Articles | Volume 12, issue 2
The Cryosphere, 12, 721–739, 2018
https://doi.org/10.5194/tc-12-721-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The Cryosphere, 12, 721–739, 2018
https://doi.org/10.5194/tc-12-721-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article 28 Feb 2018
Research article | 28 Feb 2018
Calving relation for tidewater glaciers based on detailed stress field analysis
Rémy Mercenier et al.
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James C. Ferguson and Andreas Vieli
The Cryosphere, 15, 3377–3399, https://doi.org/10.5194/tc-15-3377-2021, https://doi.org/10.5194/tc-15-3377-2021, 2021
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Debris-covered glaciers have a greater extent than their debris-free counterparts due to insulation from the debris cover. However, the transient response to climate change remains poorly understood. We use a numerical model that couples ice dynamics and debris transport and varies the climate signal. We find that debris cover delays the transient response, especially for the extent. However, adding cryokarst features near the terminus greatly enhances the response.
Jan Beutel, Andreas Biri, Ben Buchli, Alessandro Cicoira, Reynald Delaloye, Reto Da Forno, Isabelle Gaertner-Roer, Stephan Gruber, Tonio Gsell, Andreas Hasler, Roman Lim, Phillipe Limpach, Raphael Mayoraz, Matthias Meyer, Jeannette Noetzli, Marcia Phillips, Eric Pointner, Hugo Raetzo, Cristian Scapoza, Tazio Strozzi, Lothar Thiele, Andreas Vieli, Daniel Vonder Mühll, Samuel Weber, and Vanessa Wirz
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2021-176, https://doi.org/10.5194/essd-2021-176, 2021
Preprint under review for ESSD
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Using standard GPS receivers it is possible to track terrain movements at the sub centimeter scale. This paper documents experiments using this technique monitoring different cryosphere-related mass movement in high-alpine terrain: rock glaciers, landslides as well as steep bedrock. The data serves basic research but also decision making and mitigation of natural hazard as well as adaptation to climate change. It is the largest data set of it’s kind comprising over 209’000 daily positions.
Adrien Wehrlé, Martin P. Lüthi, Andrea Walter, Guillaume Jouvet, and Andreas Vieli
The Cryosphere Discuss., https://doi.org/10.5194/tc-2021-33, https://doi.org/10.5194/tc-2021-33, 2021
Revised manuscript accepted for TC
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We developed a novel automated method for the detection and the quantification of ocean waves generated by glacier calving. This method was applied to data recorded with a terrestrial radar interferometer at Eqip Sermia, Greenland. Results show a high calving activity at the glacier front sector ending in deep water linked with more frequent meltwater plumes. This suggests that rising subglacial meltwater plumes strongly affect glacier calving in deep water, but weakly in shallow water.
Andrea Walter, Martin P. Lüthi, and Andreas Vieli
The Cryosphere, 14, 1051–1066, https://doi.org/10.5194/tc-14-1051-2020, https://doi.org/10.5194/tc-14-1051-2020, 2020
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Glacier calving plays a key role in the dynamic mass loss of ocean-terminating glaciers in Greenland. Source areas and volumes of 900 individual calving events were analysed for size and timing related to environmental forcings. We found that calving volume distribution and style vary along the calving front and are controlled by the water depth and front geometry. We suggest that in deep water both oceanic melt and subaquatic calving contribute substantially to the frontal mass loss.
Guillaume Jouvet, Eef van Dongen, Martin P. Lüthi, and Andreas Vieli
Geosci. Instrum. Method. Data Syst., 9, 1–10, https://doi.org/10.5194/gi-9-1-2020, https://doi.org/10.5194/gi-9-1-2020, 2020
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We report the first-ever in situ measurements of ice flow motion using a remotely controlled drone. We used a quadcopter to land on a highly crevassed area of Eqip Sermia Glacier, Greenland. The drone measured 70 cm of ice displacement over more than 4 h thanks to an accurate onboard GPS. Our study demonstrates that drones have great potential for geoscientists, especially to deploy sensors in hostile environments such as glaciers.
Christoph Rohner, David Small, Jan Beutel, Daniel Henke, Martin P. Lüthi, and Andreas Vieli
The Cryosphere, 13, 2953–2975, https://doi.org/10.5194/tc-13-2953-2019, https://doi.org/10.5194/tc-13-2953-2019, 2019
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The recent increase in ice flow and calving rates of ocean–terminating glaciers contributes substantially to the mass loss of the Greenland Ice Sheet. Using in situ reference observations, we validate the satellite–based method of iterative offset tracking of Sentinel–1A data for deriving flow speeds. Our investigations highlight the importance of spatial resolution near the fast–flowing calving front, resulting in significantly higher ice velocities compared to large–scale operational products.
Samuel Weber, Jan Beutel, Reto Da Forno, Alain Geiger, Stephan Gruber, Tonio Gsell, Andreas Hasler, Matthias Keller, Roman Lim, Philippe Limpach, Matthias Meyer, Igor Talzi, Lothar Thiele, Christian Tschudin, Andreas Vieli, Daniel Vonder Mühll, and Mustafa Yücel
Earth Syst. Sci. Data, 11, 1203–1237, https://doi.org/10.5194/essd-11-1203-2019, https://doi.org/10.5194/essd-11-1203-2019, 2019
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In this paper, we describe a unique 10-year or more data record obtained from in situ measurements in steep bedrock permafrost in an Alpine environment on the Matterhorn Hörnligrat, Zermatt, Switzerland, at 3500 m a.s.l. By documenting and sharing these data in this form, we contribute to facilitating future research based on them, e.g., in the area of analysis methodology, comparative studies, assessment of change in the environment, natural hazard warning and the development of process models.
Jérome Faillettaz, Martin Funk, Jan Beutel, and Andreas Vieli
Nat. Hazards Earth Syst. Sci., 19, 1399–1413, https://doi.org/10.5194/nhess-19-1399-2019, https://doi.org/10.5194/nhess-19-1399-2019, 2019
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We developed a new strategy for real-time early warning of
gravity-driven slope failures (such as landslides, rockfalls, glacier break-off, etc.). This method enables us to investigate natural slope stability based on continuous monitoring and interpretation of seismic waves generated by the potential instability. Thanks to a pilot experiment, we detected typical patterns of precursory events prior to slide events, demonstrating the potential of this method for real-word applications.
