Articles | Volume 16, issue 6
https://doi.org/10.5194/tc-16-2265-2022
© Author(s) 2022. 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-16-2265-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Jun 2022
Research article |
| 15 Jun 2022
| 15 Jun 2022
Impact of runoff temporal distribution on ice dynamics
Basile de Fleurian
CORRESPONDING AUTHOR
Department of Earth Science, University of Bergen, Bjerknes Centre for Climate Research, Bergen, Norway
Richard Davy
Nansen Environmental and Remote Sensing Centre, Bjerknes Centre for Climate Research, Bergen, Norway
Petra M. Langebroek
NORCE Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Bergen, Norway
Related authors
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
Short summary
Short summary
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.
Silje Smith-Johnsen, Basile de Fleurian, Nicole Schlegel, Helene Seroussi, and Kerim Nisancioglu
The Cryosphere, 14, 841–854, https://doi.org/10.5194/tc-14-841-2020, https://doi.org/10.5194/tc-14-841-2020, 2020
Short summary
Short summary
The Northeast Greenland Ice Stream (NEGIS) drains a large part of Greenland and displays fast flow far inland. However, the flow pattern is not well represented in ice sheet models. The fast flow has been explained by abnormally high geothermal heat flux. The heat melts the base of the ice sheet and the water produced may lubricate the bed and induce fast flow. By including high geothermal heat flux and a hydrology model, we successfully reproduce NEGIS flow pattern in an ice sheet model.
Nadine Steiger, Kerim H. Nisancioglu, Henning Åkesson, Basile de Fleurian, and Faezeh M. Nick
The Cryosphere, 12, 2249–2266, https://doi.org/10.5194/tc-12-2249-2018, https://doi.org/10.5194/tc-12-2249-2018, 2018
Short summary
Short summary
We use an ice flow model to reconstruct the retreat of Jakobshavn Isbræ since 1850, forced by increased ocean warming and calving. Fjord geometry governs locations of rapid retreat: narrow and shallow areas act as intermittent pinning points for decades, followed by delayed rapid retreat without additional climate warming. These areas may be used to locate potential moraine buildup. Evidently, historic retreat and geometric influences have to be analyzed individually for each glacier system.
B. de Fleurian, O. Gagliardini, T. Zwinger, G. Durand, E. Le Meur, D. Mair, and P. Råback
The Cryosphere, 8, 137–153, https://doi.org/10.5194/tc-8-137-2014, https://doi.org/10.5194/tc-8-137-2014, 2014
O. Gagliardini, T. Zwinger, F. Gillet-Chaulet, G. Durand, L. Favier, B. de Fleurian, R. Greve, M. Malinen, C. Martín, P. Råback, J. Ruokolainen, M. Sacchettini, M. Schäfer, H. Seddik, and J. Thies
Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, https://doi.org/10.5194/gmd-6-1299-2013, 2013
Stephen Outten and Richard Davy
EGUsphere, https://doi.org/10.5194/egusphere-2023-2832, https://doi.org/10.5194/egusphere-2023-2832, 2023
Short summary
Short summary
The North Atlantic Oscillation is linked to wintertime weather events over Europe. One feature often overlooked is how much the climate variability explained by the NAO has changed over time. We show that there has been a considerable increase in the percentage variance explained by the NAO over the 20th century, and that this is not reproduced by 50 CMIP6 climate models, which are generally biased too high. This has implications for projections and prediction of weather events in the region.
Emily A. Hill, Benoît Urruty, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek
The Cryosphere, 17, 3739–3759, https://doi.org/10.5194/tc-17-3739-2023, https://doi.org/10.5194/tc-17-3739-2023, 2023
Short summary
Short summary
The grounding lines of the Antarctic Ice Sheet could enter phases of irreversible retreat or advance. We use three ice sheet models to show that the present-day locations of Antarctic grounding lines are reversible with respect to a small perturbation away from their current position. This indicates that present-day retreat of the grounding lines is not yet irreversible or self-enhancing.
Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann
The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, https://doi.org/10.5194/tc-17-3761-2023, 2023
Short summary
Short summary
We use an ice sheet model to test where current climate conditions in Antarctica might lead. We find that present-day ocean and atmosphere conditions might commit an irreversible collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not irreversible yet.
David M. Chandler and Petra M. Langebroek
EGUsphere, https://doi.org/10.5194/egusphere-2023-850, https://doi.org/10.5194/egusphere-2023-850, 2023
Short summary
Short summary
Sea-level rise and global climate change caused by ice melt in Antarctica is a puzzle of feedbacks between the climate, ocean and ice sheets, over tens to thousands of years. Antarctic Ice Sheet melting is caused mainly by warm deep water from the Southern Ocean. Here, we analyse close relationships between deep water temperatures and global climate in the last 800,000 years. This knowledge can help us to better understanding how climate and sea-level are likely to change in the future.
Stephen Outten, Camille Li, Martin P. King, Lingling Suo, Peter Y. F. Siew, Hoffman Cheung, Richard Davy, Etienne Dunn-Sigouin, Tore Furevik, Shengping He, Erica Madonna, Stefan Sobolowski, Thomas Spengler, and Tim Woollings
Weather Clim. Dynam., 4, 95–114, https://doi.org/10.5194/wcd-4-95-2023, https://doi.org/10.5194/wcd-4-95-2023, 2023
Short summary
Short summary
Strong disagreement exists in the scientific community over the role of Arctic sea ice in shaping wintertime Eurasian cooling. The observed Eurasian cooling can arise naturally without sea-ice loss but is expected to be a rare event. We propose a framework that incorporates sea-ice retreat and natural variability as contributing factors. A helpful analogy is of a dice roll that may result in cooling, warming, or anything in between, with sea-ice loss acting to load the dice in favour of cooling.
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
Short summary
Short summary
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.
Daniel J. Lunt, Fran Bragg, Wing-Le Chan, David K. Hutchinson, Jean-Baptiste Ladant, Polina Morozova, Igor Niezgodzki, Sebastian Steinig, Zhongshi Zhang, Jiang Zhu, Ayako Abe-Ouchi, Eleni Anagnostou, Agatha M. de Boer, Helen K. Coxall, Yannick Donnadieu, Gavin Foster, Gordon N. Inglis, Gregor Knorr, Petra M. Langebroek, Caroline H. Lear, Gerrit Lohmann, Christopher J. Poulsen, Pierre Sepulchre, Jessica E. Tierney, Paul J. Valdes, Evgeny M. Volodin, Tom Dunkley Jones, Christopher J. Hollis, Matthew Huber, and Bette L. Otto-Bliesner
Clim. Past, 17, 203–227, https://doi.org/10.5194/cp-17-203-2021, https://doi.org/10.5194/cp-17-203-2021, 2021
Short summary
Short summary
This paper presents the first modelling results from the Deep-Time Model Intercomparison Project (DeepMIP), in which we focus on the early Eocene climatic optimum (EECO, 50 million years ago). We show that, in contrast to previous work, at least three models (CESM, GFDL, and NorESM) produce climate states that are consistent with proxy indicators of global mean temperature and polar amplification, and they achieve this at a CO2 concentration that is consistent with the CO2 proxy record.
Silje Smith-Johnsen, Basile de Fleurian, Nicole Schlegel, Helene Seroussi, and Kerim Nisancioglu
The Cryosphere, 14, 841–854, https://doi.org/10.5194/tc-14-841-2020, https://doi.org/10.5194/tc-14-841-2020, 2020
Short summary
Short summary
The Northeast Greenland Ice Stream (NEGIS) drains a large part of Greenland and displays fast flow far inland. However, the flow pattern is not well represented in ice sheet models. The fast flow has been explained by abnormally high geothermal heat flux. The heat melts the base of the ice sheet and the water produced may lubricate the bed and induce fast flow. By including high geothermal heat flux and a hydrology model, we successfully reproduce NEGIS flow pattern in an ice sheet model.
