Articles | Volume 6, issue 5
https://doi.org/10.5194/tc-6-1203-2012
© Author(s) 2012. 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-6-1203-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
24 Oct 2012
Research article |
| 24 Oct 2012
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica
S. Fujita
National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan
P. Holmlund
Department of Physical Geography and Quaternary Geology, Stockholm University, 106 91 Stockholm Sweden
K. Matsuoka
Norwegian Polar Institute, Tromsø, Norway
H. Enomoto
National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan
Kitami Institute of Technology, Kitami, Japan
K. Fukui
National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan
now at: Tateyama Caldera Sabo Museum, Toyama, Japan
F. Nakazawa
National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan
S. Sugiyama
Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
S. Surdyk
National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan
Related subject area
Ice Sheets
Reconstructing dynamics of the Baltic Ice Stream Complex during deglaciation of the Last Scandinavian Ice Sheet
Assessing the potential for ice flow piracy between the Totten and Vanderford glaciers, East Antarctica
Stagnant ice and age modelling in the Dome C region, Antarctica
Polar firn properties in Greenland and Antarctica and related effects on microwave brightness temperatures
A model of the weathering crust and microbial activity on an ice-sheet surface
PISM-LakeCC: Implementing an adaptive proglacial lake boundary in an ice sheet model
Remapping of Greenland ice sheet surface mass balance anomalies for large ensemble sea-level change projections
Brief communication: On calculating the sea-level contribution in marine ice-sheet models
A simple stress-based cliff-calving law
Scaling of instability timescales of Antarctic outlet glaciers based on one-dimensional similitude analysis
A statistical fracture model for Antarctic ice shelves and glaciers
Modelled fracture and calving on the Totten Ice Shelf
Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison
Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years
Influence of temperature fluctuations on equilibrium
ice sheet volume
GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
Analysis of ice shelf flexure and its InSAR representation in the grounding zone of the southern McMurdo Ice Shelf
Boundary layer models for calving marine outlet glaciers
Liquid water content in ice estimated through a full-depth ground radar profile and borehole measurements in western Greenland
Dynamic influence of pinning points on marine ice-sheet stability: a numerical study in Dronning Maud Land, East Antarctica
Persistence and variability of ice-stream grounding lines on retrograde bed slopes
Similitude of ice dynamics against scaling of geometry and physical parameters
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data
Inversion of geothermal heat flux in a thermomechanically coupled nonlinear Stokes ice sheet model
The influence of a model subglacial lake on ice dynamics and internal layering
Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland
SeaRISE experiments revisited: potential sources of spread in multi-model projections of the Greenland ice sheet
Elevation change of the Greenland Ice Sheet due to surface mass balance and firn processes, 1960–2014
Ice sheet mass loss caused by dust and black carbon accumulation
Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system
Evolution of ice-shelf channels in Antarctic ice shelves
Oceanic and atmospheric forcing of Larsen C Ice-Shelf thinning
How do icebergs affect the Greenland ice sheet under pre-industrial conditions? – a model study with a fully coupled ice-sheet–climate model
Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties
Seismic wave propagation in anisotropic ice – Part 2: Effects of crystal anisotropy in geophysical data
Simulating the Greenland ice sheet under present-day and palaeo constraints including a new discharge parameterization
Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2
The importance of insolation changes for paleo ice sheet modeling
Parameterization of basal friction near grounding lines in a one-dimensional ice sheet model
A range correction for ICESat and its potential impact on ice-sheet mass balance studies
Brief Communication: Further summer speedup of Jakobshavn Isbræ
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf
Scatter of mass changes estimates at basin scale for Greenland and Antarctica
Influence of ice-sheet geometry and supraglacial lakes on seasonal ice-flow variability
Hindcasting to measure ice sheet model sensitivity to initial states
Surface undulations of Antarctic ice streams tightly controlled by bedrock topography
Manufactured solutions and the verification of three-dimensional Stokes ice-sheet models
Greenland ice sheet contribution to sea-level rise from a new-generation ice-sheet model
Ice velocity changes in the Ross and Ronne sectors observed using satellite radar data from 1997 and 2009
A simple inverse method for the distribution of basal sliding coefficients under ice sheets, applied to Antarctica
Izabela Szuman, Jakub Z. Kalita, Christiaan R. Diemont, Stephen J. Livingstone, Chris D. Clark, and Martin Margold
The Cryosphere, 18, 2407–2428, https://doi.org/10.5194/tc-18-2407-2024, https://doi.org/10.5194/tc-18-2407-2024, 2024
Short summary
Short summary
A Baltic-wide glacial landform-based map is presented, filling in a geographical gap in the record that has been speculated about by palaeoglaciologists for over a century. Here we used newly available bathymetric data and provide landform evidence of corridors of fast ice flow that we interpret as ice streams. Where previous ice-sheet-scale investigations inferred a single ice source, our mapping identifies flow and ice margin geometries from both Swedish and Bothnian sources.
