Articles | Volume 17, issue 2
https://doi.org/10.5194/tc-17-789-2023
© 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-17-789-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Feb 2023
Research article |
| 16 Feb 2023
| 16 Feb 2023
Evaluating Greenland surface-mass-balance and firn-densification data using ICESat-2 altimetry
Polar Science
Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98122, USA
Brooke Medley
Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center,
Greenbelt, MD 20771, USA
Xavier Fettweis
Spheres research unit, Geography, University of Liège, Liège,
Belgium
Tyler Sutterley
Polar Science
Center, Applied Physics Laboratory, University of Washington, Seattle, WA 98122, USA
Patrick Alexander
Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY
10964, USA
NASA Goddard Institute for Space Studies, New York, NY 10025, USA
David Porter
Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY
10964, USA
Marco Tedesco
Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY
10964, USA
NASA Goddard Institute for Space Studies, New York, NY 10025, USA
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D. N. Goldberg, P. Heimbach, I. Joughin, and B. Smith
The Cryosphere, 9, 2429–2446, https://doi.org/10.5194/tc-9-2429-2015, https://doi.org/10.5194/tc-9-2429-2015, 2015
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I. M. Howat, C. Porter, M. J. Noh, B. E. Smith, and S. Jeong
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R. T. W. L. Hurkmans, J. L. Bamber, C. H. Davis, I. R. Joughin, K. S. Khvorostovsky, B. S. Smith, and N. Schoen
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D. Callens, K. Matsuoka, D. Steinhage, B. Smith, E. Witrant, and F. Pattyn
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M. J. Siegert, N. Ross, H. Corr, B. Smith, T. Jordan, R. G. Bingham, F. Ferraccioli, D. M. Rippin, and A. Le Brocq
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Weiran Li, Stef Lhermitte, Bert Wouters, Cornelis Slobbe, Max Brils, and Xavier Fettweis
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Due to the melt events in recent decades, the snow condition over Greenland has been changed. To observe this, we use a parameter (leading edge width; LeW) derived from satellite altimetry, and analyse its spatial and temporal variations. By comparing the LeW variations with modelled firn parameters, we concluded that the 2012 melt event has a long-lasting impact on the volume scattering of Greenland firn. This impact cannot fully recover due to the recent and more frequent melt events.
Sylvie Charbit, Christophe Dumas, Fabienne Maignan, Catherine Ottlé, Nina Raoult, Xavier Fettweis, and Philippe Conesa
The Cryosphere, 18, 5067–5099, https://doi.org/10.5194/tc-18-5067-2024, https://doi.org/10.5194/tc-18-5067-2024, 2024
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The evolution of the Greenland ice sheet is highly dependent on surface melting and therefore on the processes operating at the snow–atmosphere interface and within the snow cover. Here we present new developments to apply a snow model to the Greenland ice sheet. The performance of this model is analysed in terms of its ability to simulate ablation processes. Our analysis shows that the model performs well when compared with the MAR regional polar atmospheric model.
Allison M. Chartrand, Ian M. Howat, Ian R. Joughin, and Benjamin E. Smith
The Cryosphere, 18, 4971–4992, https://doi.org/10.5194/tc-18-4971-2024, https://doi.org/10.5194/tc-18-4971-2024, 2024
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This study uses high-resolution remote-sensing data to show that shrinking of the West Antarctic Thwaites Glacier’s ice shelf (floating extension) is exacerbated by several sub-ice-shelf meltwater channels that form as the glacier transitions from full contact with the seafloor to fully floating. In mapping these channels, the position of the transition zone, and thinning rates of the Thwaites Glacier, this work elucidates important processes driving its rapid contribution to sea level rise.
Horst Machguth, Andrew Tedstone, Peter Kuipers Munneke, Max Brils, Brice Noël, Nicole Clerx, Nicolas Jullien, Xavier Fettweis, and Michiel van den Broeke
EGUsphere, https://doi.org/10.5194/egusphere-2024-2750, https://doi.org/10.5194/egusphere-2024-2750, 2024
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Due to increasing air temperatures, surface melt expands to higher elevations on the Greenland ice sheet. This is visible on satellite imagery in the form of rivers of meltwater running across the surface of the ice sheet. We compare model results of meltwater at high elevations on the ice sheet to satellite observations. We find that each of the models shows strengths and weaknesses. A detailed look into the model results reveals potential reasons for the differences between models.
Marissa E. Dattler, Brooke Medley, and C. Max Stevens
The Cryosphere, 18, 3613–3631, https://doi.org/10.5194/tc-18-3613-2024, https://doi.org/10.5194/tc-18-3613-2024, 2024
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We developed an algorithm based on combining models and satellite observations to identify the presence of surface melt on the Antarctic Ice Sheet. We find that this method works similarly to previous methods by assessing 13 sites and the Larsen C ice shelf. Unlike previous methods, this algorithm is based on physical parameters, and updates to this method could allow the meltwater present on the Antarctic Ice Sheet to be quantified instead of simply detected.
Jean-François Grailet, Robin J. Hogan, Nicolas Ghilain, Xavier Fettweis, and Marilaure Grégoire
EGUsphere, https://doi.org/10.5194/egusphere-2024-1858, https://doi.org/10.5194/egusphere-2024-1858, 2024
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The MAR model is a regional climate model used for weather forecasting and studying the climate over various regions. This paper presents an update of MAR thanks to which it can decompose solar radiation into various ranges. In particular, MAR can now simulate precisely solar radiation in the ultraviolet and photosynthesis ranges, both being critical to human health and ecosystems. As a first application of this new capability, this paper presents a method for predicting UV indices with MAR.
Michael Studinger, Benjamin E. Smith, Nathan Kurtz, Alek Petty, Tyler Sutterley, and Rachel Tilling
The Cryosphere, 18, 2625–2652, https://doi.org/10.5194/tc-18-2625-2024, https://doi.org/10.5194/tc-18-2625-2024, 2024
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We use green lidar data and natural-color imagery over sea ice to quantify elevation biases potentially impacting estimates of change in ice thickness of the polar regions. We complement our analysis using a model of scattering of light in snow and ice that predicts the shape of lidar waveforms reflecting from snow and ice surfaces based on the shape of the transmitted pulse. We find that biased elevations exist in airborne and spaceborne data products from green lidars.
Alison Delhasse, Johanna Beckmann, Christoph Kittel, and Xavier Fettweis
The Cryosphere, 18, 633–651, https://doi.org/10.5194/tc-18-633-2024, https://doi.org/10.5194/tc-18-633-2024, 2024
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Aiming to study the long-term influence of an extremely warm climate in the Greenland Ice Sheet contribution to sea level rise, a new regional atmosphere–ice sheet model setup was established. The coupling, explicitly considering the melt–elevation feedback, is compared to an offline method to consider this feedback. We highlight mitigation of the feedback due to local changes in atmospheric circulation with changes in surface topography, making the offline correction invalid on the margins.
Baptiste Vandecrux, Robert S. Fausto, Jason E. Box, Federico Covi, Regine Hock, Åsa K. Rennermalm, Achim Heilig, Jakob Abermann, Dirk van As, Elisa Bjerre, Xavier Fettweis, Paul C. J. P. Smeets, Peter Kuipers Munneke, Michiel R. van den Broeke, Max Brils, Peter L. Langen, Ruth Mottram, and Andreas P. Ahlstrøm
The Cryosphere, 18, 609–631, https://doi.org/10.5194/tc-18-609-2024, https://doi.org/10.5194/tc-18-609-2024, 2024
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How fast is the Greenland ice sheet warming? In this study, we compiled 4500+ temperature measurements at 10 m below the ice sheet surface (T10m) from 1912 to 2022. We trained a machine learning model on these data and reconstructed T10m for the ice sheet during 1950–2022. After a slight cooling during 1950–1985, the ice sheet warmed at a rate of 0.7 °C per decade until 2022. Climate models showed mixed results compared to our observations and underestimated the warming in key regions.
Idunn Aamnes Mostue, Stefan Hofer, Trude Storelvmo, and Xavier Fettweis
The Cryosphere, 18, 475–488, https://doi.org/10.5194/tc-18-475-2024, https://doi.org/10.5194/tc-18-475-2024, 2024
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The latest generation of climate models (Coupled Model Intercomparison Project Phase 6 – CMIP6) warm more over Greenland and the Arctic and thus also project a larger mass loss from the Greenland Ice Sheet (GrIS) compared to the previous generation of climate models (CMIP5). Our work suggests for the first time that part of the greater mass loss in CMIP6 over the GrIS is driven by a difference in the surface mass balance sensitivity from a change in cloud representation in the CMIP6 models.
Wenwen Li, Chia-Yu Hsu, and Marco Tedesco
EGUsphere, https://doi.org/10.5194/egusphere-2023-2831, https://doi.org/10.5194/egusphere-2023-2831, 2024
Preprint withdrawn
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This review paper fills a knowledge gap in comprehensive literature review at the junction of AI-Arctic sea ice research. We provide a fine-grained review of AI applications in a variety of sea ice research domains. Based on these analyses, we point out exciting opportunities where the Arctic sea ice community can continue benefiting from cutting-edge AI. These future research directions will foster the continuous growth of the Arctic sea ice–AI research community.
Laura J. Dietrich, Hans Christian Steen-Larsen, Sonja Wahl, Anne-Katrine Faber, and Xavier Fettweis
The Cryosphere, 18, 289–305, https://doi.org/10.5194/tc-18-289-2024, https://doi.org/10.5194/tc-18-289-2024, 2024
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The contribution of the humidity flux to the surface mass balance in the accumulation zone of the Greenland Ice Sheet is uncertain. Here, we evaluate the regional climate model MAR using a multi-annual dataset of eddy covariance measurements and bulk estimates of the humidity flux. The humidity flux largely contributes to the summer surface mass balance (SMB) in the accumulation zone, indicating its potential importance for the annual SMB in a warming climate.
Marco Tedesco, Paolo Colosio, Xavier Fettweis, and Guido Cervone
The Cryosphere, 17, 5061–5074, https://doi.org/10.5194/tc-17-5061-2023, https://doi.org/10.5194/tc-17-5061-2023, 2023
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We developed a technique to improve the outputs of a model that calculates the gain and loss of Greenland and consequently its contribution to sea level rise. Our technique generates “sharper” images of the maps generated by the model to better understand and quantify where losses occur. This has implications for improving models, understanding what drives the contributions of Greenland to sea level rise, and more.
