Articles | Volume 12, issue 12
https://doi.org/10.5194/tc-12-3931-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-12-3931-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Dec 2018
Research article |
| 19 Dec 2018
| 19 Dec 2018
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream
Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, P.O. Box 60 12 03,
14412 Potsdam, Germany
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
Thomas Kleiner
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
Vadym Aizinger
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
Department of Mathematics, Friedrich–Alexander University Erlangen–Nürnberg, Erlangen, Germany
Martin Rückamp
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
Angelika Humbert
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
Faculty of Geosciences, University of Bremen, Bremen, Germany
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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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Martin Rückamp, Thomas Kleiner, and Angelika Humbert
The Cryosphere, 16, 1675–1696, https://doi.org/10.5194/tc-16-1675-2022, https://doi.org/10.5194/tc-16-1675-2022, 2022
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Ole Zeising, Daniel Steinhage, Keith W. Nicholls, Hugh F. J. Corr, Craig L. Stewart, and Angelika Humbert
The Cryosphere, 16, 1469–1482, https://doi.org/10.5194/tc-16-1469-2022, https://doi.org/10.5194/tc-16-1469-2022, 2022
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Timm Schultz, Ralf Müller, Dietmar Gross, and Angelika Humbert
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Ole Zeising and Angelika Humbert
The Cryosphere, 15, 3119–3128, https://doi.org/10.5194/tc-15-3119-2021, https://doi.org/10.5194/tc-15-3119-2021, 2021
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Coen Hofstede, Sebastian Beyer, Hugh Corr, Olaf Eisen, Tore Hattermann, Veit Helm, Niklas Neckel, Emma C. Smith, Daniel Steinhage, Ole Zeising, and Angelika Humbert
The Cryosphere, 15, 1517–1535, https://doi.org/10.5194/tc-15-1517-2021, https://doi.org/10.5194/tc-15-1517-2021, 2021
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Christian B. Rodehacke, Madlene Pfeiffer, Tido Semmler, Özgür Gurses, and Thomas Kleiner
Earth Syst. Dynam., 11, 1153–1194, https://doi.org/10.5194/esd-11-1153-2020, https://doi.org/10.5194/esd-11-1153-2020, 2020
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Martin Rückamp, Heiko Goelzer, and Angelika Humbert
The Cryosphere, 14, 3309–3327, https://doi.org/10.5194/tc-14-3309-2020, https://doi.org/10.5194/tc-14-3309-2020, 2020
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Martin Rückamp, Angelika Humbert, Thomas Kleiner, Mathieu Morlighem, and Helene Seroussi
Geosci. Model Dev., 13, 4491–4501, https://doi.org/10.5194/gmd-13-4491-2020, https://doi.org/10.5194/gmd-13-4491-2020, 2020
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We present enthalpy formulations within the Ice-Sheet and Sea-Level System model that show better performance than earlier implementations. A first experiment indicates that the treatment of discontinuous conductivities of the solid–fluid system with a geometric mean produce accurate results when applied to coarse vertical resolutions. In a second experiment, we propose a novel stabilization formulation that avoids the problem of thin elements. This method provides accurate and stable results.
Heiko Goelzer, Sophie Nowicki, Anthony Payne, Eric Larour, Helene Seroussi, William H. Lipscomb, Jonathan Gregory, Ayako Abe-Ouchi, Andrew Shepherd, Erika Simon, Cécile Agosta, Patrick Alexander, Andy Aschwanden, Alice Barthel, Reinhard Calov, Christopher Chambers, Youngmin Choi, Joshua Cuzzone, Christophe Dumas, Tamsin Edwards, Denis Felikson, Xavier Fettweis, Nicholas R. Golledge, Ralf Greve, Angelika Humbert, Philippe Huybrechts, Sebastien Le clec'h, Victoria Lee, Gunter Leguy, Chris Little, Daniel P. Lowry, Mathieu Morlighem, Isabel Nias, Aurelien Quiquet, Martin Rückamp, Nicole-Jeanne Schlegel, Donald A. Slater, Robin S. Smith, Fiamma Straneo, Lev Tarasov, Roderik van de Wal, and Michiel van den Broeke
The Cryosphere, 14, 3071–3096, https://doi.org/10.5194/tc-14-3071-2020, https://doi.org/10.5194/tc-14-3071-2020, 2020
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In this paper we use a large ensemble of Greenland ice sheet models forced by six different global climate models to project ice sheet changes and sea-level rise contributions over the 21st century.
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Hélène Seroussi, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
The Cryosphere, 14, 3033–3070, https://doi.org/10.5194/tc-14-3033-2020, https://doi.org/10.5194/tc-14-3033-2020, 2020
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The Antarctic ice sheet has been losing mass over at least the past 3 decades in response to changes in atmospheric and oceanic conditions. This study presents an ensemble of model simulations of the Antarctic evolution over the 2015–2100 period based on various ice sheet models, climate forcings and emission scenarios. Results suggest that the West Antarctic ice sheet will continue losing a large amount of ice, while the East Antarctic ice sheet could experience increased snow accumulation.
