Articles | Volume 12, issue 3
https://doi.org/10.5194/tc-12-1047-2018
© Author(s) 2018. 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-12-1047-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Implementing an empirical scalar constitutive relation for ice with flow-induced polycrystalline anisotropy in large-scale ice sheet models
Felicity S. Graham
CORRESPONDING AUTHOR
Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
Mathieu Morlighem
Department of Earth System Science, University of California, Irvine, California, USA
Roland C. Warner
Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
Adam Treverrow
Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
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Extreme El Niño-Southern Oscillation (ENSO) events have global impacts but their Antarctic impacts are poorly understood. Examining Antarctic snow accumulation impacts of past observed extreme ENSO events, we show that accumulation changes differ between events & are unsignificant during most events. Remarkable changes occur during 2015/16 & in Enderby Land during all extreme El Niños. Historical data limits conclusions but future greater extremes could cause Antarctic accumulation changes.
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Using subglacial hydrology model outputs for Denman Glacier, East Antarctica, we investigated the effects of various friction laws and effective pressure inputs on ice dynamics modeling over the same glacier. The Schoof friction law outperformed the Budd friction law, and effective pressure outputs from the hydrology model outperformed a typically prescribed effective pressure. We propose an empirical prescription of effective pressure to be used in the absence of hydrology model outputs.
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Accurate estimates of englacial temperature and geothermal heat flux are incredibly important
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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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The surface elevation of the Greenland Ice Sheet is changing due to surface mass balance processes and ice dynamics, each exhibiting distinct spatiotemporal patterns. Here, we employ satellite and airborne altimetry data with fine spatial (1 km) and temporal (monthly) resolutions to document this spatiotemporal evolution from 2003 to 2023. This dataset of fine-resolution altimetry data in both space and time will support studies of ice mass loss and useful for GIS ice sheet modelling.
Jessica M. A. Macha, Andrew N. Mackintosh, Felicity S. Mccormack, Benjamin J. Henley, Helen V. McGregor, Christiaan T. van Dalum, and Ariaan Purich
EGUsphere, https://doi.org/10.5194/egusphere-2024-3425, https://doi.org/10.5194/egusphere-2024-3425, 2024
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Extreme El Niño-Southern Oscillation (ENSO) events have global impacts but their Antarctic impacts are poorly understood. Examining Antarctic snow accumulation impacts of past observed extreme ENSO events, we show that accumulation changes differ between events & are unsignificant during most events. Remarkable changes occur during 2015/16 & in Enderby Land during all extreme El Niños. Historical data limits conclusions but future greater extremes could cause Antarctic accumulation changes.
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Calving, the breaking of ice bodies from the terminus of a glacier, plays an important role in the mass losses of Greenland ice sheets. However, calving parameters have been poorly understood because of the intensive computational demands of traditional numerical models. To address this issue and find the optimal calving parameter that best represents real observations, we develop deep-learning emulators based on graph neural network architectures.
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The Cryosphere, 18, 1139–1155, https://doi.org/10.5194/tc-18-1139-2024, https://doi.org/10.5194/tc-18-1139-2024, 2024
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This study conducted 3D thermodynamic ice sheet model experiments, and modeled temperatures were compared with 15 observed borehole temperature profiles. We found that using incompressibility of ice without sliding agrees well with observed temperature profiles in slow-flow regions, while incorporating sliding in fast-flow regions captures observed temperature profiles. Also, the choice of vertical velocity scheme has a greater impact on the shape of the modeled temperature profile.
Anjali Sandip, Ludovic Räss, and Mathieu Morlighem
Geosci. Model Dev., 17, 899–909, https://doi.org/10.5194/gmd-17-899-2024, https://doi.org/10.5194/gmd-17-899-2024, 2024
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Youngmin Choi, Helene Seroussi, Mathieu Morlighem, Nicole-Jeanne Schlegel, and Alex Gardner
The Cryosphere, 17, 5499–5517, https://doi.org/10.5194/tc-17-5499-2023, https://doi.org/10.5194/tc-17-5499-2023, 2023
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Ice sheet models are often initialized using snapshot observations of present-day conditions, but this approach has limitations in capturing the transient evolution of the system. To more accurately represent the accelerating changes in glaciers, we employed time-dependent data assimilation. We found that models calibrated with the transient data better capture past trends and more accurately reproduce changes after the calibration period, even with limited observations.
Francesca Baldacchino, Nicholas R. Golledge, Huw Horgan, Mathieu Morlighem, Alanna V. Alevropoulos-Borrill, Alena Malyarenko, Alexandra Gossart, Daniel P. Lowry, and Laurine van Haastrecht
EGUsphere, https://doi.org/10.5194/egusphere-2023-2793, https://doi.org/10.5194/egusphere-2023-2793, 2023
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Understanding how the Ross Ice Shelf flow is changing in a warming world is important for monitoring mass changes. The flow displays an intra-annual variation; however, it is unclear what mechanisms drive this variability. Sensitivity maps are modelled showing areas of the ice shelf where changes in basal melt most influence the ice flow. We suggest that basal melting partly drives the flow variability along the calving front of the ice shelf and will continue to do so in a warming world.
Hélène Seroussi, Vincent Verjans, 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, Peter Van Katwyk, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
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Mass loss from Antarctica is a key contributor to sea level rise over the 21st century, and the associated uncertainty dominates sea level projections. We highlight here the Antarctic glaciers showing the largest changes and quantify the main sources of uncertainty in their future evolution using an ensemble of ice flow models. We show that on top of Pine Island and Thwaites glaciers, Totten and Moscow University glaciers show rapid changes and a strong sensitivity to warmer ocean conditions.
Joel A. Wilner, Mathieu Morlighem, and Gong Cheng
The Cryosphere, 17, 4889–4901, https://doi.org/10.5194/tc-17-4889-2023, https://doi.org/10.5194/tc-17-4889-2023, 2023
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We use numerical modeling to study iceberg calving off of ice shelves in Antarctica. We examine four widely used mathematical descriptions of calving (
calving laws), under the assumption that Antarctic ice shelf front positions should be in steady state under the current climate forcing. We quantify how well each of these calving laws replicates the observed front positions. Our results suggest that the eigencalving and von Mises laws are most suitable for Antarctic ice shelves.
