Articles | Volume 7, issue 4
https://doi.org/10.5194/tc-7-1083-2013
© Author(s) 2013. 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-7-1083-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
10 Jul 2013
Research article |
| 10 Jul 2013
Hindcasting to measure ice sheet model sensitivity to initial states
A. Aschwanden
Arctic Region Supercomputing Center, University of Alaska Fairbanks, Fairbanks, Alaska, USA
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
G. Aðalgeirsdóttir
Danish Meteorological Institute, Copenhagen, Denmark
C. Khroulev
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
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This manuscript describes the second version of a radiostratigraphic database for the Greenland Ice Sheet. It includes numerous improvements to original database from 2015, and includes more and more high-quality radar-sounding data in its assessment. It represents a unique and widespread potential constraint on the history of the ice sheet that could be targeted by ice-sheet models.
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This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
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Estimating how much ice loss from Greenland and Antarctica will contribute to sea level rise is of critical societal importance. However, our analysis shows that recent efforts are not trustworthy because the models fail at reproducing contemporary ice melt. Here we present a roadmap towards making more credible estimates of ice sheet melt.
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
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In this paper we use a large ensemble of Greenland ice sheet models forced by six different global climate models to project ice sheet changes and sea-level rise contributions over the 21st century.
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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.
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We use a regional 3-D outlet glacier model to simulate the behaviour of Jakobshavn Isbræ (JI) during 1990–2014. The model simulates two major accelerations in 1998 and 2003 that are consistent with observations. We find that most of the JI retreat during the simulated period is driven by the ocean parametrization used, and the glacier's subsequent response, which is largely governed by bed geometry. The study shows progress in modelling the temporal variability of the flow at JI.
S. A. Khan, K. K. Kjeldsen, K. H. Kjær, S. Bevan, A. Luckman, A. Aschwanden, A. A. Bjørk, N. J. Korsgaard, J. E. Box, M. van den Broeke, T. M. van Dam, and A. Fitzner
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Joseph A. MacGregor, Mark A. Fahnestock, John D. Paden, Jilu Li, Jeremy P. Harbeck, and Andy Aschwanden
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-578, https://doi.org/10.5194/essd-2024-578, 2025
Preprint under review for ESSD
Short summary
Short summary
This manuscript describes the second version of a radiostratigraphic database for the Greenland Ice Sheet. It includes numerous improvements to original database from 2015, and includes more and more high-quality radar-sounding data in its assessment. It represents a unique and widespread potential constraint on the history of the ice sheet that could be targeted by ice-sheet models.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
Short summary
Short summary
This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Andy Aschwanden, Timothy C. Bartholomaus, Douglas J. Brinkerhoff, and Martin Truffer
The Cryosphere, 15, 5705–5715, https://doi.org/10.5194/tc-15-5705-2021, https://doi.org/10.5194/tc-15-5705-2021, 2021
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Short summary
Estimating how much ice loss from Greenland and Antarctica will contribute to sea level rise is of critical societal importance. However, our analysis shows that recent efforts are not trustworthy because the models fail at reproducing contemporary ice melt. Here we present a roadmap towards making more credible estimates of ice sheet melt.
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
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Short summary
Short summary
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.
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
Short summary
Short summary
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.
Ioana S. Muresan, Shfaqat A. Khan, Andy Aschwanden, Constantine Khroulev, Tonie Van Dam, Jonathan Bamber, Michiel R. van den Broeke, Bert Wouters, Peter Kuipers Munneke, and Kurt H. Kjær
The Cryosphere, 10, 597–611, https://doi.org/10.5194/tc-10-597-2016, https://doi.org/10.5194/tc-10-597-2016, 2016
Short summary
Short summary
We use a regional 3-D outlet glacier model to simulate the behaviour of Jakobshavn Isbræ (JI) during 1990–2014. The model simulates two major accelerations in 1998 and 2003 that are consistent with observations. We find that most of the JI retreat during the simulated period is driven by the ocean parametrization used, and the glacier's subsequent response, which is largely governed by bed geometry. The study shows progress in modelling the temporal variability of the flow at JI.
S. A. Khan, K. K. Kjeldsen, K. H. Kjær, S. Bevan, A. Luckman, A. Aschwanden, A. A. Bjørk, N. J. Korsgaard, J. E. Box, M. van den Broeke, T. M. van Dam, and A. Fitzner
The Cryosphere, 8, 1497–1507, https://doi.org/10.5194/tc-8-1497-2014, https://doi.org/10.5194/tc-8-1497-2014, 2014
J. Seguinot, C. Khroulev, I. Rogozhina, A. P. Stroeven, and Q. Zhang
The Cryosphere, 8, 1087–1103, https://doi.org/10.5194/tc-8-1087-2014, https://doi.org/10.5194/tc-8-1087-2014, 2014
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We provide a simple stress-based parameterization for cliff calving of ice sheets. According to the resulting increasing dependence of the calving rate on ice thickness, the parameterization might lead to a runaway ice loss in large parts of Greenland and Antarctica.