Tuukka Petäjä, Ella-Maria Duplissy, Ksenia Tabakova, Julia Schmale, Barbara Altstädter, Gerard Ancellet, Mikhail Arshinov, Yurii Balin, Urs Baltensperger, Jens Bange, Alison Beamish, Boris Belan, Antoine Berchet, Rossana Bossi, Warren R. L. Cairns, Ralf Ebinghaus, Imad El Haddad, Beatriz Ferreira-Araujo, Anna Franck, Lin Huang, Antti Hyvärinen, Angelika Humbert, Athina-Cerise Kalogridis, Pavel Konstantinov, Astrid Lampert, Matthew MacLeod, Olivier Magand, Alexander Mahura, Louis Marelle, Vladimir Masloboev, Dmitri Moisseev, Vaios Moschos, Niklas Neckel, Tatsuo Onishi, Stefan Osterwalder, Aino Ovaska, Pauli Paasonen, Mikhail Panchenko, Fidel Pankratov, Jakob B. Pernov, Andreas Platis, Olga Popovicheva, Jean-Christophe Raut, Aurélie Riandet, Torsten Sachs, Rosamaria Salvatori, Roberto Salzano, Ludwig Schröder, Martin Schön, Vladimir Shevchenko, Henrik Skov, Jeroen E. Sonke, Andrea Spolaor, Vasileios K. Stathopoulos, Mikko Strahlendorff, Jennie L. Thomas, Vito Vitale, Sterios Vratolis, Carlo Barbante, Sabine Chabrillat, Aurélien Dommergue, Konstantinos Eleftheriadis, Jyri Heilimo, Kathy S. Law, Andreas Massling, Steffen M. Noe, Jean-Daniel Paris, André S. H. Prévôt, Ilona Riipinen, Birgit Wehner, Zhiyong Xie, and Hanna K. Lappalainen
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The role of polar regions is increasing in terms of megatrends such as globalization, new transport routes, demography, and the use of natural resources with consequent effects on regional and transported pollutant concentrations. Here we summarize initial results from our integrative project exploring the Arctic environment and pollution to deliver data products, metrics, and indicators for stakeholders.
Stephen L. Cornford, Helene Seroussi, Xylar S. Asay-Davis, G. Hilmar Gudmundsson, Rob Arthern, Chris Borstad, Julia Christmann, Thiago Dias dos Santos, Johannes Feldmann, Daniel Goldberg, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, Gunter Leguy, William H. Lipscomb, Nacho Merino, Gaël Durand, Mathieu Morlighem, David Pollard, Martin Rückamp, C. Rosie Williams, and Hongju Yu
The Cryosphere, 14, 2283–2301, https://doi.org/10.5194/tc-14-2283-2020, https://doi.org/10.5194/tc-14-2283-2020, 2020
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We present the results of the third Marine Ice Sheet Intercomparison Project (MISMIP+). MISMIP+ is one in a series of exercises that test numerical models of ice sheet flow in simple situations. This particular exercise concentrates on the response of ice sheet models to the thinning of their floating ice shelves, which is of interest because numerical models are currently used to model the response to contemporary and near-future thinning in Antarctic ice shelves.
Michael Kern, Robert Cullen, Bruno Berruti, Jerome Bouffard, Tania Casal, Mark R. Drinkwater, Antonio Gabriele, Arnaud Lecuyot, Michael Ludwig, Rolv Midthassel, Ignacio Navas Traver, Tommaso Parrinello, Gerhard Ressler, Erik Andersson, Cristina Martin-Puig, Ole Andersen, Annett Bartsch, Sinead Farrell, Sara Fleury, Simon Gascoin, Amandine Guillot, Angelika Humbert, Eero Rinne, Andrew Shepherd, Michiel R. van den Broeke, and John Yackel
The Cryosphere, 14, 2235–2251, https://doi.org/10.5194/tc-14-2235-2020, https://doi.org/10.5194/tc-14-2235-2020, 2020
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The Copernicus Polar Ice and Snow Topography Altimeter will provide high-resolution sea ice thickness and land ice elevation measurements and the capability to determine the properties of snow cover on ice to serve operational products and services of direct relevance to the polar regions. This paper describes the mission objectives, identifies the key contributions the CRISTAL mission will make, and presents a concept – as far as it is already defined – for the mission payload.
Anders Levermann, Ricarda Winkelmann, Torsten Albrecht, Heiko Goelzer, Nicholas R. Golledge, Ralf Greve, Philippe Huybrechts, Jim Jordan, Gunter Leguy, Daniel Martin, Mathieu Morlighem, Frank Pattyn, David Pollard, Aurelien Quiquet, Christian Rodehacke, Helene Seroussi, Johannes Sutter, Tong Zhang, Jonas Van Breedam, Reinhard Calov, Robert DeConto, Christophe Dumas, Julius Garbe, G. Hilmar Gudmundsson, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, William H. Lipscomb, Malte Meinshausen, Esmond Ng, Sophie M. J. Nowicki, Mauro Perego, Stephen F. Price, Fuyuki Saito, Nicole-Jeanne Schlegel, Sainan Sun, and Roderik S. W. van de Wal
Earth Syst. Dynam., 11, 35–76, https://doi.org/10.5194/esd-11-35-2020, https://doi.org/10.5194/esd-11-35-2020, 2020
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We provide an estimate of the future sea level contribution of Antarctica from basal ice shelf melting up to the year 2100. The full uncertainty range in the warming-related forcing of basal melt is estimated and applied to 16 state-of-the-art ice sheet models using a linear response theory approach. The sea level contribution we obtain is very likely below 61 cm under unmitigated climate change until 2100 (RCP8.5) and very likely below 40 cm if the Paris Climate Agreement is kept.
