Articles | Volume 17, issue 1
https://doi.org/10.5194/tc-17-309-2023
© Author(s) 2023. 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-17-309-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
23 Jan 2023
Research article |
| 23 Jan 2023
| 23 Jan 2023
The control of short-term ice mélange weakening episodes on calving activity at major Greenland outlet glaciers
Institute of Geography, University of Zurich, 8052 Zurich, Switzerland
Martin P. Lüthi
Institute of Geography, University of Zurich, 8052 Zurich, Switzerland
Andreas Vieli
Institute of Geography, University of Zurich, 8052 Zurich, Switzerland
Related authors
Adrien Wehrlé, Martin P. Lüthi, Andrea Walter, Guillaume Jouvet, and Andreas Vieli
The Cryosphere, 15, 5659–5674, https://doi.org/10.5194/tc-15-5659-2021, https://doi.org/10.5194/tc-15-5659-2021, 2021
Short summary
Short summary
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.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
Short summary
Short summary
This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Alessandro Cicoira, Samuel Weber, Andreas Biri, Ben Buchli, Reynald Delaloye, Reto Da Forno, Isabelle Gärtner-Roer, Stephan Gruber, Tonio Gsell, Andreas Hasler, Roman Lim, Philippe Limpach, Raphael Mayoraz, Matthias Meyer, Jeannette Noetzli, Marcia Phillips, Eric Pointner, Hugo Raetzo, Cristian Scapozza, Tazio Strozzi, Lothar Thiele, Andreas Vieli, Daniel Vonder Mühll, Vanessa Wirz, and Jan Beutel
Earth Syst. Sci. Data, 14, 5061–5091, https://doi.org/10.5194/essd-14-5061-2022, https://doi.org/10.5194/essd-14-5061-2022, 2022
Short summary
Short summary
This paper documents a monitoring network of 54 positions, located on different periglacial landforms in the Swiss Alps: rock glaciers, landslides, and steep rock walls. The data serve basic research but also decision-making and mitigation of natural hazards. It is the largest dataset of its kind, comprising over 209 000 daily positions and additional weather data.
Adrien Wehrlé, Martin P. Lüthi, Andrea Walter, Guillaume Jouvet, and Andreas Vieli
The Cryosphere, 15, 5659–5674, https://doi.org/10.5194/tc-15-5659-2021, https://doi.org/10.5194/tc-15-5659-2021, 2021
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Rémy Mercenier, Martin P. Lüthi, and Andreas Vieli
The Cryosphere, 12, 721–739, https://doi.org/10.5194/tc-12-721-2018, https://doi.org/10.5194/tc-12-721-2018, 2018
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Discipline: Ice sheets | Subject: Greenland
Effects of extreme melt events on ice flow and sea level rise of the Greenland Ice Sheet
Precursor of disintegration of Greenland's largest floating ice tongue
An evaluation of a physics-based firn model and a semi-empirical firn model across the Greenland Ice Sheet (1980–2020)
Subglacial lake activity beneath the ablation zone of the Greenland Ice Sheet
Weekly to monthly terminus variability of Greenland's marine-terminating outlet glaciers
Choice of observation type affects Bayesian calibration of ice sheet model projections
The contribution of Humboldt Glacier, northern Greenland, to sea-level rise through 2100 constrained by recent observations of speedup and retreat
Observed mechanism for sustained glacier retreat and acceleration in response to ocean warming around Greenland
Assessing bare-ice albedo simulated by MAR over the Greenland ice sheet (2000–2021) and implications for meltwater production estimates
Drill-site selection for cosmogenic-nuclide exposure dating of the bed of the Greenland Ice Sheet
A new Level 4 multi-sensor ice surface temperature product for the Greenland Ice Sheet
High-resolution imaging of supraglacial hydrological features on the Greenland Ice Sheet with NASA's Airborne Topographic Mapper (ATM) instrument suite
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate
GBaTSv2: a revised synthesis of the likely basal thermal state of the Greenland Ice Sheet
Unravelling the long-term, locally heterogenous response of Greenland glaciers observed in archival photography
Simulating the Holocene deglaciation across a marine-terminating portion of southwestern Greenland in response to marine and atmospheric forcings
Comparison of ice dynamics using full-Stokes and Blatter–Pattyn approximation: application to the Northeast Greenland Ice Stream
Melt probabilities and surface temperature trends on the Greenland ice sheet using a Gaussian mixture model
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties
Multi-decadal retreat of marine-terminating outlet glaciers in northwest and central-west Greenland
Sources of uncertainty in Greenland surface mass balance in the 21st century
Proper orthogonal decomposition of ice velocity identifies drivers of flow variability at Sermeq Kujalleq (Jakobshavn Isbræ)
Brief communication: A roadmap towards credible projections of ice sheet contribution to sea level
Automated detection and analysis of surface calving waves with a terrestrial radar interferometer at the front of Eqip Sermia, Greenland
Generation and fate of basal meltwater during winter, western Greenland Ice Sheet
Modeling the Greenland englacial stratigraphy
Upstream flow effects revealed in the EastGRIP ice core using Monte Carlo inversion of a two-dimensional ice-flow model
Indication of high basal melting at the EastGRIP drill site on the Northeast Greenland Ice Stream
Brief communication: Reduction in the future Greenland ice sheet surface melt with the help of solar geoengineering
Contrasting regional variability of buried meltwater extent over 2 years across the Greenland Ice Sheet
Sensitivity of the Greenland surface mass and energy balance to uncertainties in key model parameters
Surface melting over the Greenland ice sheet derived from enhanced resolution passive microwave brightness temperatures (1979–2019)
Impact of updated radiative transfer scheme in snow and ice in RACMO2.3p3 on the surface mass and energy budget of the Greenland ice sheet
Winter drainage of surface lakes on the Greenland Ice Sheet from Sentinel-1 SAR imagery
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland
The GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for phase 6 of the Coupled Model Intercomparison Project (ISMIP6) – Part 1: Projections of the Greenland ice sheet evolution by the end of the 21st century
The cooling signature of basal crevasses in a hard-bedded region of the Greenland Ice Sheet
Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough
Large and irreversible future decline of the Greenland ice sheet
GrSMBMIP: intercomparison of the modelled 1980–2012 surface mass balance over the Greenland Ice Sheet
The firn meltwater Retention Model Intercomparison Project (RetMIP): evaluation of nine firn models at four weather station sites on the Greenland ice sheet
Evaluation of a new snow albedo scheme for the Greenland ice sheet in the Regional Atmospheric Climate Model (RACMO2)
Surface velocity of the Northeast Greenland Ice Stream (NEGIS): assessment of interior velocities derived from satellite data by GPS
Intercomparison of surface meltwater routing models for the Greenland ice sheet and influence on subglacial effective pressures
Sensitivity of Greenland ice sheet projections to spatial resolution in higher-order simulations: the Alfred Wegener Institute (AWI) contribution to ISMIP6 Greenland using the Ice-sheet and Sea-level System Model (ISSM)
The future sea-level contribution of the Greenland ice sheet: a multi-model ensemble study of ISMIP6
Present-day and future Greenland Ice Sheet precipitation frequency from CloudSat observations and the Community Earth System Model
The added value of high resolution in estimating the surface mass balance in southern Greenland
Horizontal ice flow impacts the firn structure of Greenland's percolation zone
Brief communication: CESM2 climate forcing (1950–2014) yields realistic Greenland ice sheet surface mass balance
Johanna Beckmann and Ricarda Winkelmann
The Cryosphere, 17, 3083–3099, https://doi.org/10.5194/tc-17-3083-2023, https://doi.org/10.5194/tc-17-3083-2023, 2023
Short summary
Short summary
Over the past decade, Greenland has experienced several extreme melt events.