Damien Maure, Christoph Kittel, Clara Lambin, Alison Delhasse, and Xavier Fettweis
The Cryosphere, 17, 4645–4659, https://doi.org/10.5194/tc-17-4645-2023, https://doi.org/10.5194/tc-17-4645-2023, 2023
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The Arctic is warming faster than the rest of the Earth. Studies have already shown that Greenland and the Canadian Arctic are experiencing a record increase in melting rates, while Svalbard has been relatively less impacted. Looking at those regions but also extending the study to Iceland and the Russian Arctic archipelagoes, we see a heterogeneity in the melting-rate response to the Arctic warming, with the Russian archipelagoes experiencing lower melting rates than other regions.
Prateek Gantayat, Alison F. Banwell, Amber A. Leeson, James M. Lea, Dorthe Petersen, Noel Gourmelen, and Xavier Fettweis
Geosci. Model Dev., 16, 5803–5823, https://doi.org/10.5194/gmd-16-5803-2023, https://doi.org/10.5194/gmd-16-5803-2023, 2023
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We developed a new supraglacial hydrology model for the Greenland Ice Sheet. This model simulates surface meltwater routing, meltwater drainage, supraglacial lake (SGL) overflow, and formation of lake ice. The model was able to reproduce 80 % of observed lake locations and provides a good match between the observed and modelled temporal evolution of SGLs.
Benjamin Smith, Michael Studinger, Tyler Sutterley, Zachary Fair, and Thomas Neumann
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-147, https://doi.org/10.5194/tc-2023-147, 2023
Revised manuscript under review for TC
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This study investigates errors (biases) that may result when green lasers are used to measure the elevation of glaciers and ice sheets. These biases are important because if the snow or ice on top of the ice sheet changes, it can make the elevation of the ice appear to change by the wrong amount. We measure these biases over the Greenland Ice Sheet with a laser system on an airplane, and explore how the use of satellite data can let us correct for the biases.
Thomas Dethinne, Quentin Glaude, Ghislain Picard, Christoph Kittel, Patrick Alexander, Anne Orban, and Xavier Fettweis
The Cryosphere, 17, 4267–4288, https://doi.org/10.5194/tc-17-4267-2023, https://doi.org/10.5194/tc-17-4267-2023, 2023
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We investigate the sensitivity of the regional climate model
Modèle Atmosphérique Régional(MAR) to the assimilation of wet-snow occurrence estimated by remote sensing datasets. The assimilation is performed by nudging the MAR snowpack temperature. The data assimilation is performed over the Antarctic Peninsula for the 2019–2021 period. The results show an increase in the melt production (+66.7 %) and a decrease in surface mass balance (−4.5 %) of the model for the 2019–2020 melt season.
Haokui Xu, Brooke Medley, Leung Tsang, Joel T. Johnson, Kenneth C. Jezek, Macro Brogioni, and Lars Kaleschke
The Cryosphere, 17, 2793–2809, https://doi.org/10.5194/tc-17-2793-2023, https://doi.org/10.5194/tc-17-2793-2023, 2023
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The density profile of polar ice sheets is a major unknown in estimating the mass loss using lidar tomography methods. In this paper, we show that combing the active radar data and passive radiometer data can provide an estimation of density properties using the new model we implemented in this paper. The new model includes the short and long timescale variations in the firn and also the refrozen layers which are not included in the previous modeling work.
Eric Keenan, Nander Wever, Jan T. M. Lenaerts, and Brooke Medley
Geosci. Model Dev., 16, 3203–3219, https://doi.org/10.5194/gmd-16-3203-2023, https://doi.org/10.5194/gmd-16-3203-2023, 2023
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Ice sheets gain mass via snowfall. However, snowfall is redistributed by the wind, resulting in accumulation differences of up to a factor of 5 over distances as short as 5 km. These differences complicate estimates of ice sheet contribution to sea level rise. For this reason, we have developed a new model for estimating wind-driven snow redistribution on ice sheets. We show that, over Pine Island Glacier in West Antarctica, the model improves estimates of snow accumulation variability.
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
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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.
Inès N. Otosaka, Andrew Shepherd, Erik R. Ivins, Nicole-Jeanne Schlegel, Charles Amory, Michiel R. van den Broeke, Martin Horwath, Ian Joughin, Michalea D. King, Gerhard Krinner, Sophie Nowicki, Anthony J. Payne, Eric Rignot, Ted Scambos, Karen M. Simon, Benjamin E. Smith, Louise S. Sørensen, Isabella Velicogna, Pippa L. Whitehouse, Geruo A, Cécile Agosta, Andreas P. Ahlstrøm, Alejandro Blazquez, William Colgan, Marcus E. Engdahl, Xavier Fettweis, Rene Forsberg, Hubert Gallée, Alex Gardner, Lin Gilbert, Noel Gourmelen, Andreas Groh, Brian C. Gunter, Christopher Harig, Veit Helm, Shfaqat Abbas Khan, Christoph Kittel, Hannes Konrad, Peter L. Langen, Benoit S. Lecavalier, Chia-Chun Liang, Bryant D. Loomis, Malcolm McMillan, Daniele Melini, Sebastian H. Mernild, Ruth Mottram, Jeremie Mouginot, Johan Nilsson, Brice Noël, Mark E. Pattle, William R. Peltier, Nadege Pie, Mònica Roca, Ingo Sasgen, Himanshu V. Save, Ki-Weon Seo, Bernd Scheuchl, Ernst J. O. Schrama, Ludwig Schröder, Sebastian B. Simonsen, Thomas Slater, Giorgio Spada, Tyler C. Sutterley, Bramha Dutt Vishwakarma, Jan Melchior van Wessem, David Wiese, Wouter van der Wal, and Bert Wouters
Earth Syst. Sci. Data, 15, 1597–1616, https://doi.org/10.5194/essd-15-1597-2023, https://doi.org/10.5194/essd-15-1597-2023, 2023
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By measuring changes in the volume, gravitational attraction, and ice flow of Greenland and Antarctica from space, we can monitor their mass gain and loss over time. Here, we present a new record of the Earth’s polar ice sheet mass balance produced by aggregating 50 satellite-based estimates of ice sheet mass change. This new assessment shows that the ice sheets have lost (7.5 x 1012) t of ice between 1992 and 2020, contributing 21 mm to sea level rise.
Jilu Li, Fernando Rodriguez-Morales, Xavier Fettweis, Oluwanisola Ibikunle, Carl Leuschen, John Paden, Daniel Gomez-Garcia, and Emily Arnold
The Cryosphere, 17, 175–193, https://doi.org/10.5194/tc-17-175-2023, https://doi.org/10.5194/tc-17-175-2023, 2023
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Alaskan glaciers' loss of ice mass contributes significantly to ocean surface rise. It is important to know how deeply and how much snow accumulates on these glaciers to comprehend and analyze the glacial mass loss process. We reported the observed seasonal snow depth distribution from our radar data taken in Alaska in 2018 and 2021, developed a method to estimate the annual snow accumulation rate at Mt. Wrangell caldera, and identified transition zones from wet-snow zones to ablation zones.
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
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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.
Brooke Medley, Thomas A. Neumann, H. Jay Zwally, Benjamin E. Smith, and C. Max Stevens
The Cryosphere, 16, 3971–4011, https://doi.org/10.5194/tc-16-3971-2022, https://doi.org/10.5194/tc-16-3971-2022, 2022
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Satellite altimeters measure the height or volume change over Earth's ice sheets, but in order to understand how that change translates into ice mass, we must account for various processes at the surface. Specifically, snowfall events generate large, transient increases in surface height, yet snow fall has a relatively low density, which means much of that height change is composed of air. This air signal must be removed from the observed height changes before we can assess ice mass change.
Christoph Kittel, Charles Amory, Stefan Hofer, Cécile Agosta, Nicolas C. Jourdain, Ella Gilbert, Louis Le Toumelin, Étienne Vignon, Hubert Gallée, and Xavier Fettweis
The Cryosphere, 16, 2655–2669, https://doi.org/10.5194/tc-16-2655-2022, https://doi.org/10.5194/tc-16-2655-2022, 2022
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Model projections suggest large differences in future Antarctic surface melting even for similar greenhouse gas scenarios and warming rates. We show that clouds containing a larger amount of liquid water lead to stronger melt. As surface melt can trigger the collapse of the ice shelves (the safety band of the Antarctic Ice Sheet), clouds could be a major source of uncertainties in projections of sea level rise.
Sébastien Doutreloup, Xavier Fettweis, Ramin Rahif, Essam Elnagar, Mohsen S. Pourkiaei, Deepak Amaripadath, and Shady Attia
Earth Syst. Sci. Data, 14, 3039–3051, https://doi.org/10.5194/essd-14-3039-2022, https://doi.org/10.5194/essd-14-3039-2022, 2022
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This data set provides historical (1980–2014) and future (2015–2100) weather data for 12 cities in Belgium. This data set is intended for architects or building or energy designers. In particular, it makes available to all users hourly open-access weather data according to certain standards to recreate a Typical and an Extreme Meteorological Year. In addition, it provides hourly data on heatwaves from 1980 to 2100. Weather data were produced from the outputs of the MAR model simulations.
Karen E. Alley, Christian T. Wild, Adrian Luckman, Ted A. Scambos, Martin Truffer, Erin C. Pettit, Atsuhiro Muto, Bruce Wallin, Marin Klinger, Tyler Sutterley, Sarah F. Child, Cyrus Hulen, Jan T. M. Lenaerts, Michelle Maclennan, Eric Keenan, and Devon Dunmire
The Cryosphere, 15, 5187–5203, https://doi.org/10.5194/tc-15-5187-2021, https://doi.org/10.5194/tc-15-5187-2021, 2021
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We present a 20-year, satellite-based record of velocity and thickness change on the Thwaites Eastern Ice Shelf (TEIS), the largest remaining floating extension of Thwaites Glacier (TG). TG holds the single greatest control on sea-level rise over the next few centuries, so it is important to understand changes on the TEIS, which controls much of TG's flow into the ocean. Our results suggest that the TEIS is progressively destabilizing and is likely to disintegrate over the next few decades.