Nikolay V. Koldunov, Vadym Aizinger, Natalja Rakowsky, Patrick Scholz, Dmitry Sidorenko, Sergey Danilov, and Thomas Jung
Geosci. Model Dev., 12, 3991–4012, https://doi.org/10.5194/gmd-12-3991-2019, https://doi.org/10.5194/gmd-12-3991-2019, 2019
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We measure how computational performance of the global FESOM2 ocean model (formulated on an unstructured mesh) changes with the increase in the number of computational cores. We find that for many components of the model the performance increases linearly but we also identify two bottlenecks: sea ice and ssh submodules. We show that FESOM2 is on par with the state-of-the-art ocean models in terms of throughput that reach 16 simulated years per day for eddy resolving configuration (1/10°).
Johanna Beckmann, Mahé Perrette, Sebastian Beyer, Reinhard Calov, Matteo Willeit, and Andrey Ganopolski
The Cryosphere, 13, 2281–2301, https://doi.org/10.5194/tc-13-2281-2019, https://doi.org/10.5194/tc-13-2281-2019, 2019
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Submarine melting (SM) has been discussed as potentially triggering the recently observed retreat at outlet glaciers in Greenland. How much it may contribute in terms of future sea level rise (SLR) has not been quantified yet. When accounting for SM in our experiments, SLR contribution of 12 outlet glaciers increases by over 3-fold until the year 2100 under RCP8.5. Scaling up from 12 to all of Greenland's outlet glaciers increases future SLR contribution of Greenland by 50 %.
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.
Anna Winter, Daniel Steinhage, Timothy T. Creyts, Thomas Kleiner, and Olaf Eisen
Earth Syst. Sci. Data, 11, 1069–1081, https://doi.org/10.5194/essd-11-1069-2019, https://doi.org/10.5194/essd-11-1069-2019, 2019
Hélène Seroussi, Sophie Nowicki, Erika Simon, Ayako Abe-Ouchi, Torsten Albrecht, Julien Brondex, Stephen Cornford, Christophe Dumas, Fabien Gillet-Chaulet, Heiko Goelzer, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Thomas Kleiner, Eric Larour, Gunter Leguy, William H. Lipscomb, Daniel Lowry, Matthias Mengel, Mathieu Morlighem, Frank Pattyn, Anthony J. Payne, David Pollard, Stephen F. Price, Aurélien Quiquet, Thomas J. Reerink, Ronja Reese, Christian B. Rodehacke, Nicole-Jeanne Schlegel, Andrew Shepherd, Sainan Sun, Johannes Sutter, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, and Tong Zhang
The Cryosphere, 13, 1441–1471, https://doi.org/10.5194/tc-13-1441-2019, https://doi.org/10.5194/tc-13-1441-2019, 2019
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We compare a wide range of Antarctic ice sheet simulations with varying initialization techniques and model parameters to understand the role they play on the projected evolution of this ice sheet under simple scenarios. Results are improved compared to previous assessments and show that continued improvements in the representation of the floating ice around Antarctica are critical to reduce the uncertainty in the future ice sheet contribution to sea level rise.
Martin Rückamp, Ulrike Falk, Katja Frieler, Stefan Lange, and Angelika Humbert
Earth Syst. Dynam., 9, 1169–1189, https://doi.org/10.5194/esd-9-1169-2018, https://doi.org/10.5194/esd-9-1169-2018, 2018
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Sea-level rise associated with changing climate is expected to pose a major challenge for societies. Based on the efforts of COP21 to limit global warming to 2.0 °C by the end of the 21st century (Paris Agreement), we simulate the future contribution of the Greenland ice sheet (GrIS) to sea-level change. The projected sea-level rise ranges between 21–38 mm by 2100
and 36–85 mm by 2300. Our results indicate that uncertainties in the projections stem from the underlying climate data.
Reinhard Calov, Sebastian Beyer, Ralf Greve, Johanna Beckmann, Matteo Willeit, Thomas Kleiner, Martin Rückamp, Angelika Humbert, and Andrey Ganopolski
The Cryosphere, 12, 3097–3121, https://doi.org/10.5194/tc-12-3097-2018, https://doi.org/10.5194/tc-12-3097-2018, 2018
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We present RCP 4.5 and 8.5 projections for the Greenland glacial system with the new glacial system model IGLOO 1.0, which incorporates the ice sheet model SICOPOLIS 3.3, a model of basal hydrology and a parameterization of submarine melt of outlet glaciers. Surface temperature and mass balance anomalies from the MAR climate model serve as forcing delivering projections for the contribution of the Greenland ice sheet to sea level rise and submarine melt of Helheim and Store outlet glaciers.