With progressing climate change, such extreme melt events can be expected to occur more frequently and potentially become more severe and persistent.
Strong melt events may considerably contribute to Greenland's mass loss, which in turn strongly determines future sea level rise. How important these extreme melt events could be in the future is assessed in this study for the first time.
Angelika Humbert, Veit Helm, Niklas Neckel, Ole Zeising, Martin Rückamp, Shfaqat Abbas Khan, Erik Loebel, Jörg Brauchle, Karsten Stebner, Dietmar Gross, Rabea Sondershaus, and Ralf Müller
The Cryosphere, 17, 2851–2870, https://doi.org/10.5194/tc-17-2851-2023, https://doi.org/10.5194/tc-17-2851-2023, 2023
Short summary
Short summary
The largest floating glacier mass in Greenland, the 79° N Glacier, is showing signs of instability. We investigate how crack formation at the glacier's calving front has changed over the last decades by using satellite imagery and airborne data. The calving front is about to lose contact to stabilizing ice islands. Simulations show that the glacier will accelerate as a result of this, leading to an increase in ice discharge of more than 5.1 % if its calving front retreats by 46 %.
Megan Thompson-Munson, Nander Wever, C. Max Stevens, Jan T. M. Lenaerts, and Brooke Medley
The Cryosphere, 17, 2185–2209, https://doi.org/10.5194/tc-17-2185-2023, https://doi.org/10.5194/tc-17-2185-2023, 2023
Short summary
Short summary
To better understand the Greenland Ice Sheet’s firn layer and its ability to buffer sea level rise by storing meltwater, we analyze firn density observations and output from two firn models. We find that both models, one physics-based and one semi-empirical, simulate realistic density and firn air content when compared to observations. The models differ in their representation of firn air content, highlighting the uncertainty in physical processes and the paucity of deep-firn measurements.
Yubin Fan, Chang-Qing Ke, Xiaoyi Shen, Yao Xiao, Stephen J. Livingstone, and Andrew J. Sole
The Cryosphere, 17, 1775–1786, https://doi.org/10.5194/tc-17-1775-2023, https://doi.org/10.5194/tc-17-1775-2023, 2023
Short summary
Short summary
We used the new-generation ICESat-2 altimeter to detect and monitor active subglacial lakes in unprecedented spatiotemporal detail. We created a new inventory of 18 active subglacial lakes as well as their elevation and volume changes during 2019–2020, which provides an improved understanding of how the Greenland subglacial water system operates and how these lakes are fed by water from the ice surface.
Taryn E. Black and Ian Joughin
The Cryosphere, 17, 1–13, https://doi.org/10.5194/tc-17-1-2023, https://doi.org/10.5194/tc-17-1-2023, 2023
Short summary
Short summary
The frontal positions of most ice-sheet-based glaciers in Greenland vary seasonally. On average, these glaciers begin retreating in May and begin advancing in October, and the difference between their most advanced and most retreated positions is 220 m. The timing may be related to the timing of melt on the ice sheet, and the seasonal length variation may be related to glacier speed. These seasonal variations can affect glacier behavior and, consequently, how much ice is lost from the ice sheet.
Denis Felikson, Sophie Nowicki, Isabel Nias, Beata Csatho, Anton Schenk, Michael Croteau, and Bryant Loomis
EGUsphere, https://doi.org/10.5194/egusphere-2022-1213, https://doi.org/10.5194/egusphere-2022-1213, 2022
Short summary
Short summary
We calibrate uncertainty in projections of the Greenland Ice Sheet using velocity change, dynamic thickness change, and mass change observations. We find that the type of observation that is chosen can lead to significantly different calibrated probability distributions. Further work is required to understand how to best calibrate ice sheet projections because this will improve probability distributions of projected sea-level rise, which is crucial for coastal planning and adaptation.
Trevor R. Hillebrand, Matthew J. Hoffman, Mauro Perego, Stephen F. Price, and Ian M. Howat
The Cryosphere, 16, 4679–4700, https://doi.org/10.5194/tc-16-4679-2022, https://doi.org/10.5194/tc-16-4679-2022, 2022
Short summary
Short summary
We estimate that Humboldt Glacier, northern Greenland, will contribute 5.2–8.7 mm to global sea level in 2007–2100, using an ensemble of model simulations constrained by observations of glacier retreat and speedup. This is a significant fraction of the 40–140 mm from the whole Greenland Ice Sheet predicted by the recent ISMIP6 multi-model ensemble, suggesting that calibrating models against observed velocity changes could result in higher estimates of 21st century sea-level rise from Greenland.
Evan Carnahan, Ginny Catania, and Timothy C. Bartholomaus
The Cryosphere, 16, 4305–4317, https://doi.org/10.5194/tc-16-4305-2022, https://doi.org/10.5194/tc-16-4305-2022, 2022
Short summary
Short summary
The Greenland Ice Sheet primarily loses mass through increased ice discharge. We find changes in discharge from outlet glaciers are initiated by ocean warming, which causes a change in the balance of forces resisting gravity and leads to acceleration. Vulnerable conditions for sustained retreat and acceleration are predetermined by the glacier-fjord geometry and exist around Greenland, suggesting increases in ice discharge may be sustained into the future despite a pause in ocean warming.
Raf M. Antwerpen, Marco Tedesco, Xavier Fettweis, Patrick Alexander, and Willem Jan van de Berg
The Cryosphere, 16, 4185–4199, https://doi.org/10.5194/tc-16-4185-2022, https://doi.org/10.5194/tc-16-4185-2022, 2022
Short summary
Short summary
The ice on Greenland has been melting more rapidly over the last few years. Most of this melt comes from the exposure of ice when the overlying snow melts. This ice is darker than snow and absorbs more sunlight, leading to more melt. It remains challenging to accurately simulate the brightness of the ice. We show that the color of ice simulated by Modèle Atmosphérique Régional (MAR) is too bright. We then show that this means that MAR may underestimate how fast the Greenland ice is melting.
Jason P. Briner, Caleb K. Walcott, Joerg M. Schaefer, Nicolás E. Young, Joseph A. MacGregor, Kristin Poinar, Benjamin A. Keisling, Sridhar Anandakrishnan, Mary R. Albert, Tanner Kuhl, and Grant Boeckmann
The Cryosphere, 16, 3933–3948, https://doi.org/10.5194/tc-16-3933-2022, https://doi.org/10.5194/tc-16-3933-2022, 2022
Short summary
Short summary
The 7.4 m of sea level equivalent stored as Greenland ice is getting smaller every year. The uncertain trajectory of ice loss could be better understood with knowledge of the ice sheet's response to past climate change. Within the bedrock below the present-day ice sheet is an archive of past ice-sheet history. We analyze all available data from Greenland to create maps showing where on the ice sheet scientists can drill, using currently available drills, to obtain sub-ice materials.
