi.org/10.5194/cp-15-811-2019, 2019
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The cause of the rapid warming events documented in proxy records across the Northern Hemisphere during the last glacial has been a long-standing puzzle in paleo-climate research. Here, we use high-resolution ice-core data from to cores in Greenland to investigate the progression during the onset of these events on multi-annual timescales to test their plausible triggers. We show that atmospheric circulation changes preceded the warming in Greenland and the collapse of the sea ice by a decade.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Suzanne Preunkert, Michel Legrand, Bénédicte Minster, and Martin Werner
The Cryosphere, 13, 1297–1324, https://doi.org/10.5194/tc-13-1297-2019, https://doi.org/10.5194/tc-13-1297-2019, 2019
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We report new water stable isotope records from the first highly resolved firn core drilled in Adélie Land and covering 1998–2014. Using an updated database, we show that mean values are in line with the range of coastal values. Statistical analyses show no relationship between our record and local surface air temperature. Atmospheric back trajectories and isotopic simulations suggest that water stable isotopes in Adélie provide a fingerprint of the variability of atmospheric dynamics.
François Klein, Nerilie J. Abram, Mark A. J. Curran, Hugues Goosse, Sentia Goursaud, Valérie Masson-Delmotte, Andrew Moy, Raphael Neukom, Anaïs Orsi, Jesper Sjolte, Nathan Steiger, Barbara Stenni, and Martin Werner
Clim. Past, 15, 661–684, https://doi.org/10.5194/cp-15-661-2019, https://doi.org/10.5194/cp-15-661-2019, 2019
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Antarctic temperature changes over the past millennia have been reconstructed from isotope records in ice cores in several studies. However, the link between both variables is complex. Here, we investigate the extent to which this affects the robustness of temperature reconstructions using pseudoproxy and data assimilation experiments. We show that the reconstruction skill is limited, especially at the regional scale, due to a weak and nonstationary covariance between δ18O and temperature.
Sébastien Le clec'h, Sylvie Charbit, Aurélien Quiquet, Xavier Fettweis, Christophe Dumas, Masa Kageyama, Coraline Wyard, and Catherine Ritz
The Cryosphere, 13, 373–395, https://doi.org/10.5194/tc-13-373-2019, https://doi.org/10.5194/tc-13-373-2019, 2019
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Quantifying the future contribution of the Greenland ice sheet (GrIS) to sea-level rise in response to atmospheric changes is important but remains challenging. For the first time a full representation of the feedbacks between a GrIS model and a regional atmospheric model was implemented. The authors highlight the fundamental need for representing the GrIS topography change feedbacks with respect to the atmospheric component face to the strong impact on the projected sea-level rise.
Julien Brondex, Fabien Gillet-Chaulet, and Olivier Gagliardini
The Cryosphere, 13, 177–195, https://doi.org/10.5194/tc-13-177-2019, https://doi.org/10.5194/tc-13-177-2019, 2019
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Here, we apply a synthetic perturbation to the most active drainage basin of Antarctica and show that centennial mass loss projections obtained through ice flow models depend strongly on the implemented friction law, i.e. the mathematical relationship between basal drag and sliding velocities. In particular, the commonly used Weertman law considerably underestimates the sea-level contribution of this basin in comparison to two water pressure-dependent laws which rely on stronger physical bases.
Aurélien Quiquet, Christophe Dumas, Catherine Ritz, Vincent Peyaud, and Didier M. Roche
Geosci. Model Dev., 11, 5003–5025, https://doi.org/10.5194/gmd-11-5003-2018, https://doi.org/10.5194/gmd-11-5003-2018, 2018
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This paper presents the GRISLI (Grenoble ice sheet and land ice) model in its newest revision. We present the recent model improvements from its original version (Ritz et al., 2001), together with a discussion of the model performance in reproducing the present-day Antarctic ice sheet geometry and the grounding line advances and retreats during the last 400 000 years. We show that GRISLI is a computationally cheap model, able to reproduce the large-scale behaviour of ice sheets.
Jonas Beck, Michael Bock, Jochen Schmitt, Barbara Seth, Thomas Blunier, and Hubertus Fischer
Biogeosciences, 15, 7155–7175, https://doi.org/10.5194/bg-15-7155-2018, https://doi.org/10.5194/bg-15-7155-2018, 2018
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Ice core concentration and stable isotope measurements of atmospheric CH4 give valuable insights into the CH4 cycle of the past. New carbon and hydrogen stable isotope CH4 data measured on ice from both Greenland and Antarctica over the Holocene allow us to draw conclusions on the methane emission processes. In particular, our results cast doubt on a hypothesis proposing early human land use to be responsible for the atmospheric methane concentration increase in the second half of the Holocene.
Florian Adolphi, Christopher Bronk Ramsey, Tobias Erhardt, R. Lawrence Edwards, Hai Cheng, Chris S. M. Turney, Alan Cooper, Anders Svensson, Sune O. Rasmussen, Hubertus Fischer, and Raimund Muscheler
Clim. Past, 14, 1755–1781, https://doi.org/10.5194/cp-14-1755-2018, https://doi.org/10.5194/cp-14-1755-2018, 2018
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The last glacial period was characterized by a number of rapid climate changes seen, for example, as abrupt warmings in Greenland and changes in monsoon rainfall intensity. However, due to chronological uncertainties it is challenging to know how tightly coupled these changes were. Here we exploit cosmogenic signals caused by changes in the Sun and Earth magnetic fields to link different climate archives and improve our understanding of the dynamics of abrupt climate change.
Amaëlle Landais, Emilie Capron, Valérie Masson-Delmotte, Samuel Toucanne, Rachael Rhodes, Trevor Popp, Bo Vinther, Bénédicte Minster, and Frédéric Prié
Clim. Past, 14, 1405–1415, https://doi.org/10.5194/cp-14-1405-2018, https://doi.org/10.5194/cp-14-1405-2018, 2018
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During the last glacial–interglacial climate transition (120 000 to 10 000 years before present), Greenland climate and midlatitude North Atlantic climate and water cycle vary in phase over the succession of millennial events. We identify here one notable exception to this behavior with a decoupling unambiguously identified through a combination of water isotopic tracers measured in a Greenland ice core. The midlatitude moisture source becomes warmer and wetter at 16 200 years before present.
Thomas M. Jordan, Christopher N. Williams, Dustin M. Schroeder, Yasmina M. Martos, Michael A. Cooper, Martin J. Siegert, John D. Paden, Philippe Huybrechts, and Jonathan L. Bamber
The Cryosphere, 12, 2831–2854, https://doi.org/10.5194/tc-12-2831-2018, https://doi.org/10.5194/tc-12-2831-2018, 2018
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Here, via analysis of radio-echo sounding data, we place a new observational constraint upon the basal water distribution beneath the Greenland Ice Sheet. In addition to the outlet glaciers, we demonstrate widespread water storage in the northern and eastern ice-sheet interior, a notable feature being a "corridor" of basal water extending from NorthGRIP to Petermann Glacier. The basal water distribution and its relationship with basal temperature provides a new constraint for numerical models.
Brice Van Liefferinge, Frank Pattyn, Marie G. P. Cavitte, Nanna B. Karlsson, Duncan A. Young, Johannes Sutter, and Olaf Eisen
The Cryosphere, 12, 2773–2787, https://doi.org/10.5194/tc-12-2773-2018, https://doi.org/10.5194/tc-12-2773-2018, 2018
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Our paper provides an important review of the state of knowledge for oldest-ice prospection, but also adds new basal geothermal heat flux constraints from recently acquired high-definition radar data sets. This is the first paper to contrast the two primary target regions for oldest ice: Dome C and Dome Fuji. Moreover, we provide statistical comparisons of all available data sets and a summary of the community's criteria for the retrieval of interpretable oldest ice since the 2013 effort.
Marianne Haseloff, Christian Schoof, and Olivier Gagliardini
The Cryosphere, 12, 2545–2568, https://doi.org/10.5194/tc-12-2545-2018, https://doi.org/10.5194/tc-12-2545-2018, 2018
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The widths of the Siple Coast ice streams evolve on decadal to centennial timescales. We investigate how the rate of thermally driven ice stream widening depends on heat dissipation in the ice stream margin and at the bed, and on the inflow of cold ice from the ice ridge. As determining the migration rate requires resolving heat transfer processes on very small scales, we derive a parametrization of the migration rate in terms of parameters that are available from large-scale model outputs.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Anaïs Orsi, and Martin Werner
Clim. Past, 14, 923–946, https://doi.org/10.5194/cp-14-923-2018, https://doi.org/10.5194/cp-14-923-2018, 2018
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Atmospheric general circulation models equipped with water stable isotopes are key tools to explore the links between climate variables and precipitation isotopic composition and thus to quantify past temperature changes using ice core records. Here, we evaluate the skills of ECHAM5-wiso to simulate the spatio-temporal characteristics of Antarctic climate and precipitation isotopic composition at the regional scale, thanks to a database of precipitation and ice core records.
Olivier Passalacqua, Marie Cavitte, Olivier Gagliardini, Fabien Gillet-Chaulet, Frédéric Parrenin, Catherine Ritz, and Duncan Young
The Cryosphere, 12, 2167–2174, https://doi.org/10.5194/tc-12-2167-2018, https://doi.org/10.5194/tc-12-2167-2018, 2018
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Locating a suitable drill site is a key step in the Antarctic oldest-ice challenge. Here we have conducted a 3-D ice flow simulation in the region of Dome C using a refined bedrock description. Five selection criteria are computed that together provide an objective overview on the local ice flow conditions. We delineate kilometer-scale favorable areas that overlap with the ones recently proposed by another group. We propose a few drill sites that should be surveyed during the next field seasons.
Emmanuel Le Meur, Olivier Magand, Laurent Arnaud, Michel Fily, Massimo Frezzotti, Marie Cavitte, Robert Mulvaney, and Stefano Urbini
The Cryosphere, 12, 1831–1850, https://doi.org/10.5194/tc-12-1831-2018, https://doi.org/10.5194/tc-12-1831-2018, 2018
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This paper presents surface mass balance measurements from both GPR and ice core data collected during a traverse in a so-far-unexplored area between the DC and Vostok stations. Results presented here will contribute to a better knowledge of the global mass balance of the Antarctic ice sheet and thus help in constraining its contribution to sea level rise. Another novelty of the paper resides in the comprehensive error budget proposed for the method used for inferring accumulation rates.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valerie Masson-Delmotte, and Jean Jouzel
The Cryosphere, 12, 1745–1766, https://doi.org/10.5194/tc-12-1745-2018, https://doi.org/10.5194/tc-12-1745-2018, 2018
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Ice core isotopic records rely on the knowledge of the processes involved in the archival processes of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Heiko Goelzer, Sophie Nowicki, Tamsin Edwards, Matthew Beckley, Ayako Abe-Ouchi, Andy Aschwanden, Reinhard Calov, Olivier Gagliardini, Fabien Gillet-Chaulet, Nicholas R. Golledge, Jonathan Gregory, Ralf Greve, Angelika Humbert, Philippe Huybrechts, Joseph H. Kennedy, Eric Larour, William H. Lipscomb, Sébastien Le clec'h, Victoria Lee, Mathieu Morlighem, Frank Pattyn, Antony J. Payne, Christian Rodehacke, Martin Rückamp, Fuyuki Saito, Nicole Schlegel, Helene Seroussi, Andrew Shepherd, Sainan Sun, Roderik van de Wal, and Florian A. Ziemen
The Cryosphere, 12, 1433–1460, https://doi.org/10.5194/tc-12-1433-2018, https://doi.org/10.5194/tc-12-1433-2018, 2018
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We have compared a wide spectrum of different initialisation techniques used in the ice sheet modelling community to define the modelled present-day Greenland ice sheet state as a starting point for physically based future-sea-level-change projections. Compared to earlier community-wide comparisons, we find better agreement across different models, which implies overall improvement of our understanding of what is needed to produce such initial states.
Marie G. P. Cavitte, Frédéric Parrenin, Catherine Ritz, Duncan A. Young, Brice Van Liefferinge, Donald D. Blankenship, Massimo Frezzotti, and Jason L. Roberts
The Cryosphere, 12, 1401–1414, https://doi.org/10.5194/tc-12-1401-2018, https://doi.org/10.5194/tc-12-1401-2018, 2018
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We reconstruct the pattern of surface accumulation in the region around Dome C, East Antarctica, over the last 73 kyr. We use internal isochrones interpreted from ice-penetrating radar surveys and a 1-D ice flow model to invert for time-averaged and paleo-accumulation rates. We observe that surface accumulation patterns are stable through the last 73 kyr, consistent with current observed regional precipitation gradients and consistent interactions between prevailing winds and surface slope.
Hafeez Jeofry, Neil Ross, Hugh F. J. Corr, Jilu Li, Mathieu Morlighem, Prasad Gogineni, and Martin J. Siegert
Earth Syst. Sci. Data, 10, 711–725, https://doi.org/10.5194/essd-10-711-2018, https://doi.org/10.5194/essd-10-711-2018, 2018
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Accurately characterizing the complexities of the ice-sheet dynamic specifically close to the grounding line across the Weddell Sea (WS) sector in the ice-sheet models provides challenges to the scientific community. Our main objective is to comprehend these complexities, adding accuracy to the projection of future ice-sheet dynamics. Therefore, we have developed a new bed elevation digital elevation model across the WS sector, which will be of value to ice-sheet modelling experiments.
