Articles | Volume 9, issue 4
https://doi.org/10.5194/tc-9-1649-2015
© Author(s) 2015. 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-9-1649-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
21 Aug 2015
Research article |
| 21 Aug 2015
Temporal variations in the flow of a large Antarctic ice stream controlled by tidally induced changes in the subglacial water system
School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB, UK
British Antarctic Survey, High Cross, Madingley Rd., Cambridge, CB3 0ET, UK
G. H. Gudmundsson
British Antarctic Survey, High Cross, Madingley Rd., Cambridge, CB3 0ET, UK
J. A. M. Green
School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB, UK
Related authors
Sebastian H. R. Rosier, G. Hilmar Gudmundsson, Adrian Jenkins, and Kaitlin A. Naughten
The Cryosphere, 19, 2527–2557, https://doi.org/10.5194/tc-19-2527-2025, https://doi.org/10.5194/tc-19-2527-2025, 2025
Short summary
Short summary
Glaciers in the Amundsen Sea region of Antarctica have been retreating and losing mass, but their future contribution to global sea level rise remains highly uncertain. We use an ice sheet model and uncertainty quantification methods to evaluate the probable range of mass loss from this region for two future climate scenarios. We find that the rate of ice loss until 2100 will likely remain similar to present-day observations, with little sensitivity to climate scenario over this short time frame.
Christian T. Wild, Reinhard Drews, Niklas Neckel, Joohan Lee, Sihyung Kim, Hyangsun Han, Won Sang Lee, Veit Helm, Sebastian Harry Reid Rosier, Oliver J. Marsh, and Wolfgang Rack
EGUsphere, https://doi.org/10.5194/egusphere-2024-3593, https://doi.org/10.5194/egusphere-2024-3593, 2024
Short summary
Short summary
The stability of the Antarctic Ice Sheet depends on how resistance along the sides of large glaciers slows down the flow of ice into the ocean. We present a method to map ice strength using the effect of ocean tides on floating ice shelves. Incorporating weaker ice in shear zones improves the accuracy of model predictions compared to satellite observations. This demonstrates the untapped potential of radar satellites to map ice stiffness in the most critical areas for ice sheet stability.
Cristina Gerli, Sebastian Rosier, G. Hilmar Gudmundsson, and Sainan Sun
The Cryosphere, 18, 2677–2689, https://doi.org/10.5194/tc-18-2677-2024, https://doi.org/10.5194/tc-18-2677-2024, 2024
Short summary
Short summary
Recent efforts have focused on using AI and satellite imagery to track crevasses for assessing ice shelf damage and informing ice flow models. Our study reveals a weak connection between these observed products and damage maps inferred from ice flow models. While there is some improvement in crevasse-dense regions, this association remains limited. Directly mapping ice damage from satellite observations may not significantly improve the representation of these processes within ice flow models.
Sebastian H. R. Rosier, Christopher Y. S. Bull, Wai L. Woo, and G. Hilmar Gudmundsson
The Cryosphere, 17, 499–518, https://doi.org/10.5194/tc-17-499-2023, https://doi.org/10.5194/tc-17-499-2023, 2023
Short summary
Short summary
Future ice loss from Antarctica could raise sea levels by several metres, and key to this is the rate at which the ocean melts the ice sheet from below. Existing methods for modelling this process are either computationally expensive or very simplified. We present a new approach using machine learning to mimic the melt rates calculated by an ocean model but in a fraction of the time. This approach may provide a powerful alternative to existing methods, without compromising on accuracy or speed.
Emily A. Hill, Sebastian H. R. Rosier, G. Hilmar Gudmundsson, and Matthew Collins
The Cryosphere, 15, 4675–4702, https://doi.org/10.5194/tc-15-4675-2021, https://doi.org/10.5194/tc-15-4675-2021, 2021
Short summary
Short summary
Using an ice flow model and uncertainty quantification methods, we provide probabilistic projections of future sea level rise from the Filchner–Ronne region of Antarctica. We find that it is most likely that this region will contribute negatively to sea level rise over the next 300 years, largely as a result of increased surface mass balance. We identify parameters controlling ice shelf melt and snowfall contribute most to uncertainties in projections.
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.
Sebastian H. R. Rosier and G. Hilmar Gudmundsson
The Cryosphere, 14, 17–37, https://doi.org/10.5194/tc-14-17-2020, https://doi.org/10.5194/tc-14-17-2020, 2020
Short summary
Short summary
The flow of ice shelves is now known to be strongly affected by ocean tides, but the mechanism by which this happens is unclear. We use a viscoelastic model to try to reproduce observations of this behaviour on the Filchner–Ronne Ice Shelf in Antarctica. We find that tilting of the ice shelf explains the short-period behaviour, while tidally induced movement of the grounding line (the boundary between grounded and floating ice) explains the more complex long-period response.
Sebastian H. R. Rosier and G. Hilmar Gudmundsson
The Cryosphere, 12, 1699–1713, https://doi.org/10.5194/tc-12-1699-2018, https://doi.org/10.5194/tc-12-1699-2018, 2018
Short summary
Short summary
Ocean tides cause strong modulation of horizontal ice shelf flow, most notably at a fortnightly frequency that is absent in the vertical tidal forcing. We propose that tidal bending in the margins of the ice shelf produces sufficiently large stresses that the effective viscosity of ice in these regions is reduced during high and low tide. This effect can explain many features of the observed behaviour and implies that ice shelves in areas with strong tides move faster than they otherwise would.
Sebastian H. R. Rosier, G. Hilmar Gudmundsson, Matt A. King, Keith W. Nicholls, Keith Makinson, and Hugh F. J. Corr
Earth Syst. Sci. Data, 9, 849–860, https://doi.org/10.5194/essd-9-849-2017, https://doi.org/10.5194/essd-9-849-2017, 2017
Short summary
Short summary
Tides can affect the flow of ice at hourly to yearly timescales. In some cases the ice responds at a different frequency than is found in the tidal forcing; for example, on Rutford Ice Stream the strongest response is at a fortnightly period. A new compilation of GPS data across the Ronne Ice Shelf and adjoining ice streams shows that this fortnightly modulation in ice flow is found across the entire region. Measurements of this kind can provide insights into ice rheology and basal processes.