Anders Levermann and Johannes Feldmann
The Cryosphere, 13, 1621–1633, https://doi.org/10.5194/tc-13-1621-2019, https://doi.org/10.5194/tc-13-1621-2019, 2019
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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.
Sue Cook, Jan Åström, Thomas Zwinger, Benjamin Keith Galton-Fenzi, Jamin Stevens Greenbaum, and Richard Coleman
The Cryosphere, 12, 2401–2411, https://doi.org/10.5194/tc-12-2401-2018, https://doi.org/10.5194/tc-12-2401-2018, 2018
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The growth of fractures on Antarctic ice shelves is important because it controls the amount of ice lost as icebergs. We use a model constructed of multiple interconnected blocks to predict the locations where fractures will form on the Totten Ice Shelf in East Antarctica. The results show that iceberg calving is controlled not only by fractures forming near the front of the ice shelf but also by fractures which formed many kilometres upstream.
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
Short summary
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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.
Alex S. Gardner, Geir Moholdt, Ted Scambos, Mark Fahnstock, Stefan Ligtenberg, Michiel van den Broeke, and Johan Nilsson
The Cryosphere, 12, 521–547, https://doi.org/10.5194/tc-12-521-2018, https://doi.org/10.5194/tc-12-521-2018, 2018
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We map present-day Antarctic surface velocities from Landsat imagery and compare to earlier estimates from radar. Flow accelerations across the grounding lines of West Antarctica's Amundsen Sea Embayment, Getz Ice Shelf and the western Antarctic Peninsula, account for 89 % of the observed increase in ice discharge. In contrast, glaciers draining the East Antarctic have been remarkably stable. Our work suggests that patterns of mass loss are part of a longer-term phase of enhanced flow.
ice sheet volume
Troels Bøgeholm Mikkelsen, Aslak Grinsted, and Peter Ditlevsen
The Cryosphere, 12, 39–47, https://doi.org/10.5194/tc-12-39-2018, https://doi.org/10.5194/tc-12-39-2018, 2018
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The atmospheric temperature increase poses a real risk of ice sheets collapsing. We show that this risk might have been underestimated since variations in temperature will move the ice sheets to the tipping point of destabilization.
We show this by using a simple computer model of a large ice sheet and investigate what happens if the temperature varies from year to year. The total volume of the ice sheet decreases because a cold year followed by an equally warm year do not cancel out.
David E. Shean, Knut Christianson, Kristine M. Larson, Stefan R. M. Ligtenberg, Ian R. Joughin, Ben E. Smith, C. Max Stevens, Mitchell Bushuk, and David M. Holland
The Cryosphere, 11, 2655–2674, https://doi.org/10.5194/tc-11-2655-2017, https://doi.org/10.5194/tc-11-2655-2017, 2017
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We used long-term GPS data and interferometric reflectometry (GPS-IR) to measure velocity, strain rate and surface elevation for the PIG ice shelf – a site of significant mass loss in recent decades. We combined these observations with high-res DEMs and firn model output to constrain surface mass balance and basal melt rates. We document notable spatial variability in basal melt rates but limited temporal variability from 2012 to 2014 despite significant changes in sub-shelf ocean heat content.
Wolfgang Rack, Matt A. King, Oliver J. Marsh, Christian T. Wild, and Dana Floricioiu
The Cryosphere, 11, 2481–2490, https://doi.org/10.5194/tc-11-2481-2017, https://doi.org/10.5194/tc-11-2481-2017, 2017
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Predicting changes of the Antarctic Ice Sheet involves fully understanding ice dynamics at the transition between grounded and floating ice. We map tidal bending of ice by satellite using InSAR, and we use precise GPS measurements with assumptions of tidal elastic bending to better interpret the satellite signal. It allows us to better define the grounding-line position and to refine the shape of tidal flexure profiles.