Masa Kageyama, Pascale Braconnot, Sandy P. Harrison, Alan M. Haywood, Johann H. Jungclaus, Bette L. Otto-Bliesner, Jean-Yves Peterschmitt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Chris Brierley, Michel Crucifix, Aisling Dolan, Laura Fernandez-Donado, Hubertus Fischer, Peter O. Hopcroft, Ruza F. Ivanovic, Fabrice Lambert, Daniel J. Lunt, Natalie M. Mahowald, W. Richard Peltier, Steven J. Phipps, Didier M. Roche, Gavin A. Schmidt, Lev Tarasov, Paul J. Valdes, Qiong Zhang, and Tianjun Zhou
Geosci. Model Dev., 11, 1033–1057, https://doi.org/10.5194/gmd-11-1033-2018, https://doi.org/10.5194/gmd-11-1033-2018, 2018
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The Paleoclimate Modelling Intercomparison Project (PMIP) takes advantage of the existence of past climate states radically different from the recent past to test climate models used for climate projections and to better understand these climates. This paper describes the PMIP contribution to CMIP6 (Coupled Model Intercomparison Project, 6th phase) and possible analyses based on PMIP results, as well as on other CMIP6 projects.
Taku Umezawa, Carl A. M. Brenninkmeijer, Thomas Röckmann, Carina van der Veen, Stanley C. Tyler, Ryo Fujita, Shinji Morimoto, Shuji Aoki, Todd Sowers, Jochen Schmitt, Michael Bock, Jonas Beck, Hubertus Fischer, Sylvia E. Michel, Bruce H. Vaughn, John B. Miller, James W. C. White, Gordon Brailsford, Hinrich Schaefer, Peter Sperlich, Willi A. Brand, Michael Rothe, Thomas Blunier, David Lowry, Rebecca E. Fisher, Euan G. Nisbet, Andrew L. Rice, Peter Bergamaschi, Cordelia Veidt, and Ingeborg Levin
Atmos. Meas. Tech., 11, 1207–1231, https://doi.org/10.5194/amt-11-1207-2018, https://doi.org/10.5194/amt-11-1207-2018, 2018
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Isotope measurements are useful for separating different methane sources. However, the lack of widely accepted standards and calibration methods for stable carbon and hydrogen isotopic ratios of methane in air has caused significant measurement offsets among laboratories. We conducted worldwide interlaboratory comparisons, surveyed the literature and assessed them systematically. This study may be of help in future attempts to harmonize data sets of isotopic composition of atmospheric methane.
Pascal Bohleber, Tobias Erhardt, Nicole Spaulding, Helene Hoffmann, Hubertus Fischer, and Paul Mayewski
Clim. Past, 14, 21–37, https://doi.org/10.5194/cp-14-21-2018, https://doi.org/10.5194/cp-14-21-2018, 2018
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The Colle Gnifetti (CG) glacier is the only drilling site in the European Alps offering ice core records back to some 1000 years. We aim to fully exploit these unique long-term records by establishing a reliable long-term age scale and an improved ice core proxy interpretation for reconstructing temperature. Our findings reveal a site-specific temperature-related signal in the trends of the mineral dust proxy Ca2+ that may supplement other proxy evidence over the last millennium.
Kévin Fourteau, Xavier Faïn, Patricia Martinerie, Amaëlle Landais, Alexey A. Ekaykin, Vladimir Ya. Lipenkov, and Jérôme Chappellaz
Clim. Past, 13, 1815–1830, https://doi.org/10.5194/cp-13-1815-2017, https://doi.org/10.5194/cp-13-1815-2017, 2017
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We measured methane concentrations from a polar ice core to quantify the differences between the ice record and the past true atmospheric conditions. Two effects were investigated by combining data analysis and modeling: the stratification of polar snow before gas enclosure driving chronological hiatuses in the record and the gradual formation of bubbles in the ice attenuating fast atmospheric variations. This study will contribute to improving future climatic interpretations from ice archives.
Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elizabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Martin Werner, and Massimo Frezzotti
Clim. Past, 13, 1609–1634, https://doi.org/10.5194/cp-13-1609-2017, https://doi.org/10.5194/cp-13-1609-2017, 2017
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Within PAGES Antarctica2k, we build an enlarged database of ice core water stable isotope records. We produce isotopic composites and temperature reconstructions since 0 CE for seven distinct Antarctic regions. We find a significant cooling trend from 0 to 1900 CE across all regions. Since 1900 CE, significant warming trends are identified for three regions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of last-2000-year natural variability.
Elizabeth R. Thomas, J. Melchior van Wessem, Jason Roberts, Elisabeth Isaksson, Elisabeth Schlosser, Tyler J. Fudge, Paul Vallelonga, Brooke Medley, Jan Lenaerts, Nancy Bertler, Michiel R. van den Broeke, Daniel A. Dixon, Massimo Frezzotti, Barbara Stenni, Mark Curran, and Alexey A. Ekaykin
Clim. Past, 13, 1491–1513, https://doi.org/10.5194/cp-13-1491-2017, https://doi.org/10.5194/cp-13-1491-2017, 2017
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Regional Antarctic snow accumulation derived from 79 ice core records is evaluated as part of the PAGES Antarctica 2k working group. Our results show that surface mass balance for the total Antarctic ice sheet has increased at a rate of 7 ± 0.13 Gt dec-1 since 1800 AD, representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~ 0.04 mm dec-1 since 1900 AD. The largest contribution is from the Antarctic Peninsula.
Bette L. Otto-Bliesner, Pascale Braconnot, Sandy P. Harrison, Daniel J. Lunt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Emilie Capron, Anders E. Carlson, Andrea Dutton, Hubertus Fischer, Heiko Goelzer, Aline Govin, Alan Haywood, Fortunat Joos, Allegra N. LeGrande, William H. Lipscomb, Gerrit Lohmann, Natalie Mahowald, Christoph Nehrbass-Ahles, Francesco S. R. Pausata, Jean-Yves Peterschmitt, Steven J. Phipps, Hans Renssen, and Qiong Zhang
Geosci. Model Dev., 10, 3979–4003, https://doi.org/10.5194/gmd-10-3979-2017, https://doi.org/10.5194/gmd-10-3979-2017, 2017
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The PMIP4 and CMIP6 mid-Holocene and Last Interglacial simulations provide an opportunity to examine the impact of two different changes in insolation forcing on climate at times when other forcings were relatively similar to present. This will allow exploration of the role of feedbacks relevant to future projections. Evaluating these simulations using paleoenvironmental data will provide direct out-of-sample tests of the reliability of state-of-the-art models to simulate climate changes.
Elisabeth Schlosser, Anna Dittmann, Barbara Stenni, Jordan G. Powers, Kevin W. Manning, Valérie Masson-Delmotte, Mauro Valt, Anselmo Cagnati, Paolo Grigioni, and Claudio Scarchilli
The Cryosphere, 11, 2345–2361, https://doi.org/10.5194/tc-11-2345-2017, https://doi.org/10.5194/tc-11-2345-2017, 2017
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To derive paleotemperatures from ice cores we must know all processes involved in ice formation. At the Antarctic base Dome C, a unique precipitation data set plus stable water isotope data enabled us to study atmospheric processes influencing isotope ratios of precipitation in detail. Meteorological data from both automatic weather station and an atmospheric model were used to investigate how different atmospheric flow patterns determine the precipitation parameters used in paleoclimatology.
Olivier Passalacqua, Catherine Ritz, Frédéric Parrenin, Stefano Urbini, and Massimo Frezzotti
The Cryosphere, 11, 2231–2246, https://doi.org/10.5194/tc-11-2231-2017, https://doi.org/10.5194/tc-11-2231-2017, 2017
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As the Dome C region is a key area for oldest-ice research, we need to better constrain the geothermal flux (GF) so that past basal melt rates are well constrained. Our inverse heat model significantly reduces the confidence intervals of the GF regional field around Dome C, which ranges from 48 to 60 mW m−2. Radar echoes need to be interpreted knowing the time lag of the climate signal to reach the bed. Several old-ice targets are confirmed and a new one is suggested, in which the GF is very low.
Jason Roberts, Andrew Moy, Christopher Plummer, Tas van Ommen, Mark Curran, Tessa Vance, Samuel Poynter, Yaping Liu, Joel Pedro, Adam Treverrow, Carly Tozer, Lenneke Jong, Pippa Whitehouse, Laetitia Loulergue, Jerome Chappellaz, Vin Morgan, Renato Spahni, Adrian Schilt, Cecilia MacFarling Meure, David Etheridge, and Thomas Stocker
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-96, https://doi.org/10.5194/cp-2017-96, 2017
Preprint withdrawn
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Here we present a revised Law Dome, Dome Summit South (DSS) ice core age model (denoted LD2017) that significantly improves the chronology over the last 88 thousand years. An ensemble approach was used, allowing for the computation of both a median age and associated uncertainty as a function of depth. We use a non-linear interpolation between age ties and unlike previous studies, we made an independent estimate of the snow accumulation rate, where required, for the use of gas based age ties.
Duncan A. Young, Jason L. Roberts, Catherine Ritz, Massimo Frezzotti, Enrica Quartini, Marie G. P. Cavitte, Carly R. Tozer, Daniel Steinhage, Stefano Urbini, Hugh F. J. Corr, Tas van Ommen, and Donald D. Blankenship
The Cryosphere, 11, 1897–1911, https://doi.org/10.5194/tc-11-1897-2017, https://doi.org/10.5194/tc-11-1897-2017, 2017
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To find records of the greenhouse gases found in key periods of climate transition, we need to find sites of unmelted old ice at the base of the Antarctic ice sheet for ice core retrieval. A joint US–Australian–EU team performed a high-resolution survey of such a site (1 km line spacing) near Concordia Station in East Antarctica, using airborne ice-penetrating radar. We found promising targets in rough subglacial terrain, surrounded by subglacial lakes restricted below a minimum hydraulic head.
James Hansen, Makiko Sato, Pushker Kharecha, Karina von Schuckmann, David J. Beerling, Junji Cao, Shaun Marcott, Valerie Masson-Delmotte, Michael J. Prather, Eelco J. Rohling, Jeremy Shakun, Pete Smith, Andrew Lacis, Gary Russell, and Reto Ruedy
Earth Syst. Dynam., 8, 577–616, https://doi.org/10.5194/esd-8-577-2017, https://doi.org/10.5194/esd-8-577-2017, 2017
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Global temperature now exceeds +1.25 °C relative to 1880–1920, similar to warmth of the Eemian period. Keeping warming less than 1.5 °C or CO2 below 350 ppm now requires extraction of CO2 from the air. If rapid phaseout of fossil fuel emissions begins soon, most extraction can be via improved agricultural and forestry practices. In contrast, continued high emissions places a burden on young people of massive technological CO2 extraction with large risks, high costs and uncertain feasibility.
Mélanie Wary, Frédérique Eynaud, Didier Swingedouw, Valérie Masson-Delmotte, Jens Matthiessen, Catherine Kissel, Jena Zumaque, Linda Rossignol, and Jean Jouzel
Clim. Past, 13, 729–739, https://doi.org/10.5194/cp-13-729-2017, https://doi.org/10.5194/cp-13-729-2017, 2017
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The last glacial period was punctuated by abrupt climatic variations, whose cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here we provide direct evidence of a regional paradoxical see-saw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases.
Peter Köhler, Christoph Nehrbass-Ahles, Jochen Schmitt, Thomas F. Stocker, and Hubertus Fischer
Earth Syst. Sci. Data, 9, 363–387, https://doi.org/10.5194/essd-9-363-2017, https://doi.org/10.5194/essd-9-363-2017, 2017
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We document our best available data compilation of published ice core records of the greenhouse gases CO2, CH4, and N2O and recent measurements on firn air and atmospheric samples covering the time window from 156 000 years BP to the beginning of the year 2016 CE. A smoothing spline method is applied to translate the discrete and irregularly spaced data points into continuous time series. The radiative forcing for each greenhouse gas is computed using well-established, simple formulations.
Léa Gest, Frédéric Parrenin, Jai Chowdhry Beeman, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-71, https://doi.org/10.5194/cp-2017-71, 2017
Revised manuscript has not been submitted
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In this manuscript, we place the atmospheric CO2 and Antarctic temperature records onto a common age scale during the last deglaciation. Moreover, we evaluate the phase relationship between those two records in order to discuss possible climatic and carbon cycle scenarios. Indeed, this phase relationship is central to determine the role of the former in past (and therefore future) climatic variations. This scientific problem was even discussed by some policy makers (e.g., in the USA senate).
Thomas M. Jordan, Michael A. Cooper, Dustin M. Schroeder, Christopher N. Williams, John D. Paden, Martin J. Siegert, and Jonathan L. Bamber
The Cryosphere, 11, 1247–1264, https://doi.org/10.5194/tc-11-1247-2017, https://doi.org/10.5194/tc-11-1247-2017, 2017
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Using radio-echo sounding data from northern Greenland, we demonstrate that subglacial roughness exhibits self-affine (fractal) scaling behaviour. This enables us to assess topographic control upon the bed-echo waveform, and explain the spatial distribution of the degree of scattering (specular and diffuse reflections). Via comparison with a prediction for the basal thermal state (thawed and frozen regions of the bed) we discuss the consequences of our study for basal water discrimination.
Anna Kozachek, Vladimir Mikhalenko, Valérie Masson-Delmotte, Alexey Ekaykin, Patrick Ginot, Stanislav Kutuzov, Michel Legrand, Vladimir Lipenkov, and Susanne Preunkert
Clim. Past, 13, 473–489, https://doi.org/10.5194/cp-13-473-2017, https://doi.org/10.5194/cp-13-473-2017, 2017
Felicity S. Graham, Jason L. Roberts, Ben K. Galton-Fenzi, Duncan Young, Donald Blankenship, and Martin J. Siegert
Earth Syst. Sci. Data, 9, 267–279, https://doi.org/10.5194/essd-9-267-2017, https://doi.org/10.5194/essd-9-267-2017, 2017
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Antarctic bed topography datasets are interpolated onto low-resolution grids because our observed topography data are sparsely sampled. This has implications for ice-sheet model simulations, especially in regions prone to instability, such as grounding lines, where detailed knowledge of the topography is required. Here, we constructed a high-resolution synthetic bed elevation dataset using observed covariance properties to assess the dependence of simulated ice-sheet dynamics on grid resolution.