Nico Mölg, Tobias Bolch, Andrea Walter, and Andreas Vieli
The Cryosphere, 13, 1889–1909, https://doi.org/10.5194/tc-13-1889-2019, https://doi.org/10.5194/tc-13-1889-2019, 2019
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Debris can partly protect glaciers from melting. But many debris-covered glaciers change similar to debris-free glaciers. To better understand the debris influence we investigated 150 years of evolution of Zmutt Glacier in Switzerland. We found an increase in debris extent over time and a link to glacier flow velocity changes. We also found an influence of debris on the melt locally, but only a small volume change reduction over the whole glacier, also because of the influence of ice cliffs.
Alessandro Cicoira, Jan Beutel, Jérome Faillettaz, Isabelle Gärtner-Roer, and Andreas Vieli
The Cryosphere, 13, 927–942, https://doi.org/10.5194/tc-13-927-2019, https://doi.org/10.5194/tc-13-927-2019, 2019
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Rock glacier flow varies on multiple timescales. The variations have been linked to climatic forcing, but a quantitative understanding is still missing.
We use a 1-D numerical modelling approach coupling heat conduction to a creep model in order to study the influence of temperature variations on rock glacier flow. Our results show that heat conduction alone cannot explain the observed variations. Other processes, likely linked to water, must dominate the short-term velocity signal.
Florian Frank, Brian W. McArdell, Nicole Oggier, Patrick Baer, Marc Christen, and Andreas Vieli
Nat. Hazards Earth Syst. Sci., 17, 801–815, https://doi.org/10.5194/nhess-17-801-2017, https://doi.org/10.5194/nhess-17-801-2017, 2017
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This study describes a sensitivity analysis of the RAMMS debris-flow entrainment model, which is intended to help solve problems related to predicting the runout of debris flows. The results indicate that the entrainment model predicts plausible erosion volumes in comparison with field data. These eroded volumes are sensitive to the initial landslide volume, suggesting that this tool may be useful for both reconstruction of historical events and modeling of debris flow scenarios.
Samuel Weber, Jan Beutel, Jérome Faillettaz, Andreas Hasler, Michael Krautblatter, and Andreas Vieli
The Cryosphere, 11, 567–583, https://doi.org/10.5194/tc-11-567-2017, https://doi.org/10.5194/tc-11-567-2017, 2017
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We present a 8-year continuous time series of measured fracture kinematics and thermal conditions on steep permafrost bedrock at Hörnligrat, Matterhorn. Based on this unique dataset and a conceptual model for strong fractured bedrock, we develop a novel quantitative approach that allows to separate reversible from irreversible fracture kinematics and assign the dominant forcing. A new index of irreversibility provides useful indication for the occurrence and timing of irreversible displacements.
Johann Müller, Andreas Vieli, and Isabelle Gärtner-Roer
The Cryosphere, 10, 2865–2886, https://doi.org/10.5194/tc-10-2865-2016, https://doi.org/10.5194/tc-10-2865-2016, 2016
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Rock glaciers are landforms indicative of permafrost creep and received considerable attention concerning their dynamical and thermal changes. We use a holistic approach to analyze and model the current and long-term dynamical development of two rock glaciers in the Swiss Alps. The modeling results show the impact of variations in temperature and sediment–ice supply on rock glacier evolution and describe proceeding signs of degradation due to climate warming.
Martin P. Lüthi and Andreas Vieli
The Cryosphere, 10, 995–1002, https://doi.org/10.5194/tc-10-995-2016, https://doi.org/10.5194/tc-10-995-2016, 2016
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Glaciers flowing into the ocean sometimes release huge pieces of ice and
cause violent tsunami waves which, upon landfall, can cause severe
destruction. During an exceptionally well-documented event at Eqip Sermia,
west Greenland, the collapse of a 200 m high ice cliff caused a tsunami wave
of 50 m height, traveling at a speed exceeding 100 km h−1. This tsunami wave
was filmed from a tour boat, and was simultaneously observed with several
instruments, as was the run-up of 15 m on the shore.
Sarah S. Thompson, Bernd Kulessa, Richard L. H. Essery, and Martin P. Lüthi
The Cryosphere, 10, 433–444, https://doi.org/10.5194/tc-10-433-2016, https://doi.org/10.5194/tc-10-433-2016, 2016
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We show that strong electrical self-potential fields are generated in melting in in situ snowpacks at Rhone Glacier and Jungfraujoch Glacier, Switzerland. We conclude that the electrical self-potential method is a promising snow and firn hydrology sensor, owing to its suitability for sensing lateral and vertical liquid water flows directly and minimally invasively, complementing established observational programs and monitoring autonomously at a low cost.
V. Wirz, S. Gruber, R. S. Purves, J. Beutel, I. Gärtner-Roer, S. Gubler, and A. Vieli
Earth Surf. Dynam., 4, 103–123, https://doi.org/10.5194/esurf-4-103-2016, https://doi.org/10.5194/esurf-4-103-2016, 2016
F. Frank, B. W. McArdell, C. Huggel, and A. Vieli
Nat. Hazards Earth Syst. Sci., 15, 2569–2583, https://doi.org/10.5194/nhess-15-2569-2015, https://doi.org/10.5194/nhess-15-2569-2015, 2015
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The sudden onset of large and erosive debris flows has been observed recently in different catchments in Switzerland, implicating the importance of erosion for debris flow modelling. Therefore, an erosion model was established based on field data (relationship between maximum shear stress and erosion depth and rate) of several debris flows measured at the Illgraben. Erosion model tests at the Spreitgraben showed considerable improvements in runout pattern as well as hydrograph propagation.