Koi McArthur, Felicity S. McCormack, and Christine F. Dow
The Cryosphere, 17, 4705–4727, https://doi.org/10.5194/tc-17-4705-2023, https://doi.org/10.5194/tc-17-4705-2023, 2023
Short summary
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Using subglacial hydrology model outputs for Denman Glacier, East Antarctica, we investigated the effects of various friction laws and effective pressure inputs on ice dynamics modeling over the same glacier. The Schoof friction law outperformed the Budd friction law, and effective pressure outputs from the hydrology model outperformed a typically prescribed effective pressure. We propose an empirical prescription of effective pressure to be used in the absence of hydrology model outputs.
Felicity S. McCormack, Jason L. Roberts, Bernd Kulessa, Alan Aitken, Christine F. Dow, Lawrence Bird, Benjamin K. Galton-Fenzi, Katharina Hochmuth, Richard S. Jones, Andrew N. Mackintosh, and Koi McArthur
The Cryosphere, 17, 4549–4569, https://doi.org/10.5194/tc-17-4549-2023, https://doi.org/10.5194/tc-17-4549-2023, 2023
Short summary
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Changes in Antarctic surface elevation can cause changes in ice and basal water flow, impacting how much ice enters the ocean. We find that ice and basal water flow could divert from the Totten to the Vanderford Glacier, East Antarctica, under only small changes in the surface elevation, with implications for estimates of ice loss from this region. Further studies are needed to determine when this could occur and if similar diversions could occur elsewhere in Antarctica due to climate change.
Alice C. Frémand, Peter Fretwell, Julien A. Bodart, Hamish D. Pritchard, Alan Aitken, Jonathan L. Bamber, Robin Bell, Cesidio Bianchi, Robert G. Bingham, Donald D. Blankenship, Gino Casassa, Ginny Catania, Knut Christianson, Howard Conway, Hugh F. J. Corr, Xiangbin Cui, Detlef 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, Andrew O. Hoffman, Per Holmlund, Nicholas Holschuh, John W. Holt, Annika N. Horlings, Angelika Humbert, Robert W. Jacobel, Daniela Jansen, Adrian Jenkins, Wilfried Jokat, Tom Jordan, Edward King, Jack Kohler, William Krabill, Mette Kusk Gillespie, Kirsty Langley, Joohan Lee, German Leitchenkov, Carlton Leuschen, Bruce Luyendyk, Joseph MacGregor, Emma MacKie, Kenichi Matsuoka, Mathieu Morlighem, Jérémie Mouginot, Frank O. Nitsche, Yoshifumi Nogi, Ole A. Nost, John Paden, Frank Pattyn, Sergey V. Popov, Eric Rignot, David M. Rippin, Andrés Rivera, Jason Roberts, Neil Ross, Anotonia 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, 15, 2695–2710, https://doi.org/10.5194/essd-15-2695-2023, https://doi.org/10.5194/essd-15-2695-2023, 2023
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This paper presents the release of over 60 years of ice thickness, bed elevation, 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.
Dominic Saunderson, Andrew Mackintosh, Felicity McCormack, Richard Selwyn Jones, and Ghislain Picard
The Cryosphere, 16, 4553–4569, https://doi.org/10.5194/tc-16-4553-2022, https://doi.org/10.5194/tc-16-4553-2022, 2022
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We investigate the variability in surface melt on the Shackleton Ice Shelf in East Antarctica over the last 2 decades (2003–2021). Using daily satellite observations and the machine learning approach of a self-organising map, we identify nine distinct spatial patterns of melt. These patterns allow comparisons of melt within and across melt seasons and highlight the importance of both air temperatures and local controls such as topography, katabatic winds, and albedo in driving surface melt.
Francesca Baldacchino, Mathieu Morlighem, Nicholas R. Golledge, Huw Horgan, and Alena Malyarenko
The Cryosphere, 16, 3723–3738, https://doi.org/10.5194/tc-16-3723-2022, https://doi.org/10.5194/tc-16-3723-2022, 2022
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Understanding how the Ross Ice Shelf will evolve in a warming world is important to the future stability of Antarctica. It remains unclear what changes could drive the largest mass loss in the future and where places are most likely to trigger larger mass losses. Sensitivity maps are modelled showing that the RIS is sensitive to changes in environmental and glaciological controls at regions which are currently experiencing changes. These regions need to be monitored in a warming world.
Joshua K. Cuzzone, Nicolás E. Young, Mathieu Morlighem, Jason P. Briner, and Nicole-Jeanne Schlegel
The Cryosphere, 16, 2355–2372, https://doi.org/10.5194/tc-16-2355-2022, https://doi.org/10.5194/tc-16-2355-2022, 2022
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We use an ice sheet model to determine what influenced the Greenland Ice Sheet to retreat across a portion of southwestern Greenland during the Holocene (about the last 12 000 years). Our simulations, constrained by observations from geologic markers, show that atmospheric warming and ice melt primarily caused the ice sheet to retreat rapidly across this domain. We find, however, that iceberg calving at the interface where the ice meets the ocean significantly influenced ice mass change.
Zhiang Xie, Dietmar Dommenget, Felicity S. McCormack, and Andrew N. Mackintosh
Geosci. Model Dev., 15, 3691–3719, https://doi.org/10.5194/gmd-15-3691-2022, https://doi.org/10.5194/gmd-15-3691-2022, 2022
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Paleoclimate research requires better numerical model tools to explore interactions among the cryosphere, atmosphere, ocean and land surface. To explore those interactions, this study offers a tool, the GREB-ISM, which can be run for 2 million model years within 1 month on a personal computer. A series of experiments show that the GREB-ISM is able to reproduce the modern ice sheet distribution as well as classic climate oscillation features under paleoclimate conditions.
Yannic Fischler, Martin Rückamp, Christian Bischof, Vadym Aizinger, Mathieu Morlighem, and Angelika Humbert
Geosci. Model Dev., 15, 3753–3771, https://doi.org/10.5194/gmd-15-3753-2022, https://doi.org/10.5194/gmd-15-3753-2022, 2022
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Ice sheet models are used to simulate the changes of ice sheets in future but are currently often run in coarse resolution and/or with neglecting important physics to make them affordable in terms of computational costs. We conducted a study simulating the Greenland Ice Sheet in high resolution and adequate physics to test where the ISSM ice sheet code is using most time and what could be done to improve its performance for future computer architectures that allow massive parallel computing.