Kenneth D. Mankoff, Xavier Fettweis, Peter L. Langen, Martin Stendel, Kristian K. Kjeldsen, Nanna B. Karlsson, Brice Noël, Michiel R. van den Broeke, Anne Solgaard, William Colgan, Jason E. Box, Sebastian B. Simonsen, Michalea D. King, Andreas P. Ahlstrøm, Signe Bech Andersen, and Robert S. Fausto
Earth Syst. Sci. Data, 13, 5001–5025, https://doi.org/10.5194/essd-13-5001-2021, https://doi.org/10.5194/essd-13-5001-2021, 2021
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We estimate the daily mass balance and its components (surface, marine, and basal mass balance) for the Greenland ice sheet. Our time series begins in 1840 and has annual resolution through 1985 and then daily from 1986 through next week. Results are operational (updated daily) and provided for the entire ice sheet or by commonly used regions or sectors. This is the first input–output mass balance estimate to include the basal mass balance.
Ruth Mottram, Nicolaj Hansen, Christoph Kittel, J. Melchior van Wessem, Cécile Agosta, Charles Amory, Fredrik Boberg, Willem Jan van de Berg, Xavier Fettweis, Alexandra Gossart, Nicole P. M. van Lipzig, Erik van Meijgaard, Andrew Orr, Tony Phillips, Stuart Webster, Sebastian B. Simonsen, and Niels Souverijns
The Cryosphere, 15, 3751–3784, https://doi.org/10.5194/tc-15-3751-2021, https://doi.org/10.5194/tc-15-3751-2021, 2021
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We compare the calculated surface mass budget (SMB) of Antarctica in five different regional climate models. On average ~ 2000 Gt of snow accumulates annually, but different models vary by ~ 10 %, a difference equivalent to ± 0.5 mm of global sea level rise. All models reproduce observed weather, but there are large differences in regional patterns of snowfall, especially in areas with very few observations, giving greater uncertainty in Antarctic mass budget than previously identified.
Louis Le Toumelin, Charles Amory, Vincent Favier, Christoph Kittel, Stefan Hofer, Xavier Fettweis, Hubert Gallée, and Vinay Kayetha
The Cryosphere, 15, 3595–3614, https://doi.org/10.5194/tc-15-3595-2021, https://doi.org/10.5194/tc-15-3595-2021, 2021
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Snow is frequently eroded from the surface by the wind in Adelie Land (Antarctica) and suspended in the lower atmosphere. By performing model simulations, we show firstly that suspended snow layers interact with incoming radiation similarly to a near-surface cloud. Secondly, suspended snow modifies the atmosphere's thermodynamic structure and energy exchanges with the surface. Our results suggest snow transport by the wind should be taken into account in future model studies over the region.
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
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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.
David J. Purnell, Natalya Gomez, William Minarik, David Porter, and Gregory Langston
Earth Surf. Dynam., 9, 673–685, https://doi.org/10.5194/esurf-9-673-2021, https://doi.org/10.5194/esurf-9-673-2021, 2021
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We present a new technique for precisely monitoring water levels (e.g. sea level, rivers or lakes) using low-cost equipment (approximately USD 100–200) that is simple to build and install. The technique builds on previous work using antennas that were designed for navigation purposes. Multiple antennas in the same location are used to obtain more precise measurements than those obtained when using a single antenna. Software for analysis is provided with the article.
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
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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.
Charles Amory, Christoph Kittel, Louis Le Toumelin, Cécile Agosta, Alison Delhasse, Vincent Favier, and Xavier Fettweis
Geosci. Model Dev., 14, 3487–3510, https://doi.org/10.5194/gmd-14-3487-2021, https://doi.org/10.5194/gmd-14-3487-2021, 2021
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This paper presents recent developments in the drifting-snow scheme of the regional climate model MAR and its application to simulate drifting snow and the surface mass balance of Adélie Land in East Antarctica. The model is extensively described and evaluated against a multi-year drifting-snow dataset and surface mass balance estimates available in the area. The model sensitivity to input parameters and improvements over a previously published version are also assessed.
Matthew G. Cooper, Laurence C. Smith, Asa K. Rennermalm, Marco Tedesco, Rohi Muthyala, Sasha Z. Leidman, Samiah E. Moustafa, and Jessica V. Fayne
The Cryosphere, 15, 1931–1953, https://doi.org/10.5194/tc-15-1931-2021, https://doi.org/10.5194/tc-15-1931-2021, 2021
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We measured sunlight transmitted into glacier ice to improve models of glacier ice melt and satellite measurements of glacier ice surfaces. We found that very small concentrations of impurities inside the ice increase absorption of sunlight, but the amount was small enough to enable an estimate of ice absorptivity. We confirmed earlier results that the absorption minimum is near 390 nm. We also found that a layer of highly reflective granular "white ice" near the surface reduces transmittance.
Christoph Kittel, Charles Amory, Cécile Agosta, Nicolas C. Jourdain, Stefan Hofer, Alison Delhasse, Sébastien Doutreloup, Pierre-Vincent Huot, Charlotte Lang, Thierry Fichefet, and Xavier Fettweis
The Cryosphere, 15, 1215–1236, https://doi.org/10.5194/tc-15-1215-2021, https://doi.org/10.5194/tc-15-1215-2021, 2021
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The future surface mass balance (SMB) of the Antarctic ice sheet (AIS) will influence the ice dynamics and the contribution of the ice sheet to the sea level rise. We investigate the AIS sensitivity to different warmings using physical and statistical downscaling of CMIP5 and CMIP6 models. Our results highlight a contrasting effect between the grounded ice sheet (where the SMB is projected to increase) and ice shelves (where the future SMB depends on the emission scenario).
Eric Keenan, Nander Wever, Marissa Dattler, Jan T. M. Lenaerts, Brooke Medley, Peter Kuipers Munneke, and Carleen Reijmer
The Cryosphere, 15, 1065–1085, https://doi.org/10.5194/tc-15-1065-2021, https://doi.org/10.5194/tc-15-1065-2021, 2021
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Snow density is required to convert observed changes in ice sheet volume into mass, which ultimately drives ice sheet contribution to sea level rise. However, snow properties respond dynamically to wind-driven redistribution. Here we include a new wind-driven snow density scheme into an existing snow model. Our results demonstrate an improved representation of snow density when compared to observations and can therefore be used to improve retrievals of ice sheet mass balance.
Tessa Gorte, Jan T. M. Lenaerts, and Brooke Medley
The Cryosphere, 14, 4719–4733, https://doi.org/10.5194/tc-14-4719-2020, https://doi.org/10.5194/tc-14-4719-2020, 2020
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In this paper, we analyze several spatial and temporal criteria to assess the ability of models in the CMIP5 and CMIP6 frameworks to recreate past Antarctic surface mass balance. We then compared a subset of the top performing models to all remaining models to refine future surface mass balance predictions under different forcing scenarios. We found that the top performing models predict lower surface mass balance by 2100, indicating less buffering than otherwise expected of sea level rise.
Andrew O. Hoffman, Knut Christianson, Daniel Shapero, Benjamin E. Smith, and Ian Joughin
The Cryosphere, 14, 4603–4609, https://doi.org/10.5194/tc-14-4603-2020, https://doi.org/10.5194/tc-14-4603-2020, 2020
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The West Antarctic Ice Sheet has long been considered geometrically prone to collapse, and Thwaites Glacier, the largest glacier in the Amundsen Sea, is likely in the early stages of disintegration. Using observations of Thwaites Glacier velocity and elevation change, we show that the transport of ~2 km3 of water beneath Thwaites Glacier has only a small and transient effect on glacier speed relative to ongoing thinning driven by ocean melt.
Martin Ménégoz, Evgenia Valla, Nicolas C. Jourdain, Juliette Blanchet, Julien Beaumet, Bruno Wilhelm, Hubert Gallée, Xavier Fettweis, Samuel Morin, and Sandrine Anquetin
Hydrol. Earth Syst. Sci., 24, 5355–5377, https://doi.org/10.5194/hess-24-5355-2020, https://doi.org/10.5194/hess-24-5355-2020, 2020
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The study investigates precipitation changes in the Alps, using observations and a 7 km resolution climate simulation over 1900–2010. An increase in mean precipitation is found in winter over the Alps, whereas a drying occurred in summer in the surrounding plains. A general increase in the daily annual maximum of precipitation is evidenced (20 to 40 % per century), suggesting an increase in extreme events that is significant only when considering long time series, typically 50 to 80 years.
Kenneth D. Mankoff, Brice Noël, Xavier Fettweis, Andreas P. Ahlstrøm, William Colgan, Ken Kondo, Kirsty Langley, Shin Sugiyama, Dirk van As, and Robert S. Fausto
Earth Syst. Sci. Data, 12, 2811–2841, https://doi.org/10.5194/essd-12-2811-2020, https://doi.org/10.5194/essd-12-2811-2020, 2020
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This work partitions regional climate model (RCM) runoff from the MAR and RACMO RCMs to hydrologic outlets at the ice margin and coast. Temporal resolution is daily from 1959 through 2019. Spatial grid is ~ 100 m, resolving individual streams. In addition to discharge at outlets, we also provide the streams, outlets, and basin geospatial data, as well as a script to query and access the geospatial or time series discharge data from the data files.
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
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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.
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
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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.
Michael Studinger, Brooke C. Medley, Kelly M. Brunt, Kimberly A. Casey, Nathan T. Kurtz, Serdar S. Manizade, Thomas A. Neumann, and Thomas B. Overly
The Cryosphere, 14, 3287–3308, https://doi.org/10.5194/tc-14-3287-2020, https://doi.org/10.5194/tc-14-3287-2020, 2020
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We use repeat airborne geophysical data consisting of laser altimetry, snow, and Ku-band radar and optical imagery to analyze the spatial and temporal variability in surface roughness, slope, wind deposition, and snow accumulation at 88° S. We find small–scale variability in snow accumulation based on the snow radar subsurface layering, indicating areas of strong wind redistribution are prevalent at 88° S. There is no slope–independent relationship between surface roughness and accumulation.
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
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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.
Tom A. Jordan, David Porter, Kirsty Tinto, Romain Millan, Atsuhiro Muto, Kelly Hogan, Robert D. Larter, Alastair G. C. Graham, and John D. Paden
The Cryosphere, 14, 2869–2882, https://doi.org/10.5194/tc-14-2869-2020, https://doi.org/10.5194/tc-14-2869-2020, 2020
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Linking ocean and ice sheet processes allows prediction of sea level change. Ice shelves form a floating buffer between the ice–ocean systems, but the water depth beneath is often a mystery, leaving a critical blind spot in our understanding of how these systems interact. Here, we use airborne measurements of gravity to reveal the bathymetry under the ice shelves flanking the rapidly changing Thwaites Glacier and adjacent glacier systems, providing new insights and data for future models.