M. P. Lüthi, C. Ryser, L. C. Andrews, G. A. Catania, M. Funk, R. L. Hawley, M. J. Hoffman, and T. A. Neumann
The Cryosphere, 9, 245–253, https://doi.org/10.5194/tc-9-245-2015, https://doi.org/10.5194/tc-9-245-2015, 2015
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We analyze the thermal structure of the Greenland Ice Sheet with a heat flow model. New borehole measurements indicate that more heat is stored within the ice than would be expected from heat diffusion alone. We conclude that temperate paleo-firn and cyro-hydrologic warming are essential processes that explain the measurements.
M. P. Lüthi
The Cryosphere, 8, 639–650, https://doi.org/10.5194/tc-8-639-2014, https://doi.org/10.5194/tc-8-639-2014, 2014
B. F. Morriss, R. L. Hawley, J. W. Chipman, L. C. Andrews, G. A. Catania, M. J. Hoffman, M. P. Lüthi, and T. A. Neumann
The Cryosphere, 7, 1869–1877, https://doi.org/10.5194/tc-7-1869-2013, https://doi.org/10.5194/tc-7-1869-2013, 2013
E. M. Enderlin, I. M. Howat, and A. Vieli
The Cryosphere, 7, 1579–1590, https://doi.org/10.5194/tc-7-1579-2013, https://doi.org/10.5194/tc-7-1579-2013, 2013
E. M. Enderlin, I. M. Howat, and A. Vieli
The Cryosphere, 7, 1007–1015, https://doi.org/10.5194/tc-7-1007-2013, https://doi.org/10.5194/tc-7-1007-2013, 2013
Related subject area
Numerical Modelling
Elements of future snowpack modeling – Part 2: A modular and extendable Eulerian–Lagrangian numerical scheme for coupled transport, phase changes and settling processes
Assessment of neutrons from secondary cosmic rays at mountain altitudes – Geant4 simulations of environmental parameters including soil moisture and snow cover
A seasonal algorithm of the snow-covered area fraction for mountainous terrain
Edge displacement scores
The 21st-century fate of the Mocho-Choshuenco ice cap in southern Chile
Lateral thermokarst patterns in permafrost peat plateaus in northern Norway
Modelling steady states and the transient response of debris-covered glaciers
Marine ice sheet experiments with the Community Ice Sheet Model
Twentieth century global glacier mass change: an ensemble-based model reconstruction
A method for solving heat transfer with phase change in ice or soil that allows for large time steps while guaranteeing energy conservation
The transferability of adjoint inversion products between different ice flow models
Inferring the basal sliding coefficient field for the Stokes ice sheet model under rheological uncertainty
The tipping points and early warning indicators for Pine Island Glacier, West Antarctica
Elements of future snowpack modeling – part 1: A physical instability arising from the non-linear coupling of transport and phase changes
Effects of multi-scale heterogeneity on the simulated evolution of ice-rich permafrost lowlands under a warming climate
On the Contribution of Grain Boundary Sliding to Firn Densification – an Assessment using an Optimisation Approach
Sensitivity of ice sheet surface velocity and elevation to variations in basal friction and topography in the full Stokes and shallow-shelf approximation frameworks using adjoint equations
Snow cover duration trends observed at sites and predicted by multiple models
Mapping the age of ice of Gauligletscher combining surface radionuclide contamination and ice flow modeling
Modelling the evolution of Djankuat Glacier, North Caucasus, from 1752 until 2100 CE
Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model
Toward a method for downscaling sea ice pressure for navigation purposes
Deep ice layer formation in an alpine snowpack: monitoring and modeling
Brief communication: Time step dependence (and fixes) in Stokes simulations of calving ice shelves
Modelling regional glacier length changes over the last millennium using the Open Global Glacier Model
Evaluating permafrost physics in the Coupled Model Intercomparison Project 6 (CMIP6) models and their sensitivity to climate change
Bayesian calibration of firn densification models
A kinematic formalism for tracking ice–ocean mass exchange on the Earth's surface and estimating sea-level change
The contrasting response of outlet glaciers to interior and ocean forcing
The Arctic Ocean Observation Operator for 6.9 GHz (ARC3O) – Part 1: How to obtain sea ice brightness temperatures at 6.9 GHz from climate model output
The Arctic Ocean Observation Operator for 6.9 GHz (ARC3O) – Part 2: Development and evaluation
Results of the third Marine Ice Sheet Model Intercomparison Project (MISMIP+)
Satellite-retrieved sea ice concentration uncertainty and its effect on modelling wave evolution in marginal ice zones
Ocean-forced evolution of the Amundsen Sea catchment, West Antarctica, by 2100
Multi-physics ensemble snow modelling in the western Himalaya
Parameter sensitivity analysis of dynamic ice sheet models – numerical computations
Deep learning applied to glacier evolution modelling
Feature-based comparison of sea ice deformation in lead-permitting sea ice simulations
Micromechanical modeling of snow failure
Changing characteristics of runoff and freshwater export from watersheds draining northern Alaska
Initialization of a global glacier model based on present-day glacier geometry and past climate information: an ensemble approach
Simulated retreat of Jakobshavn Isbræ during the 21st century
Wave energy attenuation in fields of colliding ice floes – Part 1: Discrete-element modelling of dissipation due to ice–water drag
Contrasting thinning patterns between lake- and land-terminating glaciers in the Bhutanese Himalaya
Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska
Modeling the response of Greenland outlet glaciers to global warming using a coupled flow line–plume model
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations
Development of physically based liquid water schemes for Greenland firn-densification models
Validation of the sea ice surface albedo scheme of the regional climate model HIRHAM–NAOSIM using aircraft measurements during the ACLOUD/PASCAL campaigns
Regional grid refinement in an Earth system model: impacts on the simulated Greenland surface mass balance
Anna Simson, Henning Löwe, and Julia Kowalski
The Cryosphere, 15, 5423–5445, https://doi.org/10.5194/tc-15-5423-2021, https://doi.org/10.5194/tc-15-5423-2021, 2021
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This companion paper deals with numerical particularities of partial differential equations underlying one-dimensional snow models. In this second part we include mechanical settling and develop a new hybrid (Eulerian–Lagrangian) method for solving the advection-dominated ice mass conservation on a moving mesh alongside Eulerian diffusion (heat and vapor) and phase changes. The scheme facilitates a modular and extendable solver strategy while retaining controls on numerical accuracy.
