Articles | Volume 14, issue 1
https://doi.org/10.5194/tc-14-17-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-14-17-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Jan 2020
Research article |
| 09 Jan 2020
| 09 Jan 2020
Exploring mechanisms responsible for tidal modulation in flow of the Filchner–Ronne Ice Shelf
Sebastian H. R. Rosier
CORRESPONDING AUTHOR
Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK
G. Hilmar Gudmundsson
Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK
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This preprint is open for discussion and under review for The Cryosphere (TC).
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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
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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
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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.
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
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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.
Jowan M. Barnes, Thiago Dias dos Santos, Daniel Goldberg, G. Hilmar Gudmundsson, Mathieu Morlighem, and Jan De Rydt
The Cryosphere, 15, 1975–2000, https://doi.org/10.5194/tc-15-1975-2021, https://doi.org/10.5194/tc-15-1975-2021, 2021
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Some properties of ice flow models must be initialised using observed data before they can be used to produce reliable predictions of the future. Different models have different ways of doing this, and the process is generally seen as being specific to an individual model. We compare the methods used by three different models and show that they produce similar outputs. We also demonstrate that the outputs from one model can be used in other models without introducing large uncertainties.
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
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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
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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
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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
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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.
Stephen L. Cornford, Helene Seroussi, Xylar S. Asay-Davis, G. Hilmar Gudmundsson, Rob Arthern, Chris Borstad, Julia Christmann, Thiago Dias dos Santos, Johannes Feldmann, Daniel Goldberg, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, Gunter Leguy, William H. Lipscomb, Nacho Merino, Gaël Durand, Mathieu Morlighem, David Pollard, Martin Rückamp, C. Rosie Williams, and Hongju Yu
The Cryosphere, 14, 2283–2301, https://doi.org/10.5194/tc-14-2283-2020, https://doi.org/10.5194/tc-14-2283-2020, 2020
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We present the results of the third Marine Ice Sheet Intercomparison Project (MISMIP+). MISMIP+ is one in a series of exercises that test numerical models of ice sheet flow in simple situations. This particular exercise concentrates on the response of ice sheet models to the thinning of their floating ice shelves, which is of interest because numerical models are currently used to model the response to contemporary and near-future thinning in Antarctic ice shelves.
Anders Levermann, Ricarda Winkelmann, Torsten Albrecht, Heiko Goelzer, Nicholas R. Golledge, Ralf Greve, Philippe Huybrechts, Jim Jordan, Gunter Leguy, Daniel Martin, Mathieu Morlighem, Frank Pattyn, David Pollard, Aurelien Quiquet, Christian Rodehacke, Helene Seroussi, Johannes Sutter, Tong Zhang, Jonas Van Breedam, Reinhard Calov, Robert DeConto, Christophe Dumas, Julius Garbe, G. Hilmar Gudmundsson, Matthew J. Hoffman, Angelika Humbert, Thomas Kleiner, William H. Lipscomb, Malte Meinshausen, Esmond Ng, Sophie M. J. Nowicki, Mauro Perego, Stephen F. Price, Fuyuki Saito, Nicole-Jeanne Schlegel, Sainan Sun, and Roderik S. W. van de Wal
Earth Syst. Dynam., 11, 35–76, https://doi.org/10.5194/esd-11-35-2020, https://doi.org/10.5194/esd-11-35-2020, 2020
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We provide an estimate of the future sea level contribution of Antarctica from basal ice shelf melting up to the year 2100. The full uncertainty range in the warming-related forcing of basal melt is estimated and applied to 16 state-of-the-art ice sheet models using a linear response theory approach. The sea level contribution we obtain is very likely below 61 cm under unmitigated climate change until 2100 (RCP8.5) and very likely below 40 cm if the Paris Climate Agreement is kept.
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
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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.
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
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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
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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
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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
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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.
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
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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
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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
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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
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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.