Yu Wang, Chen Zhao, Rupert Gladstone, Ben Galton-Fenzi, and Roland Warner
The Cryosphere, 16, 1221–1245, https://doi.org/10.5194/tc-16-1221-2022, https://doi.org/10.5194/tc-16-1221-2022, 2022
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The thermal structure of the Amery Ice Shelf and its spatial pattern are evaluated and analysed through temperature observations from six boreholes and numerical simulations. The simulations demonstrate significant ice warming downstream along the ice flow and a great variation of the thermal structure across the ice flow. We suggest that the thermal structure of the Amery Ice Shelf is unlikely to be affected by current climate changes on decadal timescales.
Thomas Frank, Henning Åkesson, Basile de Fleurian, Mathieu Morlighem, and Kerim H. Nisancioglu
The Cryosphere, 16, 581–601, https://doi.org/10.5194/tc-16-581-2022, https://doi.org/10.5194/tc-16-581-2022, 2022
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The shape of a fjord can promote or inhibit glacier retreat in response to climate change. We conduct experiments with a synthetic setup under idealized conditions in a numerical model to study and quantify the processes involved. We find that friction between ice and fjord is the most important factor and that it is possible to directly link ice discharge and grounding line retreat to fjord topography in a quantitative way.
Thiago Dias dos Santos, Mathieu Morlighem, and Douglas Brinkerhoff
The Cryosphere, 16, 179–195, https://doi.org/10.5194/tc-16-179-2022, https://doi.org/10.5194/tc-16-179-2022, 2022
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Projecting the future evolution of Greenland and Antarctica and their potential contribution to sea level rise often relies on computer simulations carried out by numerical ice sheet models. Here we present a new vertically integrated ice sheet model and assess its performance using different benchmarks. The new model shows results comparable to a three-dimensional model at relatively lower computational cost, suggesting that it is an excellent alternative for long-term simulations.
Matt O'Regan, Thomas M. Cronin, Brendan Reilly, Aage Kristian Olsen Alstrup, Laura Gemery, Anna Golub, Larry A. Mayer, Mathieu Morlighem, Matthias Moros, Ole L. Munk, Johan Nilsson, Christof Pearce, Henrieka Detlef, Christian Stranne, Flor Vermassen, Gabriel West, and Martin Jakobsson
The Cryosphere, 15, 4073–4097, https://doi.org/10.5194/tc-15-4073-2021, https://doi.org/10.5194/tc-15-4073-2021, 2021
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Ryder Glacier is a marine-terminating glacier in north Greenland discharging ice into the Lincoln Sea. Here we use marine sediment cores to reconstruct its retreat and advance behavior through the Holocene. We show that while Sherard Osborn Fjord has a physiography conducive to glacier and ice tongue stability, Ryder still retreated more than 40 km inland from its current position by the Middle Holocene. This highlights the sensitivity of north Greenland's marine glaciers to climate change.
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 %.
Thiago Dias dos Santos, Mathieu Morlighem, and Hélène Seroussi
Geosci. Model Dev., 14, 2545–2573, https://doi.org/10.5194/gmd-14-2545-2021, https://doi.org/10.5194/gmd-14-2545-2021, 2021
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Numerical models are routinely used to understand the past and future behavior of ice sheets in response to climate evolution. As is always the case with numerical modeling, one needs to minimize biases and numerical artifacts due to the choice of numerical scheme employed in such models. Here, we assess different numerical schemes in time-dependent simulations of ice sheets. We also introduce a new parameterization for the driving stress, the force that drives the ice sheet flow.
Jowan M. Barnes, Thiago Dias dos Santos, Daniel Goldberg, G. Hilmar Gudmundsson, Mathieu Morlighem, and Jan De Rydt
The Cryosphere, 15, 1975–2000, https://doi.org/10.5194/tc-15-1975-2021, https://doi.org/10.5194/tc-15-1975-2021, 2021
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Some properties of ice flow models must be initialised using observed data before they can be used to produce reliable predictions of the future. Different models have different ways of doing this, and the process is generally seen as being specific to an individual model. We compare the methods used by three different models and show that they produce similar outputs. We also demonstrate that the outputs from one model can be used in other models without introducing large uncertainties.
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.
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.
Eric Larour, Lambert Caron, Mathieu Morlighem, Surendra Adhikari, Thomas Frederikse, Nicole-Jeanne Schlegel, Erik Ivins, Benjamin Hamlington, Robert Kopp, and Sophie Nowicki
Geosci. Model Dev., 13, 4925–4941, https://doi.org/10.5194/gmd-13-4925-2020, https://doi.org/10.5194/gmd-13-4925-2020, 2020
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ISSM-SLPS is a new projection system for future sea level that increases the resolution and accuracy of current projection systems and improves the way uncertainty is treated in such projections. This will pave the way for better inclusion of state-of-the-art results from existing intercomparison efforts carried out by the scientific community, such as GlacierMIP2 or ISMIP6, into sea-level projections.
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.
The results for two different greenhouse gas concentration scenarios indicate that the Greenland ice sheet will continue to lose mass until 2100, with contributions to sea-level rise of 90 ± 50 mm and 32 ± 17 mm for the high (RCP8.5) and low (RCP2.6) scenario, respectively.
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.
Sophie Nowicki, Heiko Goelzer, Hélène Seroussi, Anthony J. Payne, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Patrick Alexander, Xylar S. Asay-Davis, Alice Barthel, Thomas J. Bracegirdle, Richard Cullather, Denis Felikson, Xavier Fettweis, Jonathan M. Gregory, Tore Hattermann, Nicolas C. Jourdain, Peter Kuipers Munneke, Eric Larour, Christopher M. Little, Mathieu Morlighem, Isabel Nias, Andrew Shepherd, Erika Simon, Donald Slater, Robin S. Smith, Fiammetta Straneo, Luke D. Trusel, Michiel R. van den Broeke, and Roderik van de Wal
The Cryosphere, 14, 2331–2368, https://doi.org/10.5194/tc-14-2331-2020, https://doi.org/10.5194/tc-14-2331-2020, 2020
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This paper describes the experimental protocol for ice sheet models taking part in the Ice Sheet Model Intercomparion Project for CMIP6 (ISMIP6) and presents an overview of the atmospheric and oceanic datasets to be used for the simulations. The ISMIP6 framework allows for exploring the uncertainty in 21st century sea level change from the Greenland and Antarctic ice sheets.
