Articles | Volume 16, issue 8
https://doi.org/10.5194/tc-16-3033-2022
© Author(s) 2022. 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-16-3033-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Aug 2022
Research article |
| 01 Aug 2022
| 01 Aug 2022
GBaTSv2: a revised synthesis of the likely basal thermal state of the Greenland Ice Sheet
Joseph A. MacGregor
CORRESPONDING AUTHOR
Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center,
Greenbelt, Maryland, United States of America
Winnie Chu
School of Earth and Atmospheric Sciences, Georgia Institute of
Technology, Atlanta, Georgia, United States of America
William T. Colgan
Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Mark A. Fahnestock
Geophysical Institute, University of Alaska Fairbanks, Fairbanks,
Alaska, United States of America
Denis Felikson
Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center,
Greenbelt, Maryland, United States of America
Universities Space Research Association, Columbia, Maryland, United
States of America
Nanna B. Karlsson
Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Sophie M. J. Nowicki
Department of Geology, University at Buffalo, Buffalo, New York,
United States of America
Michael Studinger
Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center,
Greenbelt, Maryland, United States of America
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Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. Mackie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Verjan Višnjević, Rodrigo Zamora, and Alexandra Zuhr
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The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative to work together on this archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica, and how this will be used to reconstruct past and predict future ice and climate behaviour.
Benjamin Reynolds, Sophie Nowicki, and Kristin Poinar
EGUsphere, https://doi.org/10.5194/egusphere-2024-2424, https://doi.org/10.5194/egusphere-2024-2424, 2024
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Nanna B. Karlsson, Dustin M. Schroeder, Louise Sandberg Sørensen, Winnie Chu, Jørgen Dall, Natalia H. Andersen, Reese Dobson, Emma J. Mackie, Simon J. Köhn, Jillian E. Steinmetz, Angelo S. Tarzona, Thomas O. Teisberg, and Niels Skou
Earth Syst. Sci. Data, 16, 3333–3344, https://doi.org/10.5194/essd-16-3333-2024, https://doi.org/10.5194/essd-16-3333-2024, 2024
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The Greenland Ice Sheet interior is covered by a layer of firn, which is important for surface meltwater runoff and contributions to global sea-level rise. Here, we combine airborne radar sounding and laser altimetry measurements to delineate vertically homogeneous and heterogeneous firn. Our results reveal changes in firn between 2011–2019, aligning well with known climatic events. This approach can be used to outline firn areas primed for significantly changing future meltwater runoff.
Louise Sandberg Sørensen, Rasmus Bahbah, Sebastian B. Simonsen, Natalia Havelund Andersen, Jade Bowling, Noel Gourmelen, Alex Horton, Nanna B. Karlsson, Amber Leeson, Jennifer Maddalena, Malcolm McMillan, Anne Solgaard, and Birgit Wessel
The Cryosphere, 18, 505–523, https://doi.org/10.5194/tc-18-505-2024, https://doi.org/10.5194/tc-18-505-2024, 2024
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Under the right topographic and hydrological conditions, lakes may form beneath the large ice sheets. Some of these subglacial lakes are active, meaning that they periodically drain and refill. When a subglacial lake drains rapidly, it may cause the ice surface above to collapse, and here we investigate how to improve the monitoring of active subglacial lakes in Greenland by monitoring how their associated collapse basins change over time.
Tong Zhang, William Colgan, Agnes Wansing, Anja Løkkegaard, Gunter Leguy, William H. Lipscomb, and Cunde Xiao
The Cryosphere, 18, 387–402, https://doi.org/10.5194/tc-18-387-2024, https://doi.org/10.5194/tc-18-387-2024, 2024
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The geothermal heat flux determines how much heat enters from beneath the ice sheet, and thus impacts the temperature and the flow of the ice sheet. In this study we investigate how much geothermal heat flux impacts the initialization of the Greenland ice sheet. We use the Community Ice Sheet Model with two different initialization methods. We find a non-trivial influence of the choice of heat flow boundary conditions on the ice sheet initializations for further designs of ice sheet modeling.