Shujie Wang, Marco Tedesco, Patrick Alexander, Min Xu, and Xavier Fettweis
The Cryosphere, 14, 2687–2713, https://doi.org/10.5194/tc-14-2687-2020, https://doi.org/10.5194/tc-14-2687-2020, 2020
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Glacial algal blooms play a significant role in darkening the Greenland Ice Sheet during summertime. The dark pigments generated by glacial algae could substantially reduce the bare ice albedo and thereby enhance surface melt. We used satellite data to map the spatial distribution of glacial algae and characterized the seasonal growth pattern and interannual trends of glacial algae in southwestern Greenland. Our study is important for bridging microbial activities with ice sheet mass balance.
Sophie Nowicki, Heiko Goelzer, Hélène Seroussi, Anthony J. Payne, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Patrick Alexander, Xylar S. Asay-Davis, Alice Barthel, Thomas J. Bracegirdle, Richard Cullather, Denis Felikson, Xavier Fettweis, Jonathan M. Gregory, Tore Hattermann, Nicolas C. Jourdain, Peter Kuipers Munneke, Eric Larour, Christopher M. Little, Mathieu Morlighem, Isabel Nias, Andrew Shepherd, Erika Simon, Donald Slater, Robin S. Smith, Fiammetta Straneo, Luke D. Trusel, Michiel R. van den Broeke, and Roderik van de Wal
The Cryosphere, 14, 2331–2368, https://doi.org/10.5194/tc-14-2331-2020, https://doi.org/10.5194/tc-14-2331-2020, 2020
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This paper describes the experimental protocol for ice sheet models taking part in the Ice Sheet Model Intercomparion Project for CMIP6 (ISMIP6) and presents an overview of the atmospheric and oceanic datasets to be used for the simulations. The ISMIP6 framework allows for exploring the uncertainty in 21st century sea level change from the Greenland and Antarctic ice sheets.
Heiko Goelzer, Brice P. Y. Noël, Tamsin L. Edwards, Xavier Fettweis, Jonathan M. Gregory, William H. Lipscomb, Roderik S. W. van de Wal, and Michiel R. van den Broeke
The Cryosphere, 14, 1747–1762, https://doi.org/10.5194/tc-14-1747-2020, https://doi.org/10.5194/tc-14-1747-2020, 2020
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Future sea-level change projections with process-based ice sheet models are typically driven with surface mass balance forcing derived from climate models. In this work we address the problems arising from a mismatch of the modelled ice sheet geometry with the one used by the climate model. The proposed remapping method reproduces the original forcing data closely when applied to the original geometry and produces a physically meaningful forcing when applied to different modelled geometries.
Colleen Mortimer, Lawrence Mudryk, Chris Derksen, Kari Luojus, Ross Brown, Richard Kelly, and Marco Tedesco
The Cryosphere, 14, 1579–1594, https://doi.org/10.5194/tc-14-1579-2020, https://doi.org/10.5194/tc-14-1579-2020, 2020
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Existing stand-alone passive microwave SWE products have markedly different climatological SWE patterns compared to reanalysis-based datasets. The AMSR-E SWE has low spatial and temporal correlations with the four reanalysis-based products evaluated and GlobSnow and perform poorly in comparisons with snow transect data from Finland, Russia, and Canada. There is better agreement with in situ data when multiple SWE products, excluding the stand-alone passive microwave SWE products, are combined.
Marco Tedesco and Xavier Fettweis
The Cryosphere, 14, 1209–1223, https://doi.org/10.5194/tc-14-1209-2020, https://doi.org/10.5194/tc-14-1209-2020, 2020
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Unprecedented atmospheric conditions occurring in the summer of 2019 over Greenland promoted new record or close-to-record values of mass loss. Summer of 2019 was characterized by an exceptional persistence of anticyclonic conditions that enhanced melting.
Marco Tedesco, Steven McAlpine, and Jeremy R. Porter
Nat. Hazards Earth Syst. Sci., 20, 907–920, https://doi.org/10.5194/nhess-20-907-2020, https://doi.org/10.5194/nhess-20-907-2020, 2020
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Quantifying the exposure of house property to extreme weather events is crucial to study their impact on economy. Here, we show that value of property exposed to Hurricane Florence in September 2018 was USD 52 billion vs. USD 10 billion that would have occurred at the beginning of the 19th century due to urban expansion that increased after 1950s and the increasing number of houses built near water, showing the importance of accounting for the distribution of new buildings in risk and exposure.
Donald A. Slater, Denis Felikson, Fiamma Straneo, Heiko Goelzer, Christopher M. Little, Mathieu Morlighem, Xavier Fettweis, and Sophie Nowicki
The Cryosphere, 14, 985–1008, https://doi.org/10.5194/tc-14-985-2020, https://doi.org/10.5194/tc-14-985-2020, 2020
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Changes in the ocean around Greenland play an important role in determining how much the ice sheet will contribute to global sea level over the coming century. However, capturing these links in models is very challenging. This paper presents a strategy enabling an ensemble of ice sheet models to feel the effect of the ocean for the first time and should therefore result in a significant improvement in projections of the Greenland ice sheet's contribution to future sea level change.
Alison Delhasse, Christoph Kittel, Charles Amory, Stefan Hofer, Dirk van As, Robert S. Fausto, and Xavier Fettweis
The Cryosphere, 14, 957–965, https://doi.org/10.5194/tc-14-957-2020, https://doi.org/10.5194/tc-14-957-2020, 2020
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The ERA5 reanalysis of the ECMWF replaced the ERA-Interim in August 2019 and has never been evaluated over Greenland. The aim was to evaluate the performance of ERA5 to simulate the near-surface climate of the Greenland Ice sheet (GrIS) against ERA-Interim and regional climate models with the help of in situ observations from the PROMICE dataset. We also highlighted that polar regional climate models are still a useful tool to study the GrIS climate compared to ERA5.
Alison Delhasse, Edward Hanna, Christoph Kittel, and Xavier Fettweis
The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-332, https://doi.org/10.5194/tc-2019-332, 2020
Preprint withdrawn
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Significant melting events over Greenland ice sheet related to unusual atmospheric pattern in summer, as observed this summer 2019, are still not considered by the new generation of Earth-system models (CMIP6) and therefore the projected surface melt increase of the ice sheet is likely to be underestimated if such changes persist in the next decades.
Marion Donat-Magnin, Nicolas C. Jourdain, Hubert Gallée, Charles Amory, Christoph Kittel, Xavier Fettweis, Jonathan D. Wille, Vincent Favier, Amine Drira, and Cécile Agosta
The Cryosphere, 14, 229–249, https://doi.org/10.5194/tc-14-229-2020, https://doi.org/10.5194/tc-14-229-2020, 2020
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Modeling the interannual variability of the surface conditions over Antarctic glaciers is important for the identification of climate trends and climate predictions and to assess models. We simulate snow accumulation and surface melting in the Amundsen sector (West Antarctica) over 1979–2017. For all the glaciers, the interannual variability of summer snow accumulation and surface melting is driven by two distinct mechanisms related to variations in the Amundsen Sea Low strength and position.
Ian Joughin, David E. Shean, Benjamin E. Smith, and Dana Floricioiu
The Cryosphere, 14, 211–227, https://doi.org/10.5194/tc-14-211-2020, https://doi.org/10.5194/tc-14-211-2020, 2020
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Jakobshavn Isbræ, considered to be Greenland's fastest glacier, has varied its speed and thinned dramatically since the 1990s. Here we examine the glacier's behaviour over the last decade to better understand this behaviour. We find that when the floating ice (mélange) in front of the glacier freezes in place during the winter, it can control the glacier's speed and thinning rate. A recently colder ocean has strengthened this mélange, allowing the glacier to recoup some of its previous losses.
David A. Lilien, Ian Joughin, Benjamin Smith, and Noel Gourmelen
The Cryosphere, 13, 2817–2834, https://doi.org/10.5194/tc-13-2817-2019, https://doi.org/10.5194/tc-13-2817-2019, 2019
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We used a number of computer simulations to understand the recent retreat of a rapidly changing group of glaciers in West Antarctica. We found that significant melt underneath the floating extensions of the glaciers, driven by relatively warm ocean water at depth, was likely needed to cause the large retreat that has been observed. If melt continues around current rates, retreat is likely to continue through the coming century and extend beyond the present-day drainage area of these glaciers.
David E. Shean, Ian R. Joughin, Pierre Dutrieux, Benjamin E. Smith, and Etienne Berthier
The Cryosphere, 13, 2633–2656, https://doi.org/10.5194/tc-13-2633-2019, https://doi.org/10.5194/tc-13-2633-2019, 2019
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We produced an 8-year, high-resolution DEM record for Pine Island Glacier (PIG), a site of substantial Antarctic mass loss in recent decades. We developed methods to study the spatiotemporal evolution of ice shelf basal melting, which is responsible for ~ 60 % of PIG mass loss. We present shelf-wide basal melt rates and document relative melt rates for kilometer-scale basal channels and keels, offering new indirect observations of ice–ocean interaction beneath a vulnerable ice shelf.
Donald A. Slater, Fiamma Straneo, Denis Felikson, Christopher M. Little, Heiko Goelzer, Xavier Fettweis, and James Holte
The Cryosphere, 13, 2489–2509, https://doi.org/10.5194/tc-13-2489-2019, https://doi.org/10.5194/tc-13-2489-2019, 2019
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The ocean's influence on the retreat of Greenland's tidewater glaciers is a key factor determining future sea level. By considering observations of ~200 glaciers from 1960, we find a significant relationship between retreat and melting in the ocean. Projected forwards, this relationship estimates the future evolution of Greenland's tidewater glaciers and provides a practical and empirically validated way of representing ice–ocean interaction in large-scale models used to estimate sea level rise.