Natalia Gnatiuk, Iuliia Radchenko, Richard Davy, Evgeny Morozov, and Leonid Bobylev
Biogeosciences, 17, 1199–1212, https://doi.org/10.5194/bg-17-1199-2020, https://doi.org/10.5194/bg-17-1199-2020, 2020
Short summary
Short summary
We analysed the ability of 34 climate models to reproduce main factors affecting the coccolithophore Emiliania huxleyi blooms in six Arctic and sub-Arctic seas. Furthermore, we proposed a procedure of ranking and selecting these models based on the model’s skill in reproducing 10 important oceanographic, meteorological, and biochemical variables in comparison with observation data and demonstrated that the proposed methodology shows a better result than commonly used all-model averaging.
Andreas Plach, Kerim H. Nisancioglu, Petra M. Langebroek, Andreas Born, and Sébastien Le clec'h
The Cryosphere, 13, 2133–2148, https://doi.org/10.5194/tc-13-2133-2019, https://doi.org/10.5194/tc-13-2133-2019, 2019
Short summary
Short summary
Meltwater from the Greenland ice sheet (GrIS) rises sea level and knowing how the GrIS behaved in the past will help to become better in predicting its future. Here, the evolution of the past GrIS is shown to be dominated by how much ice melts (a result of the prevailing climate) rather than how ice flow is represented in the simulations. Therefore, it is very important to know past climates accurately, in order to be able to simulate the evolution of the GrIS and its contribution to sea level.
Mikhail Varentsov, Pavel Konstantinov, Alexander Baklanov, Igor Esau, Victoria Miles, and Richard Davy
Atmos. Chem. Phys., 18, 17573–17587, https://doi.org/10.5194/acp-18-17573-2018, https://doi.org/10.5194/acp-18-17573-2018, 2018
Short summary
Short summary
This study reports on the urban heat island (UHI) in a typical Arctic city in winter. Using in situ observations, remote sensing data and modeling, we show that the urban temperature anomaly reaches up to 11 K with a mean value of 1.9 K. At least 50 % of this anomaly is caused by the UHI effect, driven mostly by heating. The rest is created by natural microclimatic variability over the hilly terrain. This is a strong argument in support of energy efficiency measures in the Arctic cities.
Andreas Plach, Kerim H. Nisancioglu, Sébastien Le clec'h, Andreas Born, Petra M. Langebroek, Chuncheng Guo, Michael Imhof, and Thomas F. Stocker
Clim. Past, 14, 1463–1485, https://doi.org/10.5194/cp-14-1463-2018, https://doi.org/10.5194/cp-14-1463-2018, 2018
Short summary
Short summary
The Greenland ice sheet is a huge frozen water reservoir which is crucial for predictions of sea level in a warming future climate. Therefore, computer models are needed to reliably simulate the melt of ice sheets. In this study, we use climate model simulations of the last period where it was warmer than today in Greenland. We test different melt models under these climatic conditions and show that the melt models show very different results under these warmer conditions.
Nadine Steiger, Kerim H. Nisancioglu, Henning Åkesson, Basile de Fleurian, and Faezeh M. Nick
The Cryosphere, 12, 2249–2266, https://doi.org/10.5194/tc-12-2249-2018, https://doi.org/10.5194/tc-12-2249-2018, 2018
Short summary
Short summary
We use an ice flow model to reconstruct the retreat of Jakobshavn Isbræ since 1850, forced by increased ocean warming and calving. Fjord geometry governs locations of rapid retreat: narrow and shallow areas act as intermittent pinning points for decades, followed by delayed rapid retreat without additional climate warming. These areas may be used to locate potential moraine buildup. Evidently, historic retreat and geometric influences have to be analyzed individually for each glacier system.
Peter W. Thorne, Fabio Madonna, Joerg Schulz, Tim Oakley, Bruce Ingleby, Marco Rosoldi, Emanuele Tramutola, Antti Arola, Matthias Buschmann, Anna C. Mikalsen, Richard Davy, Corinne Voces, Karin Kreher, Martine De Maziere, and Gelsomina Pappalardo
Geosci. Instrum. Method. Data Syst., 6, 453–472, https://doi.org/10.5194/gi-6-453-2017, https://doi.org/10.5194/gi-6-453-2017, 2017
Short summary
Short summary
The term system-of-systems with respect to observational capabilities is frequently used, but what does it mean and how can it be assessed? Here, we define one possible interpretation of a system-of-systems architecture that is based upon demonstrable aspects of observing capabilities. We develop a set of assessment strands and then apply these to a set of atmospheric observational networks to decide which observations may be suitable for characterising satellite platforms in future work.
Daniel J. Lunt, Matthew Huber, Eleni Anagnostou, Michiel L. J. Baatsen, Rodrigo Caballero, Rob DeConto, Henk A. Dijkstra, Yannick Donnadieu, David Evans, Ran Feng, Gavin L. Foster, Ed Gasson, Anna S. von der Heydt, Chris J. Hollis, Gordon N. Inglis, Stephen M. Jones, Jeff Kiehl, Sandy Kirtland Turner, Robert L. Korty, Reinhardt Kozdon, Srinath Krishnan, Jean-Baptiste Ladant, Petra Langebroek, Caroline H. Lear, Allegra N. LeGrande, Kate Littler, Paul Markwick, Bette Otto-Bliesner, Paul Pearson, Christopher J. Poulsen, Ulrich Salzmann, Christine Shields, Kathryn Snell, Michael Stärz, James Super, Clay Tabor, Jessica E. Tierney, Gregory J. L. Tourte, Aradhna Tripati, Garland R. Upchurch, Bridget S. Wade, Scott L. Wing, Arne M. E. Winguth, Nicky M. Wright, James C. Zachos, and Richard E. Zeebe
Geosci. Model Dev., 10, 889–901, https://doi.org/10.5194/gmd-10-889-2017, https://doi.org/10.5194/gmd-10-889-2017, 2017
Short summary
Short summary
In this paper we describe the experimental design for a set of simulations which will be carried out by a range of climate models, all investigating the climate of the Eocene, about 50 million years ago. The intercomparison of model results is called 'DeepMIP', and we anticipate that we will contribute to the next IPCC report through an analysis of these simulations and the geological data to which we will compare them.
Amaelle Landais, Valérie Masson-Delmotte, Emilie Capron, Petra M. Langebroek, Pepijn Bakker, Emma J. Stone, Niklaus Merz, Christoph C. Raible, Hubertus Fischer, Anaïs Orsi, Frédéric Prié, Bo Vinther, and Dorthe Dahl-Jensen
Clim. Past, 12, 1933–1948, https://doi.org/10.5194/cp-12-1933-2016, https://doi.org/10.5194/cp-12-1933-2016, 2016
Short summary
Short summary
The last lnterglacial (LIG; 116 000 to 129 000 years before present) surface temperature at the upstream Greenland NEEM deposition site is estimated to be warmer by +7 to +11 °C compared to the preindustrial period. We show that under such warm temperatures, melting of snow probably led to a significant surface melting. There is a paradox between the extent of the Greenland ice sheet during the LIG and the strong warming during this period that models cannot solve.
Igor Esau, Victoria V. Miles, Richard Davy, Martin W. Miles, and Anna Kurchatova
Atmos. Chem. Phys., 16, 9563–9577, https://doi.org/10.5194/acp-16-9563-2016, https://doi.org/10.5194/acp-16-9563-2016, 2016
Short summary
Short summary
Vegetation cover in the remote and cold areas of northern West Siberia is rapidly changing. Analysis of summer maximum vegetation productivity index collected over 15 years (2000–2014) by Terra/Aqua satellites revealed “greening” over the northern (tundra/tundra-forest) and widespread “browning” over the southern (taiga) parts of the region. The vegetation changes around 28 urbanized areas were different. Many Siberian cities become greener even against wider browning trends at the background.
P.M. Langebroek and K.H. Nisancioglu
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-15, https://doi.org/10.5194/tc-2016-15, 2016
Revised manuscript has not been submitted
Short summary
Short summary
Last interglacial (LIG) temperatures over Greenland were several degrees higher than today, causing melting of the Greenland ice sheet (GIS). We use temperatures and precipitation from the Norwegian Earth System Model to simulate the GIS during the LIG. Present-day observations of the GIS, together with paleo elevation data from ice cores, constrain our ice sheet simulations. We find a GIS reduction of 0.8–2.2 m compared to today, with the strongest melt occurring in the southwest.