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.
Donald A. Slater, Denis Felikson, Fiamma Straneo, Heiko Goelzer, Christopher M. Little, Mathieu Morlighem, Xavier Fettweis, and Sophie Nowicki
The Cryosphere, 14, 985–1008, https://doi.org/10.5194/tc-14-985-2020, https://doi.org/10.5194/tc-14-985-2020, 2020
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Changes in the ocean around Greenland play an important role in determining how much the ice sheet will contribute to global sea level over the coming century. However, capturing these links in models is very challenging. This paper presents a strategy enabling an ensemble of ice sheet models to feel the effect of the ocean for the first time and should therefore result in a significant improvement in projections of the Greenland ice sheet's contribution to future sea level change.
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.
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.
Tyler Pelle, Mathieu Morlighem, and Johannes H. Bondzio
The Cryosphere, 13, 1043–1049, https://doi.org/10.5194/tc-13-1043-2019, https://doi.org/10.5194/tc-13-1043-2019, 2019
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How ocean-induced melt under floating ice shelves will change as ocean currents evolve remains a big uncertainty in projections of sea level rise. In this study, we combine two of the most recently developed melt models to form PICOP, which overcomes the limitations of past models and produces accurate ice shelf melt rates. We find that our model is easy to set up and computationally efficient, providing researchers an important tool to improve the accuracy of their future glacial projections.
Joshua K. Cuzzone, Nicole-Jeanne Schlegel, Mathieu Morlighem, Eric Larour, Jason P. Briner, Helene Seroussi, and Lambert Caron
The Cryosphere, 13, 879–893, https://doi.org/10.5194/tc-13-879-2019, https://doi.org/10.5194/tc-13-879-2019, 2019
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We present ice sheet modeling results of ice retreat over southwestern Greenland during the last 12 000 years, and we also test the impact that model horizontal resolution has on differences in the simulated spatial retreat and its associated rate. Results indicate that model resolution plays a minor role in simulated retreat in areas where bed topography is not complex but plays an important role in areas where bed topography is complex (such as fjords).
Mathieu Morlighem, Michael Wood, Hélène Seroussi, Youngmin Choi, and Eric Rignot
The Cryosphere, 13, 723–734, https://doi.org/10.5194/tc-13-723-2019, https://doi.org/10.5194/tc-13-723-2019, 2019
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Many glaciers along the coast of Greenland have been retreating. It has been suggested that this retreat is triggered by the presence of warm water in the fjords, and surface melt at the top of the ice sheet is exacerbating this problem. Here, we quantify the vulnerability of northwestern Greenland to further warming using a numerical model. We find that in current conditions, this sector alone will contribute more than 1 cm to sea rise level by 2100, and up to 3 cm in the most extreme scenario.
Thiago Dias dos Santos, Mathieu Morlighem, Hélène Seroussi, Philippe Remy Bernard Devloo, and Jefferson Cardia Simões
Geosci. Model Dev., 12, 215–232, https://doi.org/10.5194/gmd-12-215-2019, https://doi.org/10.5194/gmd-12-215-2019, 2019
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The reduction of numerical errors in ice sheet modeling increases the results' accuracy reliability. We improve numerical accuracy by better capturing grounding line dynamics, while maintaining a low computational cost. We implement an adaptive mesh refinement (AMR) technique in the Ice Sheet System Model and compare AMR simulations with uniformly refined meshes. Our results show that the computational time with AMR is significantly shorter than for uniformly refined meshes for a given accuracy.
Hongju Yu, Eric Rignot, Helene Seroussi, and Mathieu Morlighem
The Cryosphere, 12, 3861–3876, https://doi.org/10.5194/tc-12-3861-2018, https://doi.org/10.5194/tc-12-3861-2018, 2018
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Thwaites Glacier, West Antarctica, has experienced rapid grounding line retreat and mass loss in the past decades. In this study, we simulate the evolution of Thwaites Glacier over the next century using different model configurations. Overall, we estimate a 5 mm contribution to global sea level rise from Thwaites Glacier in the next 30 years. However, a 300 % uncertainty is found over the next 100 years, ranging from 14 to 42 mm, depending on the model setup.
Youngmin Choi, Mathieu Morlighem, Michael Wood, and Johannes H. Bondzio
The Cryosphere, 12, 3735–3746, https://doi.org/10.5194/tc-12-3735-2018, https://doi.org/10.5194/tc-12-3735-2018, 2018
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Calving is an important mechanism that controls the dynamics of Greenland outlet glaciers. We test and compare four calving laws and assess which calving law has better predictive abilities. Overall, the calving law based on von Mises stress is more satisfactory than other laws, but new parameterizations should be derived to better capture the detailed processes involved in calving.
Nicole-Jeanne Schlegel, Helene Seroussi, Michael P. Schodlok, Eric Y. Larour, Carmen Boening, Daniel Limonadi, Michael M. Watkins, Mathieu Morlighem, and Michiel R. van den Broeke
The Cryosphere, 12, 3511–3534, https://doi.org/10.5194/tc-12-3511-2018, https://doi.org/10.5194/tc-12-3511-2018, 2018
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Using NASA supercomputers and a novel framework, in which Sandia National Laboratories' statistical software is embedded in the Jet Propulsion Laboratory's ice sheet model, we run a range of 100-year warming scenarios for Antarctica. We find that 1.2 m of sea level contribution is achievable, but not likely. Also, we find that bedrock topography beneath the ice drives potential for regional sea level contribution, highlighting the need for accurate bedrock mapping of the ice sheet interior.
Veronika Emetc, Paul Tregoning, Mathieu Morlighem, Chris Borstad, and Malcolm Sambridge
The Cryosphere, 12, 3187–3213, https://doi.org/10.5194/tc-12-3187-2018, https://doi.org/10.5194/tc-12-3187-2018, 2018
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The paper includes a model that can be used to predict zones of fracture formation in both floating and grounded ice in Antarctica. We used observations and a statistics-based model to predict fractures in most ice shelves in Antarctica as an alternative to the damage-based approach. We can predict the location of observed fractures with an average success rate of 84% for grounded ice and 61% for floating ice and mean overestimation error of 26% and 20%, respectively.