Thomas Brall, Vladimir Mares, Rolf Bütikofer, and Werner Rühm
The Cryosphere, 15, 4769–4780, https://doi.org/10.5194/tc-15-4769-2021, https://doi.org/10.5194/tc-15-4769-2021, 2021
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Neutrons from secondary cosmic rays, measured at 2660 m a.s.l. at Zugspitze, Germany, are highly affected by the environment, in particular by snow, soil moisture, and mountain shielding. To quantify these effects, computer simulations were carried out, including a sensitivity analysis on snow depth and soil moisture. This provides a possibility for snow depth estimation based on the measured number of secondary neutrons. This method was applied at Zugspitze in 2018.
Nora Helbig, Michael Schirmer, Jan Magnusson, Flavia Mäder, Alec van Herwijnen, Louis Quéno, Yves Bühler, Jeff S. Deems, and Simon Gascoin
The Cryosphere, 15, 4607–4624, https://doi.org/10.5194/tc-15-4607-2021, https://doi.org/10.5194/tc-15-4607-2021, 2021
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The snow cover spatial variability in mountains changes considerably over the course of a snow season. In applications such as weather, climate and hydrological predictions the fractional snow-covered area is therefore an essential parameter characterizing how much of the ground surface in a grid cell is currently covered by snow. We present a seasonal algorithm and a spatiotemporal evaluation suggesting that the algorithm can be applied in other geographic regions by any snow model application.
Arne Melsom
The Cryosphere, 15, 3785–3796, https://doi.org/10.5194/tc-15-3785-2021, https://doi.org/10.5194/tc-15-3785-2021, 2021
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This study presents new methods to assess how well observations of sea ice expansion are reproduced by results from models. The aim is to provide information about the quality of forecasts for changes in the sea ice extent to operators in or near ice-infested waters. A test using 2 years of model results demonstrates the practical applicability and usefulness of the methods that are presented.
Matthias Scheiter, Marius Schaefer, Eduardo Flández, Deniz Bozkurt, and Ralf Greve
The Cryosphere, 15, 3637–3654, https://doi.org/10.5194/tc-15-3637-2021, https://doi.org/10.5194/tc-15-3637-2021, 2021
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We simulate the current state and future evolution of the Mocho-Choshuenco ice cap in southern Chile (40°S, 72°W) with the ice-sheet model SICOPOLIS. Under different global warming scenarios, we project ice mass losses between 56 % and 97 % by the end of the 21st century. We quantify the uncertainties based on an ensemble of climate models and on the temperature dependence of the equilibrium line altitude. Our results suggest a considerable deglaciation in southern Chile in the next 80 years.
Léo C. P. Martin, Jan Nitzbon, Johanna Scheer, Kjetil S. Aas, Trond Eiken, Moritz Langer, Simon Filhol, Bernd Etzelmüller, and Sebastian Westermann
The Cryosphere, 15, 3423–3442, https://doi.org/10.5194/tc-15-3423-2021, https://doi.org/10.5194/tc-15-3423-2021, 2021
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It is important to understand how permafrost landscapes respond to climate changes because their thaw can contribute to global warming. We investigate how a common permafrost morphology degrades using both field observations of the surface elevation and numerical modeling. We show that numerical models accounting for topographic changes related to permafrost degradation can reproduce the observed changes in nature and help us understand how parameters such as snow influence this phenomenon.
James C. Ferguson and Andreas Vieli
The Cryosphere, 15, 3377–3399, https://doi.org/10.5194/tc-15-3377-2021, https://doi.org/10.5194/tc-15-3377-2021, 2021
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Debris-covered glaciers have a greater extent than their debris-free counterparts due to insulation from the debris cover. However, the transient response to climate change remains poorly understood. We use a numerical model that couples ice dynamics and debris transport and varies the climate signal. We find that debris cover delays the transient response, especially for the extent. However, adding cryokarst features near the terminus greatly enhances the response.
Gunter R. Leguy, William H. Lipscomb, and Xylar S. Asay-Davis
The Cryosphere, 15, 3229–3253, https://doi.org/10.5194/tc-15-3229-2021, https://doi.org/10.5194/tc-15-3229-2021, 2021
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We present numerical features of the Community Ice Sheet Model in representing ocean termini glaciers. Using idealized test cases, we show that applying melt in a partly grounded cell is beneficial, in contrast to recent studies. We confirm that parameterizing partly grounded cells yields accurate ice sheet representation at a grid resolution of ~2 km (arguably 4 km), allowing ice sheet simulations at a continental scale. The choice of basal friction law also influences the ice flow.
Jan-Hendrik Malles and Ben Marzeion
The Cryosphere, 15, 3135–3157, https://doi.org/10.5194/tc-15-3135-2021, https://doi.org/10.5194/tc-15-3135-2021, 2021
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To better estimate the uncertainty in glacier mass change modeling during the 20th century we ran an established model with an ensemble of meteorological data sets. We find that the total ensemble uncertainty, especially in the early 20th century, when glaciological and meteorological observations at glacier locations were sparse, increases considerably compared to individual ensemble runs. This stems from regions with a lot of ice mass but few observations (e.g., Greenland periphery).
Niccolò Tubini, Stephan Gruber, and Riccardo Rigon
The Cryosphere, 15, 2541–2568, https://doi.org/10.5194/tc-15-2541-2021, https://doi.org/10.5194/tc-15-2541-2021, 2021
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We present a new method to compute temperature changes with melting and freezing – a fundamental challenge in cryosphere research – extremely efficiently and with guaranteed correctness of the energy balance for any time step size. This is a key feature since the integration time step can then be chosen according to the timescale of the processes to be studied, from seconds to days.
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.