Ioanna Karagali, Magnus Barfod Suhr, Ruth Mottram, Pia Nielsen-Englyst, Gorm Dybkjær, Darren Ghent, and Jacob L. Høyer
The Cryosphere, 16, 3703–3721, https://doi.org/10.5194/tc-16-3703-2022, https://doi.org/10.5194/tc-16-3703-2022, 2022
Short summary
Short summary
Ice surface temperature (IST) products were used to develop the first multi-sensor, gap-free Level 4 (L4) IST product of the Greenland Ice Sheet (GIS) for 2012, when a significant melt event occurred. For the melt season, mean IST was −15 to −1 °C, and almost the entire GIS experienced at least 1 to 5 melt days. Inclusion of the L4 IST to a surface mass budget (SMB) model improved simulated surface temperatures during the key onset of the melt season, where biases are typically large.
Michael Studinger, Serdar S. Manizade, Matthew A. Linkswiler, and James K. Yungel
The Cryosphere, 16, 3649–3668, https://doi.org/10.5194/tc-16-3649-2022, https://doi.org/10.5194/tc-16-3649-2022, 2022
Short summary
Short summary
The footprint density and high-resolution imagery of airborne surveys reveal details in supraglacial hydrological features that are currently not obtainable from spaceborne data. The accuracy and resolution of airborne measurements complement spaceborne measurements, can support calibration and validation of spaceborne methods, and provide information necessary for process studies of the hydrological system on ice sheets that currently cannot be achieved from spaceborne observations alone.
Tiago Silva, Jakob Abermann, Brice Noël, Sonika Shahi, Willem Jan van de Berg, and Wolfgang Schöner
The Cryosphere, 16, 3375–3391, https://doi.org/10.5194/tc-16-3375-2022, https://doi.org/10.5194/tc-16-3375-2022, 2022
Short summary
Short summary
To overcome internal climate variability, this study uses k-means clustering to combine NAO, GBI and IWV over the Greenland Ice Sheet (GrIS) and names the approach as the North Atlantic influence on Greenland (NAG). With the support of a polar-adapted RCM, spatio-temporal changes on SEB components within NAG phases are investigated. We report atmospheric warming and moistening across all NAG phases as well as large-scale and regional-scale contributions to GrIS mass loss and their interactions.
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, and Michael Studinger
The Cryosphere, 16, 3033–3049, https://doi.org/10.5194/tc-16-3033-2022, https://doi.org/10.5194/tc-16-3033-2022, 2022
Short summary
Short summary
Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known, yet knowing this state is increasingly important to interpret modern changes in ice flow there. We produced a second synthesis of knowledge of the basal thermal state of the ice sheet using airborne and satellite observations and numerical models. About one-third of the ice sheet’s bed is likely thawed; two-fifths is likely frozen; and the remainder is too uncertain to specify.
Michael A. Cooper, Paulina Lewińska, William A. P. Smith, Edwin R. Hancock, Julian A. Dowdeswell, and David M. Rippin
The Cryosphere, 16, 2449–2470, https://doi.org/10.5194/tc-16-2449-2022, https://doi.org/10.5194/tc-16-2449-2022, 2022
Short summary
Short summary
Here we use old photographs gathered several decades ago to expand the temporal record of glacier change in part of East Greenland. This is important because the longer the record of past glacier change, the better we are at predicting future glacier behaviour. Our work also shows that despite all these glaciers retreating, the rate at which they do this varies markedly. It is therefore important to consider outlet glaciers from Greenland individually to take account of this differing behaviour.
Joshua K. Cuzzone, Nicolás E. Young, Mathieu Morlighem, Jason P. Briner, and Nicole-Jeanne Schlegel
The Cryosphere, 16, 2355–2372, https://doi.org/10.5194/tc-16-2355-2022, https://doi.org/10.5194/tc-16-2355-2022, 2022
Short summary
Short summary
We use an ice sheet model to determine what influenced the Greenland Ice Sheet to retreat across a portion of southwestern Greenland during the Holocene (about the last 12 000 years). Our simulations, constrained by observations from geologic markers, show that atmospheric warming and ice melt primarily caused the ice sheet to retreat rapidly across this domain. We find, however, that iceberg calving at the interface where the ice meets the ocean significantly influenced ice mass change.
Martin Rückamp, Thomas Kleiner, and Angelika Humbert
The Cryosphere, 16, 1675–1696, https://doi.org/10.5194/tc-16-1675-2022, https://doi.org/10.5194/tc-16-1675-2022, 2022
Short summary
Short summary
We present a comparative modelling study between the full-Stokes (FS) and Blatter–Pattyn (BP) approximation applied to the Northeast Greenland Ice Stream. Both stress regimes are implemented in one single ice sheet code to eliminate numerical issues. The simulations unveil minor differences in the upper ice stream but become considerable at the grounding line of the 79° North Glacier. Model differences are stronger for a power-law friction than a linear friction law.
Daniel Clarkson, Emma Eastoe, and Amber Leeson
The Cryosphere, 16, 1597–1607, https://doi.org/10.5194/tc-16-1597-2022, https://doi.org/10.5194/tc-16-1597-2022, 2022
Short summary
Short summary
The Greenland ice sheet has seen large amounts of melt in recent years, and accurately modelling temperatures is vital to understand how much of the ice sheet is melting. We estimate the probability of melt from ice surface temperature data to identify which areas of the ice sheet have experienced melt and estimate temperature quantiles. Our results suggest that for large areas of the ice sheet, melt has become more likely over the past 2 decades and high temperatures are also becoming warmer.
Benjamin Joseph Davison, Tom Cowton, Andrew Sole, Finlo Cottier, and Pete Nienow
The Cryosphere, 16, 1181–1196, https://doi.org/10.5194/tc-16-1181-2022, https://doi.org/10.5194/tc-16-1181-2022, 2022
Short summary
Short summary
The ocean is an important driver of Greenland glacier retreat. Icebergs influence ocean temperature in the vicinity of glaciers, which will affect glacier retreat rates, but the effect of icebergs on water temperature is poorly understood. In this study, we use a model to show that icebergs cause large changes to water properties next to Greenland's glaciers, which could influence ocean-driven glacier retreat around Greenland.
Taryn E. Black and Ian Joughin
The Cryosphere, 16, 807–824, https://doi.org/10.5194/tc-16-807-2022, https://doi.org/10.5194/tc-16-807-2022, 2022
Short summary
Short summary
We used satellite images to create a comprehensive record of annual glacier change in northwest Greenland from 1972 through 2021. We found that nearly all glaciers in our study area have retreated and glacier retreat accelerated from around 1996. Comparing these results with climate data, we found that glacier retreat is most sensitive to water runoff and moderately sensitive to ocean temperatures. These can affect glacier fronts in several ways, so no process clearly dominates glacier retreat.
Katharina M. Holube, Tobias Zolles, and Andreas Born
The Cryosphere, 16, 315–331, https://doi.org/10.5194/tc-16-315-2022, https://doi.org/10.5194/tc-16-315-2022, 2022
Short summary
Short summary
We simulated the surface mass balance of the Greenland Ice Sheet in the 21st century by forcing a snow model with the output of many Earth system models and four greenhouse gas emission scenarios. We quantify the contribution to uncertainty in surface mass balance of these two factors and the choice of parameters of the snow model. The results show that the differences between Earth system models are the main source of uncertainty. This effect is localised mostly near the equilibrium line.