Robert E. Kopp, Gregory G. Garner, Tim H. J. Hermans, Shantenu Jha, Praveen Kumar, Alexander Reedy, Aimée B. A. Slangen, Matteo Turilli, Tamsin L. Edwards, Jonathan M. Gregory, George Koubbe, Anders Levermann, Andre Merzky, Sophie Nowicki, Matthew D. Palmer, and Chris Smith
Geosci. Model Dev., 16, 7461–7489, https://doi.org/10.5194/gmd-16-7461-2023, https://doi.org/10.5194/gmd-16-7461-2023, 2023
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Future sea-level rise projections exhibit multiple forms of uncertainty, all of which must be considered by scientific assessments intended to inform decision-making. The Framework for Assessing Changes To Sea-level (FACTS) is a new software package intended to support assessments of global mean, regional, and extreme sea-level rise. An early version of FACTS supported the development of the IPCC Sixth Assessment Report sea-level projections.
Dominik Fahrner, Donald Slater, Aman KC, Claudia Cenedese, David A. Sutherland, Ellyn Enderlin, Femke de Jong, Kristian K. Kjeldsen, Michael Wood, Peter Nienow, Sophie Nowicki, and Till Wagner
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2023-411, https://doi.org/10.5194/essd-2023-411, 2023
Preprint withdrawn
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Marine-terminating glaciers can lose mass through frontal ablation, which comprises submarine and surface melting, and iceberg calving. We estimate frontal ablation for 49 marine-terminating glaciers in Greenland by combining existing, satellite derived data and calculating volume change near the glacier front over time. The dataset offers exciting opportunities to study the influence of climate forcings on marine-terminating glaciers in Greenland over multi-decadal timescales.
Hélène Seroussi, Vincent Verjans, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Peter Van Katwyk, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
The Cryosphere, 17, 5197–5217, https://doi.org/10.5194/tc-17-5197-2023, https://doi.org/10.5194/tc-17-5197-2023, 2023
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Mass loss from Antarctica is a key contributor to sea level rise over the 21st century, and the associated uncertainty dominates sea level projections. We highlight here the Antarctic glaciers showing the largest changes and quantify the main sources of uncertainty in their future evolution using an ensemble of ice flow models. We show that on top of Pine Island and Thwaites glaciers, Totten and Moscow University glaciers show rapid changes and a strong sensitivity to warmer ocean conditions.
Baptiste Vandecrux, Jason E. Box, Andreas P. Ahlstrøm, Signe B. Andersen, Nicolas Bayou, William T. Colgan, Nicolas J. Cullen, Robert S. Fausto, Dominik Haas-Artho, Achim Heilig, Derek A. Houtz, Penelope How, Ionut Iosifescu Enescu, Nanna B. Karlsson, Rebecca Kurup Buchholz, Kenneth D. Mankoff, Daniel McGrath, Noah P. Molotch, Bianca Perren, Maiken K. Revheim, Anja Rutishauser, Kevin Sampson, Martin Schneebeli, Sandy Starkweather, Simon Steffen, Jeff Weber, Patrick J. Wright, Henry Jay Zwally, and Konrad Steffen
Earth Syst. Sci. Data, 15, 5467–5489, https://doi.org/10.5194/essd-15-5467-2023, https://doi.org/10.5194/essd-15-5467-2023, 2023
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The Greenland Climate Network (GC-Net) comprises stations that have been monitoring the weather on the Greenland Ice Sheet for over 30 years. These stations are being replaced by newer ones maintained by the Geological Survey of Denmark and Greenland (GEUS). The historical data were reprocessed to improve their quality, and key information about the weather stations has been compiled. This augmented dataset is available at https://doi.org/10.22008/FK2/VVXGUT (Steffen et al., 2022).