Daniel Farinotti, Douglas J. Brinkerhoff, Garry K. C. Clarke, Johannes J. Fürst, Holger Frey, Prateek Gantayat, Fabien Gillet-Chaulet, Claire Girard, Matthias Huss, Paul W. Leclercq, Andreas Linsbauer, Horst Machguth, Carlos Martin, Fabien Maussion, Mathieu Morlighem, Cyrille Mosbeux, Ankur Pandit, Andrea Portmann, Antoine Rabatel, RAAJ Ramsankaran, Thomas J. Reerink, Olivier Sanchez, Peter A. Stentoft, Sangita Singh Kumari, Ward J. J. van Pelt, Brian Anderson, Toby Benham, Daniel Binder, Julian A. Dowdeswell, Andrea Fischer, Kay Helfricht, Stanislav Kutuzov, Ivan Lavrentiev, Robert McNabb, G. Hilmar Gudmundsson, Huilin Li, and Liss M. Andreassen
The Cryosphere, 11, 949–970, https://doi.org/10.5194/tc-11-949-2017, https://doi.org/10.5194/tc-11-949-2017, 2017
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ITMIX – the Ice Thickness Models Intercomparison eXperiment – was the first coordinated performance assessment for models inferring glacier ice thickness from surface characteristics. Considering 17 different models and 21 different test cases, we show that although solutions of individual models can differ considerably, an ensemble average can yield uncertainties in the order of 10 ± 24 % the mean ice thickness. Ways forward for improving such estimates are sketched.
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
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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
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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.
S. H. R. Rosier, G. H. Gudmundsson, and J. A. M. Green
The Cryosphere, 9, 1649–1661, https://doi.org/10.5194/tc-9-1649-2015, https://doi.org/10.5194/tc-9-1649-2015, 2015
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We use a full-Stokes model to investigate the long period modulation of Rutford Ice Stream flow by the ocean tide. We find that using a nonlinear sliding law cannot fully explain the measurements and an additional mechanism, whereby tidally induced subglacial pressure variations are transmitted upstream from the grounding line, is also required to match the large amplitude and decay length scale of the observations.
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
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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
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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
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
Discipline: Ice sheets | Subject: Ocean Interactions
Brief communication: Sea-level projections, adaptation planning, and actionable science
Local forcing mechanisms challenge parameterizations of ocean thermal forcing for Greenland tidewater glaciers
Modelling Antarctic ice shelf basal melt patterns using the one-layer Antarctic model for dynamical downscaling of ice–ocean exchanges (LADDIE v1.0)
Basal melt rates and ocean circulation under the Ryder Glacier ice tongue and their response to climate warming: a high-resolution modelling study
Can rifts alter ocean dynamics beneath ice shelves?
Large-eddy simulations of the ice-shelf–ocean boundary layer near the ice front of Nansen Ice Shelf, Antarctica
The impact of tides on Antarctic ice shelf melting
Layered seawater intrusion and melt under grounded ice
The Antarctic Coastal Current in the Bellingshausen Sea
Surface emergence of glacial plumes determined by fjord stratification
Twenty-first century ocean forcing of the Greenland ice sheet for modelling of sea level contribution
Melt at grounding line controls observed and future retreat of Smith, Pope, and Kohler glaciers
Sensitivity of a calving glacier to ice–ocean interactions under climate change: new insights from a 3-D full-Stokes model
Brief communication: PICOP, a new ocean melt parameterization under ice shelves combining PICO and a plume model
Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing
Grounding line migration through the calving season at Jakobshavn Isbræ, Greenland, observed with terrestrial radar interferometry
William H. Lipscomb, David Behar, and Monica Ainhorn Morrison
The Cryosphere, 19, 793–803, https://doi.org/10.5194/tc-19-793-2025, https://doi.org/10.5194/tc-19-793-2025, 2025
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As communities try to adapt to climate change, they look for "actionable science" that can inform decision-making. There are risks in relying on novel results that are not yet accepted by the science community. We propose a practical criterion for determining which scientific claims are actionable. We show how premature acceptance of sea-level-rise predictions can lead to confusion and backtracking, and we suggest best practices for communication between scientists and adaptation planners.
Alexander O. Hager, David A. Sutherland, and Donald A. Slater
The Cryosphere, 18, 911–932, https://doi.org/10.5194/tc-18-911-2024, https://doi.org/10.5194/tc-18-911-2024, 2024
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Warming ocean temperatures cause considerable ice loss from the Greenland Ice Sheet; however climate models are unable to resolve the complex ocean processes within fjords that influence near-glacier ocean temperatures. Here, we use a computer model to test the accuracy of assumptions that allow climate and ice sheet models to project near-glacier ocean temperatures, and thus glacier melt, into the future. We then develop new methods that improve accuracy by accounting for local ocean processes.
Erwin Lambert, André Jüling, Roderik S. W. van de Wal, and Paul R. Holland
The Cryosphere, 17, 3203–3228, https://doi.org/10.5194/tc-17-3203-2023, https://doi.org/10.5194/tc-17-3203-2023, 2023
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A major uncertainty in the study of sea level rise is the melting of the Antarctic ice sheet by the ocean. Here, we have developed a new model, named LADDIE, that simulates this ocean-driven melting of the floating parts of the Antarctic ice sheet. This model simulates fine-scale patterns of melting and freezing and requires significantly fewer computational resources than state-of-the-art ocean models. LADDIE can be used as a new tool to force high-resolution ice sheet models.