David W. Ashmore, Douglas W. F. Mair, Jonathan E. Higham, Stephen Brough, James M. Lea, and Isabel J. Nias
The Cryosphere, 16, 219–236, https://doi.org/10.5194/tc-16-219-2022, https://doi.org/10.5194/tc-16-219-2022, 2022
Short summary
Short summary
In this paper we explore the use of a transferrable and flexible statistical technique to try and untangle the multiple influences on marine-terminating glacier dynamics, as measured from space. We decompose a satellite-derived ice velocity record into ranked sets of static maps and temporal coefficients. We present evidence that the approach can identify velocity variability mainly driven by changes in terminus position and velocity variation mainly driven by subglacial hydrological processes.
Andy Aschwanden, Timothy C. Bartholomaus, Douglas J. Brinkerhoff, and Martin Truffer
The Cryosphere, 15, 5705–5715, https://doi.org/10.5194/tc-15-5705-2021, https://doi.org/10.5194/tc-15-5705-2021, 2021
Short summary
Short summary
Estimating how much ice loss from Greenland and Antarctica will contribute to sea level rise is of critical societal importance. However, our analysis shows that recent efforts are not trustworthy because the models fail at reproducing contemporary ice melt. Here we present a roadmap towards making more credible estimates of ice sheet melt.
Adrien Wehrlé, Martin P. Lüthi, Andrea Walter, Guillaume Jouvet, and Andreas Vieli
The Cryosphere, 15, 5659–5674, https://doi.org/10.5194/tc-15-5659-2021, https://doi.org/10.5194/tc-15-5659-2021, 2021
Short summary
Short summary
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.
Joel Harper, Toby Meierbachtol, Neil Humphrey, Jun Saito, and Aidan Stansberry
The Cryosphere, 15, 5409–5421, https://doi.org/10.5194/tc-15-5409-2021, https://doi.org/10.5194/tc-15-5409-2021, 2021
Short summary
Short summary
We use surface and borehole measurements to investigate the generation and fate of basal meltwater in the ablation zone of western Greenland. The rate of basal meltwater generation at borehole study sites increases by up to 20 % over the winter period. Accommodation of all basal meltwater by expansion of isolated subglacial cavities is implausible. Other sinks for water do not likely balance basal meltwater generation, implying water evacuation through a connected drainage system in winter.
Andreas Born and Alexander Robinson
The Cryosphere, 15, 4539–4556, https://doi.org/10.5194/tc-15-4539-2021, https://doi.org/10.5194/tc-15-4539-2021, 2021
Short summary
Short summary
Ice penetrating radar reflections from the Greenland ice sheet are the best available record of past accumulation and how these layers have been deformed over time by the flow of ice. Direct simulations of this archive hold great promise for improving our models and for uncovering details of ice sheet dynamics that neither models nor data could achieve alone. We present the first three-dimensional ice sheet model that explicitly simulates individual layers of accumulation and how they deform.
Tamara Annina Gerber, Christine Schøtt Hvidberg, Sune Olander Rasmussen, Steven Franke, Giulia Sinnl, Aslak Grinsted, Daniela Jansen, and Dorthe Dahl-Jensen
The Cryosphere, 15, 3655–3679, https://doi.org/10.5194/tc-15-3655-2021, https://doi.org/10.5194/tc-15-3655-2021, 2021
Short summary
Short summary
We simulate the ice flow in the onset region of the Northeast Greenland Ice Stream to determine the source area and past accumulation rates of ice found in the EastGRIP ice core. This information is required to correct for bias in ice-core records introduced by the upstream flow effects. Our results reveal that the increasing accumulation rate with increasing upstream distance is predominantly responsible for the constant annual layer thicknesses observed in the upper 900 m of the ice core.
Ole Zeising and Angelika Humbert
The Cryosphere, 15, 3119–3128, https://doi.org/10.5194/tc-15-3119-2021, https://doi.org/10.5194/tc-15-3119-2021, 2021
Short summary
Short summary
Greenland’s largest ice stream – the Northeast Greenland Ice Stream (NEGIS) – extends far into the interior of the ice sheet. Basal meltwater acts as a lubricant for glaciers and sustains sliding. Hence, observations of basal melt rates are of high interest. We performed two time series of precise ground-based radar measurements in the upstream region of NEGIS and found high melt rates of 0.19 ± 0.04 m per year.
Xavier Fettweis, Stefan Hofer, Roland Séférian, Charles Amory, Alison Delhasse, Sébastien Doutreloup, Christoph Kittel, Charlotte Lang, Joris Van Bever, Florent Veillon, and Peter Irvine
The Cryosphere, 15, 3013–3019, https://doi.org/10.5194/tc-15-3013-2021, https://doi.org/10.5194/tc-15-3013-2021, 2021
Short summary
Short summary
Without any reduction in our greenhouse gas emissions, the Greenland ice sheet surface mass loss can be brought in line with a medium-mitigation emissions scenario by reducing the solar downward flux at the top of the atmosphere by 1.5 %. In addition to reducing global warming, these solar geoengineering measures also dampen the well-known positive melt–albedo feedback over the ice sheet by 6 %. However, only stronger reductions in solar radiation could maintain a stable ice sheet in 2100.
Devon Dunmire, Alison F. Banwell, Nander Wever, Jan T. M. Lenaerts, and Rajashree Tri Datta
The Cryosphere, 15, 2983–3005, https://doi.org/10.5194/tc-15-2983-2021, https://doi.org/10.5194/tc-15-2983-2021, 2021
Short summary
Short summary
Here, we automatically detect buried lakes (meltwater lakes buried below layers of snow) across the Greenland Ice Sheet, providing insight into a poorly studied meltwater feature. For 2018 and 2019, we compare areal extent of buried lakes. We find greater buried lake extent in 2019, especially in northern Greenland, which we attribute to late-summer surface melt and high autumn temperatures. We also provide evidence that buried lakes form via different processes across Greenland.
Tobias Zolles and Andreas Born
The Cryosphere, 15, 2917–2938, https://doi.org/10.5194/tc-15-2917-2021, https://doi.org/10.5194/tc-15-2917-2021, 2021
Short summary
Short summary
We investigate the sensitivity of a glacier surface mass and the energy balance model of the Greenland ice sheet for the cold period of the Last Glacial Maximum (LGM) and the present-day climate. The results show that the model sensitivity changes with climate. While for present-day simulations inclusions of sublimation and hoar formation are of minor importance, they cannot be neglected during the LGM. To simulate the surface mass balance over long timescales, a water vapor scheme is necessary.
Paolo Colosio, Marco Tedesco, Roberto Ranzi, and Xavier Fettweis
The Cryosphere, 15, 2623–2646, https://doi.org/10.5194/tc-15-2623-2021, https://doi.org/10.5194/tc-15-2623-2021, 2021
Short summary
Short summary
We use a new satellite dataset to study the spatiotemporal evolution of surface melting over Greenland at an enhanced resolution of 3.125 km. Using meteorological data and the MAR model, we observe that a dynamic algorithm can best detect surface melting. We found that the melting season is elongating, the melt extent is increasing and that high-resolution data better describe the spatiotemporal evolution of the melting season, which is crucial to improve estimates of sea level rise.