Denis Felikson, Sophie Nowicki, Isabel Nias, Beata Csatho, Anton Schenk, Michael J. Croteau, and Bryant Loomis
The Cryosphere, 17, 4661–4673, https://doi.org/10.5194/tc-17-4661-2023, https://doi.org/10.5194/tc-17-4661-2023, 2023
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We narrow the spread in model simulations of the Greenland Ice Sheet using velocity change, dynamic thickness change, and mass change observations. We find that the type of observation chosen can lead to significantly different calibrated probability distributions. Further work is required to understand how to best calibrate ensembles of ice sheet simulations because this will improve probability distributions of projected sea-level rise, which is crucial for coastal planning and adaptation.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
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This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Alice C. Frémand, Peter Fretwell, Julien A. Bodart, Hamish D. Pritchard, Alan Aitken, Jonathan L. Bamber, Robin Bell, Cesidio Bianchi, Robert G. Bingham, Donald D. Blankenship, Gino Casassa, Ginny Catania, Knut Christianson, Howard Conway, Hugh F. J. Corr, Xiangbin Cui, Detlef Damaske, Volkmar Damm, Reinhard Drews, Graeme Eagles, Olaf Eisen, Hannes Eisermann, Fausto Ferraccioli, Elena Field, René Forsberg, Steven Franke, Shuji Fujita, Yonggyu Gim, Vikram Goel, Siva Prasad Gogineni, Jamin Greenbaum, Benjamin Hills, Richard C. A. Hindmarsh, Andrew O. Hoffman, Per Holmlund, Nicholas Holschuh, John W. Holt, Annika N. Horlings, Angelika Humbert, Robert W. Jacobel, Daniela Jansen, Adrian Jenkins, Wilfried Jokat, Tom Jordan, Edward King, Jack Kohler, William Krabill, Mette Kusk Gillespie, Kirsty Langley, Joohan Lee, German Leitchenkov, Carlton Leuschen, Bruce Luyendyk, Joseph MacGregor, Emma MacKie, Kenichi Matsuoka, Mathieu Morlighem, Jérémie Mouginot, Frank O. Nitsche, Yoshifumi Nogi, Ole A. Nost, John Paden, Frank Pattyn, Sergey V. Popov, Eric Rignot, David M. Rippin, Andrés Rivera, Jason Roberts, Neil Ross, Anotonia Ruppel, Dustin M. Schroeder, Martin J. Siegert, Andrew M. Smith, Daniel Steinhage, Michael Studinger, Bo Sun, Ignazio Tabacco, Kirsty Tinto, Stefano Urbini, David Vaughan, Brian C. Welch, Douglas S. Wilson, Duncan A. Young, and Achille Zirizzotti
Earth Syst. Sci. Data, 15, 2695–2710, https://doi.org/10.5194/essd-15-2695-2023, https://doi.org/10.5194/essd-15-2695-2023, 2023
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This paper presents the release of over 60 years of ice thickness, bed elevation, and surface elevation data acquired over Antarctica by the international community. These data are a crucial component of the Antarctic Bedmap initiative which aims to produce a new map and datasets of Antarctic ice thickness and bed topography for the international glaciology and geophysical community.
William Colgan, Christopher Shields, Pavel Talalay, Xiaopeng Fan, Austin P. Lines, Joshua Elliott, Harihar Rajaram, Kenneth Mankoff, Morten Jensen, Mira Backes, Yunchen Liu, Xianzhe Wei, Nanna B. Karlsson, Henrik Spanggård, and Allan Ø. Pedersen
Geosci. Instrum. Method. Data Syst., 12, 121–140, https://doi.org/10.5194/gi-12-121-2023, https://doi.org/10.5194/gi-12-121-2023, 2023
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We describe a new drill for glaciers and ice sheets. Instead of drilling down into the ice, via mechanical action, our drill melts into the ice. Our goal is simply to pull a cable of temperature sensors on a one-way trip down to the ice–bed interface. Here, we describe the design and testing of our drill. Under laboratory conditions, our melt-tip drill has an efficiency of ∼ 35 % with a theoretical maximum penetration rate of ∼ 12 m h−1. Under field conditions, our efficiency is just ∼ 15 %.
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.
Julien A. Bodart, Robert G. Bingham, Duncan A. Young, Joseph A. MacGregor, David W. Ashmore, Enrica Quartini, Andrew S. Hein, David G. Vaughan, and Donald D. Blankenship
The Cryosphere, 17, 1497–1512, https://doi.org/10.5194/tc-17-1497-2023, https://doi.org/10.5194/tc-17-1497-2023, 2023
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Estimating how West Antarctica will change in response to future climatic change depends on our understanding of past ice processes. Here, we use a reflector widely visible on airborne radar data across West Antarctica to estimate accumulation rates over the past 4700 years. By comparing our estimates with current atmospheric data, we find that accumulation rates were 18 % greater than modern rates. This has implications for our understanding of past ice processes in the region.
Jason P. Briner, Caleb K. Walcott, Joerg M. Schaefer, Nicolás E. Young, Joseph A. MacGregor, Kristin Poinar, Benjamin A. Keisling, Sridhar Anandakrishnan, Mary R. Albert, Tanner Kuhl, and Grant Boeckmann
The Cryosphere, 16, 3933–3948, https://doi.org/10.5194/tc-16-3933-2022, https://doi.org/10.5194/tc-16-3933-2022, 2022
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The 7.4 m of sea level equivalent stored as Greenland ice is getting smaller every year. The uncertain trajectory of ice loss could be better understood with knowledge of the ice sheet's response to past climate change. Within the bedrock below the present-day ice sheet is an archive of past ice-sheet history. We analyze all available data from Greenland to create maps showing where on the ice sheet scientists can drill, using currently available drills, to obtain sub-ice materials.