Jonathan Wiskandt, Inga Monika Koszalka, and Johan Nilsson
The Cryosphere, 17, 2755–2777, https://doi.org/10.5194/tc-17-2755-2023, https://doi.org/10.5194/tc-17-2755-2023, 2023
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Understanding ice–ocean interactions under floating ice tongues in Greenland and Antarctica is a major challenge in climate modelling and a source of uncertainty in future sea level projections. We use a high-resolution ocean model to investigate basal melting and melt-driven circulation under the floating tongue of Ryder Glacier, northwestern Greenland. We study the response to oceanic and atmospheric warming. Our results are universal and relevant for the development of climate models.
Mattia Poinelli, Michael Schodlok, Eric Larour, Miren Vizcaino, and Riccardo Riva
The Cryosphere, 17, 2261–2283, https://doi.org/10.5194/tc-17-2261-2023, https://doi.org/10.5194/tc-17-2261-2023, 2023
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Rifts are fractures on ice shelves that connect the ice on top to the ocean below. The impact of rifts on ocean circulation below Antarctic ice shelves has been largely unexplored as ocean models are commonly run at resolutions that are too coarse to resolve the presence of rifts. Our model simulations show that a kilometer-wide rift near the ice-shelf front modulates heat intrusion beneath the ice and inhibits basal melt. These processes are therefore worthy of further investigation.
Ji Sung Na, Taekyun Kim, Emilia Kyung Jin, Seung-Tae Yoon, Won Sang Lee, Sukyoung Yun, and Jiyeon Lee
The Cryosphere, 16, 3451–3468, https://doi.org/10.5194/tc-16-3451-2022, https://doi.org/10.5194/tc-16-3451-2022, 2022
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Beneath the Antarctic ice shelf, sub-ice-shelf plume flow that can cause turbulent mixing exists. In this study, we investigate how this flow affects ocean dynamics and ice melting near the ice front. Our results obtained by validated simulation show that higher turbulence intensity results in vigorous ice melting due to the high heat entrainment. Moreover, this flow with meltwater created by this flow highly affects the ocean overturning circulations near the ice front.
Ole Richter, David E. Gwyther, Matt A. King, and Benjamin K. Galton-Fenzi
The Cryosphere, 16, 1409–1429, https://doi.org/10.5194/tc-16-1409-2022, https://doi.org/10.5194/tc-16-1409-2022, 2022
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Tidal currents may play an important role in Antarctic ice sheet retreat by changing the rate at which the ocean melts glaciers. Here, using a computational ocean model, we derive the first estimate of present-day tidal melting that covers all of Antarctica. Our results suggest that large-scale ocean models aiming to accurately predict ice melt rates will need to account for the effects of tides. The inclusion of tide-induced friction at the ice–ocean interface should be prioritized.
Alexander A. Robel, Earle Wilson, and Helene Seroussi
The Cryosphere, 16, 451–469, https://doi.org/10.5194/tc-16-451-2022, https://doi.org/10.5194/tc-16-451-2022, 2022
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Warm seawater may intrude as a thin layer below glaciers in contact with the ocean. Mathematical theory predicts that this intrusion may extend over distances of kilometers under realistic conditions. Computer models demonstrate that if this warm seawater causes melting of a glacier bottom, it can cause rates of glacier ice loss and sea level rise to be up to 2 times faster in response to potential future ocean warming.
Ryan Schubert, Andrew F. Thompson, Kevin Speer, Lena Schulze Chretien, and Yana Bebieva
The Cryosphere, 15, 4179–4199, https://doi.org/10.5194/tc-15-4179-2021, https://doi.org/10.5194/tc-15-4179-2021, 2021
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The Antarctic Coastal Current (AACC) is an ocean current found along the coast of Antarctica. Using measurements of temperature and salinity collected by instrumented seals, the AACC is shown to be a continuous circulation feature throughout West Antarctica. Due to its proximity to the coast, the AACC's structure influences oceanic melting of West Antarctic ice shelves. These melt rates impact the stability of the West Antarctic Ice Sheet with global implications for future sea level change.