Anna Winter, Daniel Steinhage, Emily J. Arnold, Donald D. Blankenship, Marie G. P. Cavitte, Hugh F. J. Corr, John D. Paden, Stefano Urbini, Duncan A. Young, and Olaf Eisen
The Cryosphere, 11, 653–668, https://doi.org/10.5194/tc-11-653-2017, https://doi.org/10.5194/tc-11-653-2017, 2017
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Susanne Preunkert, Michel Fily, Hubert Gallée, Bruno Jourdain, Michel Legrand, Olivier Magand, Bénédicte Minster, and Martin Werner
The Cryosphere, 11, 343–362, https://doi.org/10.5194/tc-11-343-2017, https://doi.org/10.5194/tc-11-343-2017, 2017
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Uncertainty of sea level changes is a challenge. As Antarctica is the biggest water reservoir, it is necessary to know how it will contribute. To be able to simulate it, an understanding of past climate is to be achieved, for instance, by studying the ice cores. As climate change is different in different regions, observations are needed all over the continent. Studying an ice core in Adélie Land, we can conclude that there are no changes there at decadal scale over the period 1947–2007.
Christopher N. Williams, Stephen L. Cornford, Thomas M. Jordan, Julian A. Dowdeswell, Martin J. Siegert, Christopher D. Clark, Darrel A. Swift, Andrew Sole, Ian Fenty, and Jonathan L. Bamber
The Cryosphere, 11, 363–380, https://doi.org/10.5194/tc-11-363-2017, https://doi.org/10.5194/tc-11-363-2017, 2017
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Knowledge of ice sheet bed topography and surrounding sea floor bathymetry is integral to the understanding of ice sheet processes. Existing elevation data products for Greenland underestimate fjord bathymetry due to sparse data availability. We present a new method to create physically based synthetic fjord bathymetry to fill these gaps, greatly improving on previously available datasets. This will assist in future elevation product development until further observations become available.
Rupert Michael Gladstone, Roland Charles Warner, Benjamin Keith Galton-Fenzi, Olivier Gagliardini, Thomas Zwinger, and Ralf Greve
The Cryosphere, 11, 319–329, https://doi.org/10.5194/tc-11-319-2017, https://doi.org/10.5194/tc-11-319-2017, 2017
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Computer models are used to simulate the behaviour of glaciers and ice sheets. It has been found that such models are required to be run at very high resolution (which means high computational expense) in order to accurately represent the evolution of marine ice sheets (ice sheets resting on bedrock below sea level), in certain situations which depend on sub-glacial physical processes.
Tong Zhang, Stephen Price, Lili Ju, Wei Leng, Julien Brondex, Gaël Durand, and Olivier Gagliardini
The Cryosphere, 11, 179–190, https://doi.org/10.5194/tc-11-179-2017, https://doi.org/10.5194/tc-11-179-2017, 2017
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Stokes-flow models are the highest-fidelity representation of the equations governing ice sheet flow and they are often treated as the standard against which other models are compared in model benchmark activities. We compare two different Stokes models applied to a canonical set of idealized marine ice sheet experiments and demonstrate that the solutions converge with increasing grid resolution. This provides confidence in the use of Stokes models for generating test case solution metrics.
Alexey A. Ekaykin, Diana O. Vladimirova, Vladimir Y. Lipenkov, and Valérie Masson-Delmotte
Clim. Past, 13, 61–71, https://doi.org/10.5194/cp-13-61-2017, https://doi.org/10.5194/cp-13-61-2017, 2017
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Understanding the Antarctic climate system is crucial in the context of the present-day global environmental changes, but key gaps arise from limited observations. We present a new reconstructed stacked climate record for Princess Elizabeth Land, East Antarctica. Records show 1 °C warming over the last 350 years, with a particularly cold period from the mid-18th to mid-19th century. Temperature variability with a period > 27 years is mainly related to the anomalies of the Indian Ocean Dipole mode.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, and Jean Jouzel
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-263, https://doi.org/10.5194/tc-2016-263, 2016
Revised manuscript not accepted
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Ice core isotopic records rely on the knowledge of the processes involved in the archival of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Michel Legrand, Joseph McConnell, Hubertus Fischer, Eric W. Wolff, Susanne Preunkert, Monica Arienzo, Nathan Chellman, Daiana Leuenberger, Olivia Maselli, Philip Place, Michael Sigl, Simon Schüpbach, and Mike Flannigan
Clim. Past, 12, 2033–2059, https://doi.org/10.5194/cp-12-2033-2016, https://doi.org/10.5194/cp-12-2033-2016, 2016
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Here, we review previous attempts made to reconstruct past forest fire using chemical signals recorded in Greenland ice. We showed that the Greenland ice records of ammonium, found to be a good fire proxy, consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred since the last 15 000 years, including the Little Ice Age and the last large climatic transition.
Bette L. Otto-Bliesner, Pascale Braconnot, Sandy P. Harrison, Daniel J. Lunt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Emilie Capron, Anders E. Carlson, Andrea Dutton, Hubertus Fischer, Heiko Goelzer, Aline Govin, Alan Haywood, Fortunat Joos, Allegra N. Legrande, William H. Lipscomb, Gerrit Lohmann, Natalie Mahowald, Christoph Nehrbass-Ahles, Jean-Yves Peterschmidt, Francesco S.-R. Pausata, Steven Phipps, and Hans Renssen
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-106, https://doi.org/10.5194/cp-2016-106, 2016
Preprint retracted
Barbara Stenni, Claudio Scarchilli, Valerie Masson-Delmotte, Elisabeth Schlosser, Virginia Ciardini, Giuliano Dreossi, Paolo Grigioni, Mattia Bonazza, Anselmo Cagnati, Daniele Karlicek, Camille Risi, Roberto Udisti, and Mauro Valt
The Cryosphere, 10, 2415–2428, https://doi.org/10.5194/tc-10-2415-2016, https://doi.org/10.5194/tc-10-2415-2016, 2016
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Here, we focus on the Concordia Station, central East Antarctic plateau, providing a multi-year record (2008–2010) of daily precipitation types identified from crystal morphologies, precipitation amounts and isotopic composition. Relationships between local meteorological data and precipitation oxygen isotope composition are investigated. Our dataset is available for in-depth model evaluation at the synoptic scale.
Olivier Eicher, Matthias Baumgartner, Adrian Schilt, Jochen Schmitt, Jakob Schwander, Thomas F. Stocker, and Hubertus Fischer
Clim. Past, 12, 1979–1993, https://doi.org/10.5194/cp-12-1979-2016, https://doi.org/10.5194/cp-12-1979-2016, 2016
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A new high-resolution total air content record over the NGRIP ice core, spanning 0.3–120 kyr is presented. In agreement with Antarctic ice cores, we find a strong local insolation signature but also 3–5 % decreases in total air content as a local response to Dansgaard–Oeschger events, which can only partly be explained by changes in surface pressure and temperature. Accordingly, a dynamic response of firnification to rapid climate changes on the Greenland ice sheet must have occurred.
Amaelle Landais, Valérie Masson-Delmotte, Emilie Capron, Petra M. Langebroek, Pepijn Bakker, Emma J. Stone, Niklaus Merz, Christoph C. Raible, Hubertus Fischer, Anaïs Orsi, Frédéric Prié, Bo Vinther, and Dorthe Dahl-Jensen
Clim. Past, 12, 1933–1948, https://doi.org/10.5194/cp-12-1933-2016, https://doi.org/10.5194/cp-12-1933-2016, 2016
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The last lnterglacial (LIG; 116 000 to 129 000 years before present) surface temperature at the upstream Greenland NEEM deposition site is estimated to be warmer by +7 to +11 °C compared to the preindustrial period. We show that under such warm temperatures, melting of snow probably led to a significant surface melting. There is a paradox between the extent of the Greenland ice sheet during the LIG and the strong warming during this period that models cannot solve.
Timothé Bolliet, Patrick Brockmann, Valérie Masson-Delmotte, Franck Bassinot, Valérie Daux, Dominique Genty, Amaelle Landais, Marlène Lavrieux, Elisabeth Michel, Pablo Ortega, Camille Risi, Didier M. Roche, Françoise Vimeux, and Claire Waelbroeck
Clim. Past, 12, 1693–1719, https://doi.org/10.5194/cp-12-1693-2016, https://doi.org/10.5194/cp-12-1693-2016, 2016
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This paper presents a new database of past climate proxies which aims to facilitate the distribution of data by using a user-friendly interface. Available data from the last 40 years are often fragmented, with lots of different formats, and online libraries are sometimes nonintuitive. We thus built a new dynamic web portal for data browsing, visualizing, and batch downloading of hundreds of datasets presenting a homogeneous format.
Thomas Röckmann, Simon Eyer, Carina van der Veen, Maria E. Popa, Béla Tuzson, Guillaume Monteil, Sander Houweling, Eliza Harris, Dominik Brunner, Hubertus Fischer, Giulia Zazzeri, David Lowry, Euan G. Nisbet, Willi A. Brand, Jaroslav M. Necki, Lukas Emmenegger, and Joachim Mohn
Atmos. Chem. Phys., 16, 10469–10487, https://doi.org/10.5194/acp-16-10469-2016, https://doi.org/10.5194/acp-16-10469-2016, 2016
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A dual isotope ratio mass spectrometric system (IRMS) and a quantum cascade laser absorption spectroscopy (QCLAS)-based technique were deployed at the Cabauw experimental site for atmospheric research (CESAR) in the Netherlands and performed in situ, high-frequency (approx. hourly) measurements for a period of more than 5 months, yielding a combined dataset with more than 2500 measurements of both δ13C and δD.
François Ritter, Hans Christian Steen-Larsen, Martin Werner, Valérie Masson-Delmotte, Anais Orsi, Melanie Behrens, Gerit Birnbaum, Johannes Freitag, Camille Risi, and Sepp Kipfstuhl
The Cryosphere, 10, 1647–1663, https://doi.org/10.5194/tc-10-1647-2016, https://doi.org/10.5194/tc-10-1647-2016, 2016
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We present successful continuous measurements of water vapor isotopes performed in Antarctica in January 2013. The interest is to understand the impact of the water vapor isotopic composition on the near-surface snow isotopes. Our study reveals a diurnal cycle in the snow isotopic composition in phase with the vapor. This finding suggests fractionation during the sublimation of the ice, which has an important consequence on the interpretation of water isotope variations in ice cores.
T. M. Jordan, J. L. Bamber, C. N. Williams, J. D. Paden, M. J. Siegert, P. Huybrechts, O. Gagliardini, and F. Gillet-Chaulet
The Cryosphere, 10, 1547–1570, https://doi.org/10.5194/tc-10-1547-2016, https://doi.org/10.5194/tc-10-1547-2016, 2016
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Ice penetrating radar enables determination of the basal properties of ice sheets. Existing algorithms assume stationarity in the attenuation rate, which is not justifiable at an ice sheet scale. We introduce the first ice-sheet-wide algorithm for radar attenuation that incorporates spatial variability, using the temperature field from a numerical model as an initial guess. The study is a step toward ice-sheet-wide data products for basal properties and evaluation of model temperature fields.
Mathieu Casado, Amaelle Landais, Valérie Masson-Delmotte, Christophe Genthon, Erik Kerstel, Samir Kassi, Laurent Arnaud, Ghislain Picard, Frederic Prie, Olivier Cattani, Hans-Christian Steen-Larsen, Etienne Vignon, and Peter Cermak
Atmos. Chem. Phys., 16, 8521–8538, https://doi.org/10.5194/acp-16-8521-2016, https://doi.org/10.5194/acp-16-8521-2016, 2016
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Climatic conditions in Concordia are very cold (−55 °C in average) and very dry, imposing difficult conditions to measure the water vapour isotopic composition. New developments in infrared spectroscopy enable now the measurement of isotopic composition in water vapour traces (down to 20 ppmv). Here we present the results results of a first campaign of measurement of isotopic composition of water vapour in Concordia, the site where the 800 000 years long ice core was drilled.
Olivier Passalacqua, Olivier Gagliardini, Frédéric Parrenin, Joe Todd, Fabien Gillet-Chaulet, and Catherine Ritz
Geosci. Model Dev., 9, 2301–2313, https://doi.org/10.5194/gmd-9-2301-2016, https://doi.org/10.5194/gmd-9-2301-2016, 2016
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In ice-flow modelling, computing in 3-D requires a lot of resources, but 2-D models lack physical likelihood when the flow is diverging. That is why 2-D models accounting for the divergence, so-called 2.5-D models, are an interesting trade-off. However, the applicability of these 2.5-D models has never been systematically examined. We show that these models are ineffective in the case of highly diverging flows, but also for varying temperature, which was not suspected.
Anna Dittmann, Elisabeth Schlosser, Valérie Masson-Delmotte, Jordan G. Powers, Kevin W. Manning, Martin Werner, and Koji Fujita
Atmos. Chem. Phys., 16, 6883–6900, https://doi.org/10.5194/acp-16-6883-2016, https://doi.org/10.5194/acp-16-6883-2016, 2016
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For a better understanding of the stable water isotope data from ice cores, recent time periods have to be analysed, where both measurements and model simulations are available. This was done for Dome Fuji by combining observations, synoptic analysis, back trajectories, and isotopic modelling. It was found that a more northerly moisture source does not necessarily mean a larger temperature difference between source area and deposition site and thus precipitation more depleted in heavy isotopes.
Carly R. Tozer, Tessa R. Vance, Jason L. Roberts, Anthony S. Kiem, Mark A. J. Curran, and Andrew D. Moy
Hydrol. Earth Syst. Sci., 20, 1703–1717, https://doi.org/10.5194/hess-20-1703-2016, https://doi.org/10.5194/hess-20-1703-2016, 2016
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A 1013-year annual rainfall reconstruction was developed for the Williams River catchment in coastal eastern Australia, based on a linear relationship between sea salt deposition in East Antarctica and rainfall in eastern Australia. The reconstruction allows for the instrumental climate record (~ 100 years) to be assessed in the context of millennial climate variability, allowing for better characterisation of flood and drought risk.