Hélène Seroussi and Mathieu Morlighem
The Cryosphere, 12, 3085–3096, https://doi.org/10.5194/tc-12-3085-2018, https://doi.org/10.5194/tc-12-3085-2018, 2018
Chen Zhao, Rupert M. Gladstone, Roland C. Warner, Matt A. King, Thomas Zwinger, and Mathieu Morlighem
The Cryosphere, 12, 2637–2652, https://doi.org/10.5194/tc-12-2637-2018, https://doi.org/10.5194/tc-12-2637-2018, 2018
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A combination of computer modelling and observational data were used to infer the resistance to ice flow at the bed of the Fleming Glacier on the Antarctic Peninsula. The model was also used to simulate the distribution of temperature within the ice, which governs the rate at which the ice can deform. This is especially important for glaciers like the Fleming Glacier, which has both regions of rapid deformation and regions of rapid sliding at the bed.
Chen Zhao, Rupert M. Gladstone, Roland C. Warner, Matt A. King, Thomas Zwinger, and Mathieu Morlighem
The Cryosphere, 12, 2653–2666, https://doi.org/10.5194/tc-12-2653-2018, https://doi.org/10.5194/tc-12-2653-2018, 2018
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A combination of computer modelling and observational data were used to infer the resistance to ice flow at the bed of the Fleming Glacier on the Antarctic Peninsula in both 2008 and 2015. The comparison suggests the grounding line retreated by ~ 9 km from 2008 to 2015. The retreat may be enhanced by a positive feedback between friction, melting and sliding at the glacier bed.
Aleah Sommers, Harihar Rajaram, and Mathieu Morlighem
Geosci. Model Dev., 11, 2955–2974, https://doi.org/10.5194/gmd-11-2955-2018, https://doi.org/10.5194/gmd-11-2955-2018, 2018
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Meltwater drainage beneath glaciers and ice sheets influences how fast they move and is complicated and constantly changing. Most models distinguish between
fastand
slowdrainage with different equations for each system. The SHAKTI model allows for the ice–water drainage arrangement to transition naturally between different types of flow. This model can be used to understand how drainage affects glacier speeds and the associated ice loss to further inform predictions of sea level rise.
Joshua K. Cuzzone, Mathieu Morlighem, Eric Larour, Nicole Schlegel, and Helene Seroussi
Geosci. Model Dev., 11, 1683–1694, https://doi.org/10.5194/gmd-11-1683-2018, https://doi.org/10.5194/gmd-11-1683-2018, 2018
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This paper details the implementation of higher-order vertical finite elements in the Ice Sheet System Model (ISSM). When using higher-order vertical finite elements, fewer vertical layers are needed to accurately capture the thermal structure in an ice sheet versus a conventional linear vertical interpolation, therefore greatly improving model runtime speeds, particularly in higher-order stress balance ice sheet models. The implications for paleoclimate ice sheet simulations are discussed.
Konstanze Haubner, Jason E. Box, Nicole J. Schlegel, Eric Y. Larour, Mathieu Morlighem, Anne M. Solgaard, Kristian K. Kjeldsen, Signe H. Larsen, Eric Rignot, Todd K. Dupont, and Kurt H. Kjær
The Cryosphere, 12, 1511–1522, https://doi.org/10.5194/tc-12-1511-2018, https://doi.org/10.5194/tc-12-1511-2018, 2018
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We investigate the effect of neglecting calving on Upernavik Isstrøm, West Greenland, between 1849 and 2012.
Our simulation is forced with observed terminus positions in discrete time steps and is responsive to the prescribed ice front changes.
Simulated frontal retreat is needed to obtain a realistic ice surface elevation and velocity evolution of Upernavik.
Using the prescribed terminus position change we gain insight to mass loss partitioning during different time periods.
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.
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.
Eric Larour, Daniel Cheng, Gilberto Perez, Justin Quinn, Mathieu Morlighem, Bao Duong, Lan Nguyen, Kit Petrie, Silva Harounian, Daria Halkides, and Wayne Hayes
Geosci. Model Dev., 10, 4393–4403, https://doi.org/10.5194/gmd-10-4393-2017, https://doi.org/10.5194/gmd-10-4393-2017, 2017
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This work presents a new way of carrying out simulations using the C++ based Ice Sheet System Model (ISSM) within a web page. This allows for a new generation of websites that can rely on the entire code of a climate model, without compromising or simplifying the physics implemented in such a model. We believe this approach will enable better education/outreach websites as well as improve access to complex climate models without compromising their integrity.
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.
Hongju Yu, Eric Rignot, Mathieu Morlighem, and Helene Seroussi
The Cryosphere, 11, 1283–1296, https://doi.org/10.5194/tc-11-1283-2017, https://doi.org/10.5194/tc-11-1283-2017, 2017
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We combine 2-D ice flow model with linear elastic fracture mechanics (LEFM) to model the calving behavior of Thwaites Glacier, West Antarctica. We find the combination of full-Stokes (FS) model and LEFM produces crevasses that are consistent with observations. We also find that calving is enhanced with pre-existing surface crevasses, shorter ice shelves or undercut at the ice shelf front. We conclude that the FS/LEFM combination is capable of constraining crevasse formation and iceberg calving.
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.