Christiaan T. van Dalum, Willem Jan van de Berg, and Michiel R. van den Broeke
The Cryosphere, 15, 1823–1844, https://doi.org/10.5194/tc-15-1823-2021, https://doi.org/10.5194/tc-15-1823-2021, 2021
Short summary
Short summary
Absorption of solar radiation is often limited to the surface in regional climate models. Therefore, we have implemented a new radiative transfer scheme in the model RACMO2, which allows for internal heating and improves the surface reflectivity. Here, we evaluate its impact on the surface mass and energy budget and (sub)surface temperature, by using observations and the previous model version for the Greenland ice sheet. New results match better with observations and introduce subsurface melt.
Corinne L. Benedek and Ian C. Willis
The Cryosphere, 15, 1587–1606, https://doi.org/10.5194/tc-15-1587-2021, https://doi.org/10.5194/tc-15-1587-2021, 2021
Short summary
Short summary
The surface of the Greenland Ice Sheet contains thousands of surface lakes. These lakes can deliver water through cracks to the ice sheet base and influence the speed of ice flow. Here we look at instances of lakes draining in the middle of winter using the Sentinel-1 radar satellites. Winter-draining lakes can help us understand the mechanisms for lake drainages throughout the year and can point to winter movement of water that will impact our understanding of ice sheet hydrology.
Nathan Maier, Florent Gimbert, Fabien Gillet-Chaulet, and Adrien Gilbert
The Cryosphere, 15, 1435–1451, https://doi.org/10.5194/tc-15-1435-2021, https://doi.org/10.5194/tc-15-1435-2021, 2021
Short summary
Short summary
In Greenland, ice motion and the surface geometry depend on the friction at the bed. We use satellite measurements and modeling to determine how ice speeds and friction are related across the ice sheet. The relationships indicate that ice flowing over bed bumps sets the friction across most of the ice sheet's on-land regions. This result helps simplify and improve our understanding of how ice motion will change in the future.
Aurélien Quiquet and Christophe Dumas
The Cryosphere, 15, 1015–1030, https://doi.org/10.5194/tc-15-1015-2021, https://doi.org/10.5194/tc-15-1015-2021, 2021
Short summary
Short summary
We present here the GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for CMIP6 for Greenland. The project aims to quantify the ice sheet contribution to global sea level rise for the next century. We show an important spread in the simulated Greenland ice loss in the future depending on the climate forcing used. Mass loss is primarily driven by atmospheric warming, while oceanic forcing contributes to a relatively smaller uncertainty in our simulations.
Ian E. McDowell, Neil F. Humphrey, Joel T. Harper, and Toby W. Meierbachtol
The Cryosphere, 15, 897–907, https://doi.org/10.5194/tc-15-897-2021, https://doi.org/10.5194/tc-15-897-2021, 2021
Short summary
Short summary
Ice temperature controls rates of internal deformation and the onset of basal sliding. To identify heat transfer mechanisms and englacial heat sources within Greenland's ablation zone, we examine a 2–3-year continuous temperature record from nine full-depth boreholes. Thermal decay after basal crevasses release heat in the near-basal ice likely produces the observed cooling. Basal crevasses in Greenland can affect the basal ice rheology and indicate a potentially complex basal hydrologic system.
Ingrid Leirvik Olsen, Tom Arne Rydningen, Matthias Forwick, Jan Sverre Laberg, and Katrine Husum
The Cryosphere, 14, 4475–4494, https://doi.org/10.5194/tc-14-4475-2020, https://doi.org/10.5194/tc-14-4475-2020, 2020
Short summary
Short summary
We present marine geoscientific data from Store Koldewey Trough, one of the largest glacial troughs offshore NE Greenland, to reconstruct the ice drainage pathways, ice sheet extent and ice stream dynamics of this sector during the last glacial and deglaciation. The complex landform assemblage in the trough reflects a dynamic retreat with several periods of stabilization and readvances, interrupting the deglaciation. Estimates indicate that the ice front locally retreated between 80–400 m/year.
Jonathan M. Gregory, Steven E. George, and Robin S. Smith
The Cryosphere, 14, 4299–4322, https://doi.org/10.5194/tc-14-4299-2020, https://doi.org/10.5194/tc-14-4299-2020, 2020
Short summary
Short summary
Melting of the Greenland ice sheet as a consequence of global warming could raise global-mean sea level by up to 7 m. We have studied this using a newly developed computer model. With recent climate maintained, sea level would rise by 0.5–2.5 m over many millennia due to Greenland ice loss: the warmer the climate, the greater the sea level rise. Beyond about 3.5 m it would become partially irreversible. In order to avoid this outcome, anthropogenic climate change must be reversed soon enough.
Xavier Fettweis, Stefan Hofer, Uta Krebs-Kanzow, Charles Amory, Teruo Aoki, Constantijn J. Berends, Andreas Born, Jason E. Box, Alison Delhasse, Koji Fujita, Paul Gierz, Heiko Goelzer, Edward Hanna, Akihiro Hashimoto, Philippe Huybrechts, Marie-Luise Kapsch, Michalea D. King, Christoph Kittel, Charlotte Lang, Peter L. Langen, Jan T. M. Lenaerts, Glen E. Liston, Gerrit Lohmann, Sebastian H. Mernild, Uwe Mikolajewicz, Kameswarrao Modali, Ruth H. Mottram, Masashi Niwano, Brice Noël, Jonathan C. Ryan, Amy Smith, Jan Streffing, Marco Tedesco, Willem Jan van de Berg, Michiel van den Broeke, Roderik S. W. van de Wal, Leo van Kampenhout, David Wilton, Bert Wouters, Florian Ziemen, and Tobias Zolles
The Cryosphere, 14, 3935–3958, https://doi.org/10.5194/tc-14-3935-2020, https://doi.org/10.5194/tc-14-3935-2020, 2020
Short summary
Short summary
We evaluated simulated Greenland Ice Sheet surface mass balance from 5 kinds of models. While the most complex (but expensive to compute) models remain the best, the faster/simpler models also compare reliably with observations and have biases of the same order as the regional models. Discrepancies in the trend over 2000–2012, however, suggest that large uncertainties remain in the modelled future SMB changes as they are highly impacted by the meltwater runoff biases over the current climate.
Baptiste Vandecrux, Ruth Mottram, Peter L. Langen, Robert S. Fausto, Martin Olesen, C. Max Stevens, Vincent Verjans, Amber Leeson, Stefan Ligtenberg, Peter Kuipers Munneke, Sergey Marchenko, Ward van Pelt, Colin R. Meyer, Sebastian B. Simonsen, Achim Heilig, Samira Samimi, Shawn Marshall, Horst Machguth, Michael MacFerrin, Masashi Niwano, Olivia Miller, Clifford I. Voss, and Jason E. Box
The Cryosphere, 14, 3785–3810, https://doi.org/10.5194/tc-14-3785-2020, https://doi.org/10.5194/tc-14-3785-2020, 2020
Short summary
Short summary
In the vast interior of the Greenland ice sheet, snow accumulates into a thick and porous layer called firn. Each summer, the firn retains part of the meltwater generated at the surface and buffers sea-level rise. In this study, we compare nine firn models traditionally used to quantify this retention at four sites and evaluate their performance against a set of in situ observations. We highlight limitations of certain model designs and give perspectives for future model development.