Olalekan Babaniyi, Ruanui Nicholson, Umberto Villa, and Noémi Petra
The Cryosphere, 15, 1731–1750, https://doi.org/10.5194/tc-15-1731-2021, https://doi.org/10.5194/tc-15-1731-2021, 2021
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We consider the problem of inferring unknown parameter fields under additional uncertainty for an ice sheet model from synthetic surface ice flow velocity measurements. Our results indicate that accounting for model uncertainty stemming from the presence of nuisance parameters is crucial. Namely our findings suggest that using nominal values for these parameters, as is often done in practice, without taking into account the resulting modeling error can lead to overconfident and biased results.
Sebastian H. R. Rosier, Ronja Reese, Jonathan F. Donges, Jan De Rydt, G. Hilmar Gudmundsson, and Ricarda Winkelmann
The Cryosphere, 15, 1501–1516, https://doi.org/10.5194/tc-15-1501-2021, https://doi.org/10.5194/tc-15-1501-2021, 2021
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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.
Konstantin Schürholt, Julia Kowalski, and Henning Löwe
The Cryosphere Discuss., https://doi.org/10.5194/tc-2021-72, https://doi.org/10.5194/tc-2021-72, 2021
Revised manuscript accepted for TC
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This companion paper deals with numerical particularities of partial
differential equations underlying one dimensional snow models. In this
first part we neglect mechanical settling and demonstrate that the
non-linear coupling between diffusive transport (heat and vapor),
phase changes and ice mass conservation contains a wave instability
that may be relevant for weak layer formation. Numerical requirements
are discussed in view of the underlying homogenization scheme.
Jan Nitzbon, Moritz Langer, Léo C. P. Martin, Sebastian Westermann, Thomas Schneider von Deimling, and Julia Boike
The Cryosphere, 15, 1399–1422, https://doi.org/10.5194/tc-15-1399-2021, https://doi.org/10.5194/tc-15-1399-2021, 2021
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We used a numerical model to investigate how small-scale landscape heterogeneities affect permafrost thaw under climate-warming scenarios. Our results show that representing small-scale heterogeneities in the model can decide whether a landscape is water-logged or well-drained in the future. This in turn affects how fast permafrost thaws under warming. Our research emphasizes the importance of considering small-scale processes in model assessments of permafrost thaw under climate change.
Timm Schultz, Ralf Müller, Dietmar Gross, and Angelika Humbert
The Cryosphere Discuss., https://doi.org/10.5194/tc-2021-75, https://doi.org/10.5194/tc-2021-75, 2021
Revised manuscript accepted for TC
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Firn is the interstage product between snow and ice. Simulations describing the process of firn densification are used in the context of estimating mass changes of the ice sheets and past climate reconstructions. The first stage of firn densification takes place in the upper few meters of the firn column. We investigate how well a material law describing the process of grain boundary sliding works for the numerical simulation of firn densification in this stage.
Gong Cheng, Nina Kirchner, and Per Lötstedt
The Cryosphere, 15, 715–742, https://doi.org/10.5194/tc-15-715-2021, https://doi.org/10.5194/tc-15-715-2021, 2021
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We present an inverse modeling approach to improve the understanding of spatiotemporally variable processes at the inaccessible base of an ice sheet by determining the sensitivity of direct surface observations to perturbations of basal conditions. Time dependency is proved to be important in these types of problems. The effect of perturbations is analyzed based on analytical and numerical solutions.
Richard Essery, Hyungjun Kim, Libo Wang, Paul Bartlett, Aaron Boone, Claire Brutel-Vuilmet, Eleanor Burke, Matthias Cuntz, Bertrand Decharme, Emanuel Dutra, Xing Fang, Yeugeniy Gusev, Stefan Hagemann, Vanessa Haverd, Anna Kontu, Gerhard Krinner, Matthieu Lafaysse, Yves Lejeune, Thomas Marke, Danny Marks, Christoph Marty, Cecile B. Menard, Olga Nasonova, Tomoko Nitta, John Pomeroy, Gerd Schädler, Vladimir Semenov, Tatiana Smirnova, Sean Swenson, Dmitry Turkov, Nander Wever, and Hua Yuan
The Cryosphere, 14, 4687–4698, https://doi.org/10.5194/tc-14-4687-2020, https://doi.org/10.5194/tc-14-4687-2020, 2020
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Climate models are uncertain in predicting how warming changes snow cover. This paper compares 22 snow models with the same meteorological inputs. Predicted trends agree with observations at four snow research sites: winter snow cover does not start later, but snow now melts earlier in spring than in the 1980s at two of the sites. Cold regions where snow can last until late summer are predicted to be particularly sensitive to warming because the snow then melts faster at warmer times of year.
Guillaume Jouvet, Stefan Röllin, Hans Sahli, José Corcho, Lars Gnägi, Loris Compagno, Dominik Sidler, Margit Schwikowski, Andreas Bauder, and Martin Funk
The Cryosphere, 14, 4233–4251, https://doi.org/10.5194/tc-14-4233-2020, https://doi.org/10.5194/tc-14-4233-2020, 2020
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We show that plutonium is an effective tracer to identify ice originating from the early 1960s at the surface of a mountain glacier after a long time within the ice flow, giving unique information on the long-term former ice motion. Combined with ice flow modelling, the dating can be extended to the entire glacier, and we show that an airplane which crash-landed on the Gauligletscher in 1946 will likely soon be released from the ice close to the place where pieces have emerged in recent years.
Yoni Verhaegen, Philippe Huybrechts, Oleg Rybak, and Victor V. Popovnin
The Cryosphere, 14, 4039–4061, https://doi.org/10.5194/tc-14-4039-2020, https://doi.org/10.5194/tc-14-4039-2020, 2020
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We use a numerical flow model to simulate the behaviour of the Djankuat Glacier, a WGMS reference glacier situated in the North Caucasus (Republic of Kabardino-Balkaria, Russian Federation), in response to past, present and future climate conditions (1752–2100 CE). In particular, we adapt a more sophisticated and physically based debris model, which has not been previously applied in time-dependent numerical flow line models, to look at the impact of a debris cover on the glacier’s evolution.