Sebastian H. R. Rosier, G. Hilmar Gudmundsson, Adrian Jenkins, and Kaitlin A. Naughten
The Cryosphere, 19, 2527–2557, https://doi.org/10.5194/tc-19-2527-2025, https://doi.org/10.5194/tc-19-2527-2025, 2025
Short summary
Short summary
Glaciers in the Amundsen Sea region of Antarctica have been retreating and losing mass, but their future contribution to global sea level rise remains highly uncertain. We use an ice sheet model and uncertainty quantification methods to evaluate the probable range of mass loss from this region for two future climate scenarios. We find that the rate of ice loss until 2100 will likely remain similar to present-day observations, with little sensitivity to climate scenario over this short time frame.
Ole Richter, Ralph Timmermann, G. Hilmar Gudmundsson, and Jan De Rydt
Geosci. Model Dev., 18, 2945–2960, https://doi.org/10.5194/gmd-18-2945-2025, https://doi.org/10.5194/gmd-18-2945-2025, 2025
Short summary
Short summary
The new coupled ice sheet–ocean model addresses challenges related to horizontal resolution through advanced mesh flexibility, enabled by the use of unstructured grids. We describe the new model, verify its functioning in an idealised setting and demonstrate its advantages in a global-ocean–Antarctic ice sheet domain. The results of this study comprise an important step towards improving predictions of the Antarctic contribution to sea level rise over centennial timescales.
Jowan M. Barnes, G. Hilmar Gudmundsson, Daniel N. Goldberg, and Sainan Sun
EGUsphere, https://doi.org/10.5194/egusphere-2025-328, https://doi.org/10.5194/egusphere-2025-328, 2025
Short summary
Short summary
Calving is where ice breaks off the front of glaciers. It has not been included widely in modelling as it is difficult to represent. We use our ice flow model to investigate the effects of calving floating ice shelves in West Antarctica. More calving leads to more ice loss and greater sea level rise, with local differences due to the shape of the bedrock. We find that ocean forcing and calving should be considered equally when trying to improve how models represent the real world.
Christian T. Wild, Reinhard Drews, Niklas Neckel, Joohan Lee, Sihyung Kim, Hyangsun Han, Won Sang Lee, Veit Helm, Sebastian Harry Reid Rosier, Oliver J. Marsh, and Wolfgang Rack
EGUsphere, https://doi.org/10.5194/egusphere-2024-3593, https://doi.org/10.5194/egusphere-2024-3593, 2024
Short summary
Short summary
The stability of the Antarctic Ice Sheet depends on how resistance along the sides of large glaciers slows down the flow of ice into the ocean. We present a method to map ice strength using the effect of ocean tides on floating ice shelves. Incorporating weaker ice in shear zones improves the accuracy of model predictions compared to satellite observations. This demonstrates the untapped potential of radar satellites to map ice stiffness in the most critical areas for ice sheet stability.
Richard Parsons, Sainan Sun, G. Hilmar Gudmundsson, Jan Wuite, and Thomas Nagler
The Cryosphere, 18, 5789–5801, https://doi.org/10.5194/tc-18-5789-2024, https://doi.org/10.5194/tc-18-5789-2024, 2024
Short summary
Short summary
In 2022, multi-year landfast sea ice in Antarctica's Larsen B embayment disintegrated, after which time an increase in the rate at which Crane Glacier discharged ice into the ocean was observed. As the fast ice was joined to the glacier terminus, it could provide resistance against the glacier's flow, slowing down the rate of ice discharge. We used numerical modelling to quantify this resistive stress and found that the fast ice provided significant support to Crane prior to its disintegration.
Xianwei Wang, Hilmar Gudmundsson, and David Holland
EGUsphere, https://doi.org/10.5194/egusphere-2024-2790, https://doi.org/10.5194/egusphere-2024-2790, 2024
Short summary
Short summary
Understanding why iceberg calved during drifting in the ocean is important to understand the life cycle and the influence on the surrounding ocean of an iceberg. This study explains why iceberg A68a calved when approaching the South Georgia Island in late 2020 during its drifting in the Southern Ocean using satellite observation and modeling, which was caused by collision with seamount.
Brad Reed, J. A. Mattias Green, Adrian Jenkins, and G. Hilmar Gudmundsson
The Cryosphere, 18, 4567–4587, https://doi.org/10.5194/tc-18-4567-2024, https://doi.org/10.5194/tc-18-4567-2024, 2024
Short summary
Short summary
We use a numerical ice-flow model to simulate the response of a 1940s Pine Island Glacier to changes in melting beneath its ice shelf. A decadal period of warm forcing is sufficient to push the glacier into an unstable, irreversible retreat from its long-term position on a subglacial ridge to an upstream ice plain. This retreat can only be stopped when unrealistic cold forcing is applied. These results show that short warm anomalies can lead to quick and substantial increases in ice flux.
Gong Cheng, Mathieu Morlighem, and G. Hilmar Gudmundsson
Geosci. Model Dev., 17, 6227–6247, https://doi.org/10.5194/gmd-17-6227-2024, https://doi.org/10.5194/gmd-17-6227-2024, 2024
Short summary
Short summary
We conducted a comprehensive analysis of the stabilization and reinitialization techniques currently employed in ISSM and Úa for solving level-set equations, specifically those related to the dynamic representation of moving ice fronts within numerical ice sheet models. Our results demonstrate that the streamline upwind Petrov–Galerkin (SUPG) method outperforms the other approaches. We found that excessively frequent reinitialization can lead to exceptionally high errors in simulations.
J. Rachel Carr, Emily A. Hill, and G. Hilmar Gudmundsson
The Cryosphere, 18, 2719–2737, https://doi.org/10.5194/tc-18-2719-2024, https://doi.org/10.5194/tc-18-2719-2024, 2024
Short summary
Short summary
The Greenland Ice Sheet is one of the world's largest glaciers and is melting quickly in response to climate change. It contains fast-flowing channels of ice that move ice from Greenland's centre to its coasts and allow Greenland to react quickly to climate warming. As a result, we want to predict how these glaciers will behave in the future, but there are lots of uncertainties. Here we assess the impacts of two main sources of uncertainties in glacier models.