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.
Melanie Rankl, Johannes Jakob Fürst, Angelika Humbert, and Matthias Holger Braun
The Cryosphere, 11, 1199–1211, https://doi.org/10.5194/tc-11-1199-2017, https://doi.org/10.5194/tc-11-1199-2017, 2017
Eythor Gudlaugsson, Angelika Humbert, Thomas Kleiner, Jack Kohler, and Karin Andreassen
The Cryosphere, 10, 751–760, https://doi.org/10.5194/tc-10-751-2016, https://doi.org/10.5194/tc-10-751-2016, 2016
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This paper explores the influence of a subglacial lake on ice dynamics and internal layers by means of numerical modelling as well as simulating the effect of a subglacial drainage event on isochrones. We provide an explanation for characteristic dip and ridge features found at the edges of many subglacial lakes and conclude that draining lakes can result in travelling waves at depth within isochrones, thus indicating the possibility of detecting past drainage events with ice penetrating radar.
Johannes H. Bondzio, Hélène Seroussi, Mathieu Morlighem, Thomas Kleiner, Martin Rückamp, Angelika Humbert, and Eric Y. Larour
The Cryosphere, 10, 497–510, https://doi.org/10.5194/tc-10-497-2016, https://doi.org/10.5194/tc-10-497-2016, 2016
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We implemented a level-set method in the ice sheet system model. This method allows us to dynamically evolve a calving front subject to user-defined calving rates. We apply the method to Jakobshavn Isbræ, West Greenland, and study its response to calving rate perturbations. We find its behaviour strongly dependent on the calving rate, which was to be expected. Both reduced basal drag and rheological shear margin weakening sustain the acceleration of this dynamic outlet glacier.
J. Christmann, R. Müller, K. G. Webber, D. Isaia, F. H. Schader, S. Kipfstuhl, J. Freitag, and A. Humbert
Earth Syst. Sci. Data, 7, 87–92, https://doi.org/10.5194/essd-7-87-2015, https://doi.org/10.5194/essd-7-87-2015, 2015
N. Wilkens, J. Behrens, T. Kleiner, D. Rippin, M. Rückamp, and A. Humbert
The Cryosphere, 9, 675–690, https://doi.org/10.5194/tc-9-675-2015, https://doi.org/10.5194/tc-9-675-2015, 2015
T. Kleiner, M. Rückamp, J. H. Bondzio, and A. Humbert
The Cryosphere, 9, 217–228, https://doi.org/10.5194/tc-9-217-2015, https://doi.org/10.5194/tc-9-217-2015, 2015
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We present benchmark experiments and analytical solutions to test the implementation of enthalpy and the corresponding boundary conditions in numerical ice sheet models. The results of the applied models agree well with the analytical solutions if the change in conductivity between cold and temperate ice is properly considered in the model.
V. Helm, A. Humbert, and H. Miller
The Cryosphere, 8, 1539–1559, https://doi.org/10.5194/tc-8-1539-2014, https://doi.org/10.5194/tc-8-1539-2014, 2014
Related subject area
Discipline: Ice sheets | Subject: Glacier Hydrology
Deep clustering in subglacial radar reflectance reveals subglacial lakes
Partial melting in polycrystalline ice: pathways identified in 3D neutron tomographic images
Evaluation of satellite methods for estimating supraglacial lake depth in southwest Greenland
Observed and modeled moulin heads in the Pâkitsoq region of Greenland suggest subglacial channel network effects
In situ measurements of meltwater flow through snow and firn in the accumulation zone of the SW Greenland Ice Sheet
Controls on Greenland moulin geometry and evolution from the Moulin Shape model
Supraglacial streamflow and meteorological drivers from southwest Greenland
Hourly surface meltwater routing for a Greenlandic supraglacial catchment across hillslopes and through a dense topological channel network
Challenges in predicting Greenland supraglacial lake drainages at the regional scale
Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers
Modelling the fate of surface melt on the Larsen C Ice Shelf
Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams
Sheng Dong, Lei Fu, Xueyuan Tang, Zefeng Li, and Xiaofei Chen
The Cryosphere, 18, 1241–1257, https://doi.org/10.5194/tc-18-1241-2024, https://doi.org/10.5194/tc-18-1241-2024, 2024
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Subglacial lakes are a unique environment at the bottom of ice sheets, and they have distinct features in radar echo images that allow for visual detection. In this study, we use machine learning to analyze radar reflection waveforms and identify candidate subglacial lakes. Our approach detects more lakes than known inventories and can be used to expand the subglacial lake inventory. Additionally, this analysis may also provide insights into interpreting other subglacial conditions.