Inga Labuhn, Valérie Daux, Olivier Girardclos, Michel Stievenard, Monique Pierre, and Valérie Masson-Delmotte
Clim. Past, 12, 1101–1117, https://doi.org/10.5194/cp-12-1101-2016, https://doi.org/10.5194/cp-12-1101-2016, 2016
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This article presents a reconstruction of summer droughts in France for the last 680 years, based on oxygen isotope ratios in tree ring cellulose from living trees and building timbers at two sites, Fontainebleau and Angoulême. Both sites show coherent drought patterns during the 19th and 20th century, and are characterized by increasing drought in recent decades. A decoupling between sites points to a more heterogeneous climate in France during earlier centuries.
Lucie Bazin, Amaelle Landais, Emilie Capron, Valérie Masson-Delmotte, Catherine Ritz, Ghislain Picard, Jean Jouzel, Marie Dumont, Markus Leuenberger, and Frédéric Prié
Clim. Past, 12, 729–748, https://doi.org/10.5194/cp-12-729-2016, https://doi.org/10.5194/cp-12-729-2016, 2016
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We present new measurements of δO2⁄N2 and δ18Oatm performed on well-conserved ice from EDC covering MIS5 and between 380 and 800 ka. The combination of the observation of a 100 ka periodicity in the new δO2⁄N2 record with a MIS5 multi-site multi-proxy study has revealed a potential influence of local climatic parameters on δO2⁄N2. Moreover, we propose that the varying delay between d18Oatm and precession for the last 800 ka is affected by the occurrence of ice sheet discharge events.
James Hansen, Makiko Sato, Paul Hearty, Reto Ruedy, Maxwell Kelley, Valerie Masson-Delmotte, Gary Russell, George Tselioudis, Junji Cao, Eric Rignot, Isabella Velicogna, Blair Tormey, Bailey Donovan, Evgeniya Kandiano, Karina von Schuckmann, Pushker Kharecha, Allegra N. Legrande, Michael Bauer, and Kwok-Wai Lo
Atmos. Chem. Phys., 16, 3761–3812, https://doi.org/10.5194/acp-16-3761-2016, https://doi.org/10.5194/acp-16-3761-2016, 2016
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We use climate simulations, paleoclimate data and modern observations to infer that continued high fossil fuel emissions will yield cooling of Southern Ocean and North Atlantic surfaces, slowdown and shutdown of SMOC & AMOC, increasingly powerful storms and nonlinear sea level rise reaching several meters in 50–150 years, effects missed in IPCC reports because of omission of ice sheet melt and an insensitivity of most climate models, likely due to excessive ocean mixing.
Tessa R. Vance, Jason L. Roberts, Andrew D. Moy, Mark A. J. Curran, Carly R. Tozer, Ailie J. E. Gallant, Nerilie J. Abram, Tas D. van Ommen, Duncan A. Young, Cyril Grima, Don D. Blankenship, and Martin J. Siegert
Clim. Past, 12, 595–610, https://doi.org/10.5194/cp-12-595-2016, https://doi.org/10.5194/cp-12-595-2016, 2016
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This study details a systematic approach to finding a new high-resolution East Antarctic ice core site. The study initially outlines seven criteria that a new site must fulfil, encompassing specific accumulation, ice dynamics and atmospheric circulation aspects. We then use numerous techniques including Antarctic surface mass balance syntheses, ground-truthing of satellite data by airborne radar surveys and reanalysis products to pinpoint promising regions.
Shin'ya Nakano, Kazue Suzuki, Kenji Kawamura, Frédéric Parrenin, and Tomoyuki Higuchi
Nonlin. Processes Geophys., 23, 31–44, https://doi.org/10.5194/npg-23-31-2016, https://doi.org/10.5194/npg-23-31-2016, 2016
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This paper proposes a technique for dating an ice core. The proposed technique employs a hybrid method combining the sequential Monte Carlo method and the Markov chain Monte Carlo method, which is referred to as the particle Markov chain Monte Carlo method. The sequential Monte Carlo method, which is also known as the particle filter, is widely used for nonlinear time-series analysis. This paper demonstrates the usefulness of the approach in time-series analysis for dating an ice core.
O. Gagliardini, J. Brondex, F. Gillet-Chaulet, L. Tavard, V. Peyaud, and G. Durand
The Cryosphere, 10, 307–312, https://doi.org/10.5194/tc-10-307-2016, https://doi.org/10.5194/tc-10-307-2016, 2016
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In this paper it is shown that the sensitivity to the mesh resolution is not
improved for a vanishing friction at the grounding line (GL). For a discontinuous friction at the GL, we further show that the results are moreover very sensitive to the way the friction is interpolated in the close vicinity of the GL. In the light of these new insights, new results for the MISMIP3d experiments obtained for higher resolutions than previously published are made available for future comparisons.
S. Eyer, B. Tuzson, M. E. Popa, C. van der Veen, T. Röckmann, M. Rothe, W. A. Brand, R. Fisher, D. Lowry, E. G. Nisbet, M. S. Brennwald, E. Harris, C. Zellweger, L. Emmenegger, H. Fischer, and J. Mohn
Atmos. Meas. Tech., 9, 263–280, https://doi.org/10.5194/amt-9-263-2016, https://doi.org/10.5194/amt-9-263-2016, 2016
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We present a newly developed field-deployable, autonomous platform simultaneously measuring the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy.
The instrument consists of a compact quantum cascade laser absorption spectrometer (QCLAS) coupled to a preconcentration unit, called TRace gas EXtractor (TREX).
The performance of this new in situ technique was investigated during a 2-week measurement campaign and compared to other techniques.
P. Beghin, S. Charbit, C. Dumas, M. Kageyama, and C. Ritz
Clim. Past, 11, 1467–1490, https://doi.org/10.5194/cp-11-1467-2015, https://doi.org/10.5194/cp-11-1467-2015, 2015
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The present study investigates the potential impact of the North American ice sheet on the surface mass balance of the Eurasian ice sheet through changes in the past glacial atmospheric circulation. Using an atmospheric circulation model and an ice-sheet model, we show that the albedo of the American ice sheet favors the growth of the Eurasian ice sheet, whereas the topography of the American ice sheet leads to more ablation over North Eurasia, and therefore to a smaller Eurasian ice sheet.
S. Fujita, F. Parrenin, M. Severi, H. Motoyama, and E. W. Wolff
Clim. Past, 11, 1395–1416, https://doi.org/10.5194/cp-11-1395-2015, https://doi.org/10.5194/cp-11-1395-2015, 2015
G. van der Wel, H. Fischer, H. Oerter, H. Meyer, and H. A. J. Meijer
The Cryosphere, 9, 1601–1616, https://doi.org/10.5194/tc-9-1601-2015, https://doi.org/10.5194/tc-9-1601-2015, 2015
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The diffusion of the stable water isotope signal during firnification of snow is a temperature-dependent process. Therefore, past local temperatures can be derived from the differential diffusion length. In this paper we develop a new method for determining this quantity and compare it with the existing method. Both methods are applied to a large number of synthetic data sets to assess the precision and accuracy of the reconstruction and to a section of the Antarctic EDML ice core record.
J.-L. Tison, M. de Angelis, G. Littot, E. Wolff, H. Fischer, M. Hansson, M. Bigler, R. Udisti, A. Wegner, J. Jouzel, B. Stenni, S. Johnsen, V. Masson-Delmotte, A. Landais, V. Lipenkov, L. Loulergue, J.-M. Barnola, J.-R. Petit, B. Delmonte, G. Dreyfus, D. Dahl-Jensen, G. Durand, B. Bereiter, A. Schilt, R. Spahni, K. Pol, R. Lorrain, R. Souchez, and D. Samyn
The Cryosphere, 9, 1633–1648, https://doi.org/10.5194/tc-9-1633-2015, https://doi.org/10.5194/tc-9-1633-2015, 2015
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The oldest paleoclimatic information is buried within the lowermost layers of deep ice cores. It is therefore essential to judge how deep these records remain unaltered. We study the bottom 60 meters of the EPICA Dome C ice core from central Antarctica to show that the paleoclimatic signal is only affected at the small scale (decimeters) in terms of some of the global ice properties. However our data suggest that the time scale has been considerably distorted by mechanical stretching.
V. Masson-Delmotte, H. C. Steen-Larsen, P. Ortega, D. Swingedouw, T. Popp, B. M. Vinther, H. Oerter, A. E. Sveinbjornsdottir, H. Gudlaugsdottir, J. E. Box, S. Falourd, X. Fettweis, H. Gallée, E. Garnier, V. Gkinis, J. Jouzel, A. Landais, B. Minster, N. Paradis, A. Orsi, C. Risi, M. Werner, and J. W. C. White
The Cryosphere, 9, 1481–1504, https://doi.org/10.5194/tc-9-1481-2015, https://doi.org/10.5194/tc-9-1481-2015, 2015
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The deep NEEM ice core provides the oldest Greenland ice core record, enabling improved understanding of the response of ice core records to local climate. Here, we focus on shallow ice cores providing a stack record of accumulation and water-stable isotopes spanning the past centuries. For the first time, we document the ongoing warming in a Greenland ice core. By combining our data with other Greenland ice cores and model results, we characterise the spatio-temporal patterns of variability.
J. J. Fürst, G. Durand, F. Gillet-Chaulet, N. Merino, L. Tavard, J. Mouginot, N. Gourmelen, and O. Gagliardini
The Cryosphere, 9, 1427–1443, https://doi.org/10.5194/tc-9-1427-2015, https://doi.org/10.5194/tc-9-1427-2015, 2015
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We present a comprehensive high-resolution assimilation of Antarctic surface velocities with a flow model. The inferred velocities are in very good agreement with observations, even when compared to recent studies on individual shelves. This quality allows to identify a pattern in the velocity mismatch that points at pinning points not present in the input geometry. We identify seven potential pinning points around Antarctica, for now uncharted, providing prominent resistance to the ice flow.
B. Lemieux-Dudon, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, M. Guillevic, P. Kindler, F. Parrenin, and P. Martinerie
Clim. Past, 11, 959–978, https://doi.org/10.5194/cp-11-959-2015, https://doi.org/10.5194/cp-11-959-2015, 2015
F. Parrenin, L. Bazin, E. Capron, A. Landais, B. Lemieux-Dudon, and V. Masson-Delmotte
Geosci. Model Dev., 8, 1473–1492, https://doi.org/10.5194/gmd-8-1473-2015, https://doi.org/10.5194/gmd-8-1473-2015, 2015
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This manuscript describes a probabilistic model which aims at optimizing the chronology of ice cores by combining different sources of information.
J. Roberts, C. Plummer, T. Vance, T. van Ommen, A. Moy, S. Poynter, A. Treverrow, M. Curran, and S. George
Clim. Past, 11, 697–707, https://doi.org/10.5194/cp-11-697-2015, https://doi.org/10.5194/cp-11-697-2015, 2015
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The Law Dome, East Antarctica snow accumulation record is extended back to 22 BCE using a power-law vertical strain rate model. The periods of 380-442, 727-783 and 1970-2009 CE show above-average snow accumulation rates, while 663-704, 933-975 and 1429-1468 CE were below average. The calculated snow accumulation rates show good correlation with atmospheric reanalysis estimates and significant spatial correlation over a wide expanse of East Antarctica.
F. Parrenin, S. Fujita, A. Abe-Ouchi, K. Kawamura, V. Masson-Delmotte, H. Motoyama, F. Saito, M. Severi, B. Stenni, R. Uemura, and E. Wolff
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-377-2015, https://doi.org/10.5194/cpd-11-377-2015, 2015
Revised manuscript has not been submitted
K. C. Rose, N. Ross, T. A. Jordan, R. G. Bingham, H. F. J. Corr, F. Ferraccioli, A. M. Le Brocq, D. M. Rippin, and M. J. Siegert
Earth Surf. Dynam., 3, 139–152, https://doi.org/10.5194/esurf-3-139-2015, https://doi.org/10.5194/esurf-3-139-2015, 2015
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We use ice-penetrating-radar data to identify a laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope, preserved beneath the Institute and Möller ice streams, West Antarctica. We interpret these features as extensive erosion surfaces, showing that ancient (pre-glacial) surfaces can be preserved at low elevations beneath ice sheets. Different erosion regimes (e.g. fluvial and marine) may have formed these surfaces.