Daniel Farinotti, Douglas J. Brinkerhoff, Garry K. C. Clarke, Johannes J. Fürst, Holger Frey, Prateek Gantayat, Fabien Gillet-Chaulet, Claire Girard, Matthias Huss, Paul W. Leclercq, Andreas Linsbauer, Horst Machguth, Carlos Martin, Fabien Maussion, Mathieu Morlighem, Cyrille Mosbeux, Ankur Pandit, Andrea Portmann, Antoine Rabatel, RAAJ Ramsankaran, Thomas J. Reerink, Olivier Sanchez, Peter A. Stentoft, Sangita Singh Kumari, Ward J. J. van Pelt, Brian Anderson, Toby Benham, Daniel Binder, Julian A. Dowdeswell, Andrea Fischer, Kay Helfricht, Stanislav Kutuzov, Ivan Lavrentiev, Robert McNabb, G. Hilmar Gudmundsson, Huilin Li, and Liss M. Andreassen
The Cryosphere, 11, 949–970, https://doi.org/10.5194/tc-11-949-2017, https://doi.org/10.5194/tc-11-949-2017, 2017
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ITMIX – the Ice Thickness Models Intercomparison eXperiment – was the first coordinated performance assessment for models inferring glacier ice thickness from surface characteristics. Considering 17 different models and 21 different test cases, we show that although solutions of individual models can differ considerably, an ensemble average can yield uncertainties in the order of 10 ± 24 % the mean ice thickness. Ways forward for improving such estimates are sketched.
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.
Henning Åkesson, Kerim H. Nisancioglu, Rianne H. Giesen, and Mathieu Morlighem
The Cryosphere, 11, 281–302, https://doi.org/10.5194/tc-11-281-2017, https://doi.org/10.5194/tc-11-281-2017, 2017
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We present simulations of the history of Hardangerjøkulen ice cap in southern Norway using a dynamical ice sheet model. From mid-Holocene ice-free conditions 4000 years ago, Hardangerjøkulen grows nonlinearly in response to a linear climate forcing, reaching maximum extent during the Little Ice Age (~ 1750 AD). The ice cap exhibits spatially asymmetric growth and retreat and is highly sensitive to climate change. Our results call for reassessment of glacier reconstructions from proxy records.
Feras Habbal, Eric Larour, Mathieu Morlighem, Helene Seroussi, Christopher P. Borstad, and Eric Rignot
Geosci. Model Dev., 10, 155–168, https://doi.org/10.5194/gmd-10-155-2017, https://doi.org/10.5194/gmd-10-155-2017, 2017
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This work presents the results from testing a suite of numerical solvers on a standard ice sheet benchmark test. We note the relevance of this test to practical simulations and identify the fastest solvers for the transient simulation. The highlighted solvers show significant speed-ups in relation to the default solver (~1.5–100 times faster) and enable a new capability for solving massive, high-resolution models that are critical for improving projections of ice sheets and sea-level change.
Eric Larour, Jean Utke, Anton Bovin, Mathieu Morlighem, and Gilberto Perez
Geosci. Model Dev., 9, 3907–3918, https://doi.org/10.5194/gmd-9-3907-2016, https://doi.org/10.5194/gmd-9-3907-2016, 2016
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We present an approach to derive the adjoint state of the C++ coded Ice Sheet System Model. The approach enables data assimilation of observations to improve projections of polar ice sheet mass balance and contribution to sea-level rise. It is applicable to other Earth science frameworks relying on C++ and parallel computing, is non-intrusive, and enables computation of transient adjoints for any type of physics, hence providing insights into the sensitivities of any model to its inputs.
Janin Schaffer, Ralph Timmermann, Jan Erik Arndt, Steen Savstrup Kristensen, Christoph Mayer, Mathieu Morlighem, and Daniel Steinhage
Earth Syst. Sci. Data, 8, 543–557, https://doi.org/10.5194/essd-8-543-2016, https://doi.org/10.5194/essd-8-543-2016, 2016
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The RTopo-2 data set provides consistent maps of global ocean bathymetry and ice surface topographies for Greenland and Antarctica at 30 arcsec grid spacing. We corrected data from earlier products in the areas of Petermann, Hagen Bræ, and Helheim glaciers, incorporated original data for the floating ice tongue of Nioghalvfjerdsfjorden Glacier, and applied corrections for the geometry of Getz, Abbot, and Fimbul ice shelf cavities. The data set is available from the PANGAEA database.
Adam Treverrow, Li Jun, and Tim H. Jacka
Earth Syst. Sci. Data, 8, 253–263, https://doi.org/10.5194/essd-8-253-2016, https://doi.org/10.5194/essd-8-253-2016, 2016
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We present ice crystallographic c-axis orientation and grain size data from the Dome Summit South (DSS) ice core drilled 4.7 km SSW of the summit of Law Dome, East Antarctica. These data are from 185 individual thin sections obtained between a depth of 117 m below the surface and the bottom of the DSS core at a depth of 1196 m. Observations of ice microstructures from polar ice cores play a vital role in the development and validation of ice flow relations for numerical ice sheet models.
Hongju Yu, Eric Rignot, Mathieu Morlighem, and Helene Seroussi
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-101, https://doi.org/10.5194/tc-2016-101, 2016
Revised manuscript not accepted
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We performed a 2D Full-Stokes (FS) modeling study of grounding line dynamics and calving of Thwaites Glacier, West Antarctica. We compare FS with simplified models on grounding line migration and we combine FS with Linear Elastic Fracture Mechanics to simulate crevasse propagation. We find that only FS is able to provide reliable grounding line migration and to explain observed crevasse. We conclude that it may be essential to employ FS in the grounding line region for 2D simulations.
Pierre Rampal, Sylvain Bouillon, Einar Ólason, and Mathieu Morlighem
The Cryosphere, 10, 1055–1073, https://doi.org/10.5194/tc-10-1055-2016, https://doi.org/10.5194/tc-10-1055-2016, 2016
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The Arctic sea ice cover has changed drastically over the last decades and undergone a shift in its dynamical regime, as seen by the increase of extreme fracturing events and the acceleration of sea ice drift. In this paper we present a new sea ice model, neXtSIM, that is capable of simulating both sea ice drift and deformation as observed from satellites, with similar spatial and temporal scaling properties. At the same time, the model reproduces sea ice area, extent, and volume correctly.
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.
Laura A. Stevens, Fiamma Straneo, Sarah B. Das, Albert J. Plueddemann, Amy L. Kukulya, and Mathieu Morlighem
The Cryosphere, 10, 417–432, https://doi.org/10.5194/tc-10-417-2016, https://doi.org/10.5194/tc-10-417-2016, 2016
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Here we pair detailed hydrographic measurements collected with an autonomous underwater vehicle as close as 150 m from the ice–ocean interface of the Saqqarliup sermia–Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water localized in space that are consistent with runoff discharged at two locations along the grounding line.