Clemens Schannwell, Reinhard Drews, Todd A. Ehlers, Olaf Eisen, Christoph Mayer, Mika Malinen, Emma C. Smith, and Hannes Eisermann
The Cryosphere, 14, 3917–3934, https://doi.org/10.5194/tc-14-3917-2020, https://doi.org/10.5194/tc-14-3917-2020, 2020
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To reduce uncertainties associated with sea level rise projections, an accurate representation of ice flow is paramount. Most ice sheet models rely on simplified versions of the underlying ice flow equations. Due to the high computational costs, ice sheet models based on the complete ice flow equations have been restricted to < 1000 years. Here, we present a new model setup that extends the applicability of such models by an order of magnitude, permitting simulations of 40 000 years.
Jean-François Lemieux, L. Bruno Tremblay, and Mathieu Plante
The Cryosphere, 14, 3465–3478, https://doi.org/10.5194/tc-14-3465-2020, https://doi.org/10.5194/tc-14-3465-2020, 2020
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Sea ice pressure poses great risk for navigation; it can lead to ship besetting and damages. Sea ice forecasting systems can predict the evolution of pressure. However, these systems have low spatial resolution (a few km) compared to the dimensions of ships. We study the downscaling of pressure from the km-scale to scales relevant for navigation. We find that the pressure applied on a ship beset in heavy ice conditions can be markedly larger than the pressure predicted by the forecasting system.
Louis Quéno, Charles Fierz, Alec van Herwijnen, Dylan Longridge, and Nander Wever
The Cryosphere, 14, 3449–3464, https://doi.org/10.5194/tc-14-3449-2020, https://doi.org/10.5194/tc-14-3449-2020, 2020
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Deep ice layers may form in the snowpack due to preferential water flow with impacts on the snowpack mechanical, hydrological and thermodynamical properties. We studied their formation and evolution at a high-altitude alpine site, combining a comprehensive observation dataset at a daily frequency (with traditional snowpack observations, penetration resistance and radar measurements) and detailed snowpack modeling, including a new parameterization of ice formation in the 1-D SNOWPACK model.
Brandon Berg and Jeremy Bassis
The Cryosphere, 14, 3209–3213, https://doi.org/10.5194/tc-14-3209-2020, https://doi.org/10.5194/tc-14-3209-2020, 2020
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Computer models of ice sheets and glaciers are an important component of projecting sea level rise due to climate change. For models that seek to simulate the full balance of forces within the ice, if portions of the glacier are allowed to quickly break off in a process called iceberg calving, a numerical issue arises that can cause inaccurate results. We examine the issue and propose a solution so that future models can more accurately predict the future behavior of ice sheets and glaciers.
David Parkes and Hugues Goosse
The Cryosphere, 14, 3135–3153, https://doi.org/10.5194/tc-14-3135-2020, https://doi.org/10.5194/tc-14-3135-2020, 2020
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Direct records of glacier changes rarely go back more than the last 100 years and are few and far between. We used a sophisticated glacier model to simulate glacier length changes over the last 1000 years for those glaciers that we do have long-term records of, to determine whether the model can run in a stable, realistic way over a long timescale, reproducing recent observed trends. We find that post-industrial changes are larger than other changes in this time period driven by recent warming.
Eleanor J. Burke, Yu Zhang, and Gerhard Krinner
The Cryosphere, 14, 3155–3174, https://doi.org/10.5194/tc-14-3155-2020, https://doi.org/10.5194/tc-14-3155-2020, 2020
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Permafrost will degrade under future climate change. This will have implications locally for the northern high-latitude regions and may well also amplify global climate change. There have been some recent improvements in the ability of earth system models to simulate the permafrost physical state, but further model developments are required. Models project the thawed volume of soil in the top 2 m of permafrost will increase by 10 %–40 % °C−1 of global mean surface air temperature increase.
Vincent Verjans, Amber A. Leeson, Christopher Nemeth, C. Max Stevens, Peter Kuipers Munneke, Brice Noël, and Jan Melchior van Wessem
The Cryosphere, 14, 3017–3032, https://doi.org/10.5194/tc-14-3017-2020, https://doi.org/10.5194/tc-14-3017-2020, 2020
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Ice sheets are covered by a firn layer, which is the transition stage between fresh snow and ice. Accurate modelling of firn density properties is important in many glaciological aspects. Current models show disagreements, are mostly calibrated to match specific observations of firn density and lack thorough uncertainty analysis. We use a novel calibration method for firn models based on a Bayesian statistical framework, which results in improved model accuracy and in uncertainty evaluation.
Surendra Adhikari, Erik R. Ivins, Eric Larour, Lambert Caron, and Helene Seroussi
The Cryosphere, 14, 2819–2833, https://doi.org/10.5194/tc-14-2819-2020, https://doi.org/10.5194/tc-14-2819-2020, 2020
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The mathematical formalism presented in this paper aims at simplifying computational strategies for tracking ice–ocean mass exchange in the Earth system. To this end, we define a set of generic, and quite simple, descriptions of evolving land, ocean and ice interfaces and present a unified method to compute the sea-level contribution of evolving ice sheets. The formalism can be applied to arbitrary geometries and at all timescales.
John Erich Christian, Alexander A. Robel, Cristian Proistosescu, Gerard Roe, Michelle Koutnik, and Knut Christianson
The Cryosphere, 14, 2515–2535, https://doi.org/10.5194/tc-14-2515-2020, https://doi.org/10.5194/tc-14-2515-2020, 2020
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We use simple, physics-based models to compare how marine-terminating glaciers respond to changes at their marine margin vs. inland surface melt. Initial glacier retreat is more rapid for ocean changes than for inland changes, but in both cases, glaciers will continue responding for millennia. We analyze several implications of these differing pathways of change. In particular, natural ocean variability must be better understood to correctly identify the anthropogenic role in glacier retreat.
Clara Burgard, Dirk Notz, Leif T. Pedersen, and Rasmus T. Tonboe
The Cryosphere, 14, 2369–2386, https://doi.org/10.5194/tc-14-2369-2020, https://doi.org/10.5194/tc-14-2369-2020, 2020
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The high disagreement between observations of Arctic sea ice makes it difficult to evaluate climate models with observations. We investigate the possibility of translating the model state into what a satellite could observe. We find that we do not need complex information about the vertical distribution of temperature and salinity inside the ice but instead are able to assume simplified distributions to reasonably translate the simulated sea ice into satellite
language.