Christopher J. L. Wilson, Mark Peternell, Filomena Salvemini, Vladimir Luzin, Frieder Enzmann, Olga Moravcova, and Nicholas J. R. Hunter
The Cryosphere, 18, 819–836, https://doi.org/10.5194/tc-18-819-2024, https://doi.org/10.5194/tc-18-819-2024, 2024
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As the temperature increases within a deforming ice aggregate, composed of deuterium (D2O) ice and water (H2O) ice, a set of meltwater segregations are produced. These are composed of H2O and HDO and are located in conjugate shear bands and in compaction bands which accommodate the deformation and weaken the ice aggregate. This has major implications for the passage of meltwater in ice sheets and the formation of the layering recognized in glaciers.
Laura Melling, Amber Leeson, Malcolm McMillan, Jennifer Maddalena, Jade Bowling, Emily Glen, Louise Sandberg Sørensen, Mai Winstrup, and Rasmus Lørup Arildsen
The Cryosphere, 18, 543–558, https://doi.org/10.5194/tc-18-543-2024, https://doi.org/10.5194/tc-18-543-2024, 2024
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Lakes on glaciers hold large volumes of water which can drain through the ice, influencing estimates of sea level rise. To estimate water volume, we must calculate lake depth. We assessed the accuracy of three satellite-based depth detection methods on a study area in western Greenland and considered the implications for quantifying the volume of water within lakes. We found that the most popular method of detecting depth on the ice sheet scale has higher uncertainty than previously assumed.
Celia Trunz, Kristin Poinar, Lauren C. Andrews, Matthew D. Covington, Jessica Mejia, Jason Gulley, and Victoria Siegel
The Cryosphere, 17, 5075–5094, https://doi.org/10.5194/tc-17-5075-2023, https://doi.org/10.5194/tc-17-5075-2023, 2023
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Models simulating water pressure variations at the bottom of glaciers must use large storage parameters to produce realistic results. Whether that storage occurs englacially (in moulins) or subglacially is a matter of debate. Here, we directly simulate moulin volume to constrain the storage there. We find it is not enough. Instead, subglacial processes, including basal melt and input from upstream moulins, must be responsible for stabilizing these water pressure fluctuations.
Nicole Clerx, Horst Machguth, Andrew Tedstone, Nicolas Jullien, Nander Wever, Rolf Weingartner, and Ole Roessler
The Cryosphere, 16, 4379–4401, https://doi.org/10.5194/tc-16-4379-2022, https://doi.org/10.5194/tc-16-4379-2022, 2022
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Meltwater runoff is one of the main contributors to mass loss on the Greenland Ice Sheet that influences global sea level rise. However, it remains unclear where meltwater runs off and what processes cause this. We measured the velocity of meltwater flow through snow on the ice sheet, which ranged from 0.17–12.8 m h−1 for vertical percolation and from 1.3–15.1 m h−1 for lateral flow. This is an important step towards understanding where, when and why meltwater runoff occurs on the ice sheet.
Lauren C. Andrews, Kristin Poinar, and Celia Trunz
The Cryosphere, 16, 2421–2448, https://doi.org/10.5194/tc-16-2421-2022, https://doi.org/10.5194/tc-16-2421-2022, 2022
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We introduce a model for moulin geometry motivated by the wide range of sizes and shapes of explored moulins. Moulins comprise 10–14 % of the Greenland englacial–subglacial hydrologic system and act as time-varying water storage reservoirs. Moulin geometry can vary approximately 10 % daily and over 100 % seasonally. Moulin shape modulates the efficiency of the subglacial system that controls ice flow and should thus be included in hydrologic models.
Rohi Muthyala, Åsa K. Rennermalm, Sasha Z. Leidman, Matthew G. Cooper, Sarah W. Cooley, Laurence C. Smith, and Dirk van As
The Cryosphere, 16, 2245–2263, https://doi.org/10.5194/tc-16-2245-2022, https://doi.org/10.5194/tc-16-2245-2022, 2022
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In situ measurements of meltwater discharge through supraglacial stream networks are rare. The unprecedentedly long record of discharge captures diurnal and seasonal variability. Two major findings are (1) a change in the timing of peak discharge through the melt season that could impact meltwater delivery in the subglacial system and (2) though the primary driver of stream discharge is shortwave radiation, longwave radiation and turbulent heat fluxes play a major role during high-melt episodes.
Colin J. Gleason, Kang Yang, Dongmei Feng, Laurence C. Smith, Kai Liu, Lincoln H. Pitcher, Vena W. Chu, Matthew G. Cooper, Brandon T. Overstreet, Asa K. Rennermalm, and Jonathan C. Ryan
The Cryosphere, 15, 2315–2331, https://doi.org/10.5194/tc-15-2315-2021, https://doi.org/10.5194/tc-15-2315-2021, 2021
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We apply first-principle hydrology models designed for global river routing to route flows hourly through 10 000 individual supraglacial channels in Greenland. Our results uniquely show the role of process controls (network density, hillslope flow, channel friction) on routed meltwater. We also confirm earlier suggestions that large channels do not dewater overnight despite the shutdown of runoff and surface mass balance runoff being mistimed and overproducing runoff, as validated in situ.