M. Guillevic, L. Bazin, A. Landais, C. Stowasser, V. Masson-Delmotte, T. Blunier, F. Eynaud, S. Falourd, E. Michel, B. Minster, T. Popp, F. Prié, and B. M. Vinther
Clim. Past, 10, 2115–2133, https://doi.org/10.5194/cp-10-2115-2014, https://doi.org/10.5194/cp-10-2115-2014, 2014
J. Krug, J. Weiss, O. Gagliardini, and G. Durand
The Cryosphere, 8, 2101–2117, https://doi.org/10.5194/tc-8-2101-2014, https://doi.org/10.5194/tc-8-2101-2014, 2014
H. C. Steen-Larsen, A. E. Sveinbjörnsdottir, A. J. Peters, V. Masson-Delmotte, M. P. Guishard, G. Hsiao, J. Jouzel, D. Noone, J. K. Warren, and J. W. C. White
Atmos. Chem. Phys., 14, 7741–7756, https://doi.org/10.5194/acp-14-7741-2014, https://doi.org/10.5194/acp-14-7741-2014, 2014
D. M. Roche, C. Dumas, M. Bügelmayer, S. Charbit, and C. Ritz
Geosci. Model Dev., 7, 1377–1394, https://doi.org/10.5194/gmd-7-1377-2014, https://doi.org/10.5194/gmd-7-1377-2014, 2014
M. Bock, J. Schmitt, J. Beck, R. Schneider, and H. Fischer
Atmos. Meas. Tech., 7, 1999–2012, https://doi.org/10.5194/amt-7-1999-2014, https://doi.org/10.5194/amt-7-1999-2014, 2014
V. Bastrikov, H. C. Steen-Larsen, V. Masson-Delmotte, K. Gribanov, O. Cattani, J. Jouzel, and V. Zakharov
Atmos. Meas. Tech., 7, 1763–1776, https://doi.org/10.5194/amt-7-1763-2014, https://doi.org/10.5194/amt-7-1763-2014, 2014
K. Gribanov, J. Jouzel, V. Bastrikov, J.-L. Bonne, F.-M. Breon, M. Butzin, O. Cattani, V. Masson-Delmotte, N. Rokotyan, M. Werner, and V. Zakharov
Atmos. Chem. Phys., 14, 5943–5957, https://doi.org/10.5194/acp-14-5943-2014, https://doi.org/10.5194/acp-14-5943-2014, 2014
M. Butzin, M. Werner, V. Masson-Delmotte, C. Risi, C. Frankenberg, K. Gribanov, J. Jouzel, and V. I. Zakharov
Atmos. Chem. Phys., 14, 5853–5869, https://doi.org/10.5194/acp-14-5853-2014, https://doi.org/10.5194/acp-14-5853-2014, 2014
J.-L. Bonne, V. Masson-Delmotte, O. Cattani, M. Delmotte, C. Risi, H. Sodemann, and H. C. Steen-Larsen
Atmos. Chem. Phys., 14, 4419–4439, https://doi.org/10.5194/acp-14-4419-2014, https://doi.org/10.5194/acp-14-4419-2014, 2014
D. E. Gwyther, B. K. Galton-Fenzi, J. R. Hunter, and J. L. Roberts
Ocean Sci., 10, 267–279, https://doi.org/10.5194/os-10-267-2014, https://doi.org/10.5194/os-10-267-2014, 2014
M. Baumgartner, P. Kindler, O. Eicher, G. Floch, A. Schilt, J. Schwander, R. Spahni, E. Capron, J. Chappellaz, M. Leuenberger, H. Fischer, and T. F. Stocker
Clim. Past, 10, 903–920, https://doi.org/10.5194/cp-10-903-2014, https://doi.org/10.5194/cp-10-903-2014, 2014
B. Bonan, M. Nodet, C. Ritz, and V. Peyaud
Nonlin. Processes Geophys., 21, 569–582, https://doi.org/10.5194/npg-21-569-2014, https://doi.org/10.5194/npg-21-569-2014, 2014
H. C. Steen-Larsen, V. Masson-Delmotte, M. Hirabayashi, R. Winkler, K. Satow, F. Prié, N. Bayou, E. Brun, K. M. Cuffey, D. Dahl-Jensen, M. Dumont, M. Guillevic, S. Kipfstuhl, A. Landais, T. Popp, C. Risi, K. Steffen, B. Stenni, and A. E. Sveinbjörnsdottír
Clim. Past, 10, 377–392, https://doi.org/10.5194/cp-10-377-2014, https://doi.org/10.5194/cp-10-377-2014, 2014
P. Beghin, S. Charbit, C. Dumas, M. Kageyama, D. M. Roche, and C. Ritz
Clim. Past, 10, 345–358, https://doi.org/10.5194/cp-10-345-2014, https://doi.org/10.5194/cp-10-345-2014, 2014
J. Krug, J. Weiss, O. Gagliardini, and G. Durand
The Cryosphere Discuss., https://doi.org/10.5194/tcd-8-1111-2014, https://doi.org/10.5194/tcd-8-1111-2014, 2014
Preprint withdrawn
F. Colleoni, S. Masina, A. Cherchi, A. Navarra, C. Ritz, V. Peyaud, and B. Otto-Bliesner
Clim. Past, 10, 269–291, https://doi.org/10.5194/cp-10-269-2014, https://doi.org/10.5194/cp-10-269-2014, 2014
G. A. Schmidt, J. D. Annan, P. J. Bartlein, B. I. Cook, E. Guilyardi, J. C. Hargreaves, S. P. Harrison, M. Kageyama, A. N. LeGrande, B. Konecky, S. Lovejoy, M. E. Mann, V. Masson-Delmotte, C. Risi, D. Thompson, A. Timmermann, L.-B. Tremblay, and P. Yiou
Clim. Past, 10, 221–250, https://doi.org/10.5194/cp-10-221-2014, https://doi.org/10.5194/cp-10-221-2014, 2014
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 181–194, https://doi.org/10.5194/tc-8-181-2014, https://doi.org/10.5194/tc-8-181-2014, 2014
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 195–208, https://doi.org/10.5194/tc-8-195-2014, https://doi.org/10.5194/tc-8-195-2014, 2014
A. Legchenko, C. Vincent, J. M. Baltassat, J. F. Girard, E. Thibert, O. Gagliardini, M. Descloitres, A. Gilbert, S. Garambois, A. Chevalier, and H. Guyard
The Cryosphere, 8, 155–166, https://doi.org/10.5194/tc-8-155-2014, https://doi.org/10.5194/tc-8-155-2014, 2014
B. de Fleurian, O. Gagliardini, T. Zwinger, G. Durand, E. Le Meur, D. Mair, and P. Råback
The Cryosphere, 8, 137–153, https://doi.org/10.5194/tc-8-137-2014, https://doi.org/10.5194/tc-8-137-2014, 2014
S. Schüpbach, U. Federer, P. R. Kaufmann, S. Albani, C. Barbante, T. F. Stocker, and H. Fischer
Clim. Past, 9, 2789–2807, https://doi.org/10.5194/cp-9-2789-2013, https://doi.org/10.5194/cp-9-2789-2013, 2013
R. Schneider, J. Schmitt, P. Köhler, F. Joos, and H. Fischer
Clim. Past, 9, 2507–2523, https://doi.org/10.5194/cp-9-2507-2013, https://doi.org/10.5194/cp-9-2507-2013, 2013
H. Fischer, J. Severinghaus, E. Brook, E. Wolff, M. Albert, O. Alemany, R. Arthern, C. Bentley, D. Blankenship, J. Chappellaz, T. Creyts, D. Dahl-Jensen, M. Dinn, M. Frezzotti, S. Fujita, H. Gallee, R. Hindmarsh, D. Hudspeth, G. Jugie, K. Kawamura, V. Lipenkov, H. Miller, R. Mulvaney, F. Parrenin, F. Pattyn, C. Ritz, J. Schwander, D. Steinhage, T. van Ommen, and F. Wilhelms
Clim. Past, 9, 2489–2505, https://doi.org/10.5194/cp-9-2489-2013, https://doi.org/10.5194/cp-9-2489-2013, 2013
O. Gagliardini, T. Zwinger, F. Gillet-Chaulet, G. Durand, L. Favier, B. de Fleurian, R. Greve, M. Malinen, C. Martín, P. Råback, J. Ruokolainen, M. Sacchettini, M. Schäfer, H. Seddik, and J. Thies
Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, https://doi.org/10.5194/gmd-6-1299-2013, 2013
L. Bazin, A. Landais, B. Lemieux-Dudon, H. Toyé Mahamadou Kele, D. Veres, F. Parrenin, P. Martinerie, C. Ritz, E. Capron, V. Lipenkov, M.-F. Loutre, D. Raynaud, B. Vinther, A. Svensson, S. O. Rasmussen, M. Severi, T. Blunier, M. Leuenberger, H. Fischer, V. Masson-Delmotte, J. Chappellaz, and E. Wolff
Clim. Past, 9, 1715–1731, https://doi.org/10.5194/cp-9-1715-2013, https://doi.org/10.5194/cp-9-1715-2013, 2013
D. Veres, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, B. Lemieux-Dudon, F. Parrenin, P. Martinerie, E. Blayo, T. Blunier, E. Capron, J. Chappellaz, S. O. Rasmussen, M. Severi, A. Svensson, B. Vinther, and E. W. Wolff
Clim. Past, 9, 1733–1748, https://doi.org/10.5194/cp-9-1733-2013, https://doi.org/10.5194/cp-9-1733-2013, 2013
H. C. Steen-Larsen, S. J. Johnsen, V. Masson-Delmotte, B. Stenni, C. Risi, H. Sodemann, D. Balslev-Clausen, T. Blunier, D. Dahl-Jensen, M. D. Ellehøj, S. Falourd, A. Grindsted, V. Gkinis, J. Jouzel, T. Popp, S. Sheldon, S. B. Simonsen, J. Sjolte, J. P. Steffensen, P. Sperlich, A. E. Sveinbjörnsdóttir, B. M. Vinther, and J. W. C. White
Atmos. Chem. Phys., 13, 4815–4828, https://doi.org/10.5194/acp-13-4815-2013, https://doi.org/10.5194/acp-13-4815-2013, 2013
M. Guillevic, L. Bazin, A. Landais, P. Kindler, A. Orsi, V. Masson-Delmotte, T. Blunier, S. L. Buchardt, E. Capron, M. Leuenberger, P. Martinerie, F. Prié, and B. M. Vinther
Clim. Past, 9, 1029–1051, https://doi.org/10.5194/cp-9-1029-2013, https://doi.org/10.5194/cp-9-1029-2013, 2013
E. Capron, A. Landais, D. Buiron, A. Cauquoin, J. Chappellaz, M. Debret, J. Jouzel, M. Leuenberger, P. Martinerie, V. Masson-Delmotte, R. Mulvaney, F. Parrenin, and F. Prié
Clim. Past, 9, 983–999, https://doi.org/10.5194/cp-9-983-2013, https://doi.org/10.5194/cp-9-983-2013, 2013
S. Charbit, C. Dumas, M. Kageyama, D. M. Roche, and C. Ritz
The Cryosphere, 7, 681–698, https://doi.org/10.5194/tc-7-681-2013, https://doi.org/10.5194/tc-7-681-2013, 2013
M. Casado, P. Ortega, V. Masson-Delmotte, C. Risi, D. Swingedouw, V. Daux, D. Genty, F. Maignan, O. Solomina, B. Vinther, N. Viovy, and P. Yiou
Clim. Past, 9, 871–886, https://doi.org/10.5194/cp-9-871-2013, https://doi.org/10.5194/cp-9-871-2013, 2013
S. Zürcher, R. Spahni, F. Joos, M. Steinacher, and H. Fischer
Biogeosciences, 10, 1963–1981, https://doi.org/10.5194/bg-10-1963-2013, https://doi.org/10.5194/bg-10-1963-2013, 2013
A. Svensson, M. Bigler, T. Blunier, H. B. Clausen, D. Dahl-Jensen, H. Fischer, S. Fujita, K. Goto-Azuma, S. J. Johnsen, K. Kawamura, S. Kipfstuhl, M. Kohno, F. Parrenin, T. Popp, S. O. Rasmussen, J. Schwander, I. Seierstad, M. Severi, J. P. Steffensen, R. Udisti, R. Uemura, P. Vallelonga, B. M. Vinther, A. Wegner, F. Wilhelms, and M. Winstrup
Clim. Past, 9, 749–766, https://doi.org/10.5194/cp-9-749-2013, https://doi.org/10.5194/cp-9-749-2013, 2013
A. S. Drouet, D. Docquier, G. Durand, R. Hindmarsh, F. Pattyn, O. Gagliardini, and T. Zwinger
The Cryosphere, 7, 395–406, https://doi.org/10.5194/tc-7-395-2013, https://doi.org/10.5194/tc-7-395-2013, 2013
P. Fretwell, H. D. Pritchard, D. G. Vaughan, J. L. Bamber, N. E. Barrand, R. Bell, C. Bianchi, R. G. Bingham, D. D. Blankenship, G. Casassa, G. Catania, D. Callens, H. Conway, A. J. Cook, H. F. J. Corr, D. Damaske, V. Damm, F. Ferraccioli, R. Forsberg, S. Fujita, Y. Gim, P. Gogineni, J. A. Griggs, R. C. A. Hindmarsh, P. Holmlund, J. W. Holt, R. W. Jacobel, A. Jenkins, W. Jokat, T. Jordan, E. C. King, J. Kohler, W. Krabill, M. Riger-Kusk, K. A. Langley, G. Leitchenkov, C. Leuschen, B. P. Luyendyk, K. Matsuoka, J. Mouginot, F. O. Nitsche, Y. Nogi, O. A. Nost, S. V. Popov, E. Rignot, D. M. Rippin, A. Rivera, J. Roberts, N. Ross, M. J. Siegert, A. M. Smith, D. Steinhage, M. Studinger, B. Sun, B. K. Tinto, B. C. Welch, D. Wilson, D. A. Young, C. Xiangbin, and A. Zirizzotti
The Cryosphere, 7, 375–393, https://doi.org/10.5194/tc-7-375-2013, https://doi.org/10.5194/tc-7-375-2013, 2013
A. Quiquet, C. Ritz, H. J. Punge, and D. Salas y Mélia
Clim. Past, 9, 353–366, https://doi.org/10.5194/cp-9-353-2013, https://doi.org/10.5194/cp-9-353-2013, 2013
J. L. Roberts, A. D. Moy, T. D. van Ommen, M. A. J. Curran, A. P. Worby, I. D. Goodwin, and M. Inoue
The Cryosphere, 7, 263–273, https://doi.org/10.5194/tc-7-263-2013, https://doi.org/10.5194/tc-7-263-2013, 2013
B. Bereiter, T. F. Stocker, and H. Fischer
Atmos. Meas. Tech., 6, 251–262, https://doi.org/10.5194/amt-6-251-2013, https://doi.org/10.5194/amt-6-251-2013, 2013
M. G. P. Cavitte, D. D. Blankenship, D. A. Young, M. J. Siegert, and E. Le Meur
The Cryosphere Discuss., https://doi.org/10.5194/tcd-7-321-2013, https://doi.org/10.5194/tcd-7-321-2013, 2013
Revised manuscript not accepted
F. Gillet-Chaulet, O. Gagliardini, H. Seddik, M. Nodet, G. Durand, C. Ritz, T. Zwinger, R. Greve, and D. G. Vaughan
The Cryosphere, 6, 1561–1576, https://doi.org/10.5194/tc-6-1561-2012, https://doi.org/10.5194/tc-6-1561-2012, 2012
G. H. Gudmundsson, J. Krug, G. Durand, L. Favier, and O. Gagliardini
The Cryosphere, 6, 1497–1505, https://doi.org/10.5194/tc-6-1497-2012, https://doi.org/10.5194/tc-6-1497-2012, 2012
F. Parrenin and D. Paillard
Clim. Past, 8, 2031–2037, https://doi.org/10.5194/cp-8-2031-2012, https://doi.org/10.5194/cp-8-2031-2012, 2012
Related subject area
Ice Cores
Chemical and visual characterisation of EGRIP glacial ice and cloudy bands within
Using ice core measurements from Taylor Glacier, Antarctica, to calibrate in situ cosmogenic 14C production rates by muons
Detection of ice core particles via deep neural networks
A one-dimensional temperature and age modeling study for selecting the drill site of the oldest ice core around Dome Fuji, Antarctica
Greenland and Canadian Arctic ice temperature profiles
Development of crystal orientation fabric in the Dome Fuji ice core in East Antarctica: implications for the deformation regime in ice sheets
Gas isotope thermometry in the South Pole and Dome Fuji ice cores provides evidence for seasonal rectification of ice core gas records
Chronostratigraphy of the Larsen blue-ice area in northern Victoria Land, East Antarctica, and its implications for paleoclimate
A quantitative method of resolving annual precipitation for the past millennia from Tibetan ice cores
Regional variability of diatoms in ice cores from the Antarctic Peninsula and Ellsworth Land, Antarctica
Microstructure, micro-inclusions, and mineralogy along the EGRIP (East Greenland Ice Core Project) ice core – Part 2: Implications for palaeo-mineralogy
Microstructure, micro-inclusions, and mineralogy along the EGRIP ice core – Part 1: Localisation of inclusions and deformation patterns
Fractionation of O2∕N2 and Ar∕N2 in the Antarctic ice sheet during bubble formation and bubble–clathrate hydrate transition from precise gas measurements of the Dome Fuji ice core
Deep ice as a geochemical reactor: insights from iron speciation and mineralogy of dust in the Talos Dome ice core (East Antarctica)