Cristina Gerli, Sebastian Rosier, G. Hilmar Gudmundsson, and Sainan Sun
The Cryosphere, 18, 2677–2689, https://doi.org/10.5194/tc-18-2677-2024, https://doi.org/10.5194/tc-18-2677-2024, 2024
Short summary
Short summary
Recent efforts have focused on using AI and satellite imagery to track crevasses for assessing ice shelf damage and informing ice flow models. Our study reveals a weak connection between these observed products and damage maps inferred from ice flow models. While there is some improvement in crevasse-dense regions, this association remains limited. Directly mapping ice damage from satellite observations may not significantly improve the representation of these processes within ice flow models.
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.
Sebastian H. R. Rosier, Christopher Y. S. Bull, Wai L. Woo, and G. Hilmar Gudmundsson
The Cryosphere, 17, 499–518, https://doi.org/10.5194/tc-17-499-2023, https://doi.org/10.5194/tc-17-499-2023, 2023
Short summary
Short summary
Future ice loss from Antarctica could raise sea levels by several metres, and key to this is the rate at which the ocean melts the ice sheet from below. Existing methods for modelling this process are either computationally expensive or very simplified. We present a new approach using machine learning to mimic the melt rates calculated by an ocean model but in a fraction of the time. This approach may provide a powerful alternative to existing methods, without compromising on accuracy or speed.
Bertie W. J. Miles, Chris R. Stokes, Adrian Jenkins, Jim R. Jordan, Stewart S. R. Jamieson, and G. Hilmar Gudmundsson
The Cryosphere, 17, 445–456, https://doi.org/10.5194/tc-17-445-2023, https://doi.org/10.5194/tc-17-445-2023, 2023
Short summary
Short summary
Satellite observations have shown that the Shirase Glacier catchment in East Antarctica has been gaining mass over the past 2 decades, a trend largely attributed to increased snowfall. Our multi-decadal observations of Shirase Glacier show that ocean forcing has also contributed to some of this recent mass gain. This has been caused by strengthening easterly winds reducing the inflow of warm water underneath the Shirase ice tongue, causing the glacier to slow down and thicken.
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.
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.
Julia Rulent, Lucy M. Bricheno, J. A. Mattias Green, Ivan D. Haigh, and Huw Lewis
Nat. Hazards Earth Syst. Sci., 21, 3339–3351, https://doi.org/10.5194/nhess-21-3339-2021, https://doi.org/10.5194/nhess-21-3339-2021, 2021
Short summary
Short summary
High coastal total water levels (TWLs) can lead to flooding and hazardous conditions for coastal communities and environment. In this research we are using numerical models to study the interactions between the three main components of the TWL (waves, tides, and surges) on UK and Irish coasts during winter 2013/14. The main finding of this research is that extreme waves and surges can indeed happen together, even at high tide, but they often occurred simultaneously 2–3 h before high tide.
Emily A. Hill, Sebastian H. R. Rosier, G. Hilmar Gudmundsson, and Matthew Collins
The Cryosphere, 15, 4675–4702, https://doi.org/10.5194/tc-15-4675-2021, https://doi.org/10.5194/tc-15-4675-2021, 2021
Short summary
Short summary
Using an ice flow model and uncertainty quantification methods, we provide probabilistic projections of future sea level rise from the Filchner–Ronne region of Antarctica. We find that it is most likely that this region will contribute negatively to sea level rise over the next 300 years, largely as a result of increased surface mass balance. We identify parameters controlling ice shelf melt and snowfall contribute most to uncertainties in projections.
Philip L. Woodworth, J. A. Mattias Green, Richard D. Ray, and John M. Huthnance
Ocean Sci., 17, 809–818, https://doi.org/10.5194/os-17-809-2021, https://doi.org/10.5194/os-17-809-2021, 2021
Short summary
Short summary
This special issue marks the 100th anniversary of the founding of the Liverpool Tidal Institute (LTI). The preface gives a history of the LTI founding and of its first two directors. It also gives an overview of LTI research on tides. Summaries are given of the 26 papers in the special issue. Their topics could be thought of as providing a continuation of the research first undertaken at the LTI. They provide an interesting snapshot of work on tides now being made by groups around the world.
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.
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.
Bertie W. J. Miles, Jim R. Jordan, Chris R. Stokes, Stewart S. R. Jamieson, G. Hilmar Gudmundsson, and Adrian Jenkins
The Cryosphere, 15, 663–676, https://doi.org/10.5194/tc-15-663-2021, https://doi.org/10.5194/tc-15-663-2021, 2021
Short summary
Short summary
We provide a historical overview of changes in Denman Glacier's flow speed, structure and calving events since the 1960s. Based on these observations, we perform a series of numerical modelling experiments to determine the likely cause of Denman's acceleration since the 1970s. We show that grounding line retreat, ice shelf thinning and the detachment of Denman's ice tongue from a pinning point are the most likely causes of the observed acceleration.
Jan De Rydt, Ronja Reese, Fernando S. Paolo, and G. Hilmar Gudmundsson
The Cryosphere, 15, 113–132, https://doi.org/10.5194/tc-15-113-2021, https://doi.org/10.5194/tc-15-113-2021, 2021
Short summary
Short summary
We used satellite observations and numerical simulations of Pine Island Glacier, West Antarctica, between 1996 and 2016 to show that the recent increase in its flow speed can only be reproduced by computer models if stringent assumptions are made about the material properties of the ice and its underlying bed. These assumptions are not commonly adopted in ice flow modelling, and our results therefore have implications for future simulations of Antarctic ice flow and sea level projections.
Kate Winter, Emily A. Hill, G. Hilmar Gudmundsson, and John Woodward
Earth Syst. Sci. Data, 12, 3453–3467, https://doi.org/10.5194/essd-12-3453-2020, https://doi.org/10.5194/essd-12-3453-2020, 2020
Short summary
Short summary
Satellite measurements of the English Coast in the Antarctic Peninsula reveal that glaciers are thinning and losing mass, but ice thickness data are required to assess these changes, in terms of ice flux and sea level contribution. Our ice-penetrating radar measurements reveal that low-elevation subglacial channels control fast-flowing ice streams, which release over 39 Gt of ice per year to floating ice shelves. This topography could make ice flows susceptible to future instability.