K. Le Morzadec, L. Tarasov, M. Morlighem, and H. Seroussi
Geosci. Model Dev., 8, 3199–3213, https://doi.org/10.5194/gmd-8-3199-2015, https://doi.org/10.5194/gmd-8-3199-2015, 2015
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A long-term challenge for any model of complex large-scale processes
is accounting for the impact of unresolved sub-grid (SG) processes.
We quantify the impact of SG mass-balance and ice fluxes on glacial
cycle ensemble results for North America. We find no easy solutions to
accurately capture these impacts. We show that SG process
representation and associated parametric uncertainties can have
significant impact on coarse resolution model results for glacial
cycle ice sheet evolution.
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.
E. Larour, J. Utke, B. Csatho, A. Schenk, H. Seroussi, M. Morlighem, E. Rignot, N. Schlegel, and A. Khazendar
The Cryosphere, 8, 2335–2351, https://doi.org/10.5194/tc-8-2335-2014, https://doi.org/10.5194/tc-8-2335-2014, 2014
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We present a temporal inversion of surface mass balance and basal friction for the Northeast Greenland Ice Sheet between 2003 and 2009, using the altimetry record from ICESat. The inversion relies on automatic differentiation of ISSM and demonstrates the feasibility of assimilating altimetry records into reconstructions of the Greenland Ice Sheet. The boundary conditions provide a snapshot of the state of the ice for this period and can be used for further process studies.
H. Seroussi, M. Morlighem, E. Larour, E. Rignot, and A. Khazendar
The Cryosphere, 8, 2075–2087, https://doi.org/10.5194/tc-8-2075-2014, https://doi.org/10.5194/tc-8-2075-2014, 2014
J. M. Lea, D. W. F. Mair, F. M. Nick, B. R. Rea, D. van As, M. Morlighem, P. W. Nienow, and A. Weidick
The Cryosphere, 8, 2031–2045, https://doi.org/10.5194/tc-8-2031-2014, https://doi.org/10.5194/tc-8-2031-2014, 2014
H. Seroussi, M. Morlighem, E. Rignot, J. Mouginot, E. Larour, M. Schodlok, and A. Khazendar
The Cryosphere, 8, 1699–1710, https://doi.org/10.5194/tc-8-1699-2014, https://doi.org/10.5194/tc-8-1699-2014, 2014
S. Adhikari, E. R. Ivins, E. Larour, H. Seroussi, M. Morlighem, and S. Nowicki
Solid Earth, 5, 569–584, https://doi.org/10.5194/se-5-569-2014, https://doi.org/10.5194/se-5-569-2014, 2014
Related subject area
Rheology
Multivariate state and parameter estimation with data assimilation applied to sea-ice models using a Maxwell elasto-brittle rheology
On the sensitivity of sea ice deformation statistics to plastic damage
Grain growth of ice doped with soluble impurities
The role of grain size evolution in the rheology of ice: implications for reconciling laboratory creep data and the Glen flow law
Non-normal flow rules affect fracture angles in sea ice viscous–plastic rheologies
Behavior of saline ice under cyclic flexural loading
The temperature change shortcut: effects of mid-experiment temperature changes on the deformation of polycrystalline ice
Parameter optimization in sea ice models with elastic–viscoplastic rheology
Temperature and strain controls on ice deformation mechanisms: insights from the microstructures of samples deformed to progressively higher strains at −10, −20 and −30 °C
Landfast sea ice material properties derived from ice bridge simulations using the Maxwell elasto-brittle rheology
Recrystallization processes, microstructure and crystallographic preferred orientation evolution in polycrystalline ice during high-temperature simple shear
Melting and fragmentation laws from the evolution of two large Southern Ocean icebergs estimated from satellite data
A Maxwell elasto-brittle rheology for sea ice modelling
Healing of snow surface-to-surface contacts by isothermal sintering
Yumeng Chen, Polly Smith, Alberto Carrassi, Ivo Pasmans, Laurent Bertino, Marc Bocquet, Tobias Sebastian Finn, Pierre Rampal, and Véronique Dansereau
The Cryosphere, 18, 2381–2406, https://doi.org/10.5194/tc-18-2381-2024, https://doi.org/10.5194/tc-18-2381-2024, 2024
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We explore multivariate state and parameter estimation using a data assimilation approach through idealised simulations in a dynamics-only sea-ice model based on novel rheology. We identify various potential issues that can arise in complex operational sea-ice models when model parameters are estimated. Even though further investigation will be needed for such complex sea-ice models, we show possibilities of improving the observed and the unobserved model state forecast and parameter accuracy.
Antoine Savard and Bruno Tremblay
The Cryosphere, 18, 2017–2034, https://doi.org/10.5194/tc-18-2017-2024, https://doi.org/10.5194/tc-18-2017-2024, 2024
Short summary
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We include a suitable plastic damage parametrization in the standard viscous–plastic (VP) sea ice model to disentangle its effect from resolved model physics (visco-plastic with and without damage) on its ability to reproduce observed scaling laws of deformation. This study shows that including a damage parametrization in the VP model improves its performance in simulating the statistical behavior of fracture patterns. Therefore, a damage parametrization is a powerful tuning knob.
Qinyu Wang, Sheng Fan, and Chao Qi
The Cryosphere, 18, 1053–1084, https://doi.org/10.5194/tc-18-1053-2024, https://doi.org/10.5194/tc-18-1053-2024, 2024
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We explored how the grain size of polycrystalline ice is affected by soluble impurities by conducting experiments on ice-containing salts. Results showed that above/below the eutectic point, impurities enhance/hinder grain growth, due to production of melts/precipitation of salt hydrates. Our findings offer insights into the dynamics of natural ice masses.
Mark D. Behn, David L. Goldsby, and Greg Hirth
The Cryosphere, 15, 4589–4605, https://doi.org/10.5194/tc-15-4589-2021, https://doi.org/10.5194/tc-15-4589-2021, 2021
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Grain size is a key microphysical property of ice, controlling the rheological behavior of ice sheets and glaciers. In this study, we develop a new model for grain size evolution in ice and show that it accurately predicts grain size in laboratory experiments and in natural ice core data. The model provides a physical explanation for the power-law relationship between stress and strain rate known as the Glen law and can be used as a predictive tool for modeling ice flow in natural systems.