Michael Studinger, Serdar S. Manizade, Matthew A. Linkswiler, and James K. Yungel
The Cryosphere, 16, 3649–3668, https://doi.org/10.5194/tc-16-3649-2022, https://doi.org/10.5194/tc-16-3649-2022, 2022
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The footprint density and high-resolution imagery of airborne surveys reveal details in supraglacial hydrological features that are currently not obtainable from spaceborne data. The accuracy and resolution of airborne measurements complement spaceborne measurements, can support calibration and validation of spaceborne methods, and provide information necessary for process studies of the hydrological system on ice sheets that currently cannot be achieved from spaceborne observations alone.
Mimmi Oksman, Anna Bang Kvorning, Signe Hillerup Larsen, Kristian Kjellerup Kjeldsen, Kenneth David Mankoff, William Colgan, Thorbjørn Joest Andersen, Niels Nørgaard-Pedersen, Marit-Solveig Seidenkrantz, Naja Mikkelsen, and Sofia Ribeiro
The Cryosphere, 16, 2471–2491, https://doi.org/10.5194/tc-16-2471-2022, https://doi.org/10.5194/tc-16-2471-2022, 2022
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One of the questions facing the cryosphere community today is how increasing runoff from the Greenland Ice Sheet impacts marine ecosystems. To address this, long-term data are essential. Here, we present multi-site records of fjord productivity for SW Greenland back to the 19th century. We show a link between historical freshwater runoff and productivity, which is strongest in the inner fjord – influenced by marine-terminating glaciers – where productivity has increased since the late 1990s.
William Colgan, Agnes Wansing, Kenneth Mankoff, Mareen Lösing, John Hopper, Keith Louden, Jörg Ebbing, Flemming G. Christiansen, Thomas Ingeman-Nielsen, Lillemor Claesson Liljedahl, Joseph A. MacGregor, Árni Hjartarson, Stefan Bernstein, Nanna B. Karlsson, Sven Fuchs, Juha Hartikainen, Johan Liakka, Robert S. Fausto, Dorthe Dahl-Jensen, Anders Bjørk, Jens-Ove Naslund, Finn Mørk, Yasmina Martos, Niels Balling, Thomas Funck, Kristian K. Kjeldsen, Dorthe Petersen, Ulrik Gregersen, Gregers Dam, Tove Nielsen, Shfaqat A. Khan, and Anja Løkkegaard
Earth Syst. Sci. Data, 14, 2209–2238, https://doi.org/10.5194/essd-14-2209-2022, https://doi.org/10.5194/essd-14-2209-2022, 2022
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We assemble all available geothermal heat flow measurements collected in and around Greenland into a new database. We use this database of point measurements, in combination with other geophysical datasets, to model geothermal heat flow in and around Greenland. Our geothermal heat flow model is generally cooler than previous models of Greenland, especially in southern Greenland. It does not suggest any high geothermal heat flows resulting from Icelandic plume activity over 50 million years ago.
Christian J. Taubenberger, Denis Felikson, and Thomas Neumann
The Cryosphere, 16, 1341–1348, https://doi.org/10.5194/tc-16-1341-2022, https://doi.org/10.5194/tc-16-1341-2022, 2022
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Outlet glaciers are projected to account for half of the total ice loss from the Greenland Ice Sheet over the 21st century. We classify patterns of seasonal dynamic thickness changes of outlet glaciers using new observations from the Ice, Cloud and land Elevation Satellite-2 (ICESat-2). Our results reveal seven distinct patterns that differ across glaciers even within the same region. Future work can use our results to improve our understanding of processes that drive seasonal ice sheet changes.
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.