Kristin Poinar and Lauren C. Andrews
The Cryosphere, 15, 1455–1483, https://doi.org/10.5194/tc-15-1455-2021, https://doi.org/10.5194/tc-15-1455-2021, 2021
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This study addresses Greenland supraglacial lake drainages. We analyze ice deformation associated with lake drainages over 18 summers to assess whether
precursorstrain-rate events consistently precede lake drainages. We find that currently available remote sensing data products cannot resolve these events, and thus we cannot predict future lake drainages. Thus, future avenues for evaluating this hypothesis will require major field-based GPS or photogrammetry efforts.
Léo Decaux, Mariusz Grabiec, Dariusz Ignatiuk, and Jacek Jania
The Cryosphere, 13, 735–752, https://doi.org/10.5194/tc-13-735-2019, https://doi.org/10.5194/tc-13-735-2019, 2019
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Due to the fast melting of glaciers around the world, it is important to characterize the evolution of the meltwater circulation beneath them as it highly impacts their velocity. By using very
high-resolution satellite images and field measurements, we modelized it for two Svalbard glaciers. We determined that for most of Svalbard glaciers it is crucial to include their surface morphology to obtain a reliable model, which is not currently done. Having good models is key to predicting our future.
Sammie Buzzard, Daniel Feltham, and Daniela Flocco
The Cryosphere, 12, 3565–3575, https://doi.org/10.5194/tc-12-3565-2018, https://doi.org/10.5194/tc-12-3565-2018, 2018
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Surface lakes on ice shelves can not only change the amount of solar energy the ice shelf receives, but may also play a pivotal role in sudden ice shelf collapse such as that of the Larsen B Ice Shelf in 2002.
Here we simulate current and future melting on Larsen C, Antarctica’s most northern ice shelf and one on which lakes have been observed. We find that should future lakes occur closer to the ice shelf front, they may contain sufficient meltwater to contribute to ice shelf instability.
Thomas Lelandais, Édouard Ravier, Stéphane Pochat, Olivier Bourgeois, Christopher Clark, Régis Mourgues, and Pierre Strzerzynski
The Cryosphere, 12, 2759–2772, https://doi.org/10.5194/tc-12-2759-2018, https://doi.org/10.5194/tc-12-2759-2018, 2018
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Scattered observations suggest that subglacial meltwater routes drive ice stream dynamics and ice sheet stability. We use a new experimental approach to reconcile such observations into a coherent story connecting ice stream life cycles with subglacial hydrology and bed erosion. Results demonstrate that subglacial flooding, drainage reorganization, and valley development can control an ice stream lifespan, thus opening new perspectives on subglacial processes controlling ice sheet instabilities.
Cited articles
Bartholomew, I., Nienow, P., Mair, D., Hubbard, A., King, M. A., and Sole, A.:
Seasonal evolution of subglacial drainage and acceleration in a Greenland
outlet glacier, Nat. Geosci., 3, 408–411, https://doi.org/10.1038/ngeo863, 2010. a
Blatter, H.: Velocity and stress fields in grounded glaciers: a simple
algorithm for including deviatoric stress gradients, J. Glaciol.,
41, 333–344, https://doi.org/10.3189/S002214300001621X, 1995. a
Bondzio, J. H., Morlighem, M., Seroussi, H., Kleiner, T., Rückamp, M.,
Mouginot, J., Moon, T., Larour, E. Y., and Humbert, A.: The mechanisms behind
Jakobshavn Isbræ's acceleration and mass loss: A 3-D thermomechanical
model study, Geophys. Res. Lett., 44, 6252–6260,
https://doi.org/10.1002/2017GL073309, 2017. a
Bueler, E. and van Pelt, W.: Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model version 0.6,
Geosci. Model Dev., 8, 1613–1635, https://doi.org/10.5194/gmd-8-1613-2015, 2015. a
Celia, M. A., Bouloutas, E. T., and Zarba, R. L.: A general mass-conservative
numerical solution for the unsaturated flow equation, Water Resour. Res., 26, 1483–1496, https://doi.org/10.1029/WR026i007p01483, 1990. a
de Fleurian, B., Gagliardini, O., Zwinger, T., Durand, G., Le Meur, E., Mair, D., and Råback, P.: A double continuum
hydrological model for glacier applications, The Cryosphere, 8, 137–153, https://doi.org/10.5194/tc-8-137-2014, 2014. a, b, c, d