J. A. Mattias Green and David T. Pugh
Ocean Sci., 16, 1337–1345, https://doi.org/10.5194/os-16-1337-2020, https://doi.org/10.5194/os-16-1337-2020, 2020
Short summary
Short summary
Bardsey Island lies 3 km offshore the western end of the Llŷn Peninsula in northwestern Wales. However, the island is too small to show up in tidal databases based on satellite data, and thus they may not provide the correct local tides. Our new sea level data shows that the tidal currents in the satellite databases are one-third of the observed currents. Any investigation of other coastal activities, e.g. renewable energy installations, must use local observations to get the correct tides.
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.
Marie Laugié, Yannick Donnadieu, Jean-Baptiste Ladant, J. A. Mattias Green, Laurent Bopp, and François Raisson
Clim. Past, 16, 953–971, https://doi.org/10.5194/cp-16-953-2020, https://doi.org/10.5194/cp-16-953-2020, 2020
Short summary
Short summary
To quantify the impact of major climate forcings on the Cretaceous climate, we use Earth system modelling to progressively reconstruct the Cretaceous state by changing boundary conditions one by one. Between the preindustrial and the Cretaceous simulations, the model simulates a global warming of more than 11°C. The study confirms the primary control exerted by atmospheric CO2 on atmospheric temperatures. Palaeogeographic changes represent the second major contributor to the warming.
Hannah S. Davies, J. A. Mattias Green, and Joao C. Duarte
Earth Syst. Dynam., 11, 291–299, https://doi.org/10.5194/esd-11-291-2020, https://doi.org/10.5194/esd-11-291-2020, 2020
Short summary
Short summary
We have confirmed that there is a supertidal cycle associated with the supercontinent cycle. As continents drift due to plate tectonics, oceans also change size, controlling the strength of the tides and causing periods of supertides. In this work, we used a coupled tectonic–tidal model of Earth's future to test four different scenarios that undergo different styles of ocean closure and periods of supertides. This has implications for the Earth system and for other planets with liquid oceans.
Anders Levermann, Ricarda Winkelmann, Torsten Albrecht, Heiko Goelzer, Nicholas R. Golledge, Ralf Greve, Philippe Huybrechts, Jim Jordan, Gunter Leguy, Daniel Martin, Mathieu Morlighem, Frank Pattyn, David Pollard, Aurelien Quiquet, Christian Rodehacke, Helene Seroussi, Johannes Sutter, Tong Zhang, Jonas Van Breedam, Reinhard Calov, Robert DeConto, Christophe Dumas, Julius Garbe, G. Hilmar Gudmundsson, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, William H. Lipscomb, Malte Meinshausen, Esmond Ng, Sophie M. J. Nowicki, Mauro Perego, Stephen F. Price, Fuyuki Saito, Nicole-Jeanne Schlegel, Sainan Sun, and Roderik S. W. van de Wal
Earth Syst. Dynam., 11, 35–76, https://doi.org/10.5194/esd-11-35-2020, https://doi.org/10.5194/esd-11-35-2020, 2020
Short summary
Short summary
We provide an estimate of the future sea level contribution of Antarctica from basal ice shelf melting up to the year 2100. The full uncertainty range in the warming-related forcing of basal melt is estimated and applied to 16 state-of-the-art ice sheet models using a linear response theory approach. The sea level contribution we obtain is very likely below 61 cm under unmitigated climate change until 2100 (RCP8.5) and very likely below 40 cm if the Paris Climate Agreement is kept.
Sebastian H. R. Rosier and G. Hilmar Gudmundsson
The Cryosphere, 14, 17–37, https://doi.org/10.5194/tc-14-17-2020, https://doi.org/10.5194/tc-14-17-2020, 2020
Short summary
Short summary
The flow of ice shelves is now known to be strongly affected by ocean tides, but the mechanism by which this happens is unclear. We use a viscoelastic model to try to reproduce observations of this behaviour on the Filchner–Ronne Ice Shelf in Antarctica. We find that tilting of the ice shelf explains the short-period behaviour, while tidally induced movement of the grounding line (the boundary between grounded and floating ice) explains the more complex long-period response.
Jan De Rydt, Gudmundur Hilmar Gudmundsson, Thomas Nagler, and Jan Wuite
The Cryosphere, 13, 2771–2787, https://doi.org/10.5194/tc-13-2771-2019, https://doi.org/10.5194/tc-13-2771-2019, 2019
Short summary
Short summary
Two large icebergs are about to break off from the Brunt Ice Shelf in Antarctica. Rifting started several years ago and is now approaching its final phase. Satellite data and computer simulations show that over the past 2 decades, growth of the ice shelf has caused a build-up of forces within the ice, which culminated in its fracture. These natural changes in geometry coincided with large variations in flow speed, a process that is thought to be relevant for all Antarctic ice shelf margins.
Alexander Harker, J. A. Mattias Green, Michael Schindelegger, and Sophie-Berenice Wilmes
Ocean Sci., 15, 147–159, https://doi.org/10.5194/os-15-147-2019, https://doi.org/10.5194/os-15-147-2019, 2019
Short summary
Short summary
We used a computer model to help predict how changing sea levels around Australia will affect the ebb and flow of the tide. We found that sea-level rise and coastal flooding affect where energy from the tide is dissipated and how the tide flows around the coastline. We found that we must consider how sea-level rise will affect tides across the rest of the world, as that will have an impact on Australia too. This sort of investigation can help direct coastal management and protection efforts.
Emily A. Hill, G. Hilmar Gudmundsson, J. Rachel Carr, and Chris R. Stokes
The Cryosphere, 12, 3907–3921, https://doi.org/10.5194/tc-12-3907-2018, https://doi.org/10.5194/tc-12-3907-2018, 2018
Short summary
Short summary
Floating ice tongues in Greenland buttress inland ice, and their removal could accelerate ice flow. Petermann Glacier recently lost large sections of its ice tongue, but there was little glacier acceleration. Here, we assess the impact of future calving events on ice speeds. We find that removing the lower portions of the ice tongue does not accelerate flow. However, future iceberg calving closer to the grounding line could accelerate ice flow and increase ice discharge and sea level rise.