Clara Burgard, Dirk Notz, Leif T. Pedersen, and Rasmus T. Tonboe
The Cryosphere, 14, 2387–2407, https://doi.org/10.5194/tc-14-2387-2020, https://doi.org/10.5194/tc-14-2387-2020, 2020
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The high disagreement between observations of Arctic sea ice inhibits the evaluation of climate models with observations. We develop a tool that translates the simulated Arctic Ocean state into what a satellite could observe from space in the form of brightness temperatures, a measure for the radiation emitted by the surface. We find that the simulated brightness temperatures compare well with the observed brightness temperatures. This tool brings a new perspective for climate model evaluation.
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.
Takehiko Nose, Takuji Waseda, Tsubasa Kodaira, and Jun Inoue
The Cryosphere, 14, 2029–2052, https://doi.org/10.5194/tc-14-2029-2020, https://doi.org/10.5194/tc-14-2029-2020, 2020
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Accurate wave modelling in and near ice-covered ocean requires true sea ice concentration mapping of the model region. The information derived from satellite instruments has considerable uncertainty depending on retrieval algorithms and sensors. This study shows that the accuracy of satellite-retrieved sea ice concentration estimates is a major error source in wave–ice models. A similar feedback effect of sea ice concentration uncertainty may also apply to modelling lower atmospheric conditions.
Alanna V. Alevropoulos-Borrill, Isabel J. Nias, Antony J. Payne, Nicholas R. Golledge, and Rory J. Bingham
The Cryosphere, 14, 1245–1258, https://doi.org/10.5194/tc-14-1245-2020, https://doi.org/10.5194/tc-14-1245-2020, 2020
David M. W. Pritchard, Nathan Forsythe, Greg O'Donnell, Hayley J. Fowler, and Nick Rutter
The Cryosphere, 14, 1225–1244, https://doi.org/10.5194/tc-14-1225-2020, https://doi.org/10.5194/tc-14-1225-2020, 2020
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This study compares different snowpack model configurations applied in the western Himalaya. The results show how even sparse local observations can help to delineate climate input errors from model structure errors, which provides insights into model performance variation. The results also show how interactions between processes affect sensitivities to climate variability in different model configurations, with implications for model selection in climate change projections.
Gong Cheng and Per Lötstedt
The Cryosphere, 14, 673–691, https://doi.org/10.5194/tc-14-673-2020, https://doi.org/10.5194/tc-14-673-2020, 2020
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We present a time-dependent inverse method for ice sheet modeling. By investigating the sensitivity of the observations of the velocity and the height at the surface to the basal conditions of the ice, we show that if the basal parameters are time dependent, then time cannot be ignored in the inversion. By looking at the numerical features, we conclude that adding the height information of an ice sheet in the velocity inversion procedure could improve the robustness of the inference.
Jordi Bolibar, Antoine Rabatel, Isabelle Gouttevin, Clovis Galiez, Thomas Condom, and Eric Sauquet
The Cryosphere, 14, 565–584, https://doi.org/10.5194/tc-14-565-2020, https://doi.org/10.5194/tc-14-565-2020, 2020
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We introduce a novel approach for simulating glacier mass balances using a deep artificial neural network (i.e. deep learning) from climate and topographical data. This has been added as a component of a new open-source parameterized glacier evolution model. Deep learning is found to outperform linear machine learning methods, mainly due to its nonlinearity. Potential applications range from regional mass balance reconstructions from observations to simulations for past and future climates.
Nils Hutter and Martin Losch
The Cryosphere, 14, 93–113, https://doi.org/10.5194/tc-14-93-2020, https://doi.org/10.5194/tc-14-93-2020, 2020
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Sea ice is composed of a multitude of floes that constantly deform due to wind and ocean currents and thereby form leads and pressure ridges. These features are visible in the ice as stripes of open-ocean or high-piled ice. High-resolution sea ice models start to resolve these deformation features. In this paper we present two simulations that agree with satellite data according to a new evaluation metric that detects deformation features and compares their spatial and temporal characteristics.
Grégoire Bobillier, Bastian Bergfeld, Achille Capelli, Jürg Dual, Johan Gaume, Alec van Herwijnen, and Jürg Schweizer
The Cryosphere, 14, 39–49, https://doi.org/10.5194/tc-14-39-2020, https://doi.org/10.5194/tc-14-39-2020, 2020
Michael A. Rawlins, Lei Cai, Svetlana L. Stuefer, and Dmitry Nicolsky
The Cryosphere, 13, 3337–3352, https://doi.org/10.5194/tc-13-3337-2019, https://doi.org/10.5194/tc-13-3337-2019, 2019
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We investigate the changing character of runoff, river discharge and other hydrological elements across watershed draining the North Slope of Alaska over the period 1981–2010. Our synthesis of observations and modeling reveals significant increases in the proportion of subsurface runoff and cold season discharge. These and other changes we describe are consistent with warming and thawing permafrost, and have implications for water, carbon and nutrient cycling in coastal environments.
Julia Eis, Fabien Maussion, and Ben Marzeion
The Cryosphere, 13, 3317–3335, https://doi.org/10.5194/tc-13-3317-2019, https://doi.org/10.5194/tc-13-3317-2019, 2019
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To provide estimates of past glacier mass changes, an adequate initial state is required. However, information about past glacier states at regional or global scales is largely incomplete. Our study presents a new way to initialize the Open Global Glacier Model from past climate information and present-day geometries. We show that even with perfectly known but incomplete boundary conditions, the problem of model initialization leads to nonunique solutions, and we propose an ensemble approach.