P.M. Langebroek and K. H. Nisancioglu
Clim. Past, 10, 1305–1318, https://doi.org/10.5194/cp-10-1305-2014, https://doi.org/10.5194/cp-10-1305-2014, 2014
B. de Fleurian, O. Gagliardini, T. Zwinger, G. Durand, E. Le Meur, D. Mair, and P. Råback
The Cryosphere, 8, 137–153, https://doi.org/10.5194/tc-8-137-2014, https://doi.org/10.5194/tc-8-137-2014, 2014
O. Gagliardini, T. Zwinger, F. Gillet-Chaulet, G. Durand, L. Favier, B. de Fleurian, R. Greve, M. Malinen, C. Martín, P. Råback, J. Ruokolainen, M. Sacchettini, M. Schäfer, H. Seddik, and J. Thies
Geosci. Model Dev., 6, 1299–1318, https://doi.org/10.5194/gmd-6-1299-2013, https://doi.org/10.5194/gmd-6-1299-2013, 2013
I. Esau, R. Davy, S. Outten, S. Tyuryakov, and S. Zilitinkevich
Nonlin. Processes Geophys., 20, 589–604, https://doi.org/10.5194/npg-20-589-2013, https://doi.org/10.5194/npg-20-589-2013, 2013
G. Lohmann, A. Wackerbarth, P. M. Langebroek, M. Werner, J. Fohlmeister, D. Scholz, and A. Mangini
Clim. Past, 9, 89–98, https://doi.org/10.5194/cp-9-89-2013, https://doi.org/10.5194/cp-9-89-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Numerical Modelling
Modeling the timing of Patagonian Ice Sheet retreat in the Chilean Lake District from 22–10 ka
Using specularity content to evaluate eight geothermal heat flow maps of Totten Glacier
Surging of a Hudson Strait-scale ice stream: subglacial hydrology matters but the process details mostly do not
Regularization and L-curves in ice sheet inverse models: a case study in the Filchner–Ronne catchment
Quantifying the uncertainty in the Eurasian ice-sheet geometry at the Penultimate Glacial Maximum (Marine Isotope Stage 6)
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded
The stability of present-day Antarctic grounding lines – Part 1: No indication of marine ice sheet instability in the current geometry
Geothermal heat flux is the dominant source of uncertainty in englacial-temperature-based dating of ice rise formation
Improving interpretation of sea-level projections through a machine-learning-based local explanation approach
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing
The predictive power of ice sheet models and the regional sensitivity of ice loss to basal sliding parameterisations: a case study of Pine Island and Thwaites glaciers, West Antarctica
Simulations of firn processes over the Greenland and Antarctic ice sheets: 1980–2021
Evaluation of six geothermal heat flux maps for the Antarctic Lambert–Amery glacial system
Can changes in deformation regimes be inferred from crystallographic preferred orientations in polar ice?
Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet
Effective coefficient of diffusion and permeability of firn at Dome C and Lock In, Antarctica, and of various snow types – estimates over the 100–850 kg m−3 density range
The instantaneous impact of calving and thinning on the Larsen C Ice Shelf
Derivation of bedrock topography measurement requirements for the reduction of uncertainty in ice-sheet model projections of Thwaites Glacier
A comparison of the stability and performance of depth-integrated ice-dynamics solvers
A new vertically integrated MOno-Layer Higher-Order (MOLHO) ice flow model
On the contribution of grain boundary sliding type creep to firn densification – an assessment using an optimization approach
Marine ice sheet experiments with the Community Ice Sheet Model
The transferability of adjoint inversion products between different ice flow models
Inferring the basal sliding coefficient field for the Stokes ice sheet model under rheological uncertainty
The tipping points and early warning indicators for Pine Island Glacier, West Antarctica
Sensitivity of ice sheet surface velocity and elevation to variations in basal friction and topography in the full Stokes and shallow-shelf approximation frameworks using adjoint equations
Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model
Bayesian calibration of firn densification models
A kinematic formalism for tracking ice–ocean mass exchange on the Earth's surface and estimating sea-level change
Results of the third Marine Ice Sheet Model Intercomparison Project (MISMIP+)
Ocean-forced evolution of the Amundsen Sea catchment, West Antarctica, by 2100
Parameter sensitivity analysis of dynamic ice sheet models – numerical computations
Simulated retreat of Jakobshavn Isbræ during the 21st century
Development of physically based liquid water schemes for Greenland firn-densification models
Regional grid refinement in an Earth system model: impacts on the simulated Greenland surface mass balance
initMIP-Antarctica: an ice sheet model initialization experiment of ISMIP6
Modeling the response of northwest Greenland to enhanced ocean thermal forcing and subglacial discharge
Assessment of the Greenland ice sheet–atmosphere feedbacks for the next century with a regional atmospheric model coupled to an ice sheet model
Sensitivity of centennial mass loss projections of the Amundsen basin to the friction law
Retreat of Thwaites Glacier, West Antarctica, over the next 100 years using various ice flow models, ice shelf melt scenarios and basal friction laws
Comparison of four calving laws to model Greenland outlet glaciers
Neutral equilibrium and forcing feedbacks in marine ice sheet modelling
Representation of basal melting at the grounding line in ice flow models
Stopping the flood: could we use targeted geoengineering to mitigate sea level rise?
Basal friction of Fleming Glacier, Antarctica – Part 1: Sensitivity of inversion to temperature and bedrock uncertainty
Basal friction of Fleming Glacier, Antarctica – Part 2: Evolution from 2008 to 2015
Simulated dynamic regrounding during marine ice sheet retreat
Dynamic response of Antarctic Peninsula Ice Sheet to potential collapse of Larsen C and George VI ice shelves
Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry
A Bayesian hierarchical model for glacial dynamics based on the shallow ice approximation and its evaluation using analytical solutions
Joshua Cuzzone, Matias Romero, and Shaun A. Marcott
The Cryosphere, 18, 1381–1398, https://doi.org/10.5194/tc-18-1381-2024, https://doi.org/10.5194/tc-18-1381-2024, 2024
Short summary
Short summary
We simulate the retreat history of the Patagonian Ice Sheet (PIS) across the Chilean Lake District from 22–10 ka. These results improve our understanding of the response of the PIS to deglacial warming and the patterns of deglacial ice margin retreat where gaps in the geologic record still exist, and they indicate that changes in large-scale precipitation during the last deglaciation played an important role in modulating the response of ice margin change across the PIS to deglacial warming.
Yan Huang, Liyun Zhao, Michael Wolovick, Yiliang Ma, and John C. Moore
The Cryosphere, 18, 103–119, https://doi.org/10.5194/tc-18-103-2024, https://doi.org/10.5194/tc-18-103-2024, 2024
Short summary
Short summary
Geothermal heat flux (GHF) is an important factor affecting the basal thermal environment of an ice sheet and crucial for its dynamics. But it is poorly defined for the Antarctic ice sheet. We simulate the basal temperature and basal melting rate with eight different GHF datasets. We use specularity content as a two-sided constraint to discriminate between local wet or dry basal conditions. Two medium-magnitude GHF distribution maps rank well, showing that most of the inland bed area is frozen.
Matthew Drew and Lev Tarasov
The Cryosphere, 17, 5391–5415, https://doi.org/10.5194/tc-17-5391-2023, https://doi.org/10.5194/tc-17-5391-2023, 2023
Short summary
Short summary
The interaction of fast-flowing regions of continental ice sheets with their beds governs how quickly they slide and therefore flow. The coupling of fast ice to its bed is controlled by the pressure of meltwater at its base. It is currently poorly understood how the physical details of these hydrologic systems affect ice speedup. Using numerical models we find, surprisingly, that they largely do not, except for the duration of the surge. This suggests that cheap models are sufficient.
Michael Wolovick, Angelika Humbert, Thomas Kleiner, and Martin Rückamp
The Cryosphere, 17, 5027–5060, https://doi.org/10.5194/tc-17-5027-2023, https://doi.org/10.5194/tc-17-5027-2023, 2023
Short summary
Short summary
The friction underneath ice sheets can be inferred from observed velocity at the top, but this inference requires smoothing. The selection of smoothing has been highly variable in the literature. Here we show how to rigorously select the best smoothing, and we show that the inferred friction converges towards the best knowable field as model resolution improves. We use this to learn about the best description of basal friction and to formulate recommended best practices for other modelers.