Edward C. King, Jan De Rydt, and G. Hilmar Gudmundsson
The Cryosphere, 12, 3361–3372, https://doi.org/10.5194/tc-12-3361-2018, https://doi.org/10.5194/tc-12-3361-2018, 2018
Short summary
Short summary
Ice shelves are thick sheets of ice floating on the ocean off the coasts of Antarctica and Greenland. They help regulate the flow of ice off the continent. Ice shelves undergo a natural cycle of seaward flow, fracture, iceberg production and regrowth. The Brunt Ice Shelf recently developed two large cracks. We used ground-penetrating radar to find out how the internal structure of the ice might influence the present crack development and the future stability of the ice shelf.
Ronja Reese, Ricarda Winkelmann, and G. Hilmar Gudmundsson
The Cryosphere, 12, 3229–3242, https://doi.org/10.5194/tc-12-3229-2018, https://doi.org/10.5194/tc-12-3229-2018, 2018
Short summary
Short summary
Accurately representing grounding-line flux is essential for modelling the evolution of the Antarctic Ice Sheet. Currently, in some large-scale ice-flow modelling studies a condition on ice flux across grounding lines is imposed using an analytically motivated parameterisation. Here we test this expression for Antarctic grounding lines and find that it provides inaccurate and partly unphysical estimates of ice flux for the highly buttressed ice streams.
Emily A. Hill, J. Rachel Carr, Chris R. Stokes, and G. Hilmar Gudmundsson
The Cryosphere, 12, 3243–3263, https://doi.org/10.5194/tc-12-3243-2018, https://doi.org/10.5194/tc-12-3243-2018, 2018
Short summary
Short summary
The dynamic behaviour (i.e. acceleration and retreat) of outlet glaciers in northern Greenland remains understudied. Here, we provide a new long-term (68-year) record of terminus change. Overall, recent retreat rates (1995–2015) are higher than the last 47 years. Despite region-wide retreat, we found disparities in dynamic behaviour depending on terminus type; grounded glaciers accelerated and thinned following retreat, while glaciers with floating ice tongues were insensitive to recent retreat.
J. A. Mattias Green, David G. Bowers, and Hannah A. M. Byrne
Ocean Sci. Discuss., https://doi.org/10.5194/os-2018-72, https://doi.org/10.5194/os-2018-72, 2018
Preprint withdrawn
Short summary
Short summary
In a double tide the ocean reaches high or low tide, starts to fall or rise, only to go back to a new high or low. Here, we describe three ways this can happen by dividing locations with observed double tides into three classes. This showed that double tides are more common than we thought, and more complicated than most textbooks claim because they only describe one class of double tides. This matters to shipping, coastal flood management, and other disciplines interested in sea-level change.
Sebastian H. R. Rosier and G. Hilmar Gudmundsson
The Cryosphere, 12, 1699–1713, https://doi.org/10.5194/tc-12-1699-2018, https://doi.org/10.5194/tc-12-1699-2018, 2018
Short summary
Short summary
Ocean tides cause strong modulation of horizontal ice shelf flow, most notably at a fortnightly frequency that is absent in the vertical tidal forcing. We propose that tidal bending in the margins of the ice shelf produces sufficiently large stresses that the effective viscosity of ice in these regions is reduced during high and low tide. This effect can explain many features of the observed behaviour and implies that ice shelves in areas with strong tides move faster than they otherwise would.
Jan De Rydt, G. Hilmar Gudmundsson, Thomas Nagler, Jan Wuite, and Edward C. King
The Cryosphere, 12, 505–520, https://doi.org/10.5194/tc-12-505-2018, https://doi.org/10.5194/tc-12-505-2018, 2018
Short summary
Short summary
We provide an unprecedented view into the dynamics of two active rifts in the Brunt Ice Shelf through a unique set of field observations, novel satellite data products, and a state-of-the-art ice flow model. We describe the evolution of fracture width and length in great detail, pushing the boundaries of both spatial and temporal coverage, and provide a deeper insight into the process of iceberg formation, which exerts an important control over the mass balance of the Antarctic Ice Sheet.
Werner M. J. Lazeroms, Adrian Jenkins, G. Hilmar Gudmundsson, and Roderik S. W. van de Wal
The Cryosphere, 12, 49–70, https://doi.org/10.5194/tc-12-49-2018, https://doi.org/10.5194/tc-12-49-2018, 2018
Short summary
Short summary
Basal melting of ice shelves is a major factor in the decline of the Antarctic Ice Sheet, which can contribute significantly to sea-level rise. Here, we investigate a new basal melt model based on the dynamics of meltwater plumes. For the first time, this model is applied to all Antarctic ice shelves. The model results in a realistic melt-rate pattern given suitable data for the topography and ocean temperature, making it a promising tool for future simulations of the Antarctic Ice Sheet.
Sebastian H. R. Rosier, G. Hilmar Gudmundsson, Matt A. King, Keith W. Nicholls, Keith Makinson, and Hugh F. J. Corr
Earth Syst. Sci. Data, 9, 849–860, https://doi.org/10.5194/essd-9-849-2017, https://doi.org/10.5194/essd-9-849-2017, 2017
Short summary
Short summary
Tides can affect the flow of ice at hourly to yearly timescales. In some cases the ice responds at a different frequency than is found in the tidal forcing; for example, on Rutford Ice Stream the strongest response is at a fortnightly period. A new compilation of GPS data across the Ronne Ice Shelf and adjoining ice streams shows that this fortnightly modulation in ice flow is found across the entire region. Measurements of this kind can provide insights into ice rheology and basal processes.
Hannah A. M. Byrne, J. A. Mattias Green, and David G. Bowers
Ocean Sci., 13, 599–607, https://doi.org/10.5194/os-13-599-2017, https://doi.org/10.5194/os-13-599-2017, 2017
Short summary
Short summary
Some places experience double high tides, where the tide starts to ebb for a short while, only to briefly flood again before finally receding. The result is a very long high tide with weak currents, and is important for navigational purposes. The existing theory for when and where double high tides occur does not always capture them, and it can only be applied to double highs occurring on a twice-daily tide. Here, the criterion has been generalized to capture all double high or low tides.