Robert S. Fausto, Dirk van As, Kenneth D. Mankoff, Baptiste Vandecrux, Michele Citterio, Andreas P. Ahlstrøm, Signe B. Andersen, William Colgan, Nanna B. Karlsson, Kristian K. Kjeldsen, Niels J. Korsgaard, Signe H. Larsen, Søren Nielsen, Allan Ø. Pedersen, Christopher L. Shields, Anne M. Solgaard, and Jason E. Box
Earth Syst. Sci. Data, 13, 3819–3845, https://doi.org/10.5194/essd-13-3819-2021, https://doi.org/10.5194/essd-13-3819-2021, 2021
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The Programme for Monitoring of the Greenland Ice Sheet (PROMICE) has been measuring climate and ice sheet properties since 2007. Here, we present our data product from weather and ice sheet measurements from a network of automatic weather stations mainly located in the melt area of the ice sheet. Currently the PROMICE automatic weather station network includes 25 instrumented sites in Greenland.
Anne Solgaard, Anders Kusk, John Peter Merryman Boncori, Jørgen Dall, Kenneth D. Mankoff, Andreas P. Ahlstrøm, Signe B. Andersen, Michele Citterio, Nanna B. Karlsson, Kristian K. Kjeldsen, Niels J. Korsgaard, Signe H. Larsen, and Robert S. Fausto
Earth Syst. Sci. Data, 13, 3491–3512, https://doi.org/10.5194/essd-13-3491-2021, https://doi.org/10.5194/essd-13-3491-2021, 2021
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The PROMICE Ice Velocity product is a time series of Greenland Ice Sheet ice velocity mosaics spanning September 2016 to present. It is derived from Sentinel-1 SAR data and has a spatial resolution of 500 m. Each mosaic spans 24 d (two Sentinel-1 cycles), and a new one is posted every 12 d (every Sentinel-1A cycle). The spatial comprehensiveness and temporal consistency make the product ideal for monitoring and studying ice-sheet-wide ice discharge and dynamics of glaciers.
Joseph A. MacGregor, Michael Studinger, Emily Arnold, Carlton J. Leuschen, Fernando Rodríguez-Morales, and John D. Paden
The Cryosphere, 15, 2569–2574, https://doi.org/10.5194/tc-15-2569-2021, https://doi.org/10.5194/tc-15-2569-2021, 2021
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We combine multiple recent global glacier datasets and extend one of them (GlaThiDa) to evaluate past performance of radar-sounding surveys of the thickness of Earth's temperate glaciers. An empirical envelope for radar performance as a function of center frequency is determined, its limitations are discussed and its relevance to future radar-sounder survey and system designs is considered.
William H. Lipscomb, Gunter R. Leguy, Nicolas C. Jourdain, Xylar Asay-Davis, Hélène Seroussi, and Sophie Nowicki
The Cryosphere, 15, 633–661, https://doi.org/10.5194/tc-15-633-2021, https://doi.org/10.5194/tc-15-633-2021, 2021
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This paper describes Antarctic climate change experiments in which the Community Ice Sheet Model is forced with ocean warming predicted by global climate models. Generally, ice loss begins slowly, accelerates by 2100, and then continues unabated, with widespread retreat of the West Antarctic Ice Sheet. The mass loss by 2500 varies from about 150 to 1300 mm of equivalent sea level rise, based on the predicted ocean warming and assumptions about how this warming drives melting beneath ice shelves.
Helle Astrid Kjær, Patrick Zens, Ross Edwards, Martin Olesen, Ruth Mottram, Gabriel Lewis, Christian Terkelsen Holme, Samuel Black, Kasper Holst Lund, Mikkel Schmidt, Dorthe Dahl-Jensen, Bo Vinther, Anders Svensson, Nanna Karlsson, Jason E. Box, Sepp Kipfstuhl, and Paul Vallelonga
The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-337, https://doi.org/10.5194/tc-2020-337, 2021
Manuscript not accepted for further review
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We have reconstructed accumulation in 6 firn cores and 8 snow cores in Northern Greenland and compared with a regional Climate model over Greenland. We find the model underestimate precipitation especially in north-eastern part of the ice cap- an important finding if aiming to reconstruct surface mass balance.
Temperatures at 10 meters depth at 6 sites in Greenland were also determined and show a significant warming since the 1990's of 0.9 to 2.5 °C.