Christian Schoof, Andrew D. Davis, and Tiberiu V. Popa
The Cryosphere, 11, 2283–2303, https://doi.org/10.5194/tc-11-2283-2017, https://doi.org/10.5194/tc-11-2283-2017, 2017
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We show mathematically and computationally how discharge of ice from ocean-terminating glaciers is controlled by a combination of different forces acting on ice near the grounding line of a glacier and how that combination of forces is affected by the process of iceberg formation, which limits the length of floating ice tongues extending in front of the glacier. We show that a deeper fjord may lead to a longer ice tongue providing greater drag on the glacier, slowing the rate of ice discharge.
Joel Brown, Joel Harper, and Neil Humphrey
The Cryosphere, 11, 669–679, https://doi.org/10.5194/tc-11-669-2017, https://doi.org/10.5194/tc-11-669-2017, 2017
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We use ground-penetrating radar surveys in conjunction with borehole depth and temperature data to estimate the liquid water content (wetness) of glacial ice in the ablation zone of an outlet glacier on the western side of the Greenland Ice Sheet. Our results show that the wetness of a warm basal ice layer is approximately 2.9 % to 4.6 % in our study region. This high level of wetness requires special attention when modelling ice dynamics or estimating ice thickness in the region.
Lionel Favier, Frank Pattyn, Sophie Berger, and Reinhard Drews
The Cryosphere, 10, 2623–2635, https://doi.org/10.5194/tc-10-2623-2016, https://doi.org/10.5194/tc-10-2623-2016, 2016
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We demonstrate the short-term unstable retreat of an East Antarctic outlet glacier triggered by imposed sub-ice-shelf melt, compliant with current values, using a state-of-the-art ice-sheet model. We show that pinning points – topographic highs in contact with the ice-shelf base – have a major impact on ice-sheet stability and timing of grounding-line retreat. The study therefore calls for improving our knowledge of sub-ice-shelf bathymetry in order to reduce uncertainties in future ice loss.
Alexander A. Robel, Christian Schoof, and Eli Tziperman
The Cryosphere, 10, 1883–1896, https://doi.org/10.5194/tc-10-1883-2016, https://doi.org/10.5194/tc-10-1883-2016, 2016
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Portions of the Antarctic Ice Sheet edge that rest on upward-sloping beds have the potential to collapse irreversibly and raise global sea level. Using a numerical model, we show that changes in the slipperiness of sediments beneath fast-flowing ice streams can cause them to persist on upward-sloping beds for hundreds to thousands of years before reversing direction. This type of behavior is important to consider as a possibility when interpreting observations of ongoing ice sheet change.
Johannes Feldmann and Anders Levermann
The Cryosphere, 10, 1753–1769, https://doi.org/10.5194/tc-10-1753-2016, https://doi.org/10.5194/tc-10-1753-2016, 2016
T. M. Jordan, J. L. Bamber, C. N. Williams, J. D. Paden, M. J. Siegert, P. Huybrechts, O. Gagliardini, and F. Gillet-Chaulet
The Cryosphere, 10, 1547–1570, https://doi.org/10.5194/tc-10-1547-2016, https://doi.org/10.5194/tc-10-1547-2016, 2016
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Ice penetrating radar enables determination of the basal properties of ice sheets. Existing algorithms assume stationarity in the attenuation rate, which is not justifiable at an ice sheet scale. We introduce the first ice-sheet-wide algorithm for radar attenuation that incorporates spatial variability, using the temperature field from a numerical model as an initial guess. The study is a step toward ice-sheet-wide data products for basal properties and evaluation of model temperature fields.
Hongyu Zhu, Noemi Petra, Georg Stadler, Tobin Isaac, Thomas J. R. Hughes, and Omar Ghattas
The Cryosphere, 10, 1477–1494, https://doi.org/10.5194/tc-10-1477-2016, https://doi.org/10.5194/tc-10-1477-2016, 2016
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We study how well the basal geothermal heat flux can be inferred from surface velocity observations using a thermomechanically coupled nonlinear Stokes ice sheet model. The prospects and limitations of this inversion is studied in two and three dimensional model problems. We also argue that a one-way coupled approach for the adjoint equations motivated by staggered solvers for forward multiphysics problems can lead to an incorrect gradient and premature termination of the optimization iteration.
Eythor Gudlaugsson, Angelika Humbert, Thomas Kleiner, Jack Kohler, and Karin Andreassen
The Cryosphere, 10, 751–760, https://doi.org/10.5194/tc-10-751-2016, https://doi.org/10.5194/tc-10-751-2016, 2016
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This paper explores the influence of a subglacial lake on ice dynamics and internal layers by means of numerical modelling as well as simulating the effect of a subglacial drainage event on isochrones. We provide an explanation for characteristic dip and ridge features found at the edges of many subglacial lakes and conclude that draining lakes can result in travelling waves at depth within isochrones, thus indicating the possibility of detecting past drainage events with ice penetrating radar.