Thomas J. Ballinger, Thomas L. Mote, Kyle Mattingly, Angela C. Bliss, Edward Hanna, Dirk van As, Melissa Prieto, Saeideh Gharehchahi, Xavier Fettweis, Brice Noël, Paul C. J. P. Smeets, Carleen H. Reijmer, Mads H. Ribergaard, and John Cappelen
The Cryosphere, 13, 2241–2257, https://doi.org/10.5194/tc-13-2241-2019, https://doi.org/10.5194/tc-13-2241-2019, 2019
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Arctic sea ice and the Greenland Ice Sheet (GrIS) are melting later in the year due to a warming climate. Through analyses of weather station, climate model, and reanalysis data, physical links are evaluated between Baffin Bay open water duration and western GrIS melt conditions. We show that sub-Arctic air mass movement across this portion of the GrIS strongly influences late summer and autumn melt, while near-surface, off-ice winds inhibit westerly atmospheric heat transfer from Baffin Bay.
Tyler C. Sutterley, Thorsten Markus, Thomas A. Neumann, Michiel van den Broeke, J. Melchior van Wessem, and Stefan R. M. Ligtenberg
The Cryosphere, 13, 1801–1817, https://doi.org/10.5194/tc-13-1801-2019, https://doi.org/10.5194/tc-13-1801-2019, 2019
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Most of the Antarctic ice sheet is fringed by ice shelves, floating extensions of ice that help to modulate the flow of the glaciers that float into them. We use airborne laser altimetry data to measure changes in ice thickness of ice shelves around West Antarctica and the Antarctic Peninsula. Each of our target ice shelves is susceptible to short-term changes in ice thickness. The method developed here provides a framework for processing NASA ICESat-2 data over ice shelves.
Marilena Oltmanns, Fiammetta Straneo, and Marco Tedesco
The Cryosphere, 13, 815–825, https://doi.org/10.5194/tc-13-815-2019, https://doi.org/10.5194/tc-13-815-2019, 2019
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By combining reanalysis, weather station and satellite data, we show that increases in surface melt over Greenland are initiated by large-scale precipitation events year-round. Estimates from a regional climate model suggest that the initiated melting more than doubled between 1988 and 2012, amounting to ~28 % of the overall melt and revealing that, despite the involved mass gain, precipitation events are contributing to the ice sheet's decline.
Ian M. Howat, Claire Porter, Benjamin E. Smith, Myoung-Jong Noh, and Paul Morin
The Cryosphere, 13, 665–674, https://doi.org/10.5194/tc-13-665-2019, https://doi.org/10.5194/tc-13-665-2019, 2019
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The Reference Elevation Model of Antarctica (REMA) is the first continental-scale terrain map at less than 10 m resolution, and the first with a time stamp, enabling measurements of elevation change. REMA is constructed from over 300 000 individual stereoscopic elevation models (DEMs) extracted from submeter-resolution satellite imagery. REMA is vertically registered to satellite altimetry, resulting in errors of less than 1 m over most of its area and relative uncertainties of decimeters.
Sébastien Le clec'h, Sylvie Charbit, Aurélien Quiquet, Xavier Fettweis, Christophe Dumas, Masa Kageyama, Coraline Wyard, and Catherine Ritz
The Cryosphere, 13, 373–395, https://doi.org/10.5194/tc-13-373-2019, https://doi.org/10.5194/tc-13-373-2019, 2019
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Quantifying the future contribution of the Greenland ice sheet (GrIS) to sea-level rise in response to atmospheric changes is important but remains challenging. For the first time a full representation of the feedbacks between a GrIS model and a regional atmospheric model was implemented. The authors highlight the fundamental need for representing the GrIS topography change feedbacks with respect to the atmospheric component face to the strong impact on the projected sea-level rise.
Cécile Agosta, Charles Amory, Christoph Kittel, Anais Orsi, Vincent Favier, Hubert Gallée, Michiel R. van den Broeke, Jan T. M. Lenaerts, Jan Melchior van Wessem, Willem Jan van de Berg, and Xavier Fettweis
The Cryosphere, 13, 281–296, https://doi.org/10.5194/tc-13-281-2019, https://doi.org/10.5194/tc-13-281-2019, 2019
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Antarctic surface mass balance (ASMB), a component of the sea level budget, is commonly estimated through modelling as observations are scarce. The polar-oriented regional climate model MAR performs well in simulating the observed ASMB. MAR and RACMO2 share common biases we relate to drifting snow transport, with a 3 times larger magnitude than in previous estimates. Sublimation of precipitation in the katabatic layer modelled by MAR is of a magnitude similar to an observation-based estimate.
Christoph Kittel, Charles Amory, Cécile Agosta, Alison Delhasse, Sébastien Doutreloup, Pierre-Vincent Huot, Coraline Wyard, Thierry Fichefet, and Xavier Fettweis
The Cryosphere, 12, 3827–3839, https://doi.org/10.5194/tc-12-3827-2018, https://doi.org/10.5194/tc-12-3827-2018, 2018
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Regional climate models (RCMs) used to estimate the surface mass balance (SMB) of Antarctica depend on boundary forcing fields including sea surface conditions. Here, we assess the sensitivity of the Antarctic SMB to perturbations in sea surface conditions with the RCM MAR using unchanged atmospheric conditions. Significant SMB anomalies are found for SSC perturbations in the range of CMIP5 global climate model biases.
Kang Yang, Laurence C. Smith, Leif Karlstrom, Matthew G. Cooper, Marco Tedesco, Dirk van As, Xiao Cheng, Zhuoqi Chen, and Manchun Li
The Cryosphere, 12, 3791–3811, https://doi.org/10.5194/tc-12-3791-2018, https://doi.org/10.5194/tc-12-3791-2018, 2018
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A high-resolution spatially lumped hydrologic surface routing model is proposed to simulate meltwater transport over bare ice surfaces. In an ice-covered catchment, meltwater is routed by slow interfluve flow (~10−3–10−4 m s−1) followed by fast open-channel flow (~10−1 m s−1). Seasonal evolution of supraglacial stream-river networks substantially alters the magnitude and timing of moulin discharge with implications for subglacial hydrology and ice dynamics.
Alison Delhasse, Xavier Fettweis, Christoph Kittel, Charles Amory, and Cécile Agosta
The Cryosphere, 12, 3409–3418, https://doi.org/10.5194/tc-12-3409-2018, https://doi.org/10.5194/tc-12-3409-2018, 2018
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Since the 2000s, an atmospheric circulation change (CC) gauged by a negative summer shift in the North Atlantic Oscillation has been observed, enhancing surface melt over the Greenland Ice Sheet (GrIS). Future GrIS surface mass balance (SMB) projections are based on global climate models that do not represent this CC. The model MAR has been used to show that previous estimates of these projections could have been significantly overestimated if this current circulation pattern persists.
Lynn Montgomery, Lora Koenig, and Patrick Alexander
Earth Syst. Sci. Data, 10, 1959–1985, https://doi.org/10.5194/essd-10-1959-2018, https://doi.org/10.5194/essd-10-1959-2018, 2018
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The SUMup dataset is a standardized, expandable, community dataset of Arctic and Antarctic observations of surface mass balance components, including snow/firn density, snow accumulation on land ice, and snow depth on sea ice. The measurements in this dataset were compiled from field notes, papers, technical reports, and digital files. We use these observations to monitor change in the polar regions and evaluate model output as well as remote sensing measurements.
Edward Hanna, Xavier Fettweis, and Richard J. Hall
The Cryosphere, 12, 3287–3292, https://doi.org/10.5194/tc-12-3287-2018, https://doi.org/10.5194/tc-12-3287-2018, 2018
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The latest/recent generations of global climate models do not simulate the recent (last 30 years) increase in atmospheric high pressure over Greenland in summer but rather projects decreasing pressure.
This difference between climate models and observations raises serious questions about the ability of the models to accurately represent future changes in Greenland climate and ice-sheet mass balance. There are also likely effects on climate predictions downstream, e.g. over Europe.
Jiangjun Ran, Miren Vizcaino, Pavel Ditmar, Michiel R. van den Broeke, Twila Moon, Christian R. Steger, Ellyn M. Enderlin, Bert Wouters, Brice Noël, Catharina H. Reijmer, Roland Klees, Min Zhong, Lin Liu, and Xavier Fettweis
The Cryosphere, 12, 2981–2999, https://doi.org/10.5194/tc-12-2981-2018, https://doi.org/10.5194/tc-12-2981-2018, 2018
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To accurately predict future sea level rise, the mechanisms driving the observed mass loss must be better understood. Here, we combine data from the satellite gravimetry, surface mass balance, and ice discharge to analyze the mass budget of Greenland at various temporal scales. This study, for the first time, suggests the existence of a substantial meltwater storage during summer, with a peak value of 80–120 Gt in July. We highlight its importance for understanding ice sheet mass variability
Rajashree Tri Datta, Marco Tedesco, Cecile Agosta, Xavier Fettweis, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 12, 2901–2922, https://doi.org/10.5194/tc-12-2901-2018, https://doi.org/10.5194/tc-12-2901-2018, 2018
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Surface melting on the East Antarctic Peninsula (East AP) has been linked to ice shelf collapse, including the Larsen A (1995) and Larsen B (2002) ice shelves. Regional climate models (RCMs) are a valuable tool to understand how wind patterns and general warming can impact the stability of ice shelves through surface melt. Here, we evaluate one such RCM (Modèle Atmosphérique Régionale) over the East AP, including the remaining Larsen C ice shelf, by comparing it to satellite and ground data.
Ian Joughin, Ben E. Smith, and Ian Howat
The Cryosphere, 12, 2211–2227, https://doi.org/10.5194/tc-12-2211-2018, https://doi.org/10.5194/tc-12-2211-2018, 2018
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We describe several new ice velocity maps produced using Landsat 8 and Copernicus Sentinel 1A/B data. We focus on several sites where we analyse these data in conjunction with earlier data from this project, which extend back to the year 2000. In particular, we find that Jakobshavn Isbræ began slowing substantially in 2017. The growing duration of these records will allow more robust analyses of the processes controlling fast flow and how they are affected by climate and other forcings.
Achim Heilig, Olaf Eisen, Michael MacFerrin, Marco Tedesco, and Xavier Fettweis
The Cryosphere, 12, 1851–1866, https://doi.org/10.5194/tc-12-1851-2018, https://doi.org/10.5194/tc-12-1851-2018, 2018
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This paper presents data on temporal changes in snow and firn, which were not available before. We present data on water infiltration in the percolation zone of the Greenland Ice Sheet that improve our understanding of liquid water retention in snow and firn and mass transfer. We compare those findings with model simulations. It appears that simulated accumulation in terms of SWE is fairly accurate, while modeling of the individual parameters density and liquid water content is incorrect.