Eva De Andrés, Donald A. Slater, Fiamma Straneo, Jaime Otero, Sarah Das, and Francisco Navarro
The Cryosphere, 14, 1951–1969, https://doi.org/10.5194/tc-14-1951-2020, https://doi.org/10.5194/tc-14-1951-2020, 2020
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Buoyant plumes at tidewater glaciers result from localized subglacial discharges of surface melt. They promote glacier submarine melting and influence the delivery of nutrients to the fjord's surface waters. Combining plume theory with observations, we have found that increased fjord stratification, which is due to larger meltwater content, prevents the vertical growth of the plume and buffers submarine melting. We discuss the implications for nutrient fluxes, CO2 trapping and water export.
Donald A. Slater, Denis Felikson, Fiamma Straneo, Heiko Goelzer, Christopher M. Little, Mathieu Morlighem, Xavier Fettweis, and Sophie Nowicki
The Cryosphere, 14, 985–1008, https://doi.org/10.5194/tc-14-985-2020, https://doi.org/10.5194/tc-14-985-2020, 2020
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Changes in the ocean around Greenland play an important role in determining how much the ice sheet will contribute to global sea level over the coming century. However, capturing these links in models is very challenging. This paper presents a strategy enabling an ensemble of ice sheet models to feel the effect of the ocean for the first time and should therefore result in a significant improvement in projections of the Greenland ice sheet's contribution to future sea level change.
David A. Lilien, Ian Joughin, Benjamin Smith, and Noel Gourmelen
The Cryosphere, 13, 2817–2834, https://doi.org/10.5194/tc-13-2817-2019, https://doi.org/10.5194/tc-13-2817-2019, 2019
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We used a number of computer simulations to understand the recent retreat of a rapidly changing group of glaciers in West Antarctica. We found that significant melt underneath the floating extensions of the glaciers, driven by relatively warm ocean water at depth, was likely needed to cause the large retreat that has been observed. If melt continues around current rates, retreat is likely to continue through the coming century and extend beyond the present-day drainage area of these glaciers.
Joe Todd, Poul Christoffersen, Thomas Zwinger, Peter Råback, and Douglas I. Benn
The Cryosphere, 13, 1681–1694, https://doi.org/10.5194/tc-13-1681-2019, https://doi.org/10.5194/tc-13-1681-2019, 2019
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The Greenland Ice Sheet loses 30 %–60 % of its ice due to iceberg calving. Calving processes and their links to climate are not well understood or incorporated into numerical models of glaciers. Here we use a new 3-D calving model to investigate calving at Store Glacier, West Greenland, and test its sensitivity to increased submarine melting and reduced support from ice mélange (sea ice and icebergs). We find Store remains fairly stable despite these changes, but less so in the southern side.
Tyler Pelle, Mathieu Morlighem, and Johannes H. Bondzio
The Cryosphere, 13, 1043–1049, https://doi.org/10.5194/tc-13-1043-2019, https://doi.org/10.5194/tc-13-1043-2019, 2019
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How ocean-induced melt under floating ice shelves will change as ocean currents evolve remains a big uncertainty in projections of sea level rise. In this study, we combine two of the most recently developed melt models to form PICOP, which overcomes the limitations of past models and produces accurate ice shelf melt rates. We find that our model is easy to set up and computationally efficient, providing researchers an important tool to improve the accuracy of their future glacial projections.
Chad A. Greene, Duncan A. Young, David E. Gwyther, Benjamin K. Galton-Fenzi, and Donald D. Blankenship
The Cryosphere, 12, 2869–2882, https://doi.org/10.5194/tc-12-2869-2018, https://doi.org/10.5194/tc-12-2869-2018, 2018
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We show that Totten Ice Shelf accelerates each spring in response to the breakup of seasonal landfast sea ice at the ice shelf calving front. The previously unreported seasonal flow variability may have aliased measurements in at least one previous study of Totten's response to ocean forcing on interannual timescales. The role of sea ice in buttressing the flow of the ice shelf implies that long-term changes in sea ice cover could have impacts on the mass balance of the East Antarctic Ice Sheet.
Surui Xie, Timothy H. Dixon, Denis Voytenko, Fanghui Deng, and David M. Holland
The Cryosphere, 12, 1387–1400, https://doi.org/10.5194/tc-12-1387-2018, https://doi.org/10.5194/tc-12-1387-2018, 2018
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Time-varying velocity and topography of the terminus of Jakobshavn Isbræ were observed with a terrestrial radar interferometer in three summer campaigns (2012, 2015, 2016). Surface elevation and tidal responses of ice speed suggest a narrow floating zone in early summer, while in late summer the entire glacier is likely grounded. We hypothesize that Jakobshavn Isbræ advances a few km in winter to form a floating zone but loses this floating portion in the subsequent summer through calving.
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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.
The flow of ice shelves is now known to be strongly affected by ocean tides, but the mechanism...