Daniel Farinotti, Douglas J. Brinkerhoff, Garry K. C. Clarke, Johannes J. Fürst, Holger Frey, Prateek Gantayat, Fabien Gillet-Chaulet, Claire Girard, Matthias Huss, Paul W. Leclercq, Andreas Linsbauer, Horst Machguth, Carlos Martin, Fabien Maussion, Mathieu Morlighem, Cyrille Mosbeux, Ankur Pandit, Andrea Portmann, Antoine Rabatel, RAAJ Ramsankaran, Thomas J. Reerink, Olivier Sanchez, Peter A. Stentoft, Sangita Singh Kumari, Ward J. J. van Pelt, Brian Anderson, Toby Benham, Daniel Binder, Julian A. Dowdeswell, Andrea Fischer, Kay Helfricht, Stanislav Kutuzov, Ivan Lavrentiev, Robert McNabb, G. Hilmar Gudmundsson, Huilin Li, and Liss M. Andreassen
The Cryosphere, 11, 949–970, https://doi.org/10.5194/tc-11-949-2017, https://doi.org/10.5194/tc-11-949-2017, 2017
Short summary
Short summary
ITMIX – the Ice Thickness Models Intercomparison eXperiment – was the first coordinated performance assessment for models inferring glacier ice thickness from surface characteristics. Considering 17 different models and 21 different test cases, we show that although solutions of individual models can differ considerably, an ensemble average can yield uncertainties in the order of 10 ± 24 % the mean ice thickness. Ways forward for improving such estimates are sketched.
Xylar S. Asay-Davis, Stephen L. Cornford, Gaël Durand, Benjamin K. Galton-Fenzi, Rupert M. Gladstone, G. Hilmar Gudmundsson, Tore Hattermann, David M. Holland, Denise Holland, Paul R. Holland, Daniel F. Martin, Pierre Mathiot, Frank Pattyn, and Hélène Seroussi
Geosci. Model Dev., 9, 2471–2497, https://doi.org/10.5194/gmd-9-2471-2016, https://doi.org/10.5194/gmd-9-2471-2016, 2016
Short summary
Short summary
Coupled ice sheet–ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of ice sheets and glaciers, including assessing their contributions to sea level change. Here we describe the idealized experiments that make up three interrelated Model Intercomparison Projects (MIPs) for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities.
David H. Jones, Carl Robinson, and G. Hilmar Gudmundsson
Geosci. Instrum. Method. Data Syst., 5, 65–73, https://doi.org/10.5194/gi-5-65-2016, https://doi.org/10.5194/gi-5-65-2016, 2016
Short summary
Short summary
Long-term records from high-precision GPS receivers are essential for studying geophysical movement. Existing, commercially available, precision GPS receivers are not intended for long-term, autonomous deployment. We have designed a GPS receiver that is better suited for this application. In this paper, we discuss the receiver design and compare its performance with that of some of the commercially available receivers.
D. H. Jones and G. H. Gudmundsson
Nat. Hazards Earth Syst. Sci., 15, 1243–1250, https://doi.org/10.5194/nhess-15-1243-2015, https://doi.org/10.5194/nhess-15-1243-2015, 2015
Short summary
Short summary
Icebergs are a natural hazard to maritime operations in polar regions. Iceberg populations are increasing, as is the demand for access to both Arctic and Antarctic seas. Soon the ability to reliably track icebergs may become a necessity for continued operational safety. In this paper we describe the design of a tracking sensor that can be deployed from an aircraft during surveys of Antarctic icebergs, and detail the results of its first deployment operation on iceberg B-31.
J. Wuite, H. Rott, M. Hetzenecker, D. Floricioiu, J. De Rydt, G. H. Gudmundsson, T. Nagler, and M. Kern
The Cryosphere, 9, 957–969, https://doi.org/10.5194/tc-9-957-2015, https://doi.org/10.5194/tc-9-957-2015, 2015
Short summary
Short summary
We present new analysis of satellite data showing the variability of glacier velocities in the Larsen B area, Antarctic Peninsula, back to 1995. Velocity data and estimates of ice thickness are used to derive ice discharge at different epochs. Velocities of the glaciers remain to date well above the velocities of the pre-collapse period. The response of individual glaciers differs, and velocities show significant temporal fluctuations, implying major variations in ice discharge and mass balance.
C. Martín, R. Mulvaney, G. H. Gudmundsson, and H. Corr
Clim. Past, 11, 547–557, https://doi.org/10.5194/cp-11-547-2015, https://doi.org/10.5194/cp-11-547-2015, 2015
S. H. R. Rosier, G. H. Gudmundsson, and J. A. M. Green
The Cryosphere, 8, 1763–1775, https://doi.org/10.5194/tc-8-1763-2014, https://doi.org/10.5194/tc-8-1763-2014, 2014
N. Herold, J. Buzan, M. Seton, A. Goldner, J. A. M. Green, R. D. Müller, P. Markwick, and M. Huber
Geosci. Model Dev., 7, 2077–2090, https://doi.org/10.5194/gmd-7-2077-2014, https://doi.org/10.5194/gmd-7-2077-2014, 2014
R. Anderson, D. H. Jones, and G. H. Gudmundsson
Nat. Hazards Earth Syst. Sci., 14, 917–927, https://doi.org/10.5194/nhess-14-917-2014, https://doi.org/10.5194/nhess-14-917-2014, 2014
G. H. Gudmundsson
The Cryosphere, 7, 647–655, https://doi.org/10.5194/tc-7-647-2013, https://doi.org/10.5194/tc-7-647-2013, 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
G. H. Gudmundsson, J. Krug, G. Durand, L. Favier, and O. Gagliardini
The Cryosphere, 6, 1497–1505, https://doi.org/10.5194/tc-6-1497-2012, https://doi.org/10.5194/tc-6-1497-2012, 2012
Related subject area
Ice Sheets
Brief Communication: Enabling Open Cryosphere Research with Ghub
Spatiotemporal patterns of accumulation and surface roughness in interior Greenland with a GNSS-IR network
The influence of firn layer material properties on surface crevasse propagation in glaciers and ice shelves
Probabilistic projections of the Amery Ice Shelf catchment, Antarctica, under conditions of high ice-shelf basal melt
Retrieval and Validation of Total Seasonal Liquid Water Amounts in the Percolation Zone of Greenland Ice Sheet Using L-band Radiometry
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
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
Joseph P. Tulenko, Sophie A. Goliber, Renette Jones-Ivey, Justin Quinn, Abani Patra, Kristin Poinar, Sophie Nowicki, Beata M. Csatho, and Jason P. Briner
EGUsphere, https://doi.org/10.5194/egusphere-2025-894, https://doi.org/10.5194/egusphere-2025-894, 2025
Short summary
Short summary
Ghub is an online platform that hosts tools, datasets and educational resources related to ice sheet science. These resources are provided by ice sheet researchers and allow other researchers, students, educators, and interested members of the general public to analyze, visualize and download datasets that researchers use to study past and present ice sheet behavior. We describe how users can interact with Ghub, showcase some available resources, and describe the future of the Ghub Project.