Two-dimensional impurity imaging in deep Antarctic ice cores: snapshots of three climatic periods and implications for high-resolution signal interpretation
Acoustic velocity measurements for detecting the crystal orientation fabrics of a temperate ice core
Brief communication: New evidence further constraining Tibetan ice core chronologies to the Holocene
Brief communication: New radar constraints support presence of ice older than 1.5 Myr at Little Dome C
Pervasive diffusion of climate signals recorded in ice-vein ionic impurities
Radiocarbon dating of alpine ice cores with the dissolved organic carbon (DOC) fraction
Giant dust particles at Nevado Illimani: a proxy of summertime deep convection over the Bolivian Altiplano
Physical properties of shallow ice cores from Antarctic and sub-Antarctic islands
Stable water isotopes and accumulation rates in the Union Glacier region, Ellsworth Mountains, West Antarctica, over the last 35 years
Multi-tracer study of gas trapping in an East Antarctic ice core
Very old firn air linked to strong density layering at Styx Glacier, coastal Victoria Land, East Antarctica
Apparent discrepancy of Tibetan ice core δ18O records may be attributed to misinterpretation of chronology
Challenges associated with the climatic interpretation of water stable isotope records from a highly resolved firn core from Adélie Land, coastal Antarctica
Glaciological characteristics in the Dome Fuji region and new assessment for “Oldest Ice”
Age ranges of the Tibetan ice cores with emphasis on the Chongce ice cores, western Kunlun Mountains
On the similarity and apparent cycles of isotopic variations in East Antarctic snow pits
The first luminescence dating of Tibetan glacier basal sediment
Methanesulfonic acid (MSA) migration in polar ice: data synthesis and theory
Geothermal flux and basal melt rate in the Dome C region inferred from radar reflectivity and heat modelling
Constraints on post-depositional isotope modifications in East Antarctic firn from analysing temporal changes of isotope profiles
A 125-year record of climate and chemistry variability at the Pine Island Glacier ice divide, Antarctica
Calibrated cryo-cell UV-LA-ICPMS elemental concentrations from the NGRIP ice core reveal abrupt, sub-annual variability in dust across the GI-21.2 interstadial period
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy
Linking pollen deposition and snow accumulation on the Alto dell'Ortles glacier (South Tyrol, Italy) for sub-seasonal dating of a firn temperate core
Bromine, iodine and sodium in surface snow along the 2013 Talos Dome–GV7 traverse (northern Victoria Land, East Antarctica)
A 60-year ice-core record of regional climate from Adélie Land, coastal Antarctica
Radiocarbon dating of glacier ice: overview, optimisation, validation and potential
Critical investigation of calculation methods for the elastic velocities in anisotropic ice polycrystals
Surface mass balance and water stable isotopes derived from firn cores on three ice rises, Fimbul Ice Shelf, Antarctica
Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum
Ice core evidence for a 20th century increase in surface mass balance in coastal Dronning Maud Land, East Antarctica
Dispersion in deep polar firn driven by synoptic-scale surface pressure variability
Non-climatic signal in ice core records: lessons from Antarctic megadunes
A synthetic ice core approach to estimate ion relocation in an ice field site experiencing periodical melt: a case study on Lomonosovfonna, Svalbard
A comprehensive interpretation of the NEEM basal ice build-up using a multi-parametric approach
Small-scale disturbances in the stratigraphy of the NEEM ice core: observations and numerical model simulations
Nicolas Stoll, Julien Westhoff, Pascal Bohleber, Anders Svensson, Dorthe Dahl-Jensen, Carlo Barbante, and Ilka Weikusat
The Cryosphere, 17, 2021–2043, https://doi.org/10.5194/tc-17-2021-2023, https://doi.org/10.5194/tc-17-2021-2023, 2023
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Impurities in polar ice play a role regarding its climate signal and internal deformation. We bridge different scales using different methods to investigate ice from the Last Glacial Period derived from the EGRIP ice core in Greenland. We characterise different types of cloudy bands, i.e. frequently occurring milky layers in the ice, and analyse their chemistry with Raman spectroscopy and 2D imaging. We derive new insights into impurity localisation and deposition conditions.
Michael N. Dyonisius, Vasilii V. Petrenko, Andrew M. Smith, Benjamin Hmiel, Peter D. Neff, Bin Yang, Quan Hua, Jochen Schmitt, Sarah A. Shackleton, Christo Buizert, Philip F. Place, James A. Menking, Ross Beaudette, Christina Harth, Michael Kalk, Heidi A. Roop, Bernhard Bereiter, Casey Armanetti, Isaac Vimont, Sylvia Englund Michel, Edward J. Brook, Jeffrey P. Severinghaus, Ray F. Weiss, and Joseph R. McConnell
The Cryosphere, 17, 843–863, https://doi.org/10.5194/tc-17-843-2023, https://doi.org/10.5194/tc-17-843-2023, 2023
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Cosmic rays that enter the atmosphere produce secondary particles which react with surface minerals to produce radioactive nuclides. These nuclides are often used to constrain Earth's surface processes. However, the production rates from muons are not well constrained. We measured 14C in ice with a well-known exposure history to constrain the production rates from muons. 14C production in ice is analogous to quartz, but we obtain different production rates compared to commonly used estimates.
Niccolò Maffezzoli, Eliza Cook, Willem G. M. van der Bilt, Eivind N. Støren, Daniela Festi, Florian Muthreich, Alistair W. R. Seddon, François Burgay, Giovanni Baccolo, Amalie R. F. Mygind, Troels Petersen, Andrea Spolaor, Sebastiano Vascon, Marcello Pelillo, Patrizia Ferretti, Rafael S. dos Reis, Jefferson C. Simões, Yuval Ronen, Barbara Delmonte, Marco Viccaro, Jørgen Peder Steffensen, Dorthe Dahl-Jensen, Kerim H. Nisancioglu, and Carlo Barbante
The Cryosphere, 17, 539–565, https://doi.org/10.5194/tc-17-539-2023, https://doi.org/10.5194/tc-17-539-2023, 2023
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Multiple lines of research in ice core science are limited by manually intensive and time-consuming optical microscopy investigations for the detection of insoluble particles, from pollen grains to volcanic shards. To help overcome these limitations and support researchers, we present a novel methodology for the identification and autonomous classification of ice core insoluble particles based on flow image microscopy and neural networks.
Takashi Obase, Ayako Abe-Ouchi, Fuyuki Saito, Shun Tsutaki, Shuji Fujita, Kenji Kawamura, and Hideaki Motoyama
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-204, https://doi.org/10.5194/tc-2022-204, 2022
Revised manuscript accepted for TC
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We use a one-dimensional ice flow model to examine the most suitable core location near Dome Fuji (DF), Antarctica. This model computes the temporal evolutions of age and temperature from past to present. We investigate the influence of different parameters of climate and ice sheet on the ice's basal age, and compare the results with ground radar surveys. We find that the local ice thickness primarily controls the age because it is critical to the basal melting, which can eliminate the old ice.
Anja Løkkegaard, Kenneth Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel Doyle, Henrik Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat Abbas Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Robert S. Fausto, and William T. Colgan
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-138, https://doi.org/10.5194/tc-2022-138, 2022
Revised manuscript accepted for TC
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This study presents a database compiling 85 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow is highly sensitive to ice temperature. To highlight the value of the data base in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Re-occurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Tomotaka Saruya, Shuji Fujita, Yoshinori Iizuka, Atsushi Miyamoto, Hiroshi Ohno, Akira Hori, Wataru Shigeyama, Motohiro Hirabayashi, and Kumiko Goto-Azuma
The Cryosphere, 16, 2985–3003, https://doi.org/10.5194/tc-16-2985-2022, https://doi.org/10.5194/tc-16-2985-2022, 2022
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Crystal orientation fabrics (COF) of the Dome Fuji ice core were investigated with an innovative method with unprecedentedly high statistical significance and dense depth coverage. The COF profile and its fluctuation were found to be highly dependent on concentrations of chloride ion and dust. The data suggest deformation of ice at the deepest zone is highly influenced by COF fluctuations that progressively develop from the near-surface firn toward the deepest zone within ice sheets.
Jacob D. Morgan, Christo Buizert, Tyler J. Fudge, Kenji Kawamura, Jeffrey P. Severinghaus, and Cathy M. Trudinger
The Cryosphere, 16, 2947–2966, https://doi.org/10.5194/tc-16-2947-2022, https://doi.org/10.5194/tc-16-2947-2022, 2022
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The composition of air bubbles in Antarctic ice cores records information about past changes in properties of the snowpack. We find that, near the South Pole, thinner snowpack in the past is often due to steeper surface topography, in which faster winds erode the snow and deposit it in flatter areas. The slope and wind seem to also cause a seasonal bias in the composition of air bubbles in the ice core. These findings will improve interpretation of other ice cores from places with steep slopes.
Giyoon Lee, Jinho Ahn, Hyeontae Ju, Florian Ritterbusch, Ikumi Oyabu, Christo Buizert, Songyi Kim, Jangil Moon, Sambit Ghosh, Kenji Kawamura, Zheng-Tian Lu, Sangbum Hong, Chang Hee Han, Soon Do Hur, Wei Jiang, and Guo-Min Yang
The Cryosphere, 16, 2301–2324, https://doi.org/10.5194/tc-16-2301-2022, https://doi.org/10.5194/tc-16-2301-2022, 2022
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Blue-ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the area hinders constraining the age. We applied state-of-the-art techniques and found that the ages cover the last deglaciation period. Our study demonstrates that the BIA in northern Victoria Land may help reconstruct the past climate during the termination of the last glacial period.
Wangbin Zhang, Shugui Hou, Shuang-Ye Wu, Hongxi Pang, Sharon B. Sneed, Elena V. Korotkikh, Paul A. Mayewski, Theo M. Jenk, and Margit Schwikowski
The Cryosphere, 16, 1997–2008, https://doi.org/10.5194/tc-16-1997-2022, https://doi.org/10.5194/tc-16-1997-2022, 2022
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This study proposes a quantitative method to reconstruct annual precipitation records at the millennial timescale from the Tibetan ice cores through combining annual layer identification based on LA-ICP-MS measurement with an ice flow model. The reliability of this method is assessed by comparing our results with other reconstructed and modeled precipitation series for the Tibetan Plateau. The assessment shows that the method has a promising performance.
Dieter R. Tetzner, Claire S. Allen, and Elizabeth R. Thomas
The Cryosphere, 16, 779–798, https://doi.org/10.5194/tc-16-779-2022, https://doi.org/10.5194/tc-16-779-2022, 2022
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The presence of diatoms in Antarctic ice cores has been scarcely documented and poorly understood. Here we present a detailed analysis of the spatial and temporal distribution of the diatom record preserved in a set of Antarctic ice cores. Our results reveal that the timing and amount of diatoms deposited present a strong geographical division. This study highlights the potential of the diatom record preserved in Antarctic ice cores to provide useful information about past environmental changes.
Nicolas Stoll, Maria Hörhold, Tobias Erhardt, Jan Eichler, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 16, 667–688, https://doi.org/10.5194/tc-16-667-2022, https://doi.org/10.5194/tc-16-667-2022, 2022
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We mapped and analysed solid inclusion in the upper 1340 m of the EGRIP ice core with Raman spectroscopy and microstructure mapping, based on bulk dust content derived via continuous flow analysis. We observe a large variety in mineralogy throughout the core and samples. The main minerals are sulfates, especially gypsum, and terrestrial dust minerals, such as quartz, mica, and feldspar. A change in mineralogy occurs around 900 m depth indicating a climate-related imprint.