Seyedhamidreza Mojtabavi, Frank Wilhelms, Eliza Cook, Siwan M. Davies, Giulia Sinnl, Mathias Skov Jensen, Dorthe Dahl-Jensen, Anders Svensson, Bo M. Vinther, Sepp Kipfstuhl, Gwydion Jones, Nanna B. Karlsson, Sergio Henrique Faria, Vasileios Gkinis, Helle Astrid Kjær, Tobias Erhardt, Sarah M. P. Berben, Kerim H. Nisancioglu, Iben Koldtoft, and Sune Olander Rasmussen
Clim. Past, 16, 2359–2380, https://doi.org/10.5194/cp-16-2359-2020, https://doi.org/10.5194/cp-16-2359-2020, 2020
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We present a first chronology for the East Greenland Ice-core Project (EGRIP) over the Holocene and last glacial termination. After field measurements and processing of the ice-core data, the GICC05 timescale is transferred from the NGRIP core to the EGRIP core by means of matching volcanic events and common patterns (381 match points) in the ECM and DEP records. The new timescale is named GICC05-EGRIP-1 and extends back to around 15 kyr b2k.
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.
Christine S. Hvidberg, Aslak Grinsted, Dorthe Dahl-Jensen, Shfaqat Abbas Khan, Anders Kusk, Jonas Kvist Andersen, Niklas Neckel, Anne Solgaard, Nanna B. Karlsson, Helle Astrid Kjær, and Paul Vallelonga
The Cryosphere, 14, 3487–3502, https://doi.org/10.5194/tc-14-3487-2020, https://doi.org/10.5194/tc-14-3487-2020, 2020
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The Northeast Greenland Ice Stream (NEGIS) extends around 600 km from its onset in the interior of Greenland to the coast. Several maps of surface velocity and topography in Greenland exist, but accuracy is limited due to the lack of validation data. Here we present results from a 5-year GPS survey in an interior section of NEGIS. We use the data to assess a list of satellite-derived ice velocity and surface elevation products and discuss the implications for the ice stream flow in the area.
Eric Larour, Lambert Caron, Mathieu Morlighem, Surendra Adhikari, Thomas Frederikse, Nicole-Jeanne Schlegel, Erik Ivins, Benjamin Hamlington, Robert Kopp, and Sophie Nowicki
Geosci. Model Dev., 13, 4925–4941, https://doi.org/10.5194/gmd-13-4925-2020, https://doi.org/10.5194/gmd-13-4925-2020, 2020
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ISSM-SLPS is a new projection system for future sea level that increases the resolution and accuracy of current projection systems and improves the way uncertainty is treated in such projections. This will pave the way for better inclusion of state-of-the-art results from existing intercomparison efforts carried out by the scientific community, such as GlacierMIP2 or ISMIP6, into sea-level projections.
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.
Nicolas C. Jourdain, Xylar Asay-Davis, Tore Hattermann, Fiammetta Straneo, Hélène Seroussi, Christopher M. Little, and Sophie Nowicki
The Cryosphere, 14, 3111–3134, https://doi.org/10.5194/tc-14-3111-2020, https://doi.org/10.5194/tc-14-3111-2020, 2020
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To predict the future Antarctic contribution to sea level rise, we need to use ice sheet models. The Ice Sheet Model Intercomparison Project for AR6 (ISMIP6) builds an ensemble of ice sheet projections constrained by atmosphere and ocean projections from the 6th Coupled Model Intercomparison Project (CMIP6). In this work, we present and assess a method to derive ice shelf basal melting in ISMIP6 from the CMIP6 ocean outputs, and we give examples of projected melt rates.
Heiko Goelzer, Sophie Nowicki, Anthony Payne, Eric Larour, Helene Seroussi, William H. Lipscomb, Jonathan Gregory, Ayako Abe-Ouchi, Andrew Shepherd, Erika Simon, Cécile Agosta, Patrick Alexander, Andy Aschwanden, Alice Barthel, Reinhard Calov, Christopher Chambers, Youngmin Choi, Joshua Cuzzone, Christophe Dumas, Tamsin Edwards, Denis Felikson, Xavier Fettweis, Nicholas R. Golledge, Ralf Greve, Angelika Humbert, Philippe Huybrechts, Sebastien Le clec'h, Victoria Lee, Gunter Leguy, Chris Little, Daniel P. Lowry, Mathieu Morlighem, Isabel Nias, Aurelien Quiquet, Martin Rückamp, Nicole-Jeanne Schlegel, Donald A. Slater, Robin S. Smith, Fiamma Straneo, Lev Tarasov, Roderik van de Wal, and Michiel van den Broeke
The Cryosphere, 14, 3071–3096, https://doi.org/10.5194/tc-14-3071-2020, https://doi.org/10.5194/tc-14-3071-2020, 2020
Short summary
Short summary
In this paper we use a large ensemble of Greenland ice sheet models forced by six different global climate models to project ice sheet changes and sea-level rise contributions over the 21st century.