Derek J. Pickell, Robert L. Hawley, and Adam LeWinter
The Cryosphere, 19, 1013–1029, https://doi.org/10.5194/tc-19-1013-2025, https://doi.org/10.5194/tc-19-1013-2025, 2025
Short summary
Short summary
We use a low-cost, low-power GNSS network to measure surface accumulation in Greenland's interior using the interferometric reflectometry technique. Additionally, we extend this method to also estimate centimeter- to meter-scale surface roughness. Our results closely align with a validation record and highlight a period of unusually high accumulation from late 2022 to 2023, along with seasonal variations in surface roughness.
Theo Clayton, Ravindra Duddu, Tim Hageman, and Emilio Martínez-Pañeda
The Cryosphere, 18, 5573–5593, https://doi.org/10.5194/tc-18-5573-2024, https://doi.org/10.5194/tc-18-5573-2024, 2024
Short summary
Short summary
We develop and validate new analytical solutions that quantitatively consider how the properties of ice vary along the depth of ice shelves and that can be readily used in existing ice sheet models. Depth-varying firn properties are found to have a profound impact on ice sheet fracture and calving events. Our results show that grounded glaciers are less vulnerable than previously anticipated, while floating ice shelves are significantly more vulnerable to fracture and calving.
Sanket Jantre, Matthew J. Hoffman, Nathan M. Urban, Trevor Hillebrand, Mauro Perego, Stephen Price, and John D. Jakeman
The Cryosphere, 18, 5207–5238, https://doi.org/10.5194/tc-18-5207-2024, https://doi.org/10.5194/tc-18-5207-2024, 2024
Short summary
Short summary
We investigate potential sea-level rise from Antarctica's Lambert Glacier, once considered stable but now at risk due to projected ocean warming by 2100. Using statistical methods and limited supercomputer simulations, we calibrated our ice-sheet model using three observables. We find that, under high greenhouse gas emissions, glacier retreat could raise sea levels by 46–133 mm by 2300. This study highlights the need for better observations to reduce uncertainty in ice-sheet model projections.
Alamgir Hossan, Andreas Colliander, Baptiste Vandecrux, Nicole-Jeanne Schlegel, Joel Harper, Shawn Marshall, and Julie Z. Miller
EGUsphere, https://doi.org/10.5194/egusphere-2024-2563, https://doi.org/10.5194/egusphere-2024-2563, 2024
Short summary
Short summary
We used L-band observations from the SMAP mission to quantify the surface and subsurface liquid water amounts (LWA) in the percolation zone of the Greenland ice sheet. The algorithm is described, and the validation results are provided. The results demonstrate the potential for creating an LWA data product across GrIS, which will advance our understanding of ice sheet physical processes for better projection of Greenland’s contribution to global sea level rise.
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, Marco 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%.
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
Cited articles
A\dhalgeirsdóttir, G., Smith, A. M., Murray, T., King, M. A., Makinson, K., Nicholls, K. W., and Behar, A. E.: Tidal influence on Rutford Ice Stream, West Antarctica: observations of surface flow and basal processes from closely-spaced GPS and passive seismic stations, J. Glaciol., 54, 715–724, 2008.
Anandakrishnan, S. and Alley, R.: Tidal forcing of basal seismicity of ice stream C, West Antarctica, observed far inland, J.Geophys. Res., 102, 15813–15196, 1997.
Anandakrishnan, S., Voigt, D. E., and Alley, R. B.: Ice stream D flow speed is strongly modulated by the tide beneath the Ross Ice Shelf, Geophys. Res. Lett., 30, 1361, https://doi.org/10.1029/2002GL016329, 2003.
Arbic, B. K., Mitrovica, J. X., MacAyeal, D. R., and Milne, G. A.: On the factors behind large Labrador Sea tides during the last glacial cycle and the potential implications for Heinrich events, Paleoceanography, 23, PA3211, https://doi.org/10.1029/2007PA001573, 2008.
Bindschadler, R.: The importance of pressurized subglacial water in separation and sliding at the glacier bed, J. Glaciol., 29, 3–19, 1983.
Bindschadler, R. A., King, M. A., Alley, R. B., Anandakrishnan, S., and Padman, L.: Tidally controlled stick-slip discharge of a West Antarctic ice stream, Science, 301, 1087–1089, 2003a.
Bindschadler, R. A., Vornberger, P. L., King, M. A., and Padman, L.: Tidally driven stickslip motion in the mouth of Whillans Ice Stream, Antarctica, Ann. Glaciol., 36, 263–272, 2003b.
Brunt, K. M.: Tidal motion of the Ross Ice Shelf and its interaction with the Siple Coast ice streams, Antarctica, Ph.D. thesis, University of Chicago, 2008.
Budd, W. F. and Keage, P. L.: Empirical studies of ice sliding, Journal of glaciology, 23, 157–170, 1979.
Cuffey, K. M. and Patterson, W. S. B.: The Physics of Glaciers, Fourth Edition, Butterworth-Heineman, 30 Corporate Drive, Suite 400, Burlington, MA 01803, USA, 2010.
Dach, R., Beutler, G., and Gudmundsson, G.: Analysis of GPS Data from An Antarctic Ice Stream, in: Observing our Changing Earth, edited by: Sideris, M. G., vol. 133 of International Association of Geodesy Symposia, Springer Berlin Heidelberg, https://doi.org/10.1007/978-3-540-85426-5_67, 569–579, 2009.
de Fleurian, B., Gagliardini, A., 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.