Jan Melchior van Wessem, Willem Jan van de Berg, Brice P. Y. Noël, Erik van Meijgaard, Charles Amory, Gerit Birnbaum, Constantijn L. Jakobs, Konstantin Krüger, Jan T. M. Lenaerts, Stef Lhermitte, Stefan R. M. Ligtenberg, Brooke Medley, Carleen H. Reijmer, Kristof van Tricht, Luke D. Trusel, Lambertus H. van Ulft, Bert Wouters, Jan Wuite, and Michiel R. van den Broeke
The Cryosphere, 12, 1479–1498, https://doi.org/10.5194/tc-12-1479-2018, https://doi.org/10.5194/tc-12-1479-2018, 2018
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We present a detailed evaluation of the latest version of the regional atmospheric climate model RACMO2.3p2 (1979-2016) over the Antarctic ice sheet. The model successfully reproduces the present-day climate and surface mass balance (SMB) when compared with an extensive set of observations and improves on previous estimates of the Antarctic climate and SMB.
This study shows that the latest version of RACMO2 can be used for high-resolution future projections over the AIS.
David A. Lilien, Ian Joughin, Benjamin Smith, and David E. Shean
The Cryosphere, 12, 1415–1431, https://doi.org/10.5194/tc-12-1415-2018, https://doi.org/10.5194/tc-12-1415-2018, 2018
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We used remotely sensed data and a numerical model to study the processes controlling the stability of two rapidly changing ice shelves in West Antarctica. Both these ice shelves have been losing mass since at least 1996, primarily as a result of ocean-forced melt. We find that this imbalance likely results from changes initiated around 1970 or earlier. Our results also show that the shelves’ differing speedup is controlled by the strength of their margins and their grounding-line positions.
Amber A. Leeson, Emma Eastoe, and Xavier Fettweis
The Cryosphere, 12, 1091–1102, https://doi.org/10.5194/tc-12-1091-2018, https://doi.org/10.5194/tc-12-1091-2018, 2018
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Future melting of the Greenland Ice Sheet is predicted using regional climate models (RCMs). Here, we assess the ability of the MAR RCM to reproduce observed extreme temperature events and the melt energy produced during these times at 14 locations. We find that MAR underestimates temperatures by >0.5 °C during extreme events, which leads to an underestimate in melt energy by up to 41 %. This is potentially an artefact of the data used to drive the MAR simulation and needs to be corrected for.
David E. Shean, Knut Christianson, Kristine M. Larson, Stefan R. M. Ligtenberg, Ian R. Joughin, Ben E. Smith, C. Max Stevens, Mitchell Bushuk, and David M. Holland
The Cryosphere, 11, 2655–2674, https://doi.org/10.5194/tc-11-2655-2017, https://doi.org/10.5194/tc-11-2655-2017, 2017
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We used long-term GPS data and interferometric reflectometry (GPS-IR) to measure velocity, strain rate and surface elevation for the PIG ice shelf – a site of significant mass loss in recent decades. We combined these observations with high-res DEMs and firn model output to constrain surface mass balance and basal melt rates. We document notable spatial variability in basal melt rates but limited temporal variability from 2012 to 2014 despite significant changes in sub-shelf ocean heat content.
Elizabeth R. Thomas, J. Melchior van Wessem, Jason Roberts, Elisabeth Isaksson, Elisabeth Schlosser, Tyler J. Fudge, Paul Vallelonga, Brooke Medley, Jan Lenaerts, Nancy Bertler, Michiel R. van den Broeke, Daniel A. Dixon, Massimo Frezzotti, Barbara Stenni, Mark Curran, and Alexey A. Ekaykin
Clim. Past, 13, 1491–1513, https://doi.org/10.5194/cp-13-1491-2017, https://doi.org/10.5194/cp-13-1491-2017, 2017
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Regional Antarctic snow accumulation derived from 79 ice core records is evaluated as part of the PAGES Antarctica 2k working group. Our results show that surface mass balance for the total Antarctic ice sheet has increased at a rate of 7 ± 0.13 Gt dec-1 since 1800 AD, representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~ 0.04 mm dec-1 since 1900 AD. The largest contribution is from the Antarctic Peninsula.
Andrew J. Tedstone, Jonathan L. Bamber, Joseph M. Cook, Christopher J. Williamson, Xavier Fettweis, Andrew J. Hodson, and Martyn Tranter
The Cryosphere, 11, 2491–2506, https://doi.org/10.5194/tc-11-2491-2017, https://doi.org/10.5194/tc-11-2491-2017, 2017
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The bare ice albedo of the south-west Greenland ice sheet varies dramatically between years. The reasons are unclear but likely involve darkening by inorganic particulates, cryoconite and ice algae. We use satellite imagery to examine dark ice dynamics and climate model outputs to find likely climatological controls. Outcropping particulates can explain the spatial extent of dark ice, but the darkening itself is likely due to ice algae growth controlled by meltwater and light availability.
Peter Kuipers Munneke, Daniel McGrath, Brooke Medley, Adrian Luckman, Suzanne Bevan, Bernd Kulessa, Daniela Jansen, Adam Booth, Paul Smeets, Bryn Hubbard, David Ashmore, Michiel Van den Broeke, Heidi Sevestre, Konrad Steffen, Andrew Shepherd, and Noel Gourmelen
The Cryosphere, 11, 2411–2426, https://doi.org/10.5194/tc-11-2411-2017, https://doi.org/10.5194/tc-11-2411-2017, 2017
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How much snow falls on the Larsen C ice shelf? This is a relevant question, because this ice shelf might collapse sometime this century. To know if and when this could happen, we found out how much snow falls on its surface. This was difficult, because there are only very few measurements. Here, we used data from automatic weather stations, sled-pulled radars, and a climate model to find that melting the annual snowfall produces about 20 cm of water in the NE and over 70 cm in the SW.
Julienne C. Stroeve, John R. Mioduszewski, Asa Rennermalm, Linette N. Boisvert, Marco Tedesco, and David Robinson
The Cryosphere, 11, 2363–2381, https://doi.org/10.5194/tc-11-2363-2017, https://doi.org/10.5194/tc-11-2363-2017, 2017
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As the sea ice has declined strongly in recent years there has been a corresponding increase in Greenland melting. While both are likely a result of changes in atmospheric circulation patterns that favor summer melt, this study evaluates whether or not sea ice reductions around the Greenland ice sheet are having an influence on Greenland summer melt through enhanced sensible and latent heat transport from open water areas onto the ice sheet.
Johannes Jakob Fürst, Fabien Gillet-Chaulet, Toby J. Benham, Julian A. Dowdeswell, Mariusz Grabiec, Francisco Navarro, Rickard Pettersson, Geir Moholdt, Christopher Nuth, Björn Sass, Kjetil Aas, Xavier Fettweis, Charlotte Lang, Thorsten Seehaus, and Matthias Braun
The Cryosphere, 11, 2003–2032, https://doi.org/10.5194/tc-11-2003-2017, https://doi.org/10.5194/tc-11-2003-2017, 2017
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For the large majority of glaciers and ice caps, there is no information on the thickness of the ice cover. Any attempt to predict glacier demise under climatic warming and to estimate the future contribution to sea-level rise is limited as long as the glacier thickness is not well constrained. Here, we present a two-step mass-conservation approach for mapping ice thickness. Measurements are naturally reproduced. The reliability is readily assessible from a complementary map of error estimates.
Kimberly A. Casey, Chris M. Polashenski, Justin Chen, and Marco Tedesco
The Cryosphere, 11, 1781–1795, https://doi.org/10.5194/tc-11-1781-2017, https://doi.org/10.5194/tc-11-1781-2017, 2017
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We analyzed Greenland Ice Sheet (GrIS) average summer surface reflectance and albedo (2001–2016). MODIS Collection 6 data show a decreased magnitude of change over time due to sensor calibration corrections. Spectral band maps provide insight into GrIS surface processes likely occurring. Correctly measuring albedo and surface reflectance changes over time is crucial to monitoring atmosphere–ice interactions and ice mass balance. The results are applicable to many long-term MODIS studies.
Xavier Fettweis, Jason E. Box, Cécile Agosta, Charles Amory, Christoph Kittel, Charlotte Lang, Dirk van As, Horst Machguth, and Hubert Gallée
The Cryosphere, 11, 1015–1033, https://doi.org/10.5194/tc-11-1015-2017, https://doi.org/10.5194/tc-11-1015-2017, 2017
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This paper shows that the surface melt increase over the Greenland ice sheet since the end of the 1990s has been unprecedented, with respect to the last 120 years, using a regional climate model. These simulations also suggest an increase of the snowfall accumulation through the last century before a surface mass decrease in the 2000s. Such a mass gain could have impacted the ice sheet's dynamic stability and could explain the recent observed increase of the glaciers' velocity.
Benjamin E. Smith, Noel Gourmelen, Alexander Huth, and Ian Joughin
The Cryosphere, 11, 451–467, https://doi.org/10.5194/tc-11-451-2017, https://doi.org/10.5194/tc-11-451-2017, 2017
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In this paper we investigate elevation changes of Thwaites Glacier, West Antarctica, one of the main sources of excess ice discharge into the ocean. We find that in early 2013, four subglacial lakes separated by 100 km drained suddenly, discharging more than 3 km3 of water under the fastest part of the glacier in less than 6 months. Concurrent ice-speed measurements show only minor changes, suggesting that ice dynamics are not strongly sensitive to changes in water flow.
Brice Noël, Willem Jan van de Berg, Horst Machguth, Stef Lhermitte, Ian Howat, Xavier Fettweis, and Michiel R. van den Broeke
The Cryosphere, 10, 2361–2377, https://doi.org/10.5194/tc-10-2361-2016, https://doi.org/10.5194/tc-10-2361-2016, 2016
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We present a 1 km resolution data set (1958–2015) of daily Greenland ice sheet surface mass balance (SMB), statistically downscaled from the data of RACMO2.3 at 11 km using elevation dependence, precipitation and bare ice albedo corrections. The data set resolves Greenland narrow ablation zones and local outlet glaciers, and shows more realistic SMB patterns, owing to enhanced runoff at the ice sheet margins. An evaluation of the product against SMB measurements shows improved agreement.