Oliver G. Pollard, Natasha L. M. Barlow, Lauren J. Gregoire, Natalya Gomez, Víctor Cartelle, Jeremy C. Ely, and Lachlan C. Astfalck
The Cryosphere, 17, 4751–4777, https://doi.org/10.5194/tc-17-4751-2023, https://doi.org/10.5194/tc-17-4751-2023, 2023
Short summary
Short summary
We use advanced statistical techniques and a simple ice-sheet model to produce an ensemble of plausible 3D shapes of the ice sheet that once stretched across northern Europe during the previous glacial maximum (140,000 years ago). This new reconstruction, equivalent in volume to 48 ± 8 m of global mean sea-level rise, will improve the interpretation of high sea levels recorded from the Last Interglacial period (120 000 years ago) that provide a useful perspective on the future.
Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann
The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, https://doi.org/10.5194/tc-17-3761-2023, 2023
Short summary
Short summary
We use an ice sheet model to test where current climate conditions in Antarctica might lead. We find that present-day ocean and atmosphere conditions might commit an irreversible collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not irreversible yet.
Emily A. Hill, Benoît Urruty, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek
The Cryosphere, 17, 3739–3759, https://doi.org/10.5194/tc-17-3739-2023, https://doi.org/10.5194/tc-17-3739-2023, 2023
Short summary
Short summary
The grounding lines of the Antarctic Ice Sheet could enter phases of irreversible retreat or advance. We use three ice sheet models to show that the present-day locations of Antarctic grounding lines are reversible with respect to a small perturbation away from their current position. This indicates that present-day retreat of the grounding lines is not yet irreversible or self-enhancing.
Aleksandr Montelli and Jonathan Kingslake
The Cryosphere, 17, 195–210, https://doi.org/10.5194/tc-17-195-2023, https://doi.org/10.5194/tc-17-195-2023, 2023
Short summary
Short summary
Thermal modelling and Bayesian inversion techniques are used to evaluate the uncertainties inherent in inferences of ice-sheet evolution from borehole temperature measurements. We show that the same temperature profiles may result from a range of parameters, of which geothermal heat flux through underlying bedrock plays a key role. Careful model parameterisation and evaluation of heat flux are essential for inferring past ice-sheet evolution from englacial borehole thermometry.
Jeremy Rohmer, Remi Thieblemont, Goneri Le Cozannet, Heiko Goelzer, and Gael Durand
The Cryosphere, 16, 4637–4657, https://doi.org/10.5194/tc-16-4637-2022, https://doi.org/10.5194/tc-16-4637-2022, 2022
Short summary
Short summary
To improve the interpretability of process-based projections of the sea-level contribution from land ice components, we apply the machine-learning-based
SHapley Additive exPlanationsapproach to a subset of a multi-model ensemble study for the Greenland ice sheet. This allows us to quantify the influence of particular modelling decisions (related to numerical implementation, initial conditions, or parametrisation of ice-sheet processes) directly in terms of sea-level change contribution.
Elise Kazmierczak, Sainan Sun, Violaine Coulon, and Frank Pattyn
The Cryosphere, 16, 4537–4552, https://doi.org/10.5194/tc-16-4537-2022, https://doi.org/10.5194/tc-16-4537-2022, 2022
Short summary
Short summary
The water at the interface between ice sheets and underlying bedrock leads to lubrication between the ice and the bed. Due to a lack of direct observations, subglacial conditions beneath the Antarctic ice sheet are poorly understood. Here, we compare different approaches in which the subglacial water could influence sliding on the underlying bedrock and suggest that it modulates the Antarctic ice sheet response and increases uncertainties, especially in the context of global warming.
Jowan M. Barnes and G. Hilmar Gudmundsson
The Cryosphere, 16, 4291–4304, https://doi.org/10.5194/tc-16-4291-2022, https://doi.org/10.5194/tc-16-4291-2022, 2022
Short summary
Short summary
Models must represent how glaciers slide along the bed, but there are many ways to do so. In this paper, several sliding laws are tested and found to affect different regions of the Antarctic Ice Sheet in different ways and at different speeds. However, the variability in ice volume loss due to sliding-law choices is low compared to other factors, so limited empirical knowledge of sliding does not prevent us from making predictions of how an ice sheet will evolve.
Brooke Medley, Thomas A. Neumann, H. Jay Zwally, Benjamin E. Smith, and C. Max Stevens
The Cryosphere, 16, 3971–4011, https://doi.org/10.5194/tc-16-3971-2022, https://doi.org/10.5194/tc-16-3971-2022, 2022
Short summary
Short summary
Satellite altimeters measure the height or volume change over Earth's ice sheets, but in order to understand how that change translates into ice mass, we must account for various processes at the surface. Specifically, snowfall events generate large, transient increases in surface height, yet snow fall has a relatively low density, which means much of that height change is composed of air. This air signal must be removed from the observed height changes before we can assess ice mass change.
Haoran Kang, Liyun Zhao, Michael Wolovick, and John C. Moore
The Cryosphere, 16, 3619–3633, https://doi.org/10.5194/tc-16-3619-2022, https://doi.org/10.5194/tc-16-3619-2022, 2022
Short summary
Short summary
Basal thermal conditions are important to ice dynamics and sensitive to geothermal heat flux (GHF). We estimate basal thermal conditions of the Lambert–Amery Glacier system with six GHF maps. Recent GHFs inverted from aerial geomagnetic observations produce a larger warm-based area and match the observed subglacial lakes better than the other GHFs. The modelled basal melt rate is 10 to hundreds of millimetres per year in fast-flowing glaciers feeding the Amery Ice Shelf and smaller inland.
Maria-Gema Llorens, Albert Griera, Paul D. Bons, Ilka Weikusat, David J. Prior, Enrique Gomez-Rivas, Tamara de Riese, Ivone Jimenez-Munt, Daniel García-Castellanos, and Ricardo A. Lebensohn
The Cryosphere, 16, 2009–2024, https://doi.org/10.5194/tc-16-2009-2022, https://doi.org/10.5194/tc-16-2009-2022, 2022
Short summary
Short summary
Polar ice is formed by ice crystals, which form fabrics that are utilised to interpret how ice sheets flow. It is unclear whether fabrics result from the current flow regime or if they are inherited. To understand the extent to which ice crystals can be reoriented when ice flow conditions change, we simulate and evaluate multi-stage ice flow scenarios according to natural cases. We find that second deformation regimes normally overprint inherited fabrics, with a range of transitional fabrics.
Tanja Schlemm, Johannes Feldmann, Ricarda Winkelmann, and Anders Levermann
The Cryosphere, 16, 1979–1996, https://doi.org/10.5194/tc-16-1979-2022, https://doi.org/10.5194/tc-16-1979-2022, 2022
Short summary
Short summary
Marine cliff instability, if it exists, could dominate Antarctica's contribution to future sea-level rise. It is likely to speed up with ice thickness and thus would accelerate in most parts of Antarctica. Here, we investigate a possible mechanism that might stop cliff instability through cloaking by ice mélange. It is only a first step, but it shows that embayment geometry is, in principle, able to stop marine cliff instability in most parts of West Antarctica.
Neige Calonne, Alexis Burr, Armelle Philip, Frédéric Flin, and Christian Geindreau
The Cryosphere, 16, 967–980, https://doi.org/10.5194/tc-16-967-2022, https://doi.org/10.5194/tc-16-967-2022, 2022
Short summary
Short summary
Modeling gas transport in ice sheets from surface to close-off is key to interpreting climate archives. Estimates of the diffusion coefficient and permeability of snow and firn are required but remain a large source of uncertainty. We present a new dataset of diffusion coefficients and permeability from 20 to 120 m depth at two Antarctic sites. We suggest predictive formulas to estimate both properties over the entire 100–850 kg m3 density range, i.e., anywhere within the ice sheet column.
Tom Mitcham, G. Hilmar Gudmundsson, and Jonathan L. Bamber
The Cryosphere, 16, 883–901, https://doi.org/10.5194/tc-16-883-2022, https://doi.org/10.5194/tc-16-883-2022, 2022
Short summary
Short summary
We modelled the response of the Larsen C Ice Shelf (LCIS) and its tributary glaciers to the calving of the A68 iceberg and validated our results with observations. We found that the impact was limited, confirming that mostly passive ice was calved. Through further calving experiments we quantified the total buttressing provided by the LCIS and found that over 80 % of the buttressing capacity is generated in the first 5 km of the ice shelf downstream of the grounding line.