Nicolas Stoll, Jan Eichler, Maria Hörhold, Tobias Erhardt, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 15, 5717–5737, https://doi.org/10.5194/tc-15-5717-2021, https://doi.org/10.5194/tc-15-5717-2021, 2021
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We did a systematic analysis of the location of inclusions in the EGRIP ice core, the first ice core from an ice stream. We combine this with crystal orientation and grain size data, enabling the first overview about the microstructure of this unique ice core. Micro-inclusions show a strong spatial variability and patterns (clusters or horizontal layers); roughly one-third is located at grain boundaries. More holistic approaches are needed to understand deformation processes in the ice better.
Ikumi Oyabu, Kenji Kawamura, Tsutomu Uchida, Shuji Fujita, Kyotaro Kitamura, Motohiro Hirabayashi, Shuji Aoki, Shinji Morimoto, Takakiyo Nakazawa, Jeffrey P. Severinghaus, and Jacob D. Morgan
The Cryosphere, 15, 5529–5555, https://doi.org/10.5194/tc-15-5529-2021, https://doi.org/10.5194/tc-15-5529-2021, 2021
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We present O2/N2 and Ar/N2 records from the Dome Fuji ice core through the bubbly ice, bubble–clathrate transition, and clathrate ice zones without gas-loss fractionation. The insolation signal is preserved through the clathrate formation. The relationship between Ar/Ν2 and Ο2/Ν2 suggests that the fractionation for the bubble–clathrate transition is mass independent, while the bubble close-off process involves a combination of mass-independent and mass-dependent fractionation for O2 and Ar.
Giovanni Baccolo, Barbara Delmonte, Elena Di Stefano, Giannantonio Cibin, Ilaria Crotti, Massimo Frezzotti, Dariush Hampai, Yoshinori Iizuka, Augusto Marcelli, and Valter Maggi
The Cryosphere, 15, 4807–4822, https://doi.org/10.5194/tc-15-4807-2021, https://doi.org/10.5194/tc-15-4807-2021, 2021
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As scientists are pushing efforts to recover deep ice cores to extend paleoclimatic reconstructions, it is now essential to explore deep ice. The latter was considered a relatively stable environment, but this view is changing. This study shows that the conditions of deep ice promote the interaction between soluble and insoluble impurities, favoring complex geochemical reactions that lead to the englacial dissolution and precipitation of specific minerals present in atmospheric mineral dust.
Pascal Bohleber, Marco Roman, Martin Šala, Barbara Delmonte, Barbara Stenni, and Carlo Barbante
The Cryosphere, 15, 3523–3538, https://doi.org/10.5194/tc-15-3523-2021, https://doi.org/10.5194/tc-15-3523-2021, 2021
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Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers micro-destructive, micrometer-scale impurity analysis of ice cores. For improved understanding of the LA-ICP-MS signals, novel 2D impurity imaging is applied to selected glacial and interglacial samples of Antarctic deep ice cores. This allows evaluating the 2D impurity distribution in relation to ice crystal features and assessing implications for investigating highly thinned climate proxy signals in deep polar ice.
Sebastian Hellmann, Melchior Grab, Johanna Kerch, Henning Löwe, Andreas Bauder, Ilka Weikusat, and Hansruedi Maurer
The Cryosphere, 15, 3507–3521, https://doi.org/10.5194/tc-15-3507-2021, https://doi.org/10.5194/tc-15-3507-2021, 2021
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In this study, we analyse whether ultrasonic measurements on ice core samples could be employed to derive information about the particular ice crystal orientation in these samples. We discuss if such ultrasonic scans of ice core samples could provide similarly detailed results as the established methods, which usually destroy the ice samples. Our geophysical approach is minimally invasive and could support the existing methods with additional and (semi-)continuous data points along the ice core.
Shugui Hou, Wangbin Zhang, Ling Fang, Theo M. Jenk, Shuangye Wu, Hongxi Pang, and Margit Schwikowski
The Cryosphere, 15, 2109–2114, https://doi.org/10.5194/tc-15-2109-2021, https://doi.org/10.5194/tc-15-2109-2021, 2021
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We present ages for two new ice cores reaching bedrock, from the Zangser Kangri (ZK) glacier in the northwestern Tibetan Plateau and the Shulenanshan (SLNS) glacier in the western Qilian Mountains. We estimated bottom ages of 8.90±0.57/0.56 ka and 7.46±1.46/1.79 ka for the ZK and SLNS ice core respectively, constraining the time range accessible by Tibetan ice cores to the Holocene.
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.
Felix S. L. Ng
The Cryosphere, 15, 1787–1810, https://doi.org/10.5194/tc-15-1787-2021, https://doi.org/10.5194/tc-15-1787-2021, 2021
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Current theory predicts climate signals in the vein chemistry of ice cores to migrate, hampering their dating. I show that the Gibbs–Thomson effect, which has been overlooked, causes fast diffusion that prevents signals from surviving into deep ice. Hence the deep climatic peaks in Antarctic and Greenlandic ice must be due to impurities in the ice matrix (outside veins) and safe from migration. These findings reset our understanding of postdepositional changes of ice-core climate signals.
Ling Fang, Theo M. Jenk, Thomas Singer, Shugui Hou, and Margit Schwikowski
The Cryosphere, 15, 1537–1550, https://doi.org/10.5194/tc-15-1537-2021, https://doi.org/10.5194/tc-15-1537-2021, 2021
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The interpretation of the ice-core-preserved signal requires a precise chronology. Radiocarbon (14C) dating of the water-insoluble organic carbon (WIOC) fraction has become an important dating tool. However, this method is restricted by the low concentration in the ice. In this work, we report first 14C dating results using the dissolved organic carbon (DOC) fraction. The resulting ages are comparable in both fractions, but by using the DOC fraction the required ice mass can be reduced.
Filipe G. L. Lindau, Jefferson C. Simões, Barbara Delmonte, Patrick Ginot, Giovanni Baccolo, Chiara I. Paleari, Elena Di Stefano, Elena Korotkikh, Douglas S. Introne, Valter Maggi, Eduardo Garzanti, and Sergio Andò
The Cryosphere, 15, 1383–1397, https://doi.org/10.5194/tc-15-1383-2021, https://doi.org/10.5194/tc-15-1383-2021, 2021
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Information about the past climate variability in tropical South America is stored in the snow layers of the tropical Andean glaciers. Here we show evidence that the presence of very large aeolian mineral dust particles at Nevado Illimani (Bolivia) is strictly controlled by the occurrence of summer storms in the Bolivian Altiplano. Therefore, based on the snow dust content and its composition of stable water isotopes, we propose a new proxy for information on previous summer storms.
Elizabeth Ruth Thomas, Guisella Gacitúa, Joel B. Pedro, Amy Constance Faith King, Bradley Markle, Mariusz Potocki, and Dorothea Elisabeth Moser
The Cryosphere, 15, 1173–1186, https://doi.org/10.5194/tc-15-1173-2021, https://doi.org/10.5194/tc-15-1173-2021, 2021
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Here we present the first-ever radar and ice core data from the sub-Antarctic islands of Bouvet Island, Peter I Island, and Young Island. These islands have the potential to record past climate in one of the most data-sparse regions on earth. Despite their northerly location, surface melting is generally low, and the upper layer of the ice at most sites is undisturbed. We estimate that a 100 m ice core drilled on these islands could capture climate over the past 100–200 years.
Kirstin Hoffmann, Francisco Fernandoy, Hanno Meyer, Elizabeth R. Thomas, Marcelo Aliaga, Dieter Tetzner, Johannes Freitag, Thomas Opel, Jorge Arigony-Neto, Christian Florian Göbel, Ricardo Jaña, Delia Rodríguez Oroz, Rebecca Tuckwell, Emily Ludlow, Joseph R. McConnell, and Christoph Schneider
The Cryosphere, 14, 881–904, https://doi.org/10.5194/tc-14-881-2020, https://doi.org/10.5194/tc-14-881-2020, 2020
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Christoph F. Schaller, Rebecca J. Tuckwell, Henning Löwe, Laurent Arnaud, Olivier Magand, Elizabeth R. Thomas, Johannes Freitag, Robert Mulvaney, Martin Schneebeli, and Vladimir Ya. Lipenkov
The Cryosphere, 13, 3383–3403, https://doi.org/10.5194/tc-13-3383-2019, https://doi.org/10.5194/tc-13-3383-2019, 2019
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Understanding gas trapping in polar ice is essential to study the relationship between greenhouse gases and past climates. New data of bubble closure, used in a simple gas-trapping model, show inconsistency with the final air content in ice. This suggests gas trapping is not fully understood. We also use a combination of high-resolution measurements to investigate the effect of polar snow stratification on gas trapping and find that all strata have similar pores, but that some close in advance.
Youngjoon Jang, Sang Bum Hong, Christo Buizert, Hun-Gyu Lee, Sang-Young Han, Ji-Woong Yang, Yoshinori Iizuka, Akira Hori, Yeongcheol Han, Seong Joon Jun, Pieter Tans, Taejin Choi, Seong-Joong Kim, Soon Do Hur, and Jinho Ahn
The Cryosphere, 13, 2407–2419, https://doi.org/10.5194/tc-13-2407-2019, https://doi.org/10.5194/tc-13-2407-2019, 2019
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We can learn how human activity altered atmospheric air from the interstitial air in the porous snow layer (firn) on top of glaciers. However, old firn air (> 55 years) was observed only at sites where surface temperatures and snow accumulation rates are very low, such as the South Pole. In this study, we report an unusually old firn air with CO2 age of 93 years from Styx Glacier, near the Ross Sea coast in Antarctica. We hypothesize that the large snow density variations increase firn air ages.
Shugui Hou, Wangbin Zhang, Hongxi Pang, Shuang-Ye Wu, Theo M. Jenk, Margit Schwikowski, and Yetang Wang
The Cryosphere, 13, 1743–1752, https://doi.org/10.5194/tc-13-1743-2019, https://doi.org/10.5194/tc-13-1743-2019, 2019
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The apparent discrepancy between the Holocene δ18O records of the Guliya and the Chongce ice cores may be attributed to a possible misinterpretation of the Guliya ice core chronology.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Suzanne Preunkert, Michel Legrand, Bénédicte Minster, and Martin Werner
The Cryosphere, 13, 1297–1324, https://doi.org/10.5194/tc-13-1297-2019, https://doi.org/10.5194/tc-13-1297-2019, 2019
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We report new water stable isotope records from the first highly resolved firn core drilled in Adélie Land and covering 1998–2014. Using an updated database, we show that mean values are in line with the range of coastal values. Statistical analyses show no relationship between our record and local surface air temperature. Atmospheric back trajectories and isotopic simulations suggest that water stable isotopes in Adélie provide a fingerprint of the variability of atmospheric dynamics.
Nanna B. Karlsson, Tobias Binder, Graeme Eagles, Veit Helm, Frank Pattyn, Brice Van Liefferinge, and Olaf Eisen
The Cryosphere, 12, 2413–2424, https://doi.org/10.5194/tc-12-2413-2018, https://doi.org/10.5194/tc-12-2413-2018, 2018
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In this study, we investigate the probability that the Dome Fuji region in East Antarctica contains ice more than 1.5 Ma old. The retrieval of a continuous ice-core record extending beyond 1 Ma is imperative to understand why the frequency of ice ages changed from 40 to 100 ka approximately 1 Ma ago.
We use a new radar dataset to improve the ice thickness maps, and apply a thermokinematic model to predict basal temperature and age of the ice. Our results indicate several areas of interest.
Shugui Hou, Theo M. Jenk, Wangbin Zhang, Chaomin Wang, Shuangye Wu, Yetang Wang, Hongxi Pang, and Margit Schwikowski
The Cryosphere, 12, 2341–2348, https://doi.org/10.5194/tc-12-2341-2018, https://doi.org/10.5194/tc-12-2341-2018, 2018
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We present multiple lines of evidence indicating that the Chongce ice cores drilled from the northwestern Tibetan Plateau reaches back only to the early Holocene. This result is at least, 1 order of magnitude younger than the nearby Guliya ice core (~30 km away from the Chongce ice core drilling site) but similar to other Tibetan ice cores. Thus it is necessary to explore multiple dating techniques to confirm the age ranges of the Tibetan ice cores.
Thomas Laepple, Thomas Münch, Mathieu Casado, Maria Hoerhold, Amaelle Landais, and Sepp Kipfstuhl
The Cryosphere, 12, 169–187, https://doi.org/10.5194/tc-12-169-2018, https://doi.org/10.5194/tc-12-169-2018, 2018
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We explain why snow pits across different sites in East Antarctica show visually similar isotopic variations. We argue that the similarity and the apparent cycles of around 20 cm in the δD and δ18O variations are the result of a seasonal cycle in isotopes, noise, for example from precipitation intermittency, and diffusion. The near constancy of the diffusion length across many ice-coring sites explains why the structure and cycle length is largely independent of the accumulation conditions.
Zhu Zhang, Shugui Hou, and Shuangwen Yi
The Cryosphere, 12, 163–168, https://doi.org/10.5194/tc-12-163-2018, https://doi.org/10.5194/tc-12-163-2018, 2018
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We provide the first luminescence dating of the basal sediment of the Chongce ice cap in the western Kunlun Mountains on the north-western Tibetan Plateau (TP), which gives an upper constraint for the age of the bottom ice at the drilling site. The age is more than 1 order of magnitude younger than the previously suggested age of the basal ice of the nearby Guliya ice cap (~ 40 km away from the Chongce ice cap). This work provides an important step towards better understanding the TP ice cores.
Matthew Osman, Sarah B. Das, Olivier Marchal, and Matthew J. Evans
The Cryosphere, 11, 2439–2462, https://doi.org/10.5194/tc-11-2439-2017, https://doi.org/10.5194/tc-11-2439-2017, 2017
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We combine a synthesis of 22 ice core records and a model of soluble impurity transport to investigate the enigmatic, post-depositional migration of methanesulfonic acid in polar ice. Our findings suggest that migration may be universal across coastal regions of Greenland and Antarctica, though it is mitigated at sites with higher accumulation and (or) lower impurity content. Records exhibiting severe migration may still be useful for inferring decadal and lower-frequency climate variability.