T. Hughes, A. Sargent, J. Fastook, K. Purdon, J. Li, J.-B. Yan, and S. Gogineni
The Cryosphere, 10, 193–225, https://doi.org/10.5194/tc-10-193-2016, https://doi.org/10.5194/tc-10-193-2016, 2016
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The Antarctic and Greenland ice sheets are drained primarily by fast ice streams that end as ice shelves if they become afloat. Smooth transitions from slow sheet flow to fast stream flow to confined shelf flow are obtained and applied to Byrd Glacier in Antarctica after two upstream subglacial lakes suddenly drained in 2006, and to Jakobshavn Isbrae in Greenland after a confined ice shelf suddenly disintegrated in 2002. Byrd Glacier quickly stabilized, but Jakobshavn Isbrae remains unstable.
F. Saito, A. Abe-Ouchi, K. Takahashi, and H. Blatter
The Cryosphere, 10, 43–63, https://doi.org/10.5194/tc-10-43-2016, https://doi.org/10.5194/tc-10-43-2016, 2016
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This article, as the title denotes, is a follow-up study of an ice-sheet intercomparison project SeaRISE, which focuses on the response of the Greenland ice sheet to future global warming. The projections of the different SeaRISE prticipants show diversion, which has not been examined in detail to date. This study detects the main sources of the diversion by a number of sensitivity experiments and shows the importance of initialization methods as well as climate forcing methods.
P. Kuipers Munneke, S. R. M. Ligtenberg, B. P. Y. Noël, I. M. Howat, J. E. Box, E. Mosley-Thompson, J. R. McConnell, K. Steffen, J. T. Harper, S. B. Das, and M. R. van den Broeke
The Cryosphere, 9, 2009–2025, https://doi.org/10.5194/tc-9-2009-2015, https://doi.org/10.5194/tc-9-2009-2015, 2015
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The snow layer on top of the Greenland Ice Sheet is changing: it is thickening in the high and cold interior due to increased snowfall, while it is thinning around the margins. The marginal thinning is caused by compaction, and by more melt.
This knowledge is important: there are satellites that measure volume change of the ice sheet. It can be caused by increased ice discharge, or by compaction of the snow layer. Here, we quantify the latter, so that we can translate volume to mass change.
T. Goelles, C. E. Bøggild, and R. Greve
The Cryosphere, 9, 1845–1856, https://doi.org/10.5194/tc-9-1845-2015, https://doi.org/10.5194/tc-9-1845-2015, 2015
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Soot (black carbon) and dust particles darken the surface of ice sheets and glaciers as they accumulate. This causes more ice to melt, which releases more particles from within the ice. This positive feedback mechanism is studied with a new two-dimensional model, mimicking the conditions of Greenland, under different climate warming scenarios. In the warmest scenario, the additional ice sheet mass loss until the year 3000 is up to 7%.
S. H. R. Rosier, G. H. Gudmundsson, and J. A. M. Green
The Cryosphere, 9, 1649–1661, https://doi.org/10.5194/tc-9-1649-2015, https://doi.org/10.5194/tc-9-1649-2015, 2015
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We use a full-Stokes model to investigate the long period modulation of Rutford Ice Stream flow by the ocean tide. We find that using a nonlinear sliding law cannot fully explain the measurements and an additional mechanism, whereby tidally induced subglacial pressure variations are transmitted upstream from the grounding line, is also required to match the large amplitude and decay length scale of the observations.
R. Drews
The Cryosphere, 9, 1169–1181, https://doi.org/10.5194/tc-9-1169-2015, https://doi.org/10.5194/tc-9-1169-2015, 2015
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Floating ice shelves extend the continental ice of Antarctica seawards and mediate ice-ocean interactions. Many ice shelves are incised with channels where basal melting is enhanced. With data and modeling it is shown how the channel geometry depends on basal melting and along-flow advection (also for channels which are not freely floating), and how channel formation imprints the general flow pattern. This opens up the opportunity to map the channel formation from surface velocities only.
P. R. Holland, A. Brisbourne, H. F. J. Corr, D. McGrath, K. Purdon, J. Paden, H. A. Fricker, F. S. Paolo, and A. H. Fleming
The Cryosphere, 9, 1005–1024, https://doi.org/10.5194/tc-9-1005-2015, https://doi.org/10.5194/tc-9-1005-2015, 2015
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Antarctic Peninsula ice shelves have collapsed in recent decades. The surface of Larsen C Ice Shelf is lowering, but the cause of this has not been understood. This study uses eight radar surveys to show that the lowering is caused by both ice loss and a loss of air from the ice shelf's snowpack. At least two different processes are causing the lowering. The stability of Larsen C may be at risk from an ungrounding of Bawden Ice Rise or ice-front retreat past a 'compressive arch' in strain rates.