Nicole-Jeanne Schlegel, David N. Wiese, Eric Y. Larour, Michael M. Watkins, Jason E. Box, Xavier Fettweis, and Michiel R. van den Broeke
The Cryosphere, 10, 1965–1989, https://doi.org/10.5194/tc-10-1965-2016, https://doi.org/10.5194/tc-10-1965-2016, 2016
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We investigate Greenland Ice Sheet mass change from 2003–2012 by comparing observations from GRACE with state-of-the-art atmospheric and ice sheet model simulations. We find that the largest discrepancies (in the northwest and southeast) are likely controlled by errors in modeled surface climate as well as ice–ocean interaction and hydrological processes (not included in the models). Models should consider such processes at monthly to seasonal resolutions in order to improve future projections.
Lora S. Koenig, Alvaro Ivanoff, Patrick M. Alexander, Joseph A. MacGregor, Xavier Fettweis, Ben Panzer, John D. Paden, Richard R. Forster, Indrani Das, Joesph R. McConnell, Marco Tedesco, Carl Leuschen, and Prasad Gogineni
The Cryosphere, 10, 1739–1752, https://doi.org/10.5194/tc-10-1739-2016, https://doi.org/10.5194/tc-10-1739-2016, 2016
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Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor surface mass balance in order to improve sea-level rise predictions. Here, we quantify the net annual accumulation over the Greenland Ice Sheet, which comprises the largest component of surface mass balance, at a higher spatial resolution than currently available using high-resolution, airborne-radar data.
Patrick M. Alexander, Marco Tedesco, Nicole-Jeanne Schlegel, Scott B. Luthcke, Xavier Fettweis, and Eric Larour
The Cryosphere, 10, 1259–1277, https://doi.org/10.5194/tc-10-1259-2016, https://doi.org/10.5194/tc-10-1259-2016, 2016
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We compared satellite-derived estimates of spatial and seasonal variations in Greenland Ice Sheet mass with a set of model simulations, revealing an agreement between models and satellite estimates for the ice-sheet-wide seasonal fluctuations in mass, but disagreement at finer spatial scales. The model simulations underestimate low-elevation mass loss. Improving the ability of models to capture variations and trends in Greenland Ice Sheet mass is important for estimating future sea level rise.
Marco Tedesco, Sarah Doherty, Xavier Fettweis, Patrick Alexander, Jeyavinoth Jeyaratnam, and Julienne Stroeve
The Cryosphere, 10, 477–496, https://doi.org/10.5194/tc-10-477-2016, https://doi.org/10.5194/tc-10-477-2016, 2016
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Summer surface albedo over Greenland decreased at a rate of 0.02 per decade between 1996 and 2012. The decrease is due to snow grain growth, the expansion of bare ice areas, and trends in light-absorbing impurities on snow and ice surfaces. Neither aerosol models nor in situ observations indicate increasing trends in impurities in the atmosphere over Greenland. Albedo projections through to the end of the century under different warming scenarios consistently point to continued darkening.
Willem Jan van de Berg and Brooke Medley
The Cryosphere, 10, 459–463, https://doi.org/10.5194/tc-10-459-2016, https://doi.org/10.5194/tc-10-459-2016, 2016
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Regional climate models improve the spatial surface mass balance (SMB) patterns in Antarctica compared to reanalyses, but they deteriorate the representation of interannual variability in SMB. Hence, we implemented additional nudging in our regional climate model RACMO2. Using annual SMB observations of the Twaites drainage basin, Antarctica, we show that this nudging vastly improves the representation of interannual variability without significant deterioration of the modelled mean SMB fields.
M. Navari, S. A. Margulis, S. M. Bateni, M. Tedesco, P. Alexander, and X. Fettweis
The Cryosphere, 10, 103–120, https://doi.org/10.5194/tc-10-103-2016, https://doi.org/10.5194/tc-10-103-2016, 2016
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An ensemble batch smoother was used to assess the feasibility of generating a reanalysis estimate of the Greenland ice sheet (GrIS) surface mass fluxes (SMF) via integrating measured ice surface temperatures with a regional climate model estimate. The results showed that assimilation of IST were able to overcome uncertainties in meteorological forcings that drive the GrIS surface processes. We showed that the proposed methodology is able to generate posterior reanalysis estimates of the SMF.
D. N. Goldberg, P. Heimbach, I. Joughin, and B. Smith
The Cryosphere, 9, 2429–2446, https://doi.org/10.5194/tc-9-2429-2015, https://doi.org/10.5194/tc-9-2429-2015, 2015
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We calibrate a time-dependent ice model through optimal fit to transient observations of surface elevation and velocity, a novel procedure in glaciology and in particular for an ice stream with a dynamic grounding line. We show this procedure gives a level of confidence in model projections that cannot be achieved through more commonly used glaciological data assimilation methods. We show that Smith Glacier is in a state of retreat regardless of climatic forcing for the next several decades.
C. Agosta, X. Fettweis, and R. Datta
The Cryosphere, 9, 2311–2321, https://doi.org/10.5194/tc-9-2311-2015, https://doi.org/10.5194/tc-9-2311-2015, 2015
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Estimates of the Antarctic surface mass balance with regional climate models (RCMs) require proper fields for forcing; hence we evaluate 41 CMIP5 climate models over Antarctica and include six reanalyses. Most of the models are biased compared to ERA-Interim, ACCESS1-3 being the best choice for forcing RCMs. Climate change is less sensitive to global warming than it is to the present-day simulated sea ice and to the feedback between sea-ice decrease and temperature increase around Antarctica.
V. Masson-Delmotte, H. C. Steen-Larsen, P. Ortega, D. Swingedouw, T. Popp, B. M. Vinther, H. Oerter, A. E. Sveinbjornsdottir, H. Gudlaugsdottir, J. E. Box, S. Falourd, X. Fettweis, H. Gallée, E. Garnier, V. Gkinis, J. Jouzel, A. Landais, B. Minster, N. Paradis, A. Orsi, C. Risi, M. Werner, and J. W. C. White
The Cryosphere, 9, 1481–1504, https://doi.org/10.5194/tc-9-1481-2015, https://doi.org/10.5194/tc-9-1481-2015, 2015
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The deep NEEM ice core provides the oldest Greenland ice core record, enabling improved understanding of the response of ice core records to local climate. Here, we focus on shallow ice cores providing a stack record of accumulation and water-stable isotopes spanning the past centuries. For the first time, we document the ongoing warming in a Greenland ice core. By combining our data with other Greenland ice cores and model results, we characterise the spatio-temporal patterns of variability.
C. Lang, X. Fettweis, and M. Erpicum
The Cryosphere, 9, 945–956, https://doi.org/10.5194/tc-9-945-2015, https://doi.org/10.5194/tc-9-945-2015, 2015
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We simulated the 21st century Svalbard SMB with the regional model MAR (RCP8.5 scenario). Melt is projected to increase gently up to 2050 and then dramatically increase, with a larger increase in the south of the archipelago. This difference is due to larger ice albedo decrease in the south causing larger increase of absorbed solar radiation. The ablation area is projected to disappear over the entire Svalbard by 2085. The SMB decrease compared to present is projected to contribute 7mm to SLR.
I. M. Howat, C. Porter, M. J. Noh, B. E. Smith, and S. Jeong
The Cryosphere, 9, 103–108, https://doi.org/10.5194/tc-9-103-2015, https://doi.org/10.5194/tc-9-103-2015, 2015
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In the summer of 2011, a large crater appeared in the surface of the Greenland Ice Sheet. It formed when a subglacial lake, equivalent to 10,000 swimming pools, catastrophically drained in less than 14 days. This is the first direct evidence that surface meltwater that drains through cracks to the bed of the ice sheet can build up in subglacial lakes over long periods of time. The sudden drainage may have been due to more surface melting and an increase in meltwater reaching the bed.
C. Lang, X. Fettweis, and M. Erpicum
The Cryosphere, 9, 83–101, https://doi.org/10.5194/tc-9-83-2015, https://doi.org/10.5194/tc-9-83-2015, 2015
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We have modelled the surface mass balance (SMB) of Svalbard with the model MAR over 1979--2013. The mean SMB is slightly negative and the Svalbard glaciers are losing mass through surface processes (mainly precipitation and runoff), but there has been no acceleration of the surface melt, contrary to Greenland where melt records have been broken since 2006. We attributed it to a change in atmospheric circulation, resulting in northerly cold flows over Svalbard damping Arctic warming.
A. Belleflamme, X. Fettweis, and M. Erpicum
The Cryosphere, 9, 53–64, https://doi.org/10.5194/tc-9-53-2015, https://doi.org/10.5194/tc-9-53-2015, 2015
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The 2007-2012 summertime circulation anomaly over the Arctic region (i.e. more high pressure systems over the Beaufort Sea, the Canadian Arctic Archipelago, and Greenland) is put in a historical perspective. While the 2007-2012 anomaly seems to be exceptional, similar circulation conditions have occurred since 1871, on the basis of five reanalyses (ERA-Interim, ERA-40, NCEP/NCAR, ERA-20C, 20CRv2). The attribution of this anomaly (natural variability or global warming) remains debatable.