Felicity S. McCormack, Jason L. Roberts, Bernd Kulessa, Alan Aitken, Christine F. Dow, Lawrence Bird, Benjamin K. Galton-Fenzi, Katharina Hochmuth, Richard S. Jones, Andrew N. Mackintosh, and Koi McArthur
The Cryosphere, 17, 4549–4569, https://doi.org/10.5194/tc-17-4549-2023, https://doi.org/10.5194/tc-17-4549-2023, 2023
Short summary
Short summary
Changes in Antarctic surface elevation can cause changes in ice and basal water flow, impacting how much ice enters the ocean. We find that ice and basal water flow could divert from the Totten to the Vanderford Glacier, East Antarctica, under only small changes in the surface elevation, with implications for estimates of ice loss from this region. Further studies are needed to determine when this could occur and if similar diversions could occur elsewhere in Antarctica due to climate change.
Ailsa Chung, Frédéric Parrenin, Daniel Steinhage, Robert Mulvaney, Carlos Martín, Marie G. P. Cavitte, David A. Lilien, Veit Helm, Drew Taylor, Prasad Gogineni, Catherine Ritz, Massimo Frezzotti, Charles O'Neill, Heinrich Miller, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, https://doi.org/10.5194/tc-17-3461-2023, 2023
Short summary
Short summary
We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.
Haokui Xu, Brooke Medley, Leung Tsang, Joel T. Johnson, Kenneth C. Jezek, Macro Brogioni, and Lars Kaleschke
The Cryosphere, 17, 2793–2809, https://doi.org/10.5194/tc-17-2793-2023, https://doi.org/10.5194/tc-17-2793-2023, 2023
Short summary
Short summary
The density profile of polar ice sheets is a major unknown in estimating the mass loss using lidar tomography methods. In this paper, we show that combing the active radar data and passive radiometer data can provide an estimation of density properties using the new model we implemented in this paper. The new model includes the short and long timescale variations in the firn and also the refrozen layers which are not included in the previous modeling work.
Tilly Woods and Ian J. Hewitt
The Cryosphere, 17, 1967–1987, https://doi.org/10.5194/tc-17-1967-2023, https://doi.org/10.5194/tc-17-1967-2023, 2023
Short summary
Short summary
Solar radiation causes melting at and just below the surface of the Greenland ice sheet, forming a porous surface layer known as the weathering crust. The weathering crust is home to many microbes, and the growth of these microbes is linked to the melting of the weathering crust and vice versa. We use a mathematical model to investigate what controls the size and structure of the weathering crust, the number of microbes within it, and its sensitivity to climate change.