Xiaoran Guo, Liyun Zhao, Rupert M. Gladstone, Sainan Sun, and John C. Moore
The Cryosphere, 13, 3139–3153, https://doi.org/10.5194/tc-13-3139-2019, https://doi.org/10.5194/tc-13-3139-2019, 2019
Agnieszka Herman, Sukun Cheng, and Hayley H. Shen
The Cryosphere, 13, 2887–2900, https://doi.org/10.5194/tc-13-2887-2019, https://doi.org/10.5194/tc-13-2887-2019, 2019
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Sea ice interactions with waves are extensively studied in recent years, but mechanisms leading to wave energy attenuation in sea ice remain poorly understood. Close to the ice edge, processes contributing to dissipation include collisions between ice floes and turbulence generated under the ice due to velocity differences between ice and water. This paper analyses details of those processes both theoretically and by means of a numerical model.
Shun Tsutaki, Koji Fujita, Takayuki Nuimura, Akiko Sakai, Shin Sugiyama, Jiro Komori, and Phuntsho Tshering
The Cryosphere, 13, 2733–2750, https://doi.org/10.5194/tc-13-2733-2019, https://doi.org/10.5194/tc-13-2733-2019, 2019
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We investigate thickness change of Bhutanese glaciers during 2004–2011 using repeat GPS surveys and satellite-based observations. The thinning rate of Lugge Glacier (LG) is > 3 times that of Thorthormi Glacier (TG). Numerical simulations of ice dynamics and surface mass balance (SMB) demonstrate that the rapid thinning of LG is driven by both negative SMB and dynamic thinning, while the thinning of TG is minimised by a longitudinally compressive flow regime.
Beatriz Recinos, Fabien Maussion, Timo Rothenpieler, and Ben Marzeion
The Cryosphere, 13, 2657–2672, https://doi.org/10.5194/tc-13-2657-2019, https://doi.org/10.5194/tc-13-2657-2019, 2019
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We have implemented a frontal ablation parameterization into the Open Global Glacier Model and have shown that inversion methods based on mass conservation systematically underestimate the mass turnover (and therefore the thickness) of tidewater glaciers when neglecting frontal ablation. This underestimation can rise up to 19 % on a regional scale. Not accounting for frontal ablation will have an impact on the estimate of the glaciers’ potential contribution to sea level rise.
Johanna Beckmann, Mahé Perrette, Sebastian Beyer, Reinhard Calov, Matteo Willeit, and Andrey Ganopolski
The Cryosphere, 13, 2281–2301, https://doi.org/10.5194/tc-13-2281-2019, https://doi.org/10.5194/tc-13-2281-2019, 2019
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Submarine melting (SM) has been discussed as potentially triggering the recently observed retreat at outlet glaciers in Greenland. How much it may contribute in terms of future sea level rise (SLR) has not been quantified yet. When accounting for SM in our experiments, SLR contribution of 12 outlet glaciers increases by over 3-fold until the year 2100 under RCP8.5. Scaling up from 12 to all of Greenland's outlet glaciers increases future SLR contribution of Greenland by 50 %.
Matt Trevers, Antony J. Payne, Stephen L. Cornford, and Twila Moon
The Cryosphere, 13, 1877–1887, https://doi.org/10.5194/tc-13-1877-2019, https://doi.org/10.5194/tc-13-1877-2019, 2019
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Iceberg calving is a major factor in the retreat of outlet glaciers of the Greenland Ice Sheet. Massive block overturning calving events occur at major outlet glaciers. A major calving event in 2009 was triggered by the release of a smaller block of ice from above the waterline. Using a numerical model, we investigate the feasibility of this mechanism to drive large calving events. We find that relatively small perturbations induce forces large enough to open cracks in ice at the glacier bed.
Vincent Verjans, Amber A. Leeson, C. Max Stevens, Michael MacFerrin, Brice Noël, and Michiel R. van den Broeke
The Cryosphere, 13, 1819–1842, https://doi.org/10.5194/tc-13-1819-2019, https://doi.org/10.5194/tc-13-1819-2019, 2019
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Firn models rely on empirical approaches for representing the percolation and refreezing of meltwater through the firn column. We develop liquid water schemes of different levels of complexity for firn models and compare their performances with respect to observations of density profiles from Greenland. Our results demonstrate that physically advanced water schemes do not lead to better agreement with density observations. Uncertainties in other processes contribute more to model discrepancy.
Evelyn Jäkel, Johannes Stapf, Manfred Wendisch, Marcel Nicolaus, Wolfgang Dorn, and Annette Rinke
The Cryosphere, 13, 1695–1708, https://doi.org/10.5194/tc-13-1695-2019, https://doi.org/10.5194/tc-13-1695-2019, 2019
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The sea ice surface albedo parameterization of a coupled regional climate model was validated against aircraft measurements performed in May–June 2017 north of Svalbard. The albedo parameterization was run offline from the model using the measured parameters surface temperature and snow depth to calculate the surface albedo and the individual fractions of the ice surface subtypes. An adjustment of the variables and additionally accounting for cloud cover reduced the root-mean-squared error.
Leonardus van Kampenhout, Alan M. Rhoades, Adam R. Herrington, Colin M. Zarzycki, Jan T. M. Lenaerts, William J. Sacks, and Michiel R. van den Broeke
The Cryosphere, 13, 1547–1564, https://doi.org/10.5194/tc-13-1547-2019, https://doi.org/10.5194/tc-13-1547-2019, 2019
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A new tool is evaluated in which the climate and surface mass balance (SMB) of the Greenland ice sheet are resolved at 55 and 28 km resolution, while the rest of the globe is modelled at ~110 km. The local refinement of resolution leads to improved accumulation (SMB > 0) compared to observations; however ablation (SMB < 0) is deteriorated in some regions. This is attributed to changes in cloud cover and a reduced effectiveness of a model-specific vertical downscaling technique.
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Short summary
This study investigates the effect of geometrical properties on the stress state and flow regime in the vicinity of the calving front of grounded tidewater glaciers. Our analysis shows that the stress state for simple geometries can be determined solely by the water depth relative to ice thickness. This scaled relationship allows for a simple parametrization to predict calving rates of grounded tidewater glaciers that is simple, physics-based and in good agreement with observations.
This study investigates the effect of geometrical properties on the stress state and flow regime...