Blake A. Castleman, Nicole-Jeanne Schlegel, Lambert Caron, Eric Larour, and Ala Khazendar
The Cryosphere, 16, 761–778, https://doi.org/10.5194/tc-16-761-2022, https://doi.org/10.5194/tc-16-761-2022, 2022
Short summary
Short summary
In the described study, we derive an uncertainty range for global mean sea level rise (SLR) contribution from Thwaites Glacier in a 200-year period under an extreme ocean warming scenario. We derive the spatial and vertical resolutions needed for bedrock data acquisition missions in order to limit global mean SLR contribution from Thwaites Glacier to ±2 cm in a 200-year period. We conduct sensitivity experiments in order to present the locations of critical regions in need of accurate mapping.
Alexander Robinson, Daniel Goldberg, and William H. Lipscomb
The Cryosphere, 16, 689–709, https://doi.org/10.5194/tc-16-689-2022, https://doi.org/10.5194/tc-16-689-2022, 2022
Short summary
Short summary
Here we investigate the numerical stability of several commonly used methods in order to determine which of them are capable of resolving the complex physics of the ice flow and are also computationally efficient. We find that the so-called DIVA solver outperforms the others. Its representation of the physics is consistent with more complex methods, while it remains computationally efficient at high resolution.
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
Short summary
Short summary
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.
Timm Schultz, Ralf Müller, Dietmar Gross, and Angelika Humbert
The Cryosphere, 16, 143–158, https://doi.org/10.5194/tc-16-143-2022, https://doi.org/10.5194/tc-16-143-2022, 2022
Short summary
Short summary
Firn is the interstage product between snow and ice. Simulations describing the process of firn densification are used in the context of estimating mass changes of the ice sheets and past climate reconstructions. The first stage of firn densification takes place in the upper few meters of the firn column. We investigate how well a material law describing the process of grain boundary sliding works for the numerical simulation of firn densification in this stage.
Gunter R. Leguy, William H. Lipscomb, and Xylar S. Asay-Davis
The Cryosphere, 15, 3229–3253, https://doi.org/10.5194/tc-15-3229-2021, https://doi.org/10.5194/tc-15-3229-2021, 2021
Short summary
Short summary
We present numerical features of the Community Ice Sheet Model in representing ocean termini glaciers. Using idealized test cases, we show that applying melt in a partly grounded cell is beneficial, in contrast to recent studies. We confirm that parameterizing partly grounded cells yields accurate ice sheet representation at a grid resolution of ~2 km (arguably 4 km), allowing ice sheet simulations at a continental scale. The choice of basal friction law also influences the ice 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
Short summary
Short summary
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.
Olalekan Babaniyi, Ruanui Nicholson, Umberto Villa, and Noémi Petra
The Cryosphere, 15, 1731–1750, https://doi.org/10.5194/tc-15-1731-2021, https://doi.org/10.5194/tc-15-1731-2021, 2021
Short summary
Short summary
We consider the problem of inferring unknown parameter fields under additional uncertainty for an ice sheet model from synthetic surface ice flow velocity measurements. Our results indicate that accounting for model uncertainty stemming from the presence of nuisance parameters is crucial. Namely our findings suggest that using nominal values for these parameters, as is often done in practice, without taking into account the resulting modeling error can lead to overconfident and biased results.
Sebastian H. R. Rosier, Ronja Reese, Jonathan F. Donges, Jan De Rydt, G. Hilmar Gudmundsson, and Ricarda Winkelmann
The Cryosphere, 15, 1501–1516, https://doi.org/10.5194/tc-15-1501-2021, https://doi.org/10.5194/tc-15-1501-2021, 2021
Short summary
Short summary
Pine Island Glacier has contributed more to sea-level rise over the past decades than any other glacier in Antarctica. Ice-flow modelling studies have shown that it can undergo periods of rapid mass loss, but no study has shown that these future changes could cross a tipping point and therefore be effectively irreversible. Here, we assess the stability of Pine Island Glacier, quantifying the changes in ocean temperatures required to cross future tipping points using statistical methods.
Gong Cheng, Nina Kirchner, and Per Lötstedt
The Cryosphere, 15, 715–742, https://doi.org/10.5194/tc-15-715-2021, https://doi.org/10.5194/tc-15-715-2021, 2021
Short summary
Short summary
We present an inverse modeling approach to improve the understanding of spatiotemporally variable processes at the inaccessible base of an ice sheet by determining the sensitivity of direct surface observations to perturbations of basal conditions. Time dependency is proved to be important in these types of problems. The effect of perturbations is analyzed based on analytical and numerical solutions.
Clemens Schannwell, Reinhard Drews, Todd A. Ehlers, Olaf Eisen, Christoph Mayer, Mika Malinen, Emma C. Smith, and Hannes Eisermann
The Cryosphere, 14, 3917–3934, https://doi.org/10.5194/tc-14-3917-2020, https://doi.org/10.5194/tc-14-3917-2020, 2020
Short summary
Short summary
To reduce uncertainties associated with sea level rise projections, an accurate representation of ice flow is paramount. Most ice sheet models rely on simplified versions of the underlying ice flow equations. Due to the high computational costs, ice sheet models based on the complete ice flow equations have been restricted to < 1000 years. Here, we present a new model setup that extends the applicability of such models by an order of magnitude, permitting simulations of 40 000 years.
Vincent Verjans, Amber A. Leeson, Christopher Nemeth, C. Max Stevens, Peter Kuipers Munneke, Brice Noël, and Jan Melchior van Wessem
The Cryosphere, 14, 3017–3032, https://doi.org/10.5194/tc-14-3017-2020, https://doi.org/10.5194/tc-14-3017-2020, 2020
Short summary
Short summary
Ice sheets are covered by a firn layer, which is the transition stage between fresh snow and ice. Accurate modelling of firn density properties is important in many glaciological aspects. Current models show disagreements, are mostly calibrated to match specific observations of firn density and lack thorough uncertainty analysis. We use a novel calibration method for firn models based on a Bayesian statistical framework, which results in improved model accuracy and in uncertainty evaluation.
Surendra Adhikari, Erik R. Ivins, Eric Larour, Lambert Caron, and Helene Seroussi
The Cryosphere, 14, 2819–2833, https://doi.org/10.5194/tc-14-2819-2020, https://doi.org/10.5194/tc-14-2819-2020, 2020
Short summary
Short summary
The mathematical formalism presented in this paper aims at simplifying computational strategies for tracking ice–ocean mass exchange in the Earth system. To this end, we define a set of generic, and quite simple, descriptions of evolving land, ocean and ice interfaces and present a unified method to compute the sea-level contribution of evolving ice sheets. The formalism can be applied to arbitrary geometries and at all timescales.
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
Short summary
Short summary
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.
Alanna V. Alevropoulos-Borrill, Isabel J. Nias, Antony J. Payne, Nicholas R. Golledge, and Rory J. Bingham
The Cryosphere, 14, 1245–1258, https://doi.org/10.5194/tc-14-1245-2020, https://doi.org/10.5194/tc-14-1245-2020, 2020
Gong Cheng and Per Lötstedt
The Cryosphere, 14, 673–691, https://doi.org/10.5194/tc-14-673-2020, https://doi.org/10.5194/tc-14-673-2020, 2020
Short summary
Short summary
We present a time-dependent inverse method for ice sheet modeling. By investigating the sensitivity of the observations of the velocity and the height at the surface to the basal conditions of the ice, we show that if the basal parameters are time dependent, then time cannot be ignored in the inversion. By looking at the numerical features, we conclude that adding the height information of an ice sheet in the velocity inversion procedure could improve the robustness of the inference.