Sebastian Hinck, Evan J. Gowan, Xu Zhang, and Gerrit Lohmann
The Cryosphere, 16, 941–965, https://doi.org/10.5194/tc-16-941-2022, https://doi.org/10.5194/tc-16-941-2022, 2022
Short summary
Short summary
Proglacial lakes were pervasive along the retreating continental ice margins after the Last Glacial Maximum. Similarly to the marine ice boundary, interactions at the ice-lake interface impact ice sheet dynamics and mass balance. Previous numerical ice sheet modeling studies did not include a dynamical lake boundary. We describe the implementation of an adaptive lake boundary condition in PISM and apply the model to the glacial retreat of the Laurentide Ice Sheet.
Heiko Goelzer, Brice P. Y. Noël, Tamsin L. Edwards, Xavier Fettweis, Jonathan M. Gregory, William H. Lipscomb, Roderik S. W. van de Wal, and Michiel R. van den Broeke
The Cryosphere, 14, 1747–1762, https://doi.org/10.5194/tc-14-1747-2020, https://doi.org/10.5194/tc-14-1747-2020, 2020
Short summary
Short summary
Future sea-level change projections with process-based ice sheet models are typically driven with surface mass balance forcing derived from climate models. In this work we address the problems arising from a mismatch of the modelled ice sheet geometry with the one used by the climate model. The proposed remapping method reproduces the original forcing data closely when applied to the original geometry and produces a physically meaningful forcing when applied to different modelled geometries.
Heiko Goelzer, Violaine Coulon, Frank Pattyn, Bas de Boer, and Roderik van de Wal
The Cryosphere, 14, 833–840, https://doi.org/10.5194/tc-14-833-2020, https://doi.org/10.5194/tc-14-833-2020, 2020
Short summary
Short summary
In our ice-sheet modelling experience and from exchange with colleagues in different groups, we found that it is not always clear how to calculate the sea-level contribution from a marine ice-sheet model. This goes hand in hand with a lack of documentation and transparency in the published literature on how the sea-level contribution is estimated in different models. With this brief communication, we hope to stimulate awareness and discussion in the community to improve on this situation.
Tanja Schlemm and Anders Levermann
The Cryosphere, 13, 2475–2488, https://doi.org/10.5194/tc-13-2475-2019, https://doi.org/10.5194/tc-13-2475-2019, 2019
Short summary
Short summary
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
Short summary
Short summary
Using scaling analysis we propose that the currently observed marine ice-sheet instability in the Amundsen Sea sector might be faster than all other potential instabilities in Antarctica.
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
Short summary
Short summary
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
Short summary
Short summary
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
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
A. Aschwanden, G. Aðalgeirsdóttir, and C. Khroulev
The Cryosphere, 7, 1083–1093, https://doi.org/10.5194/tc-7-1083-2013, https://doi.org/10.5194/tc-7-1083-2013, 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
B. Scheuchl, J. Mouginot, and E. Rignot
The Cryosphere, 6, 1019–1030, https://doi.org/10.5194/tc-6-1019-2012, https://doi.org/10.5194/tc-6-1019-2012, 2012
D. Pollard and R. M. DeConto
The Cryosphere, 6, 953–971, https://doi.org/10.5194/tc-6-953-2012, https://doi.org/10.5194/tc-6-953-2012, 2012
Cited articles
Bamber, J. L., Vaughan, D. G., and Joughin, I.: Widespread complex flow in the interior of the Antarctic ice sheet, Science, 287, 1248–1250, https://doi.org/10.1126/science.287.5456.1248, 2000.
Bamber, J. L., Ferraccioli, F., Joughin, I., Shepherd, T., Rippin, D. M., Siegert, M. J., and Vaughan, D. G.: East Antarctic ice stream tributary underlain by major sedimentary basin, Geology, 34, 33–36, https://doi.org/10.1130/G22160.1, 2006.
Bamber, J. L., Gomez-Dans, J. L., and Griggs, J. A.: Antarctic 1 km Digital Elevation Model (DEM) from combined ERS-1 radar and ICESat Laser satellite altimetry, in: National Snow and Ice Data Center, Digital media, Boulder, Colorado, USA, 2009.