Christiaan T. van Dalum, Willem Jan van de Berg, Stef Lhermitte, and Michiel R. van den Broeke
The Cryosphere, 14, 3645–3662, https://doi.org/10.5194/tc-14-3645-2020, https://doi.org/10.5194/tc-14-3645-2020, 2020
Short summary
Short summary
The reflectivity of sunlight, which is also known as albedo, is often inadequately modeled in regional climate models. Therefore, we have implemented a new snow and ice albedo scheme in the regional climate model RACMO2. In this study, we evaluate a new RACMO2 version for the Greenland ice sheet by using observations and the previous model version. RACMO2 output compares well with observations, and by including new processes we improve the ability of RACMO2 to make future climate projections.
Christine S. Hvidberg, Aslak Grinsted, Dorthe Dahl-Jensen, Shfaqat Abbas Khan, Anders Kusk, Jonas Kvist Andersen, Niklas Neckel, Anne Solgaard, Nanna B. Karlsson, Helle Astrid Kjær, and Paul Vallelonga
The Cryosphere, 14, 3487–3502, https://doi.org/10.5194/tc-14-3487-2020, https://doi.org/10.5194/tc-14-3487-2020, 2020
Short summary
Short summary
The Northeast Greenland Ice Stream (NEGIS) extends around 600 km from its onset in the interior of Greenland to the coast. Several maps of surface velocity and topography in Greenland exist, but accuracy is limited due to the lack of validation data. Here we present results from a 5-year GPS survey in an interior section of NEGIS. We use the data to assess a list of satellite-derived ice velocity and surface elevation products and discuss the implications for the ice stream flow in the area.
Kang Yang, Aleah Sommers, Lauren C. Andrews, Laurence C. Smith, Xin Lu, Xavier Fettweis, and Manchun Li
The Cryosphere, 14, 3349–3365, https://doi.org/10.5194/tc-14-3349-2020, https://doi.org/10.5194/tc-14-3349-2020, 2020
Short summary
Short summary
This study compares hourly supraglacial moulin discharge simulations from three surface meltwater routing models. Results show that these models are superior to simply using regional climate model runoff without routing, but different routing models, different-spatial-resolution DEMs, and parameterized seasonal evolution of supraglacial stream and river networks induce significant variability in diurnal moulin discharges and corresponding subglacial effective pressures.
Martin Rückamp, Heiko Goelzer, and Angelika Humbert
The Cryosphere, 14, 3309–3327, https://doi.org/10.5194/tc-14-3309-2020, https://doi.org/10.5194/tc-14-3309-2020, 2020
Short summary
Short summary
Estimates of future sea-level contribution from the Greenland ice sheet have a large uncertainty based on different origins. We conduct numerical experiments to test the sensitivity of Greenland ice sheet projections to spatial resolution. Simulations with a higher resolution unveil up to 5 % more sea-level rise compared to coarser resolutions. The sensitivity depends on the magnitude of outlet glacier retreat. When no retreat is enforced, the sensitivity exhibits an inverse behaviour.
Heiko Goelzer, Sophie Nowicki, Anthony Payne, Eric Larour, Helene Seroussi, William H. Lipscomb, Jonathan Gregory, Ayako Abe-Ouchi, Andrew Shepherd, Erika Simon, Cécile Agosta, Patrick Alexander, Andy Aschwanden, Alice Barthel, Reinhard Calov, Christopher Chambers, Youngmin Choi, Joshua Cuzzone, Christophe Dumas, Tamsin Edwards, Denis Felikson, Xavier Fettweis, Nicholas R. Golledge, Ralf Greve, Angelika Humbert, Philippe Huybrechts, Sebastien Le clec'h, Victoria Lee, Gunter Leguy, Chris Little, Daniel P. Lowry, Mathieu Morlighem, Isabel Nias, Aurelien Quiquet, Martin Rückamp, Nicole-Jeanne Schlegel, Donald A. Slater, Robin S. Smith, Fiamma Straneo, Lev Tarasov, Roderik van de Wal, and Michiel van den Broeke
The Cryosphere, 14, 3071–3096, https://doi.org/10.5194/tc-14-3071-2020, https://doi.org/10.5194/tc-14-3071-2020, 2020
Short summary
Short summary
In this paper we use a large ensemble of Greenland ice sheet models forced by six different global climate models to project ice sheet changes and sea-level rise contributions over the 21st century.
The results for two different greenhouse gas concentration scenarios indicate that the Greenland ice sheet will continue to lose mass until 2100, with contributions to sea-level rise of 90 ± 50 mm and 32 ± 17 mm for the high (RCP8.5) and low (RCP2.6) scenario, respectively.
Jan T. M. Lenaerts, M. Drew Camron, Christopher R. Wyburn-Powell, and Jennifer E. Kay
The Cryosphere, 14, 2253–2265, https://doi.org/10.5194/tc-14-2253-2020, https://doi.org/10.5194/tc-14-2253-2020, 2020
Willem Jan van de Berg, Erik van Meijgaard, and Lambertus H. van Ulft
The Cryosphere, 14, 1809–1827, https://doi.org/10.5194/tc-14-1809-2020, https://doi.org/10.5194/tc-14-1809-2020, 2020
Short summary
Short summary
In times of increasing computer power, atmospheric models that estimate the surface mass balance of the Greenland can be run with increasing resolution. However, at which resolution is the error no longer determined by the lacking resolution but by model shortcomings? In this manuscript we show that for the majority of the southern part of the Greenland Ice Sheet, our study area, a model resolution of 20 km is sufficient although finer model resolutions are still beneficial.
Rosemary Leone, Joel Harper, Toby Meierbachtol, and Neil Humphrey
The Cryosphere, 14, 1703–1712, https://doi.org/10.5194/tc-14-1703-2020, https://doi.org/10.5194/tc-14-1703-2020, 2020
Short summary
Short summary
Horizontal ice flow transports the firn layer of Greenland’s Percolation Zone as it undergoes burial by accumulation. Here we show that the firn density and temperature fields can reflect horizontal advection of the firn column across climate gradients, the magnitude of which varies around the ice sheet. Further, time series of melt features in ice cores from the percolation zone can contain a signature from ice motion that should not be conflated with that from climate change.
Brice Noël, Leonardus van Kampenhout, Willem Jan van de Berg, Jan T. M. Lenaerts, Bert Wouters, and Michiel R. van den Broeke
The Cryosphere, 14, 1425–1435, https://doi.org/10.5194/tc-14-1425-2020, https://doi.org/10.5194/tc-14-1425-2020, 2020
Short summary
Short summary
We present a reconstruction of historical (1950–2014) surface mass balance of the Greenland ice sheet using the Community Earth System Model (CESM2; ~111 km) to force a high-resolution regional climate model (RACMO2; ~11 km), which is further refined to 1 km spatial resolution. For the first time, an Earth-system-model-based product, assimilating no observations, can reconstruct realistic historical ice sheet surface mass balance as well as the mass loss acceleration that started in the 1990s.