Xiaoran Guo, Liyun Zhao, Rupert M. Gladstone, Sainan Sun, and John C. Moore
The Cryosphere, 13, 3139–3153, https://doi.org/10.5194/tc-13-3139-2019, https://doi.org/10.5194/tc-13-3139-2019, 2019
Vincent Verjans, Amber A. Leeson, C. Max Stevens, Michael MacFerrin, Brice Noël, and Michiel R. van den Broeke
The Cryosphere, 13, 1819–1842, https://doi.org/10.5194/tc-13-1819-2019, https://doi.org/10.5194/tc-13-1819-2019, 2019
Short summary
Short summary
Firn models rely on empirical approaches for representing the percolation and refreezing of meltwater through the firn column. We develop liquid water schemes of different levels of complexity for firn models and compare their performances with respect to observations of density profiles from Greenland. Our results demonstrate that physically advanced water schemes do not lead to better agreement with density observations. Uncertainties in other processes contribute more to model discrepancy.
Leonardus van Kampenhout, Alan M. Rhoades, Adam R. Herrington, Colin M. Zarzycki, Jan T. M. Lenaerts, William J. Sacks, and Michiel R. van den Broeke
The Cryosphere, 13, 1547–1564, https://doi.org/10.5194/tc-13-1547-2019, https://doi.org/10.5194/tc-13-1547-2019, 2019
Short summary
Short summary
A new tool is evaluated in which the climate and surface mass balance (SMB) of the Greenland ice sheet are resolved at 55 and 28 km resolution, while the rest of the globe is modelled at ~110 km. The local refinement of resolution leads to improved accumulation (SMB > 0) compared to observations; however ablation (SMB < 0) is deteriorated in some regions. This is attributed to changes in cloud cover and a reduced effectiveness of a model-specific vertical downscaling technique.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Sébastien Le clec'h, Sylvie Charbit, Aurélien Quiquet, Xavier Fettweis, Christophe Dumas, Masa Kageyama, Coraline Wyard, and Catherine Ritz
The Cryosphere, 13, 373–395, https://doi.org/10.5194/tc-13-373-2019, https://doi.org/10.5194/tc-13-373-2019, 2019
Short summary
Short summary
Quantifying the future contribution of the Greenland ice sheet (GrIS) to sea-level rise in response to atmospheric changes is important but remains challenging. For the first time a full representation of the feedbacks between a GrIS model and a regional atmospheric model was implemented. The authors highlight the fundamental need for representing the GrIS topography change feedbacks with respect to the atmospheric component face to the strong impact on the projected sea-level rise.
Julien Brondex, Fabien Gillet-Chaulet, and Olivier Gagliardini
The Cryosphere, 13, 177–195, https://doi.org/10.5194/tc-13-177-2019, https://doi.org/10.5194/tc-13-177-2019, 2019
Short summary
Short summary
Here, we apply a synthetic perturbation to the most active drainage basin of Antarctica and show that centennial mass loss projections obtained through ice flow models depend strongly on the implemented friction law, i.e. the mathematical relationship between basal drag and sliding velocities. In particular, the commonly used Weertman law considerably underestimates the sea-level contribution of this basin in comparison to two water pressure-dependent laws which rely on stronger physical bases.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Rupert M. Gladstone, Yuwei Xia, and John Moore
The Cryosphere, 12, 3605–3615, https://doi.org/10.5194/tc-12-3605-2018, https://doi.org/10.5194/tc-12-3605-2018, 2018
Short summary
Short summary
Computer models for the simulation of marine ice sheets (ice sheets resting on bedrock below sea level) historically show poor numerical convergence for grounding line (the boundary between grounded and floating parts of the ice sheet) movement. We have further characterised the nature of the numerical problems leading to poor convergence and highlighted implications for the design of computer experiments that test grounding line movement.
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
Michael J. Wolovick and John C. Moore
The Cryosphere, 12, 2955–2967, https://doi.org/10.5194/tc-12-2955-2018, https://doi.org/10.5194/tc-12-2955-2018, 2018
Short summary
Short summary
In this paper, we explore the possibility of using locally targeted geoengineering to slow the rate of an ice sheet collapse. We find that an intervention as big as existing large civil engineering projects could have a 30 % probability of stopping an ice sheet collapse, while larger interventions have better odds of success. With more research to improve upon the simple designs we considered, it may be possible to perfect a design that was both achievable and had good odds of success.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Lenneke M. Jong, Rupert M. Gladstone, Benjamin K. Galton-Fenzi, and Matt A. King
The Cryosphere, 12, 2425–2436, https://doi.org/10.5194/tc-12-2425-2018, https://doi.org/10.5194/tc-12-2425-2018, 2018
Short summary
Short summary
We used an ice sheet model to simulate temporary regrounding of a marine ice sheet retreating across a retrograde bedrock slope. We show that a sliding relation incorporating water-filled cavities and the ice overburden pressure at the base allows the temporary regrounding to occur. This suggests that choice of basal sliding relation can be important when modelling grounding line behaviour of regions where potential ice rises and pinning points are present and regrounding could occur.
Clemens Schannwell, Stephen Cornford, David Pollard, and Nicholas E. Barrand
The Cryosphere, 12, 2307–2326, https://doi.org/10.5194/tc-12-2307-2018, https://doi.org/10.5194/tc-12-2307-2018, 2018
Short summary
Short summary
Despite the speculation on the state and fate of Larsen C Ice Shelf, a key unknown factor remains: what would be the effects of ice-shelf collapse on upstream drainage basins and thus global sea levels? In our paper three state-of-the-art numerical ice-sheet models were used to simulate the volume evolution of the inland ice sheet to ice-shelf collapse at Larsen C and George VI ice shelves. Our results suggest sea-level rise of up to ~ 4 mm for Larsen C ice shelf and ~ 22 for George VI ice shelf.
Nadine Steiger, Kerim H. Nisancioglu, Henning Åkesson, Basile de Fleurian, and Faezeh M. Nick
The Cryosphere, 12, 2249–2266, https://doi.org/10.5194/tc-12-2249-2018, https://doi.org/10.5194/tc-12-2249-2018, 2018
Short summary
Short summary
We use an ice flow model to reconstruct the retreat of Jakobshavn Isbræ since 1850, forced by increased ocean warming and calving. Fjord geometry governs locations of rapid retreat: narrow and shallow areas act as intermittent pinning points for decades, followed by delayed rapid retreat without additional climate warming. These areas may be used to locate potential moraine buildup. Evidently, historic retreat and geometric influences have to be analyzed individually for each glacier system.
Giri Gopalan, Birgir Hrafnkelsson, Guðfinna Aðalgeirsdóttir, Alexander H. Jarosch, and Finnur Pálsson
The Cryosphere, 12, 2229–2248, https://doi.org/10.5194/tc-12-2229-2018, https://doi.org/10.5194/tc-12-2229-2018, 2018
Short summary
Short summary
Geophysical systems can often contain scientific parameters whose values are uncertain, complex underlying dynamics, and field measurements with errors. These components are naturally modeled together within what is known as a Bayesian hierarchical model (BHM). This paper constructs such a model for shallow glaciers based on an approximation of the underlying dynamics. The evaluation of this model is aided by the use of exact analytical solutions from the literature.