Bell, R. E.: The role of subglacial water in ice-sheet mass balance, Nat. Geosci., 1, 297–304, https://doi.org/10.1038/ngeo186, 2008.
Bell, R. E., Ferraccioli, F., Creyts, T. T., Braaten, D., Corr, H., Das, I., Damaske, D., Frearson, N., Jordan, T., Rose, K., Studinger, M., and Wolovick, M.: Widespread persistent thickening of the East Antarctic ice sheet by freezing from the base, Science, 331, 1592–1595, https://doi.org/10.1126/science.1200109, 2011.
Bennett, M. R.: Ice streams as the arteries of an ice sheet: their mechanics, stability and significance, Earth-Sci. Rev., 61, 309–339, https://doi.org/10.1016/s0012-8252(02)00130-7, 2003.
Bentley, C. R., Lord, N., and Liu, C.: Radar reflections reveal a wet bed beneath stagnant ice stream C and a frozen bed beneath ridge BC, West Antarctica, J. Glaciol., 44, 149–156, 1998.
Carter, S. P.: Radar-based subglacial lake classification in Antarctica, Geochem. Geophys. Geosy., 8, Q03016, https://doi.org/10.1029/2006GC001408, 2007.
Carter, S. P., Blankenship, D. D., Young, D. A., and Holt, J. W.: Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica, J. Glaciol., 55, 1025–1040, https://doi.org/10.3189/002214309790794931, 2009.
Comiso, J. C.: Variability and trends in antarctic surface temperatures from in situ and satellite infrared measurements, J. Climate, 13, 1674–1696, https://doi.org/10.1175/1520-0442(2000)013<1674:vatias>2.0.co;2, 2000.
Christianson, K., Jacobel, R. W., Horgan, H. J., Anandakrishnan, S., and Alley, R. B.: Subglacial lake whillans: Ice-penetrating radar and gps observations of a shallow active reservoir beneath a west antarctic ice stream, Earth Planet. Sc. Lett., 331–332, 237–245, https://doi.org/10.1016/j.epsl.2012.03.013, 2012.
Fox-Maule, C., Purucker, M. E., Olsen, N., and Mosegaard, K.: Heat flux anomalies in antarctica revealed by satellite magnetic data, Science, 309, 464–467, https://doi.org/10.1126/science.1106888, 2005.
Fricker, H. A., Scambos, T., Bindschadler, R., and Padman, L.: An active subglacial water system in west antarctica mapped from space, Science, 315, 1544–1548, https://doi.org/10.1126/science.1136897, 2007.
Fujita, S., Maeno, H., Uratsuka, S., Furukawa, T., Mae, S., Fujii, Y., and Watanabe, O.: Nature of radio-echo layering in the Antarctic ice sheet detected by a two-frequency experiment, J. Geophys. Res., 104, 13013–13024, https://doi.org/10.1029/1999JB900034, 1999.
Fujita, S., Matsuoka, T., Ishida, T., Matsuoka, K., and Mae, S.: A summary of the complex dielectric permittivity of ice in the megahertz range and its applications for radar sounding, in: Physics of Ice Core Records, edited by: Hondoh, T., Hokkaido University Press, Sapporo, 185–212, 2000.
Fujita, S., Maeno, H., Furukawa, T., and Matsuoka, K.: Scattering of VHF radio waves from within the top 700 m of the Antarctic ice sheet and its relation to the depositional environment: a case study along the Syowa-Mizuho-Dome F traverse, Ann. Glaciol., 34, 157–164, https://doi.org/10.3189/172756402781817888, 2002.
Fujita, S., Maeno, H., and Matsuoka, K.: Radio-wave depolarization and scattering within ice sheets: a matrix-based model to link radar and ice-core measurements and its application, J. Glaciol., 52, 407–424, https://doi.org/10.3189/172756506781828548, 2006.