Cited articles
Amundson, J., Truffer, M., Lüthi, M. P., Fahnestock, M., Motyka, R. J., and
West, M.: Glacier, fjord, and seismic response to recent large calving
events, Jakobshavn Isbræ, Greenland, Geophys. Res. Lett.,
35, L22501, https://doi.org/10.1029/2008GL035281, 2008. a
Amundson, J. M. and Burton, J. C.: Quasi-Static Granular Flow of Ice
Mélange, J. Geophys. Res.-Earth Surf., 123, 2243–2257,
https://doi.org/10.1029/2018jf004685, 2018. a
Amundson, J. M., Fahnestock, M., Truffer, M., Brown, J., Lüthi, M., and
Motyka, R.: Ice mélange dynamics and implications for terminus stability,
Jakobshavn Isbræ, Greenland, J. Geophys. Res, 115, F01005,
https://doi.org/10.1029/2009JF001405, 2010a. a
Amundson, J. M., Fahnestock, M., Truffer, M., Brown, J., Lüthi, M. P., and
Motyka, R. J.: Ice mélange dynamics and implications for terminus
stability, Jakobshavn Isbræ, Greenland, J. Geophys. Res., 115, F01005,
https://doi.org/10.1029/2009JF001405, 2010b. a
Brough, S., Carr, J. R., Ross, N., and Lea, J. M.: Exceptional Retreat of
Kangerlussuaq Glacier, East Greenland, Between 2016 and 2018, Front.
Earth Sci., 7, 123, https://doi.org/10.3389/feart.2019.00123, 2019. a
Burton, J. C., Amundson, J. M., Cassotto, R., Kuo, C.-C., and Dennin, M.:
Quantifying Flow and Stress in Ice mélange, the World's Largest Granular
Material, P. Natl. Acad. Sci. USA, 115, 5105–5110,
https://doi.org/10.1073/pnas.1715136115, 2018. a
Cassotto, R., Fahnestock, M., Amundson, J. M., Truffer, M., and Joughin, I.:
Seasonal and Interannual Variations in Ice Melange and Its Impact on Terminus
Stability, Jakobshavn Isbræ, Greenland, J. Glaciol., 61,
76–88, https://doi.org/10.3189/2015jog13j235, 2015. a, b
Cassotto, R. K., Burton, J. C., Amundson, J. M., Fahnestock, M. A., and
Truffer, M.: Granular decoherence precedes ice mélange failure and
glacier calving at Jakobshavn Isbræ, Nat. Geosci., 14, 417–422,
2021. a
Cook, S., Rutt, I. C., Murray, T., Luckman, A., Zwinger, T., Selmes, N., Goldsack, A., and James, T. D.: Modelling environmental influences on calving at Helheim Glacier in eastern Greenland, The Cryosphere, 8, 827–841, https://doi.org/10.5194/tc-8-827-2014, 2014. a, b
Dupont, T. and Alley, R.: Assessment of the importance of ice-shelf buttressing
to ice-sheet flow, Geophys. Res. Lett., 32, L04503,
https://doi.org/10.1029/2004GL022024, 2005. a
Eik, K.: Iceberg drift modelling and validation of applied metocean hindcast
data, Cold Reg. Sci. Technol., 57, 67–90,
https://doi.org/10.1016/j.coldregions.2009.02.009, 2009. a
ESA: Copernicus Sentinel data, https://scihub.copernicus.eu (last access: 19 January 2023),
2022. a
FitzMaurice, A., Straneo, F., Cenedese, C., and Andres, M.: Effect of a sheared
flow on iceberg motion and melting, Geophys. Res. Lett., 43, 12–520,
https://doi.org/10.1002/2016gl071602, 2016. a
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A.,
Muñoz‐Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D.,
Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P.,
Biavati, G., Bidlot, J., Bonavita, M., Chiara, G., Dahlgren, P., Dee, D.,
Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer,
A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M.,
Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., Rosnay, P.,
Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.: The ERA5 global
reanalysis, Q. J. Roy. Meteor. Soc., 146,
1999–2049, https://doi.org/10.1002/qj.3803, 2020. a
Howat, I. M., Joughin, I., Tulaczyk, S., and Gogineni, S.: Rapid retreat and
acceleration of Helheim Glacier, east Greenland, Geophys. Res.
Lett., 32, L22502, https://doi.org/10.1029/2005GL024737, 2005. a
Howat, I. M., Joughin, I., Fahnestock, M., Smith, B. E., and Scambos, T. A.:
Synchronous retreat and acceleration of southeast Greenland outlet glaciers
2000–06: ice dynamics and coupling to climate, J. Glaciol., 54,
646–660, 2008. a
Howat, I. M., Box, J. E., Ahn, Y., Herrington, A., and McFadden, E. M.:
Seasonal variability in the dynamics of marine-terminating outlet glaciers in
Greenland, J. Glaciol., 56, 601–613,
https://doi.org/10.3189/002214310793146232, 2010. a
Hughes, K. G.: Pathways, Form Drag, and Turbulence in Simulations of an Ocean
Flowing Through an Ice Mélange, J. Geophys. Res.-Oceans,
127, e2021JC018228, https://doi.org/10.1029/2021jc018228, 2022. a
Jensen, H. J.: Self-Organized Criticality, Lecture notes in Physics, Cambridge
University Press, 1998. a
Joughin: MEaSUREs Greenland 6 and 12 day Ice Sheet Velocity Mosaics from SAR,
Version 1, Boulder, Colorado USA, NASA National Snow and Ice Data Center
Distributed Active Archive Center [data set], https://doi.org/10.5067/6JKYGMOZQFYJ, 2021. a
Joughin, I., Howat, I. M., Fahnestock, M., Smith, B., Krabill, W., Alley,
R. B., Stern, H., and Truffer, M.: Continued evolution of Jakobshavn
Isbrae following its rapid speedup, J. Geophys. Res., 113,
F04006, https://doi.org/10.1029/2008JF001023, 2008. a
Joughin, I., Smith, B. E., Shean, D. E., and Floricioiu, D.: Brief Communication: Further summer speedup of Jakobshavn Isbræ, The Cryosphere, 8, 209–214, https://doi.org/10.5194/tc-8-209-2014, 2014. a
Khan, S. A., Kjeldsen, K. K., Kjær, K. H., Bevan, S., Luckman, A., Aschwanden, A., Bjørk, A. A., Korsgaard, N. J., Box, J. E., van den Broeke, M., van Dam, T. M., and Fitzner, A.: Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age, The Cryosphere, 8, 1497–1507, https://doi.org/10.5194/tc-8-1497-2014, 2014. a
Khazendar, A., Fenty, I. G., Carroll, D., Gardner, A., Lee, C. M., Fukumori,
I., Wang, O., Zhang, H., Seroussi, H., Moller, D., Noël, B. P. Y., van
den Broeke, M. R., Dinardo, S., and Willis, J.: Interruption of two decades
of Jakobshavn Isbræ acceleration and thinning as regional ocean
cools, Nat. Geosci., 12, 277–283, https://doi.org/10.1038/s41561-019-0329-3,
2019. a
Kjeldsen, K. K., Korsgaard, N. J., Bjørk, A. A., Khan, S. A., Box, J. E.,