Olivier Passalacqua, Catherine Ritz, Frédéric Parrenin, Stefano Urbini, and Massimo Frezzotti
The Cryosphere, 11, 2231–2246, https://doi.org/10.5194/tc-11-2231-2017, https://doi.org/10.5194/tc-11-2231-2017, 2017
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As the Dome C region is a key area for oldest-ice research, we need to better constrain the geothermal flux (GF) so that past basal melt rates are well constrained. Our inverse heat model significantly reduces the confidence intervals of the GF regional field around Dome C, which ranges from 48 to 60 mW m−2. Radar echoes need to be interpreted knowing the time lag of the climate signal to reach the bed. Several old-ice targets are confirmed and a new one is suggested, in which the GF is very low.
Thomas Münch, Sepp Kipfstuhl, Johannes Freitag, Hanno Meyer, and Thomas Laepple
The Cryosphere, 11, 2175–2188, https://doi.org/10.5194/tc-11-2175-2017, https://doi.org/10.5194/tc-11-2175-2017, 2017
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The importance of post-depositional changes for the temperature interpretation of water isotopes is poorly constrained by observations. Here, for the first time, temporal isotope changes in the open-porous firn are directly analysed using a large array of shallow isotope profiles. By this, we can reject the possibility of post-depositional change beyond diffusion and densification as the cause of the discrepancy between isotope and local temperature variations at Kohnen Station, East Antarctica.
Franciele Schwanck, Jefferson C. Simões, Michael Handley, Paul A. Mayewski, Jeffrey D. Auger, Ronaldo T. Bernardo, and Francisco E. Aquino
The Cryosphere, 11, 1537–1552, https://doi.org/10.5194/tc-11-1537-2017, https://doi.org/10.5194/tc-11-1537-2017, 2017
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The West Antarctic Ice Sheet (WAIS) is more susceptible to marine influences than the East Antarctica Ice Sheet (EAIS). During recent decades, rapid changes have occurred in the WAIS sector, including flow velocity acceleration, retraction of ice streams, and mass loss. In this study, we use an ice core located near the Pine Island Glacier ice divide to reconstruct mineral dust and marine aerosol transport and the influence of climate variables on the elemental concentration.
Damiano Della Lunga, Wolfgang Müller, Sune Olander Rasmussen, Anders Svensson, and Paul Vallelonga
The Cryosphere, 11, 1297–1309, https://doi.org/10.5194/tc-11-1297-2017, https://doi.org/10.5194/tc-11-1297-2017, 2017
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In our study we combined the wealth of information provided by Greenland ice cores with an ultra-high-resolution technique well known in geoscience (laser ablation). Our set-up was developed and applied to investigate the variability in concentration of ions across a rapid climatic change from the oldest part of the last glaciation, showing that concentrations drop abruptly from cold to warm periods, representing a shift in atmospheric transport that happens even faster than previously thought.
Jan Eichler, Ina Kleitz, Maddalena Bayer-Giraldi, Daniela Jansen, Sepp Kipfstuhl, Wataru Shigeyama, Christian Weikusat, and Ilka Weikusat
The Cryosphere, 11, 1075–1090, https://doi.org/10.5194/tc-11-1075-2017, https://doi.org/10.5194/tc-11-1075-2017, 2017
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This study contributes to investigations of the effect of impurities on ice microstructure and flow properties. For the first time we mapped over 5000 micro-inclusions in four samples from the EDML and NEEM polar ice cores. The particle distributions show no correlation with grain boundaries and thus we conclude that particle pinning plays only a secondary role for the microstructure evolution. Alternative mechanisms are discussed.
Daniela Festi, Luca Carturan, Werner Kofler, Giancarlo dalla Fontana, Fabrizio de Blasi, Federico Cazorzi, Edith Bucher, Volkmar Mair, Paolo Gabrielli, and Klaus Oeggl
The Cryosphere, 11, 937–948, https://doi.org/10.5194/tc-11-937-2017, https://doi.org/10.5194/tc-11-937-2017, 2017
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We propose a sub-seasonal timescale based on pollen analyses for a Mt. Ortles firn core. The method can be applied to all types of glaciers, provided the proximity of the pollen source and a negligible time lag between pollen production and its deposition on the glacier. By combining pollen dating with a mass balance model we found evidence that pollen grains are resilient to downward transport by percolating water and that pollen shows a high potential for inferring past climatic conditions.
Niccolò Maffezzoli, Andrea Spolaor, Carlo Barbante, Michele Bertò, Massimo Frezzotti, and Paul Vallelonga
The Cryosphere, 11, 693–705, https://doi.org/10.5194/tc-11-693-2017, https://doi.org/10.5194/tc-11-693-2017, 2017
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Sea ice is a crucial parameter within Earth's climate system. Understanding its dynamics and its response to other climatic variables is therefore of primary importance in view of a warming climate and sea ice decline. In this work we investigate some features of a chemical parameter in ice cores, bromine enrichment, which is linked to sea ice and can therefore be used to reconstruct sea ice in the past.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Susanne Preunkert, Michel Fily, Hubert Gallée, Bruno Jourdain, Michel Legrand, Olivier Magand, Bénédicte Minster, and Martin Werner
The Cryosphere, 11, 343–362, https://doi.org/10.5194/tc-11-343-2017, https://doi.org/10.5194/tc-11-343-2017, 2017
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Uncertainty of sea level changes is a challenge. As Antarctica is the biggest water reservoir, it is necessary to know how it will contribute. To be able to simulate it, an understanding of past climate is to be achieved, for instance, by studying the ice cores. As climate change is different in different regions, observations are needed all over the continent. Studying an ice core in Adélie Land, we can conclude that there are no changes there at decadal scale over the period 1947–2007.
Chiara Uglietti, Alexander Zapf, Theo Manuel Jenk, Michael Sigl, Sönke Szidat, Gary Salazar, and Margit Schwikowski
The Cryosphere, 10, 3091–3105, https://doi.org/10.5194/tc-10-3091-2016, https://doi.org/10.5194/tc-10-3091-2016, 2016
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A meaningful interpretation of the climatic history contained in ice cores requires a precise chronology. For dating the older and deeper part of the glaciers, radiocarbon analysis can be used when organic matter such as plant or insect fragments are found in the ice. Since this happens rarely, a complementary dating tool, based on radiocarbon dating of the insoluble fraction of carbonaceous aerosols entrapped in the ice, allows for ice dating between 200 and more than 10 000 years.
Agnès Maurel, Jean-François Mercier, and Maurine Montagnat
The Cryosphere, 10, 3063–3070, https://doi.org/10.5194/tc-10-3063-2016, https://doi.org/10.5194/tc-10-3063-2016, 2016
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Crystallographic texture evolution with depth along ice cores can be evaluated using borehole sonic logging measurements. These measurements provide the velocities of elastic waves that depend on the ice polycrystal anisotropy and can further be related to the ice texture. To do so, elastic velocities need to be inverted from a modeling approach that relate elastic velocities to ice texture. The present paper presents a critical analysis of the different methods used for the inversion.
Carmen P. Vega, Elisabeth Schlosser, Dmitry V. Divine, Jack Kohler, Tõnu Martma, Anja Eichler, Margit Schwikowski, and Elisabeth Isaksson
The Cryosphere, 10, 2763–2777, https://doi.org/10.5194/tc-10-2763-2016, https://doi.org/10.5194/tc-10-2763-2016, 2016
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Surface mass balance and water stable isotopes from firn cores on three ice rises at Fimbul Ice Shelf are reported. The results suggest that the ice rises are suitable sites for the retrieval of longer firn and ice cores. The first deuterium excess data for the area suggests a possible role of seasonal moisture transport changes on the annual isotopic signal. Large-scale atmospheric circulation patterns most likely provide the dominant influence on water stable isotope ratios at the sites.
Paolo Gabrielli, Carlo Barbante, Giuliano Bertagna, Michele Bertó, Daniel Binder, Alberto Carton, Luca Carturan, Federico Cazorzi, Giulio Cozzi, Giancarlo Dalla Fontana, Mary Davis, Fabrizio De Blasi, Roberto Dinale, Gianfranco Dragà, Giuliano Dreossi, Daniela Festi, Massimo Frezzotti, Jacopo Gabrieli, Stephan P. Galos, Patrick Ginot, Petra Heidenwolf, Theo M. Jenk, Natalie Kehrwald, Donald Kenny, Olivier Magand, Volkmar Mair, Vladimir Mikhalenko, Ping Nan Lin, Klaus Oeggl, Gianni Piffer, Mirko Rinaldi, Ulrich Schotterer, Margit Schwikowski, Roberto Seppi, Andrea Spolaor, Barbara Stenni, David Tonidandel, Chiara Uglietti, Victor Zagorodnov, Thomas Zanoner, and Piero Zennaro
The Cryosphere, 10, 2779–2797, https://doi.org/10.5194/tc-10-2779-2016, https://doi.org/10.5194/tc-10-2779-2016, 2016
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New ice cores were extracted from Alto dell'Ortles, the highest glacier of South Tyrol in the Italian Alps, to check whether prehistoric ice, which is coeval to the famous 5300-yr-old Tyrolean Iceman, is still preserved in this region. Dating of the ice cores confirms the hypothesis and indicates the drilling site has been glaciated since the end of the Northern Hemisphere Climatic Optimum (7000 yrs BP). We also infer that an unprecedented acceleration of the glacier flow has recently begun.
Morgane Philippe, Jean-Louis Tison, Karen Fjøsne, Bryn Hubbard, Helle A. Kjær, Jan T. M. Lenaerts, Reinhard Drews, Simon G. Sheldon, Kevin De Bondt, Philippe Claeys, and Frank Pattyn
The Cryosphere, 10, 2501–2516, https://doi.org/10.5194/tc-10-2501-2016, https://doi.org/10.5194/tc-10-2501-2016, 2016
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The reconstruction of past snow accumulation rates is crucial in the context of recent climate change and sea level rise. We measured ~ 250 years of snow accumulation using a 120 m ice core drilled in coastal East Antarctica, where such long records are very scarce. This study is the first to show an increase in snow accumulation, beginning in the 20th and particularly marked in the last 50 years, thereby confirming model predictions of increased snowfall associated with climate change.
Christo Buizert and Jeffrey P. Severinghaus
The Cryosphere, 10, 2099–2111, https://doi.org/10.5194/tc-10-2099-2016, https://doi.org/10.5194/tc-10-2099-2016, 2016
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The upper 50–100 m of the world's ice sheets consists of the firn layer, a porous layer of snow that is slowly compacted by overlying snow. Understanding air movement inside the firn is critical for ice core climate reconstructions. Buizert and Severinghaus identify and describe a new mechanism of firn air movement. High- and low-pressure systems force air movement in the firn that drives strong mixing, called dispersion. Dispersion is the main mechanism for air mixing in the deep firn.
Alexey Ekaykin, Lutz Eberlein, Vladimir Lipenkov, Sergey Popov, Mirko Scheinert, Ludwig Schröder, and Alexey Turkeev
The Cryosphere, 10, 1217–1227, https://doi.org/10.5194/tc-10-1217-2016, https://doi.org/10.5194/tc-10-1217-2016, 2016
Carmen P. Vega, Veijo A. Pohjola, Emilie Beaudon, Björn Claremar, Ward J. J. van Pelt, Rickard Pettersson, Elisabeth Isaksson, Tõnu Martma, Margit Schwikowski, and Carl E. Bøggild
The Cryosphere, 10, 961–976, https://doi.org/10.5194/tc-10-961-2016, https://doi.org/10.5194/tc-10-961-2016, 2016
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To quantify post-depositional relocation of major ions by meltwater in snow and firn at Lomonosovfonna, Svalbard, consecutive ice cores drilled at this site were used to construct a synthetic core. The relocation length of most of the ions was on the order of 1 m between 2007 and 2010. Considering the ionic relocation lengths and annual melt percentages, we estimate that the atmospheric ionic signal remains preserved in recently drilled Lomonosovfonna ice cores at an annual or bi-annual resolution.
Thomas Goossens, Célia J. Sapart, Dorthe Dahl-Jensen, Trevor Popp, Saïda El Amri, and Jean-Louis Tison
The Cryosphere, 10, 553–567, https://doi.org/10.5194/tc-10-553-2016, https://doi.org/10.5194/tc-10-553-2016, 2016
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This first multi-parametric analysis of the basal ice layer of the NEEM ice core reveals that its formation does not result from a mixing process between local relict ice and the deepest ice layers of the advancing ice sheet during its growth phase. Instead, it is shown that the basal sequence partly originates from melting and refreezing processes acting at the ice/bedrock interface under a well-developed ice sheet. These have partially destroyed the paleoclimatic records of the ice.
D. Jansen, M.-G. Llorens, J. Westhoff, F. Steinbach, S. Kipfstuhl, P. D. Bons, A. Griera, and I. Weikusat
The Cryosphere, 10, 359–370, https://doi.org/10.5194/tc-10-359-2016, https://doi.org/10.5194/tc-10-359-2016, 2016
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In this study we present examples of typical small-scale folds observed in the NEEM ice core, North Greenland, and discuss their characteristics. Numerical modelling of viscoplastic deformation and dynamic recrystallisation was used to improve the understanding of the formation of the observed structures under simple shear boundary conditions. We conclude that the folds originate from bands of grains with a tilted lattice relative to the strong lattice preferred orientation below 1500 m depth.
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Short summary
The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC), reaching ~ 800 000 years. Obtaining an older palaeoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we estimate the age of basal ice in the Dome C area. We find that old ice (> 1.5 Myr) likely exists in two regions a few tens of kilometres away from EDC:
Little Dome C Patchand
North Patch.
The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC),...