Fujita, S., Holmlund, P., Andersson, I., Brown, I., Enomoto, H., Fujii, Y., Fujita, K., Fukui, K., Furukawa, T., Hansson, M., Hara, K., Hoshina, Y., Igarashi, M., Iizuka, Y., Imura, S., Ingvander, S., Karlin, T., Motoyama, H., Nakazawa, F., Oerter, H., Sjöberg, L. E., Sugiyama, S., Surdyk, S., Ström, J., Uemura, R., and Wilhelms, F.: Spatial and temporal variability of snow accumulation rate on the East Antarctic ice divide between Dome Fuji and EPICA DML, The Cryosphere, 5, 1057–1081, https://doi.org/10.5194/tc-5-1057-2011, 2011.
Fung, A. K.: Microwave Scattering and Emission Models and Their Applications, Boston, Artech House (1994/03) ISBN: 0890065233, 1994
Gades, A. M., Raymond, C. F., Conway, H., and Jacobel, R. W.: Bed properties of siple dome and adjacent ice streams, west antarctica, inferred from radio-echo sounding measurements, J. Glaciol., 46, 88–94, https://doi.org/10.3189/172756500781833467, 2000.
Haran, T., Bohlander, J., Scambos, T., Painter, T., and Fahnestock, M.: MODIS mosaic of Antarctica (MOA) image map, in: National Snow and Ice Data Center, Digital media, Boulder, Colorado, USA, 2005, updated 2006.
Holmlund, P. and Fujita, S.: Japanese-Swedish Antarctic Expedition JASE, in: Swedish Polar Secretariat Year Book 2008, edited by: Thorén, A., Swedish Polar Research Secretariat, Stockholm, 18, 2009.
Huybrechts, P., Rybak, O., Pattyn, F., and Steinhage, D.: Past and present accumulation rate reconstruction along the Dome Fuji-Kohnen radio echo sounding profile, Dronning Maud Land, East Antarctica, Ann. Glaciol., 50, 112–120, https://doi.org/10.3189/172756409789097513, 2009.
Hvidberg, C. S.: Steady-state thermomechanical modelling of ice flow near the centre of large ice sheets with the finite element technique, Ann. Glaciol., 23, 116–123, 1996.
Jacobel, R. W., Lapo, K. E., Stamp, J. R., Youngblood, B. W., Welch, B. C., and Bamber, J. L.: A comparison of basal reflectivity and ice velocity in East Antarctica, The Cryosphere, 4, 447–452, https://doi.org/10.5194/tc-4-447-2010, 2010.
Jouzel, J. and Masson-Delmotte, V.: Deep ice cores: the need for going back in time, Quaternary Sci. Rev., 29, 3683–3689, https://doi.org/10.1016/j.quascirev.2010.10.002, 2010.
Langley, K., Kohler, J., Matsuoka, K., Sinisalo, A., Scambos, T., Neumann, T., Muto, A., Winther, J. G., and Albert, M.: Recovery lakes, East Antarctica: radar assessment of sub-glacial water extent, Geophys. Res. Lett., 38, L05501, https://doi.org/10.1029/2010GL046094, 2010.
Lythe, M. B., Vaughan, D. G., and the BEDMAP consortium: BEDMAP: a new ice thickness and subglacial topographic model of Antarctica, J. Geophys. Res., 106, 11335–11351, https://doi.org/10.1029/2000JB900449, 2001.
Mae, S. and Naruse, R.: Possible causes of ice sheet thinning in the Mizuho Plateau, Nature, 273, 291–292, https://doi.org/10.1038/273291a0, 1978.
Martin, C., Hindmarsh, R. C. A., and Navarro, F. J.: On the effects of divide migration, along-ridge flow, and basal sliding on isochrones near an ice divide, J. Geophys. Res.-Earth, 114, F02006 https://doi.org/10.1029/2008jf001025, 2009.