Damien Ringeisen, L. Bruno Tremblay, and Martin Losch
The Cryosphere, 15, 2873–2888, https://doi.org/10.5194/tc-15-2873-2021, https://doi.org/10.5194/tc-15-2873-2021, 2021
Short summary
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Deformations in the Arctic sea ice cover take the shape of narrow lines. High-resolution sea ice models recreate these deformation lines. Recent studies have shown that the most widely used sea ice model creates fracture lines with intersection angles larger than those observed and cannot create smaller angles. In our work, we change the way sea ice deforms post-fracture. This change allows us to understand the link between the sea ice model and intersection angles and create more acute angles.
Andrii Murdza, Erland M. Schulson, and Carl E. Renshaw
The Cryosphere, 15, 2415–2428, https://doi.org/10.5194/tc-15-2415-2021, https://doi.org/10.5194/tc-15-2415-2021, 2021
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It has been suggested that the observed sudden breakup of Arctic and Antarctic floating ice covers may be due to fatigue failure associated with cyclic loading from ocean swells that can penetrate deeply into an ice pack. To investigate this possibility, we measured the flexural strength of saline ice after cyclic loading. Contrary to expectations, we find that the flexural strength of saline ice increases upon cycling, similar to the behavior of laboratory-grown ice and natural lake ice.
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 %.
Gleb Panteleev, Max Yaremchuk, Jacob N. Stroh, Oceana P. Francis, and Richard Allard
The Cryosphere, 14, 4427–4451, https://doi.org/10.5194/tc-14-4427-2020, https://doi.org/10.5194/tc-14-4427-2020, 2020
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In the CICE6 community model, rheology and landfast grounding/arching effects are simulated by functions of sea ice thickness and concentration with a set of fixed parameters empirically adjusted to optimize model performance. In this study we consider a spatially variable extension for representing these parameters in the two-dimensional elastic–viscoplastic (EVP) sea ice model and analyze the feasibility of the optimization of these parameters through the 4D-Var data assimilation approach.
Sheng Fan, Travis F. Hager, David J. Prior, Andrew J. Cross, David L. Goldsby, Chao Qi, Marianne Negrini, and John Wheeler
The Cryosphere, 14, 3875–3905, https://doi.org/10.5194/tc-14-3875-2020, https://doi.org/10.5194/tc-14-3875-2020, 2020
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We performed uniaxial compression experiments on synthetic ice samples. We report ice microstructural evolution at –20 and –30 °C that has never been reported before. Microstructural data show the opening angle of c-axis cones decreases with increasing strain or with decreasing temperature, suggesting a more active grain rotation. CPO intensity weakens with temperature because CPO of small grains is weaker, and it can be explained by grain boundary sliding or nucleation with random orientations.
Mathieu Plante, Bruno Tremblay, Martin Losch, and Jean-François Lemieux
The Cryosphere, 14, 2137–2157, https://doi.org/10.5194/tc-14-2137-2020, https://doi.org/10.5194/tc-14-2137-2020, 2020
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We study the formation of ice arches between two islands using a model that resolves crack initiation and propagation. This model uses a damage parameter to parameterize the presence or absence of cracks in the ice. We find that the damage parameter allows for cracks to propagate in the ice but in a different orientation than predicted by theory. The results call for improvement in how stress relaxation associated with this damage is parameterized.
Baptiste Journaux, Thomas Chauve, Maurine Montagnat, Andrea Tommasi, Fabrice Barou, David Mainprice, and Léa Gest
The Cryosphere, 13, 1495–1511, https://doi.org/10.5194/tc-13-1495-2019, https://doi.org/10.5194/tc-13-1495-2019, 2019
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Ice mechanics is an important tool to better predict the response of glaciers or polar ice sheets to climate variations.
Nevertheless our current predictive abilities are limited as the microscale mechanisms responsible for ice creep are poorly identified.
We show in this study, using state-of-the-art experimental techniques, which recrystallization processes control ice deformation. This will allow realistic simulations, necessary to predict the long-term effects on ice landmasses.
Nicolas Bouhier, Jean Tournadre, Frédérique Rémy, and Rozenn Gourves-Cousin
The Cryosphere, 12, 2267–2285, https://doi.org/10.5194/tc-12-2267-2018, https://doi.org/10.5194/tc-12-2267-2018, 2018
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The evolution of two large Southern Ocean icebergs, in terms of area and thickness, are used to study the melting and fragmentation laws of icebergs. The area and thickness are estimated by the mean of satellite images and radar altimeter data. Two classical formulations of melting are tested and a fragmentation law depending on the sea temperature and iceberg velocity is proposed and tested. The size distribution of the pieces generated by fragmentation is also estimated.
Véronique Dansereau, Jérôme Weiss, Pierre Saramito, and Philippe Lattes
The Cryosphere, 10, 1339–1359, https://doi.org/10.5194/tc-10-1339-2016, https://doi.org/10.5194/tc-10-1339-2016, 2016
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In this paper we present a new mechanical modelling framework for the deformation of sea ice on regional and larger scales named Maxwell elasto-brittle. The model successfully reproduces the formation of narrow, oriented leads which concentrate the deformation within the damaged, i.e., fractured, ice as well as the intermittency of the damaging process, and hence represents a relevant contribution to the ongoing development of operational modelling platforms, regional and global climate models.
E. A. Podolskiy, M. Barbero, F. Barpi, G. Chambon, M. Borri-Brunetto, O. Pallara, B. Frigo, B. Chiaia, and M. Naaim
The Cryosphere, 8, 1651–1659, https://doi.org/10.5194/tc-8-1651-2014, https://doi.org/10.5194/tc-8-1651-2014, 2014
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Short summary
Ice sheet flow is anisotropic, depending on the nature of the stress applied. However, most large-scale ice sheet models rely on the Glen flow relation, which ignores anisotropic effects. We implement a flow relation (ESTAR) for anisotropic ice in a large-scale ice sheet model. In ice shelf simulations, the Glen flow relation overestimates velocities by up to 17 % compared with ESTAR. Our results have implications for ice sheet model simulations of paleo-ice extent and sea level rise prediction.
Ice sheet flow is anisotropic, depending on the nature of the stress applied. However, most...