Funder, S., Larsen, N. K., Bamber, J. L., Colgan, W., van den Broeke, M.,
Siggaard-Andersen, M.-L., Nuth, C., Schomacker, A., Andresen, C. S.,
Willerslev, E., and Kjær, K. H.: Spatial and Temporal Distribution of
Mass Loss From the Greenland Ice Sheet Since AD 1900, Nature, 528,
396–400, https://doi.org/10.1038/nature16183, 2015. a
Krug, J., Durand, G., Gagliardini, O., and Weiss, J.: Modelling the impact of submarine frontal melting and ice mélange on glacier dynamics, The Cryosphere, 9, 989–1003, https://doi.org/10.5194/tc-9-989-2015, 2015. a
Lu, W., Amdahl, J., Lubbad, R., Yu, Z., and Løset, S.: Glacial ice impacts:
Part I: Wave-driven motion and small glacial ice feature impacts, Marine
Struct., 75, 102850, https://doi.org/10.1016/j.marstruc.2020.102850, 2021. a
Luckman, A., Murray, T., de Lange, R., and Hanna, E.: Rapid and synchronous
ice-dynamic changes in East Greenland, Geophys. Res. Lett., 33,
L03503, https://doi.org/10.1029/2005GL025428, 2006. a, b
Lüthi, M. P.: BRIMM, a simple fjord melange dynamics model (srht/master github/master e3ae4f91446e28b94b28b131b59e8a8fd756f8af), Zenodo [code], https://doi.org/10.5281/zenodo.7548884, 2023a. a
Lüthi, M. P.: BRIMM, https://github.com/MartinLuethi/BRIMM, GitHub [code], last access: 19 January 2023b. a
Moon, T., Joughin, I., and Smith, B.: Seasonal to multiyear variability of
glacier surface velocity, terminus position, and sea ice/ice mélange in
northwest Greenland, J. Geophys. Res.-Earth Surf., 120,
818–833, 2015. a
Murray, T., Scharrer, K., James, T. D., Dye, S. R., Hanna, E., Booth, A. D.,
Selmes, N., Luckman, A., Hughes, A. L. C., Cook, S., and Huybrechts, P.:
Ocean regulation hypothesis for glacier dynamics in southeast Greenland and
implications for ice sheet mass changes, J. Geophys. Res.,
115, F3, https://doi.org/10.1029/2009jf001522, 2010. a
Nick, F., Van der Veen, C., Vieli, A., and Benn, D.: A physically based
calving model applied to marine outlet glaciers and implications for the
glacier dynamics, J. Glaciol., 56, 781–794, 2010. a
Rignot, E. and Kanagaratnam, P.: Changes in the Velocity Structure of the
Greenland Ice Sheet, Science, 311, 986–990,
https://doi.org/10.1126/science.1121381, 2006. a
Robel, A. A.: Thinning sea ice weakens buttressing force of iceberg mélange
and promotes calving, Nat. Commun., 8, 1–7, https://doi.org/10.1038/ncomms14596,
2017. a, b, c
Sentinel Hub: Modified Copernicus Sentinel data 2022/Sentinel Hub,
https://www.sentinel-hub.com (last access: 19 January 2023), 2022. a
Shepherd, A., Ivins, E., Rignot, E., Smith, B., van Den Broeke, M., Velicogna,
I., Whitehouse, P., Briggs, K., Joughin, I., Krinner, G., et al.: Mass
balance of the Greenland Ice Sheet from 1992 to 2018, Nature, 579, 233–239,
2020. a
Sohn, H.-G., Jezek, K. C., and Van der Veen, C. J.: Jakobshavn Glacier,
West Greenland: 30 years of spaceborne observations, J.
Geophys. Res., 25, 2699–2702, https://doi.org/10.1029/98GL01973, 1998. a
Stearns, L. A. and Hamilton, G. S.: Rapid volume loss from two East Greenland
outlet glaciers quantified using repeat stereo satellite imagery, Geophys.
Res. Lett., 34, 5, https://doi.org/10.1029/2006gl028982, 2007. a
Sutherland, D. A., Straneo, F., and Pickart, R. S.: Characteristics and
dynamics of two major Greenland glacial fjords, J. Geophys.
Res.-Oceans, 119, 3767–3791, https://doi.org/10.1002/2013jc009786, 2014.
a, b
Todd, J. and Christoffersen, P.: Are seasonal calving dynamics forced by buttressing from ice mélange or undercutting by melting? Outcomes from full-Stokes simulations of Store Glacier, West Greenland, The Cryosphere, 8, 2353–2365, https://doi.org/10.5194/tc-8-2353-2014, 2014. a, b
Walter, A., Lüthi, M. P., and Vieli, A.: Calving event size measurements and statistics of Eqip Sermia, Greenland, from terrestrial radar interferometry, The Cryosphere, 14, 1051–1066, https://doi.org/10.5194/tc-14-1051-2020, 2020. a
Walter, J. I., Box, J. E., Tulaczyk, S., Brodsky, E. E., Howat, I. M., Ahn, Y.,
and Brown, A.: Oceanic mechanical forcing of a marine-terminating Greenland
glacier, Ann. Glaciol., 53, 181–192, https://doi.org/10.3189/2012aog60a083,
2012. a, b
Wehrlé, A.: AdrienWehrle/earthspy: v0.3.0 (v0.3.0), Zenodo [code], https://doi.org/10.5281/zenodo.7498876, 2023a. a
Wehrlé, A.: Greenland_ice_melange, Zenodo [data set], https://doi.org/10.5281/zenodo.7499245, 2023c. a
Wehrlé, A., Lüthi, M. P., Walter, A., Jouvet, G., and Vieli, A.: Automated detection and analysis of surface calving waves with a terrestrial radar interferometer at the front of Eqip Sermia, Greenland, The Cryosphere, 15, 5659–5674, https://doi.org/10.5194/tc-15-5659-2021, 2021. a
Weidick, A. and Bennike, O.: Quaternary glaciation history and glaciology of
Jakobshavn Isbræ and the Disko Bugt region, West Greenland: a
review, Tech. Rep. 14, Geological Survey of Denmark and Greenland Bulletin,
ISBN 978-87-7871-207-3, 2007. a
Williams, J. J., Gourmelen, N., Nienow, P., Bunce, C., and Slater, D.: Helheim
Glacier Poised for Dramatic Retreat, Geophys. Res. Lett., 48, e2021GL094546,
https://doi.org/10.1029/2021gl094546, 2021. a
Xie, S., Dixon, T. H., Holland, D. M., Voytenko, D., and Vaňková, I.:
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial
mélange, Nat. Commun., 10, 3250,
https://doi.org/10.1038/s41467-019-10908-4, 2019. a, b, c
Short summary
We characterized short-lived episodes of ice mélange weakening (IMW) at the front of three major Greenland outlet glaciers. Through a continuous detection at the front of Kangerdlugssuaq Glacier during the June-to-September period from 2018 to 2021, we found that 87 % of the IMW episodes occurred prior to a large-scale calving event. Using a simple model for ice mélange motion, we further characterized the IMW process as self-sustained through the existence of an IMW–calving feedback.
We characterized short-lived episodes of ice mélange weakening (IMW) at the front of three...