Matsuoka, K.: Pitfalls in radar diagnosis of ice-sheet bed conditions: Lessons from englacial attenuation models, Geophys. Res. Lett., 38, L05505, https://doi.org/10.1029/2010GL046205, 2011.
Matsuoka, K., Maeno, H., Uratsuka, S., Fujita, S., Furukawa, T., and Watanabe, O.: A ground-based, multi-frequency ice-penetrating radar system, Ann. Glaciol., 34, 171–176, https://doi.org/10.3189/172756402781817400, 2002.
Matsuoka, K., Wilen, L., Hurley, S. P., and Raymond, C. F.: Effects of birefringence within ice sheets on obliquely propagating radio waves, IEEE T. Geosci. Remote, 47, 1429–1443, https://doi.org/10.1109/TGRS.2008.2005201, 2009.
Motoyama, H.: The second deep ice coring Project at Dome Fuji, Antarctica, Scientific Drilling, 5, 41–43, https://doi.org/10.2204/Iodp.sd.5.05.2007, 2007.
Motoyama, H., Enomoto, H., Furukawa, T., Kamiyama, K., Shoji, H., Shiraiwa, T., Watanabe, K., Namasu, K., and Ikeda, H.: Preliminary study of ice flow observations along traverse routes from coast to Dome Fuji, East Antarctica by differential GPS method, Nankyoku Shiryo (Antarctic Record), 39, 94–98, 1995.
Motoyama, H., Furukawa, T., and Nishio, F.: Study of ice flow observations in Shirase drainage basin and around Dome Fuji area, East Antarctica by differential GPS method, Nankyoku Shiryo (Antarctic Record), 52, 216–231, 2008 (in Japanese).
Murshed, M. M., Faria, S. H., Kuhs, W. F., Kipfstuhl, S., and Wilhelms, F.: The role of hydrochlorofluorocarbon densifiers in the formation of clathrate hydrates in deep boreholes and subglacial environments, Ann. Glaciol., 47, 109–114, https://doi.org/10.3189/172756407786857659, 2007.
Näslund, J. O., Fastook, J. L., and Holmlund, P.: Numerical modelling of the ice sheet in Western Dronning Maud Land, East Antarctica: impacts of present, past and future climates, J. Glaciol., 46, 54–66, https://doi.org/10.3189/172756500781833331, 2000.
Pattyn, F.: Antarctic subglacial conditions inferred from a hybrid ice sheet/ice stream model, Earth Planet. Sc. Lett., 295, 451–461, https://doi.org/10.1016/j.epsl.2010.04.025, 2010.
Pattyn, F., De Brabander, S., and Huyghe, A.: Basal and thermal control mechanisms of the Ragnhild glaciers, East Antarctica, in: Annals of Glaciology, vol. 40, edited by: MacAyeal, D. R., Int. Glaciological Soc., Cambridge, 225–231, https://doi.org/10.3189/172756405781813672, 2005.
Peters, M. E., Blankenship, D. D., and Morse, D. L.: Analysis techniques for coherent airborne radar sounding: application to West Antarctic ice streams, J. Geophys. Res., 110, B06303, https://doi.org/10.1029/2004JB003222, 2005.
Popov, S. V. and Masolov, V. N.: Forty-seven new subglacial lakes in the 0–110{°} E sector of East Antarctica, J. Glaciol., 53, 289–297, https://doi.org/10.3189/172756507782202856, 2007.
Ray, P. S.: Broadband complex refractive indices of ice and water, Appl. Opt., 11, 1836–1844, https://doi.org/10.1364/A O.11.001836, 1972.
Raymond, C. F.: Deformation in the vicinity of ice devide, J. Glaciol., 29, 357–373, 1983.
Rignot, E., Mouginot, J., and Scheuchl, B.: Ice flow of the Antarctic ice sheet, Science, 333, 1427–1430, https://doi.org/10.1126/science.1208336, 2011.