de Fleurian, B., Morlighem, M., Seroussi, H., Rignot, E., van den Broeke,
M. R., Kuipers Munneke, P., Mouginot, J., Smeets, P. C. J. P., and Tedstone,
A. J.: A modeling study of the effect of runoff variability on the effective
pressure beneath Russell Glacier, West Greenland, J. Geophys. Res.-Earth, 121, 1834–1848,
https://doi.org/10.1002/2016JF003842, 2016. a, b, c
de Fleurian, B., Werder, M. A., Beyer, S., Brinkerhoff, D. J., Delaney, I.,
Dow, C. F., Downs, J., Gagliardini, O., Hoffman, M. J., LeB Hooke, R.,
Seguinot, J., and Sommers, A. N.: SHMIP The subglacial hydrology model
intercomparison project, J. Glaciol., 1–20,
https://doi.org/10.1017/jog.2018.78, 2018. a
Ehlig, C. and Halepaska, J. C.: A numerical study of confined-unconfined
aquifers including effects of delayed yield and leakage, Water Resour. Res., 12, 1175–1183, https://doi.org/10.1029/WR012i006p01175, 1976. a, b
Fahnestock, M., Abdalati, W., Joughin, I., Brozena, J., and Gogineni, P.: High
geothermal heat flow, basal melt, and the origin of rapid ice flow in central
Greenland, Science, 294, 2338–2342, https://doi.org/10.1126/science.1065370, 2001. a
Ferziger, J. H. and Perić, M.: Computational Methods for Fluid
Dynamics, Springer-Verlag Berlin Heidelberg, 3rd edn.,
https://doi.org/10.1007/978-3-642-56026-2, 2002. a
Flowers, G. E.: Modelling water flow under glaciers and ice sheets, P. R. Soc. A, 471,
20140907, https://doi.org/10.1098/rspa.2014.0907, 2015. a
Gimbert, F., Tsai, V. C., Amundson, J. M., Bartholomaus, T. C., and Walter,
J. I.: Subseasonal changes observed in subglacial channel pressure, size, and
sediment transport, Geophys. Res. Lett., 43, 3786–3794, 2016. a
Goelzer, H., Nowicki, S., Edwards, T., Beckley, M., Abe-Ouchi, A., Aschwanden, A., Calov, R., Gagliardini, O., Gillet-Chaulet, F.,
Golledge, N. R., Gregory, J., Greve, R., Humbert, A., Huybrechts, P., Kennedy, J. H., Larour, E., Lipscomb, W. H.,
Le clec'h, S., Lee, V., Morlighem, M., Pattyn, F., Payne, A. J., Rodehacke, C., Rückamp, M., Saito, F., Schlegel, N.,
Seroussi, H., Shepherd, A., Sun, S., van de Wal, R., and Ziemen, F. A.: Design and results of the ice sheet model
initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison, The Cryosphere, 12, 1433–1460, https://doi.org/10.5194/tc-12-1433-2018, 2018. a
Hewitt, I. J.: Modelling distributed and channelized subglacial drainage: the
spacing of channels, J. Glaciol., 57, 302–314,
https://doi.org/10.3189/002214311796405951, 2011. a
Hewitt, I. J.: Seasonal changes in ice sheet motion due to melt water
lubrication, Earth Planet. Sc. Lett., 371, 16–25,
https://doi.org/10.1016/j.epsl.2013.04.022, 2013. a
Hewitt, I. J., Schoof, C., and Werder, M. A.: Flotation and free surface flow
in a model for subglacial drainage. Part 2. Channel flow, J. Fluid
Mech., 702, 157–187, https://doi.org/10.1017/jfm.2012.166, 2012. a
Hill, E. A., Carr, J. R., and Stokes, C. R.: A Review of Recent Changes in
Major Marine-Terminating Outlet Glaciers in Northern Greenland,
Front. Earth Sci., 4, 111, https://doi.org/10.3389/feart.2016.00111, 2017. a
Hoffman, M. and Price, S.: Feedbacks between coupled subglacial hydrology and
glacier dynamics, J. Geophys. Res.-Earth, 119,
414–436, https://doi.org/10.1002/2013JF002943, 2014. a
Hubbard, B. P., Sharp, M. J., Willis, I. C., Nielsen, M. K., and Smart, C. C.:
Borehole water-level variations and the structure of the subglacial
hydrological system of Haut Glacier d'Arolla, Valais, Switzerland,
J. Glaciol., 41, 572–583, https://doi.org/10.3189/S0022143000034894, 1995. a
Huybrechts, P.: A 3-D model for the Antarctic ice sheet: a sensitivity study
on the glacial-interglacial contrast, Clim. Dynam., 5, 79–92,
https://doi.org/10.1007/BF00207423, 1990. a
Joughin, I., Fahnestock, M., MacAyeal, D., Bamber, J. L., and Gogineni, P.:
Observation and analysis of ice flow in the largest Greenland ice stream,
J. Geophys. Res.-Atmos., 106, 34021–34034,
https://doi.org/10.1029/2001JD900087, 2001. a
Joughin, I., Smith, B. E., Howat, I. M., Scambos, T., and Moon, T.: Greenland
flow variability from ice-sheet-wide velocity mapping, J. Glaciol.,
56, 415–430, https://doi.org/10.3189/002214310792447734, 2010. a
Kamb, B.: Glacier surge mechanism based on linked cavity configuration of the
basal water conduit system, J. Geophys. Res.-Sol. Ea., 92,
9083–9100, https://doi.org/10.1029/JB092iB09p09083, 1987. a, b