P. M. Alexander, M. Tedesco, X. Fettweis, R. S. W. van de Wal, C. J. P. P. Smeets, and M. R. van den Broeke
The Cryosphere, 8, 2293–2312, https://doi.org/10.5194/tc-8-2293-2014, https://doi.org/10.5194/tc-8-2293-2014, 2014
B. Noël, X. Fettweis, W. J. van de Berg, M. R. van den Broeke, and M. Erpicum
The Cryosphere, 8, 1871–1883, https://doi.org/10.5194/tc-8-1871-2014, https://doi.org/10.5194/tc-8-1871-2014, 2014
R. T. W. L. Hurkmans, J. L. Bamber, C. H. Davis, I. R. Joughin, K. S. Khvorostovsky, B. S. Smith, and N. Schoen
The Cryosphere, 8, 1725–1740, https://doi.org/10.5194/tc-8-1725-2014, https://doi.org/10.5194/tc-8-1725-2014, 2014
I. M. Howat, A. Negrete, and B. E. Smith
The Cryosphere, 8, 1509–1518, https://doi.org/10.5194/tc-8-1509-2014, https://doi.org/10.5194/tc-8-1509-2014, 2014
B. Medley, I. Joughin, B. E. Smith, S. B. Das, E. J. Steig, H. Conway, S. Gogineni, C. Lewis, A. S. Criscitiello, J. R. McConnell, M. R. van den Broeke, J. T. M. Lenaerts, D. H. Bromwich, J. P. Nicolas, and C. Leuschen
The Cryosphere, 8, 1375–1392, https://doi.org/10.5194/tc-8-1375-2014, https://doi.org/10.5194/tc-8-1375-2014, 2014
D. Callens, K. Matsuoka, D. Steinhage, B. Smith, E. Witrant, and F. Pattyn
The Cryosphere, 8, 867–875, https://doi.org/10.5194/tc-8-867-2014, https://doi.org/10.5194/tc-8-867-2014, 2014
C. J. Legleiter, M. Tedesco, L. C. Smith, A. E. Behar, and B. T. Overstreet
The Cryosphere, 8, 215–228, https://doi.org/10.5194/tc-8-215-2014, https://doi.org/10.5194/tc-8-215-2014, 2014
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 181–194, https://doi.org/10.5194/tc-8-181-2014, https://doi.org/10.5194/tc-8-181-2014, 2014
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, and C. Ritz
The Cryosphere, 8, 195–208, https://doi.org/10.5194/tc-8-195-2014, https://doi.org/10.5194/tc-8-195-2014, 2014
W. Colgan, W. Abdalati, M. Citterio, B. Csatho, X. Fettweis, S. Luthcke, G. Moholdt, and M. Stober
The Cryosphere Discuss., https://doi.org/10.5194/tcd-8-537-2014, https://doi.org/10.5194/tcd-8-537-2014, 2014
Revised manuscript not accepted
M. J. Siegert, N. Ross, H. Corr, B. Smith, T. Jordan, R. G. Bingham, F. Ferraccioli, D. M. Rippin, and A. Le Brocq
The Cryosphere, 8, 15–24, https://doi.org/10.5194/tc-8-15-2014, https://doi.org/10.5194/tc-8-15-2014, 2014
M. Tedesco, X. Fettweis, T. Mote, J. Wahr, P. Alexander, J. E. Box, and B. Wouters
The Cryosphere, 7, 615–630, https://doi.org/10.5194/tc-7-615-2013, https://doi.org/10.5194/tc-7-615-2013, 2013
C. L. Vernon, J. L. Bamber, J. E. Box, M. R. van den Broeke, X. Fettweis, E. Hanna, and P. Huybrechts
The Cryosphere, 7, 599–614, https://doi.org/10.5194/tc-7-599-2013, https://doi.org/10.5194/tc-7-599-2013, 2013
X. Fettweis, B. Franco, M. Tedesco, J. H. van Angelen, J. T. M. Lenaerts, M. R. van den Broeke, and H. Gallée
The Cryosphere, 7, 469–489, https://doi.org/10.5194/tc-7-469-2013, https://doi.org/10.5194/tc-7-469-2013, 2013
X. Fettweis, E. Hanna, C. Lang, A. Belleflamme, M. Erpicum, and H. Gallée
The Cryosphere, 7, 241–248, https://doi.org/10.5194/tc-7-241-2013, https://doi.org/10.5194/tc-7-241-2013, 2013
B. Franco, X. Fettweis, and M. Erpicum
The Cryosphere, 7, 1–18, https://doi.org/10.5194/tc-7-1-2013, https://doi.org/10.5194/tc-7-1-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Mass Balance Obs
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study
Globally consistent estimates of high-resolution Antarctic ice mass balance and spatially resolved glacial isostatic adjustment
On the importance of the humidity flux for the surface mass balance in the accumulation zone of the Greenland Ice Sheet
Combined GNSS reflectometry–refractometry for automated and continuous in situ surface mass balance estimation on an Antarctic ice shelf
The regional-scale surface mass balance of Pine Island Glacier, West Antarctica, over the period 2005–2014, derived from airborne radar soundings and neutron probe measurements
Sensitivity of inverse glacial isostatic adjustment estimates over Antarctica
Recent precipitation decrease across the western Greenland ice sheet percolation zone
How does the ice sheet surface mass balance relate to snowfall? Insights from a ground-based precipitation radar in East Antarctica
Spatial and temporal distributions of surface mass balance between Concordia and Vostok stations, Antarctica, from combined radar and ice core data: first results and detailed error analysis
Natasha Valencic, Linda Pan, Konstantin Latychev, Natalya Gomez, Evelyn Powell, and Jerry X. Mitrovica
The Cryosphere, 18, 2969–2978, https://doi.org/10.5194/tc-18-2969-2024, https://doi.org/10.5194/tc-18-2969-2024, 2024
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We quantify the effect of ongoing Antarctic bedrock uplift due to Ice Age or modern ice mass changes on estimates of ice thickness changes obtained from satellite-based ice height measurements. We find that variations in the Ice Age signal introduce an uncertainty in estimates of total Antarctic ice change of up to ~10%. Moreover, the usual assumption that the mapping between modern ice height and thickness changes is uniform systematically underestimates net Antarctic ice volume changes.
Matthias O. Willen, Martin Horwath, Eric Buchta, Mirko Scheinert, Veit Helm, Bernd Uebbing, and Jürgen Kusche
The Cryosphere, 18, 775–790, https://doi.org/10.5194/tc-18-775-2024, https://doi.org/10.5194/tc-18-775-2024, 2024
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Shrinkage of the Antarctic ice sheet (AIS) leads to sea level rise. Satellite gravimetry measures AIS mass changes. We apply a new method that overcomes two limitations: low spatial resolution and large uncertainties due to the Earth's interior mass changes. To do so, we additionally include data from satellite altimetry and climate and firn modelling, which are evaluated in a globally consistent way with thoroughly characterized errors. The results are in better agreement with independent data.
Laura J. Dietrich, Hans Christian Steen-Larsen, Sonja Wahl, Anne-Katrine Faber, and Xavier Fettweis
The Cryosphere, 18, 289–305, https://doi.org/10.5194/tc-18-289-2024, https://doi.org/10.5194/tc-18-289-2024, 2024
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The contribution of the humidity flux to the surface mass balance in the accumulation zone of the Greenland Ice Sheet is uncertain. Here, we evaluate the regional climate model MAR using a multi-annual dataset of eddy covariance measurements and bulk estimates of the humidity flux. The humidity flux largely contributes to the summer surface mass balance (SMB) in the accumulation zone, indicating its potential importance for the annual SMB in a warming climate.
Ladina Steiner, Holger Schmithüsen, Jens Wickert, and Olaf Eisen
The Cryosphere, 17, 4903–4916, https://doi.org/10.5194/tc-17-4903-2023, https://doi.org/10.5194/tc-17-4903-2023, 2023
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The present study illustrates the potential of a combined Global Navigation Satellite System reflectometry and refractometry (GNSS-RR) method for accurate, simultaneous, and continuous estimation of in situ snow accumulation, snow water equivalent, and snow density time series. The combined GNSS-RR method was successfully applied on a fast-moving, polar ice shelf. The combined GNSS-RR approach could be highly advantageous for a continuous quantification of ice sheet surface mass balances.
Stefan Kowalewski, Veit Helm, Elizabeth Mary Morris, and Olaf Eisen
The Cryosphere, 15, 1285–1305, https://doi.org/10.5194/tc-15-1285-2021, https://doi.org/10.5194/tc-15-1285-2021, 2021
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This study presents estimates of total mass input for the Pine Island Glacier (PIG) over the period 2005–2014 from airborne radar measurements. Our analysis reveals a total mass input similar to an earlier estimate for the period 1985–2009 and same area. This suggests a stationary total mass input contrary to the accelerated mass loss of PIG over the past decades. However, we also find that its uncertainty is highly sensitive to the geostatistical assumptions required for its calculation.
Matthias O. Willen, Martin Horwath, Ludwig Schröder, Andreas Groh, Stefan R. M. Ligtenberg, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 14, 349–366, https://doi.org/10.5194/tc-14-349-2020, https://doi.org/10.5194/tc-14-349-2020, 2020
Gabriel Lewis, Erich Osterberg, Robert Hawley, Hans Peter Marshall, Tate Meehan, Karina Graeter, Forrest McCarthy, Thomas Overly, Zayta Thundercloud, and David Ferris
The Cryosphere, 13, 2797–2815, https://doi.org/10.5194/tc-13-2797-2019, https://doi.org/10.5194/tc-13-2797-2019, 2019
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We present accumulation records from sixteen 22–32 m long firn cores and 4436 km of ground-penetrating radar, covering the past 20–60 years of accumulation, collected across the western Greenland Ice Sheet percolation zone. Trends from both radar and firn cores, as well as commonly used regional climate models, show decreasing accumulation over the 1996–2016 period.
Niels Souverijns, Alexandra Gossart, Irina V. Gorodetskaya, Stef Lhermitte, Alexander Mangold, Quentin Laffineur, Andy Delcloo, and Nicole P. M. van Lipzig
The Cryosphere, 12, 1987–2003, https://doi.org/10.5194/tc-12-1987-2018, https://doi.org/10.5194/tc-12-1987-2018, 2018
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This work is the first to gain insight into the local surface mass balance over Antarctica using accurate long-term snowfall observations. A non-linear relationship between accumulation and snowfall is discovered, indicating that total surface mass balance measurements are not a good proxy for snowfall over Antarctica. Furthermore, the meteorological drivers causing changes in the local SMB are identified.
Emmanuel Le Meur, Olivier Magand, Laurent Arnaud, Michel Fily, Massimo Frezzotti, Marie Cavitte, Robert Mulvaney, and Stefano Urbini
The Cryosphere, 12, 1831–1850, https://doi.org/10.5194/tc-12-1831-2018, https://doi.org/10.5194/tc-12-1831-2018, 2018
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This paper presents surface mass balance measurements from both GPR and ice core data collected during a traverse in a so-far-unexplored area between the DC and Vostok stations. Results presented here will contribute to a better knowledge of the global mass balance of the Antarctic ice sheet and thus help in constraining its contribution to sea level rise. Another novelty of the paper resides in the comprehensive error budget proposed for the method used for inferring accumulation rates.
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Short summary
We use repeated satellite measurements of the height of the Greenland ice sheet to learn about how three computational models of snowfall, melt, and snow compaction represent actual changes in the ice sheet. We find that the models do a good job of estimating how the parts of the ice sheet near the coast have changed but that two of the models have trouble representing surface melt for the highest part of the ice sheet. This work provides suggestions for how to better model snowmelt.
We use repeated satellite measurements of the height of the Greenland ice sheet to learn about...