M. Bügelmayer, D. M. Roche, and H. Renssen
The Cryosphere, 9, 821–835, https://doi.org/10.5194/tc-9-821-2015, https://doi.org/10.5194/tc-9-821-2015, 2015
A. Diez and O. Eisen
The Cryosphere, 9, 367–384, https://doi.org/10.5194/tc-9-367-2015, https://doi.org/10.5194/tc-9-367-2015, 2015
A. Diez, O. Eisen, C. Hofstede, A. Lambrecht, C. Mayer, H. Miller, D. Steinhage, T. Binder, and I. Weikusat
The Cryosphere, 9, 385–398, https://doi.org/10.5194/tc-9-385-2015, https://doi.org/10.5194/tc-9-385-2015, 2015
R. Calov, A. Robinson, M. Perrette, and A. Ganopolski
The Cryosphere, 9, 179–196, https://doi.org/10.5194/tc-9-179-2015, https://doi.org/10.5194/tc-9-179-2015, 2015
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Ice discharge into the ocean from outlet glaciers is an important
component of mass loss of the Greenland ice sheet. Here, we present a
simple parameterization of ice discharge for coarse resolution ice
sheet models, suitable for large ensembles or long-term palaeo
simulations. This parameterization reproduces in a good approximation
the present-day ice discharge compared with estimates, and the
simulation of the present-day ice sheet elevation is considerably
improved.
V. Helm, A. Humbert, and H. Miller
The Cryosphere, 8, 1539–1559, https://doi.org/10.5194/tc-8-1539-2014, https://doi.org/10.5194/tc-8-1539-2014, 2014
A. Robinson and H. Goelzer
The Cryosphere, 8, 1419–1428, https://doi.org/10.5194/tc-8-1419-2014, https://doi.org/10.5194/tc-8-1419-2014, 2014
G. R. Leguy, X. S. Asay-Davis, and W. H. Lipscomb
The Cryosphere, 8, 1239–1259, https://doi.org/10.5194/tc-8-1239-2014, https://doi.org/10.5194/tc-8-1239-2014, 2014
A. A. Borsa, G. Moholdt, H. A. Fricker, and K. M. Brunt
The Cryosphere, 8, 345–357, https://doi.org/10.5194/tc-8-345-2014, https://doi.org/10.5194/tc-8-345-2014, 2014
I. Joughin, B. E. Smith, D. E. Shean, and D. Floricioiu
The Cryosphere, 8, 209–214, https://doi.org/10.5194/tc-8-209-2014, https://doi.org/10.5194/tc-8-209-2014, 2014
C. P. Borstad, E. Rignot, J. Mouginot, and M. P. Schodlok
The Cryosphere, 7, 1931–1947, https://doi.org/10.5194/tc-7-1931-2013, https://doi.org/10.5194/tc-7-1931-2013, 2013
V. R. Barletta, L. S. Sørensen, and R. Forsberg
The Cryosphere, 7, 1411–1432, https://doi.org/10.5194/tc-7-1411-2013, https://doi.org/10.5194/tc-7-1411-2013, 2013
I. Joughin, S. B. Das, G. E. Flowers, M. D. Behn, R. B. Alley, M. A. King, B. E. Smith, J. L. Bamber, M. R. van den Broeke, and J. H. van Angelen
The Cryosphere, 7, 1185–1192, https://doi.org/10.5194/tc-7-1185-2013, https://doi.org/10.5194/tc-7-1185-2013, 2013
J. De Rydt, G. H. Gudmundsson, H. F. J. Corr, and P. Christoffersen
The Cryosphere, 7, 407–417, https://doi.org/10.5194/tc-7-407-2013, https://doi.org/10.5194/tc-7-407-2013, 2013
W. Leng, L. Ju, M. Gunzburger, and S. Price
The Cryosphere, 7, 19–29, https://doi.org/10.5194/tc-7-19-2013, https://doi.org/10.5194/tc-7-19-2013, 2013
F. Gillet-Chaulet, O. Gagliardini, H. Seddik, M. Nodet, G. Durand, C. Ritz, T. Zwinger, R. Greve, and D. G. Vaughan
The Cryosphere, 6, 1561–1576, https://doi.org/10.5194/tc-6-1561-2012, https://doi.org/10.5194/tc-6-1561-2012, 2012
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