Cited articles
Ahlstrøm, A. P., Petersen, D., Langen, P. L., Citterio, M., and Box, J. E.:
Abrupt shift in the observed runoff from the southwestern Greenland ice
sheet, Science Advances, 3, e1701169, https://doi.org/10.1126/sciadv.1701169, 2017. a
Anderson, R., Anderson, S., MacGregor, K., Waddington, E., O'Neel, S.,
Riihimaki, C., and Loso, M.: Strong feedbacks between hydrology and sliding
of a small alpine glacier, J. Geophys. Res., 109, 1–17,
https://doi.org/10.1029/2004JF000120, 2004. a
Bartholomaus, T. C., Anderson, R. S., and Anderson, S. P.: Response of glacier
basal motion to transient water storage, Nat. Geosci., 1, 33–37,
https://doi.org/10.1038/ngeo.2007.52, 2008. a
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
Bartholomew, I., Peter, N., Andrew, S., Douglas, M., Thomas, C., and A., K. M.:
Short-term variability in Greenland Ice Sheet motion forced by time-varying
meltwater drainage: Implications for the relationship between subglacial
drainage system behavior and ice velocity, J. Geophys. Res., 117, F03002,
https://doi.org/10.1029/2011JF002220, 2012. a
Bindschadler, R.: The importance of pressurized subglacial water in separation
and sliding at the glacier bed, J. Glaciol., 29, 3–19, 1983. a
Catania, G. A., Neumann, T. A., and Price, S. F.: Characterizing englacial
drainage in the ablation zone of the Greenland ice sheet, J. Glaciol., 54,
567–578, https://doi.org/10.3189/002214308786570854, 2008. a
Colosio, P., Tedesco, M., Ranzi, R., and Fettweis, X.: Surface melting over the Greenland ice sheet derived from enhanced resolution passive microwave brightness temperatures (1979–2019), The Cryosphere, 15, 2623–2646, https://doi.org/10.5194/tc-15-2623-2021, 2021. a
Cowton, T., Nienow, P., Sole, A., Wadham, J., Lis, G., Bartholomew, I., Mair,
D., and Chandler, D.: Evolution of drainage system morphology at a
land-terminating Greenlandic outlet glacier, J. Geophys. Res., 118, 29–41, https://doi.org/10.1029/2012jf002540, 2013. a
Cowton, T., Nienow, P., Sole, A., Bartholomew, I., and Mair, D.: Variability
in ice motion at a land-terminating Greenlandic outlet glacier: the role of
channelized and distributed drainage systems, J. Glaciol., 62, 451–466, https://doi.org/10.1017/jog.2016.36, 2016. 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
de Fleurian, B., Morlighem, M., Seroussi, H., Rignot, E., van den Broeke,
M. R., Munneke, P. K., 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., 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., and Hooke, R. L.:
SHMIP, The subglacial hydrology model intercomparison Project, J. Glaciol.,
64, 897–916, https://doi.org/10.1017/jog.2018.78, 2018. a, b, c
de Fleurian, B., Davy, R., and Langebroek, P. M.: Impact of runoff temporal distribution on ice dynamics, Zenodo [data set], https://doi.org/10.5281/zenodo.5959181, 2022. a
Doyle, S. H., Hubbard, A., Fitzpatrick, A. A. W., van As, D., Mikkelsen, A. B.,
Pettersson, R., and Hubbard, B.: Persistent flow acceleration within the
interior of the Greenland ice sheet, Geophys. Res. Lett., 41, 899–905,
https://doi.org/10.1002/2013GL058933, 2014. a
Doyle, S. H., Hubbard, A., van de Wal, R. S. W., Box, J. E., van As, D.,
Scharrer, K., Meierbachtol, T. W., Smeets, P. C. J. P., Harper, J. T.,
Johansson, E., Mottram, R. H., Mikkelsen, A. B., Wilhelms, F., Patton, H.,
Christoffersen, P., and Hubbard, B.: Amplified melt and flow of the
Greenland ice sheet driven by late-summer cyclonic rainfall, Nat. Geosci.,
8, 647–653, https://doi.org/10.1038/ngeo2482, 2015. a
Fürst, J. J., Goelzer, H., and Huybrechts, P.: Ice-dynamic projections of the Greenland ice sheet in response to atmospheric and oceanic warming, The Cryosphere, 9, 1039–1062, https://doi.org/10.5194/tc-9-1039-2015, 2015. a, b
Gagliardini, O. and Werder, M. A.: Influence of increasing surface melt over
decadal timescales on land-terminating Greenland-type outlet glaciers, J.
Glaciol., 64, 700–710, https://doi.org/10.1017/jog.2018.59, 2018. a, b, c, d
Gagliardini, O., Cohen, D., Raback, P., and Zwinger, T.: Finite-element
modeling of subglacial cavities and related friction law, J. Geophys. Res.,
112, 1–11, https://doi.org/10.1029/2006JF000576, 2007. a
Gordon, S., Sharp, M., Hubbard, B., Smart, C., Ketterling, B., and Willis, I.:
Seasonal reorganization of subglacial drainage inferred from measurements in
boreholes, Hydrol. Process., 12, 105–133,
https://doi.org/10.1002/(SICI)1099-1085(199801)12:1<105::AID-HYP566>3.3.CO;2-R, 1998. a
Hanna, E., Huybrechts, P., Steffen, K., Cappelen, J., Huff, R., Shuman, C.,
Irvine-Fynn, T., Wise, S., and Griffiths, M.: Increased runoff from melt
from the Greenland Ice Sheet: A response to global warming, J. Clim.,
21, 331–341, https://doi.org/10.1175/2007JCLI1964.1, 2008. a
Harper, J. T., Humphrey, N. F., Pfeffer, W. T., and Lazar, B.: Two modes of
accelerated glacier sliding related to water, Geophys. Res. Lett., 34, 2–5, https://doi.org/10.1029/2007GL030233, 2007. a
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A.,
Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons,
A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati,
G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D.,
Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer,
A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M.,
Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P.,
Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global
reanalysis, Q. J. R. Meteorolog. Soc., 146, 1999–2049,
https://doi.org/10.1002/qj.3803, 2020. a
Hewitt, I. J.: Seasonal changes in ice sheet motion due to melt water
lubrication, Earth Planet. Sci. Lett., 371–372, 16–25,
https://doi.org/10.1016/j.epsl.2013.04.022, 2013. a
Hoffman, M. J., Catania, G. A., Neumann, T. A., Andrews, L. C., and Rumrill,
J. A.: Links between acceleration, melting, and supraglacial lake drainage
of the western Greenland Ice Sheet, J. Geophys. Res., 116, F04035,
https://doi.org/10.1029/2010JF001934, 2011. a
Iken, A.: The effect of the subglacial water pressure on the sliding velocity
of a glacier in an idealized numerical Model, J. Glaciol., 27, 407–421,
https://doi.org/10.3189/s0022143000011448, 1981. a, b
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., 117, 1–20,
https://doi.org/10.1029/2011JF002140, 2012. a, b, c
MacAyeal, D.: Large-scale ice flow over a viscous basal sediment: Theory and
application to Ice Stream B, Antarctica, J. Geophys. Res., 94,
4071–4087, https://doi.org/10.1029/jb094ib04p04071, 1989. a
Mair, D., Nienow, P., Sharp, M., Wohlleben, T., and Willis, I.: Influence of
subglacial drainage system evolution on glacier surface motion: Haut
Glacier d'Arolla, Switzerland, J. Geophys. Res., 107, 1–8,
https://doi.org/10.1029/2001JB000514, 2002. a
Mernild, S. H., Liston, G. E., Hiemstra, C. A., and Steffen, K.: Record
2007 Greenland Ice Sheet Surface Melt Extent and Runoff, EOS. Trans. AGU, 90, 13–14, https://doi.org/10.1029/2009EO020002, 2009. a
Morland, L.: Unconfined ice shelf flow, Proceedings of Workshop on the Dynamics
of the West Antarctic Ice Sheet, Glaciology and Quaternary Geology, volume 4, edited by: van der Veen, C. J. and Oerlemans, J., University of Utrecht, May 1985, Published
by Reidel, 99–116, https://doi.org/10.1007/978-94-009-3745-1_6, 1987. a
Mote, T. L.: Greenland surface melt trends 1973-2007: Evidence of a large increase in 2007, Geophys. Res. Lett., 34, 1–5,
https://doi.org/10.1029/2007GL031976, 2007. a, b
Nghiem, S. V., Steffen, K., Neumann, G., and Huff, R.: Mapping of ice layer
extent and snow accumulation in the percolation zone of the Greenland ice
sheet, J. Geophys. Res., 110, L20502, https://doi.org/10.1029/2004JF000234, 2005. a
Nghiem, S. V., Hall, D. K., Mote, T. L., Tedesco, M., Albert, M. R., Keegan,
K., Shuman, C. A., DiGirolamo, N. E., and Neumann, G.: The extreme melt
across the Greenland ice sheet in 2012, Geophys. Res. Lett., 39, 1–6,
https://doi.org/10.1029/2012GL053611, 2012. a
Nye, J.: Water flow in glaciers: jokulhlaups, tunnels and veins, J. Glaciol.,
17, 181–207, https://doi.org/10.3189/S002214300001354X, 1976. a
Röthlisberger, H.: Water pressure in intra- and subglacial channels, J.
Glaciol., 11, 177–203, https://doi.org/10.3189/S0022143000022188, 1972. a
Sasgen, I., van den Broeke, M., Bamber, J. L., Rignot, E., Sorensen, L. S.,
Wouters, B., Martinec, Z., Velicogna, I., and Simonsen, S. B.: Timing and
origin of recent regional ice-mass loss in Greenland, Earth Planet. Sci.