Rotschky, G., Holmlund, P., Isaksson, E., Mulvaney, R., Oerter, H., Van den Broecke, M. R., and Winther, J.-G.: A new surface accumulation map for western dronning maud land, Antarctica, from interpretation of point measurements, J. Glaciol., 53, 385–398, https://doi.org/10.3189/002214307783258459, 2007.
Rybak, O., Huybrechts, P., Pattyn, F., and Steinhage, D.: Regional ice-dynamic model, Part 1. model description, performance of numerical experiments, and present-day ice-flow dynamics around Kohnen station, Materialy Gliatsiologitcheskikh Issledovanij, 102, 3–11, 2007 (in Russian).
Sawagaki, T. and Hirakawa, K.: Erosion of bedrock by subglacial meltwater, Soya Coast, East Antarctica, Geogr. Ann. A, 79, 223–238, https://doi.org/10.1111/j.0435-3676.1997.00019.x, 1997.
Sawagaki, T. and Hirakawa, K.: Hydrostatic investigations on subglacial meltwater: implications for the formation of streamlined bedforms and subglacial lakes, East Antarctica, Polar Geosci., 15, 123–147, 2002.
Seddik, H., Greve, R., Zwinger, T., and Placidi, L.: A full Stokes ice flow model for the vicinity of Dome Fuji, Antarctica, with induced anisotropy and fabric evolution, The Cryosphere, 5, 495–508, https://doi.org/10.5194/tc-5-495-2011, 2011.
Shapiro, N. M. and Ritzwoller, M. H.: Inferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica, Earth Planet. Sc. Lett., 223, 213–224, https://doi.org/10.1016/j.epsl.2004.04.011, 2004.
Siegert, M. J., Carter, S., Tabacco, I., Popov, S., and Blankenship, D.: A revised inventory of Antarctic subglacial lakes, Antarct. Sci., 17, 453–460, https://doi.org/10.1017/S0954102005002889, 2005.
Smith, B. E., Fricker, H. A., Joughin, I. R., and Tulaczyk, S.: An inventory of active subglacial lakes in Antarctica detected by ICESat (2003–2008), J. Glaciol., 55, 573–595, https://doi.org/10.3189/002214309789470879, 2009.
Ulaby, F. T., Moore, R. K., and Fung, A. K.: Microwave Remote Sensing: Active and Passive, Volume II: Radar Remote Sensing and Surface Scattering and Emission Theory, Norwood, MA, Artech House Publishers, 1986
Wesche, C., Eisen, O., Oerter, H., Schulte, D., and Steinhage, D.: Surface topography and ice flow in the vicinity of the EDML deep-drilling site, Antarctica, J. Glaciol., 53, 442–448, https://doi.org/10.3189/002214307783258512, 2007.
Wright, A. P., Young, D. A., Roberts, J. L., Schroeder, D. M., Bamber, J. L., Dowdeswell, J. A., Young, N. W., Le Brocq, A. M., Warner, R. C., Payne, A. J., Blankenship, D. D., van Ommen, T. D., and Siegert, M. J.: Evidence of a hydrological connection between the ice divide and ice sheet margin in the aurora subglacial basin, east antarctica, J. Geophys. Res.-Earth, 117, F01033, https://doi.org/10.1029/2011jf002066, 2012.
Wolff, E., Brook, E., Dahl-Jensen, D., Fujii, Y., Jouzel, J., Lipenkov, V., and Severinghaus, J.: The oldest ice core: a 1.5 million year record of climate and greenhouse gases from Antarctica, International Partnerships in Ice Core Sciences, available at: http://www.pages-igbp.org/ipics/data/ipics_oldaa.pdf, 2006.
Zirizzotti, A., Cafarella, L., and Urbini, S.: Ice and bedrock characteristics underneath Dome C (Antarctica) from radio echo sounding data analysis, IEEE T. Geosci. Remote, 50, 37–43, https://doi.org/10.1109/TGRS.2011.2160551, 2012.