Fretwell, P., Pritchard, H. D., Vaughan, D. G., Bamber, J. L., Barrand, N. E., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A. J., Corr, H. F. J., Damaske, D., Damm, V., Ferraccioli, F., Forsberg, R., Fujita, S., Gim, Y., Gogineni, P., Griggs, J. A., Hindmarsh, R. C. A., Holmlund, P., Holt, J. W., Jacobel, R. W., Jenkins, A., Jokat, W., Jordan, T., King, E. C., Kohler, J., Krabill, W., Riger-Kusk, M., Langley, K. A., Leitchenkov, G., Leuschen, C., Luyendyk, B. P., Matsuoka, K., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tinto, B. K., Welch, B. C., Wilson, D., Young, D. A., Xiangbin, C., and Zirizzotti, A.: Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375–393, https://doi.org/10.5194/tc-7-375-2013, 2013.
Gudmundsson, G. H.: Fortnightly variations in the flow velocity of Rutford Ice Stream, West Antarctica., Nature, 444, 1063–4, 2006.
Gudmundsson, G. H.: Tides and the flow of Rutford Ice Stream, West Antarctica, J. Geophys. Res., 112, F04007, https://doi.org/10.1029/2006JF000731, 2007.
Gudmundsson, G. H.: Ice-stream response to ocean tides and the form of the basal sliding law, The Cryosphere, 5, 259–270, https://doi.org/10.5194/tc-5-259-2011, 2011.
Gudmundsson, G. H. and Raymond, M. J.: On the limit to resolution and information on basal properties obtainable from surface data on ice streams, The Cryosphere, 2, 167–178, https://doi.org/10.5194/tc-2-167-2008, 2008.
King, M. A., Murray, T., and Smith, A. M.: Non-linear responses of Rutford Ice Stream, Antarctica, to semi-diurnal and diurnal tidal forcing, J. Glaciol., 56, 167–176, 2010.
King, M. A., Makinson, K., and Gudmundsson, G. H.: Nonlinear interaction between ocean tides and the Larsen C Ice Shelf system, Geophys. Res. Lett., 38, 1–5, 2011.
Makinson, K., King, M. A., Nicholls, K. W., and Gudmundsson, G. H.: Diurnal and semidiurnal tide-induced lateral movement of Ronne Ice Shelf, Antarctica, Geophys. Res. Lett., 39, L10501, https://doi.org/10.1029/2012GL051636, 2012.
MARC: Marc users manual, MSC Software Corporation, 2 MacArthur Place, Santa Ana, CA 92707, USA, 2013.
Marsh, O. J., Rack, W., Floricioiu, D., Golledge, N. R., and Lawson, W.: Tidally induced velocity variations of the Beardmore Glacier, Antarctica, and their representation in satellite measurements of ice velocity, The Cryosphere, 7, 1375–1384, https://doi.org/10.5194/tc-7-1375-2013, 2013.
Murray, T., Smith, A. M., King, M. A., and Weedon, G. P.: Ice flow modulated by tides at up to annual periods at Rutford Ice Stream, West Antarctica, Geophys. Res. Lett., 34, 6–11, 2007.
Padman, L., Erofeeva, S. Y., and Fricker, H. A.: Improving Antarctic tide models by assimilation of ICESat laser altimetry over ice shelves, Geophys. Res. Lett., 35, L22504, https://doi.org/10.1029/2008gl035592, 2008.
Raymond, M. J. and Gudmundsson, G. H.: Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data, The Cryosphere, 4, 265–278, https://doi.org/10.5194/tc-3-265-2009, 2009.
Reeh, N., Christensen, E. L., Mayer, C., and Olesen, O. B.: Tidal bending of glaciers: a linear viscoelastic approach, Ann. Glaciol., 37, 83–89, 2003.
Rignot, E. Mouginot, J. S. B.: MEaSUREs InSAR-Based Antarctica Ice Velocity Map, https://doi.org/10.5067/MEASURES/CRYOSPHERE/nsidc-0484.001, 2011.
Rodgers, C. D.: Inverse methods for atmospheric sounding: theory and practice, World Scientific Publishing, 57 Shelton street, Covent garden, London, WC2H 9HE, 2000.
Rosier, S. H. R., Green, J. A. M., Scourse, J. D., and Winkelmann, R.: Modeling Antarctic tides in response to ice shelf thinning and retreat, J. Geophys. Res.-Oceans, 119, 87–97, 2014a.
Rosier, S. H. R., Gudmundsson, G. H., and Green, J. A. M.: Insights into ice stream dynamics through modeling their response to tidal forcing, The Cryosphere Discuss., 8, 659–689, https://doi.org/10.5194/tc-8-1763-2014, 2014b.
Sayag, R. and Worster, M. G.: Elastic dynamics and tidal migration of grounding lines modify subglacial lubrication and melting, Geophys. Res. Lett., 40, 5877–5881, 2013.
Thompson, J., Simons, M., and Tsai, V. C.: Modeling the elastic transmission of tidal stresses to great distances inland in channelized ice streams, The Cryosphere Discuss., 8, 2119–2177, https://doi.org/10.5194/tc-8-2007-2014, 2014.
Walker, R. T., Christianson, K., Parizek, B. R., Anandakrishnan, S., and Alley, R. B.: A viscoelastic flowline model applied to tidal forcing of Bindschadler Ice Stream, West Antarctica, Earth Planet. Sc. Lett., 319-320, 128–132, 2012.
Walker, R. T., Parizek, B. R., Alley, R. B., Anandakrishnan, S., Riverman, K. L., and Christianson, K.: Ice-shelf tidal flexure and subglacial pressure variations, Earth Planet Sci. Lett., 361, 422–428, 2013.
Weertman, J.: Deformation of floating ice shelves, Journal of glaciology, 3, 38–42, 1957.
Winberry, J. P., Anandakrishnan, S., Alley, R. B., Bindschadler, R., and King, M. A.: Basal mechanics of ice streams: Insights from the stick-slip motion of Whillans Ice Stream, West Antarctica, J. Geophys. Res., 114, F01016, https://doi.org/10.1029/2008JF001035, 2009.
Winberry, J. P., Anandakrishnan, S., Wiens, D. A., Alley, R. B., and Christianson, K.: Dynamics of stick-slip motion, Whillans Ice Stream, Antarctica, Earth Planet Sci. Lett., 305, 283–289, 2011.
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.
We use a full-Stokes model to investigate the long period modulation of Rutford Ice Stream flow...