Lett., 333, 293–303, https://doi.org/10.1016/j.epsl.2012.03.033, 2012. a
Scholzen, C., Schuler, T. V., and Gilbert, A.: Sensitivity of subglacial drainage to water supply distribution at the Kongsfjord basin, Svalbard, The Cryosphere, 15, 2719–2738, https://doi.org/10.5194/tc-15-2719-2021, 2021. a
Schoof, C.: The effect of cavitation on glacier sliding, Proc. R. Soc. A, 461,
609–627, https://doi.org/10.1098/rspa.2004.1350, 2005. a
Schoof, C.: Ice-sheet acceleration driven by melt supply variability, Nature,
468, 803–806, https://doi.org/10.1038/nature09618, 2010. a
Seaberg, S., Seaberg, J., Hooke, R., and Wiberg, D.: Character of the englacial
and subglacial ddrainage system in the lower part of the ablation area of
Storglacieren, Sweden, as revealed by dye trace studies, J. Glaciol., 34, 217–227, https://doi.org/10.3189/s0022143000032263, 1988. a
Shannon, S. R., Payne, A. J., Bartholomew, I. D., van den Broeke, M. R.,
Edwards, T. L., Fettweis, X., Gagliardini, O., Gillet-Chaulet, F., Goelzer,
H., Hoffman, M. J., Huybrechts, P., Mair, D. W. F., Nienow, P. W., Perego,
M., Price, S. F., Smeets, C. J. P. P., Sole, A. J., van de Wal, R. S. W., and
Zwinger, T.: Enhanced basal lubrication and the contribution of the Greenland
ice sheet to future sea-level rise, P. Natl. Acad. Sci., 110, 14156–14161, https://doi.org/10.1073/pnas.1212647110, 2013. a, b
Slater, D. A., Nienow, P. W., Cowton, T. R., Goldberg, D. N., and Sole, A. J.:
Effect of near-terminus subglacial hydrology on tidewater glacier submarine
melt rates, Geophys. Res. Lett., 42, 2861–2868,
https://doi.org/10.1002/2014GL062494, 2015. a
Smith, L. C., Chu, V. W., Yang, K., Gleason, C. J., Pitcher, L. H., Rennermalm,
A. K., Legleiter, C. J., Behar, A. E., Overstreet, B. T., Moustafa, S. E.,
Tedesco, M., Forster, R. R., LeWinter, A. L., Finnegan, D. C., Sheng, Y., and
Balog, J.: Efficient meltwater drainage through supraglacial streams and
rivers on the southwest Greenland ice sheet, Proc. Natl. Acad. Sci., 112,
1001–1006, https://doi.org/10.1073/pnas.1413024112, 2015. a
Sole, A., Nienow, P., Bartholomew, I., Mair, D., Cowton, T., Tedstone, A., and
King, M. A.: Winter motion mediates dynamic response of the Greenland Ice
Sheet to warmer summers, Geophys. Res. Lett., 40, 3940–3944,
https://doi.org/10.1002/grl.50764, 2013. a, b, c
Sole, A. J., Mair, D. W. F., Nienow, P. W., Bartholomew, I. D., King, M. A.,
Burke, M. J., and Joughin, I.: Seasonal speedup of a Greenland
marine-terminating outlet glacier forced by surface melt-induced changes in
subglacial hydrology, J. Geophys. Res., 116, 1–11,
https://doi.org/10.1029/2010JF001948, 2011. a
Steffen, K., Nghiem, S., Huff, R., and Neumann, G.: The melt anomaly of
2002 on the Greenland Ice Sheet from active and passive microwave
satellite observations, Geophys. Res. Lett., 31, 1–5,
https://doi.org/10.1029/2004GL020444, 2004. a
Sundal, A. V., Shepherd, A., Nienow, P., Hanna, E., Palmer, S., and Huybrechts,
P.: Melt-induced speed-up of Greenland ice sheet offset by efficient
subglacial drainage, Nature, 469, 522–524, https://doi.org/10.1038/nature09740, 2011. a
Tedesco, M. and Fettweis, X.: Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet, The Cryosphere, 14, 1209–1223, https://doi.org/10.5194/tc-14-1209-2020, 2020. a
Tedesco, M., Fettweis, X., van den Broeke, M. R., van de Wal, R. S. W., Smeets,
C. J. P. P., van de Berg, W. J., Serreze, M. C., and Box, J. E.: The role
of albedo and accumulation in the 2010 melting record in Greenland,
Environ. Res. Lett., 6, 014005, https://doi.org/10.1088/1748-9326/6/1/014005, 2011. a, b
Tedesco, M., Fettweis, X., Mote, T., Wahr, J., Alexander, P., Box, J. E., and Wouters, B.: Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis data, The Cryosphere, 7, 615–630, https://doi.org/10.5194/tc-7-615-2013, 2013a. a, b
Tedesco, M., Willis, I. C., Hoffman, M. J., Banwell, A. F., Alexander, P., and
Arnold, N. S.: Ice dynamic response to two modes of surface lake drainage on
the Greenland ice sheet, Environ. Res. Lett., 8, 034007, https://doi.org/10.1088/1748-9326/8/3/034007, 2013b. a
Tedstone, A. J., Nienow, P. W., Gourmelen, N., Dehecq, A., Goldberg, D., and
Hanna, E.: Decadal slowdown of a land-terminating sector of the Greenland
Ice Sheet despite warming, Nature, 526, 692–695,
https://doi.org/10.1038/nature15722, 2015. a, b
Truffer, M., Harrison, W. D., and March, R. S.: Record negative glacier
balances and low velocities during the 2004 heatwave in Alaska, USA:
implications for the interpretation of observations by Zwally and others
inGreenland, J. Glaciol., 51, 663–664, https://doi.org/10.3189/172756505781829016,
2005.
a
Ugelvig, S. V., Egholm, D. L., Anderson, R. S., and Iverson, N. R.: Glacial
Erosion Driven by Variations in Meltwater Drainage, J. Geophys. Res.-Earth, 123, 2863–2877, https://doi.org/10.1029/2018JF004680, 2018. a
van de Wal, R. S. W., Smeets, C. J. P. P., Boot, W., Stoffelen, M., van Kampen, R., Doyle, S. H., Wilhelms, F., van den Broeke, M. R., Reijmer, C. H., Oerlemans, J., and Hubbard, A.: Self-regulation of ice flow varies across the ablation area in south-west Greenland, The Cryosphere, 9, 603–611, https://doi.org/10.5194/tc-9-603-2015, 2015. a, b
Vincent, C. and Moreau, L.: Sliding velocity fluctuations and subglacial
hydrology over the last two decades on Argentiere glacier, Mont Blanc area,
J. Glaciol., 62, 805–815, https://doi.org/10.1017/jog.2016.35, 2016. a
Walder, J. S. and Fowler, A.: Channelized subglacial drainage over a deformable
bed, J. Glaciol., 40, 3–15, https://doi.org/10.3189/S0022143000003750, 1994. a
Zwally, H. J., Abdalati, W., Herring, T., Larson, K., Saba, J., and Steffen,
K.: Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow, Science,
297, 218–222, https://doi.org/10.1126/science.1072708, 2002. a
Zwally, H. J., Li, J., Brenner, A. C., Beckley, M., Cornejo, H. G., Dimarzio,
J., Giovinetto, M. B., Neumann, T. A., Robbins, J., Saba, J. L., Yi, D., and
Wang, W.: Greenland ice sheet mass balance: distribution of increased mass
loss with climate warming; 2003-07 versus 1992-2002, J. Glaciol., 57,
88–102, 2011. a
Short summary
As temperature increases, more snow and ice melt at the surface of ice sheets. Here we use an ice dynamics and subglacial hydrology model with simplified geometry and climate forcing to study the impact of variations in meltwater on ice dynamics. We focus on the variations in length and intensity of the melt season. Our results show that a longer melt season leads to faster glaciers, but a more intense melt season reduces glaciers' seasonal velocities, albeit leading to higher peak velocities.
As temperature increases, more snow and ice melt at the surface of ice sheets. Here we use an...