Kolditz, O., Shao, H., Wang, W., and Bauer, S. (Eds.):
Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous
Media: Modelling and Benchmarking, Springer, 1st edn.,
https://doi.org/10.1007/978-3-319-11894-9, 2015. a
Larour, E., Seroussi, H., Morlighem, M., and Rignot, E.: Continental scale,
high order, high spatial resolution, ice sheet modeling using the Ice
Sheet System Model (ISSM), J. Geophys. Res.-Earth, 117, F01022, https://doi.org/10.1029/2011JF002140, 2012. a
Lliboutry, L.: General theory of subglacial cavitation and sliding of
temperate glaciers, J. Glaciol., 7, 21–58,
https://doi.org/10.3189/S0022143000020396, 1968. a, b
Morlighem, M., Rignot, E., Mouginot, J., Seroussi, H., and Larour, E.: Deeply
incised submarine glacial valleys beneath the Greenland ice sheet, Nat. Geosci., 7, 418–422, https://doi.org/10.1038/ngeo2167, 2014. a
Morlighem, M., Bondzio, J., Seroussi, H., Rignot, E., Larour, E., Humbert, A.,
and Rebuffi, S.: Modeling of Store Gletscher's calving dynamics, West
Greenland, in response to ocean thermal forcing, Geophys. Res. Lett., 43, 2659–2666, https://doi.org/10.1002/2016gl067695, 2016. a
Nye, J. F.: Water flow in glaciers: Jökulhlaups, tunnels and veins, J. Glaciol., 17, 181–207, https://doi.org/10.3189/S002214300001354X, 1976. a, b, c, d
Pattyn, F.: A new three-dimensional higher-order thermomechanical ice sheet
model: Basic sensitivity, ice stream development, and ice flow across
subglacial lakes, J. Geophys. Res.-Sol. Ea., 108, 2382,
https://doi.org/10.1029/2002JB002329, 2003. a
Rignot, E. and Mouginot, J.: Ice flow in Greenland for the international polar
year 2008–2009, Geophys. Res. Lett., 39, L11501,
https://doi.org/10.1029/2012GL051634, 2012.
a, b, c, d
Röthlisberger, H.: Water Pressure in Intra- and Subglacial Channels,
J. Glaciol., 11, 177–203, https://doi.org/10.1017/S0022143000022188, 1972. a, b
Schoof, C.: Ice-sheet acceleration driven by melt supply variability, Nature,
468, 803–806, https://doi.org/10.1038/nature09618, 2010. a, b
Shreve, R. L.: Movement of water in glaciers, J. Glaciol., 11,
205–214, https://doi.org/10.3189/S002214300002219X, 1972. a
Teutsch, G. and Sauter, M.:
Groundwater modeling in karst terranes: Scale effects, data acquisition and field validation,
Third Conference on Hydrogeology, Ecology, Monitoring, and Management of Ground Water in Karst Terranes,
National Ground Water Association, Dublin, Ohio,
17–35, 1991. a
Vallelonga, P., Christianson, K., Alley, R. B., Anandakrishnan, S., Christian, J. E. M., Dahl-Jensen, D., Gkinis, V., Holme, C.,
Jacobel, R. W., Karlsson, N. B., Keisling, B. A., Kipfstuhl, S., Kjær, H. A., Kristensen, M. E. L., Muto, A., Peters, L. E.,
Popp, T., Riverman, K. L., Svensson, A. M., Tibuleac, C., Vinther, B. M., Weng, Y., and Winstrup, M.: Initial results from
geophysical surveys and shallow coring of the Northeast Greenland Ice Stream (NEGIS), The Cryosphere, 8, 1275–1287, https://doi.org/10.5194/tc-8-1275-2014, 2014. a
van den Broeke, M., Box, J., Fettweis, X., Hanna, E., Noël, B., Tedesco,
M., van As, D., van de Berg, W. J., and van Kampenhout, L.: Greenland Ice
Sheet Surface Mass Loss: Recent Developments in Observation and
Modeling, Current Climate Change Reports, 3, 345–356,
https://doi.org/10.1007/s40641-017-0084-8, 2017. a
Van Siclen, C. D.: Equivalent channel network model for permeability and
electrical conductivity of fracture networks, J. Geophys.
Res.-Sol. Ea., 107, ECV 1-1–ECV 1-10, https://doi.org/10.1029/2000JB000057,
2002. a
Walder, J. S.: Hydraulics of Subglacial Cavities, J. Glaciol., 32,
439–445, https://doi.org/10.3189/S0022143000012156, 1986. a, b
Weertman, J.: On the sliding of glaciers, J. Glaciol., 3, 33–38,
https://doi.org/10.3189/S0022143000024709, 1957. a
Short summary
The evolution of subglacial channels below ice sheets is very important for the dynamics of glaciers as the water acts as a lubricant. We present a new numerical model (CUAS) that generalizes existing approaches by accounting for two different flow situations within a single porous medium layer: (1) a confined aquifer if sufficient water supply is available and (2) an unconfined aquifer, otherwise. The model is applied to artificial scenarios as well as to the Northeast Greenland Ice Stream.
The evolution of subglacial channels below ice sheets is very important for the dynamics of...