The results for two different greenhouse gas concentration scenarios indicate that the Greenland ice sheet will continue to lose mass until 2100, with contributions to sea-level rise of 90 ± 50 mm and 32 ± 17 mm for the high (RCP8.5) and low (RCP2.6) scenario, respectively.
Hélène Seroussi, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
The Cryosphere, 14, 3033–3070, https://doi.org/10.5194/tc-14-3033-2020, https://doi.org/10.5194/tc-14-3033-2020, 2020
Short summary
Short summary
The Antarctic ice sheet has been losing mass over at least the past 3 decades in response to changes in atmospheric and oceanic conditions. This study presents an ensemble of model simulations of the Antarctic evolution over the 2015–2100 period based on various ice sheet models, climate forcings and emission scenarios. Results suggest that the West Antarctic ice sheet will continue losing a large amount of ice, while the East Antarctic ice sheet could experience increased snow accumulation.
Cited articles
Aschwanden, A., Fahnestock, M. A., Truffer, M., Brinkerhoff, D. J., Hock,
R., Khroulev, C., Mottram, R., and Khan, S. A.: Contribution of the
Greenland Ice Sheet to sea level over the next millennium, Sci. Adv.,
5, eaav9396, https://doi.org/10.1126/sciadv.aav9396, 2019.
Aschwanden, A., Bartholomaus, T. C., Brinkerhoff, D. J., and Truffer, M.: Brief communication: A roadmap towards credible projections of ice sheet contribution to sea level, The Cryosphere, 15, 5705–5715, https://doi.org/10.5194/tc-15-5705-2021, 2021.
Bamber, J. L., Layberry, R. L., and Gogineni, S. P.: A new ice thickness and bed
data set for the Greenland ice sheet: 1. Measurement, data reduction and
errors, J. Geophys. Res.-Atmos., 106,
33773–33780, https://doi.org/10.1029/2001JD900054, 2001.
Bons, P. D., Jansen, D., Mundel, F., Bauer, C. C., Binder, T., Eisen, O.,
Jessell, M. W., Llorens, M.-G., Steinbach, F., Steinhage, D., and Weikusat,
I.: Converging flow and anisotropy cause large-scale folding in Greenland's
ice sheet, Nat. Commun., 7, 1–6, https://doi.org/10.1038/ncomms11427, 2016.
Bons, P. D., Kleiner, T., Llorens, M.-G., Prior, D. J., Sachau, T.,
Weikusat, I., and Jansen, D.: Greenland Ice Sheet: Higher Nonlinearity of Ice
Flow Significantly Reduces Estimated Basal Motion,
Geophys. Res. Lett., 45, 6542–6548, https://doi.org/10.1029/2018gl078356, 2018.
Bowling, J. S., Livingstone, S. J., Sole, A. J., and Chu, W.: Distribution
and dynamics of Greenland subglacial lakes, Nat. Commun., 10, 2810,
https://doi.org/10.1038/s41467-019-10821-w, 2019.
Chu, W., Schroeder, D. M., Seroussi, H., Creyts, T. T., and Bell, R. E.:
Complex Basal Thermal Transition Near the Onset of Petermann Glacier,
Greenland, J. Geophys. Res.-Ea. Surf., 123, 985–995,
https://doi.org/10.1029/2017jf004561, 2018.
Colebeck, S. and Gow, A.: The margin of the Greenland Ice Sheet at Isua,
J. Glaciol., 24, 155–165, https://doi.org/10.3189/S0022143000014714,
1979.
Colgan, W., MacGregor, J. A., Mankoff, K. D., Morlighem, M., Fahnestock, M.
A., Martos, Y. M., and Kjeldsen, K. K.: Topographic correction of geothermal
flux in Greenland and Antarctica, J. Geophys. Res.-Ea.
Surf., 126, e2020JF005598, https://doi.org/10.1029/2020JF005598, 2021.
Colgan, W., Wansing, A., Mankoff, K., Lösing, M., Hopper, J., Louden, K., Ebbing, J., Christiansen, F. G., Ingeman-Nielsen, T., Liljedahl, L. C., MacGregor, J. A., Hjartarson, Á., Bernstein, S., Karlsson, N. B., Fuchs, S., Hartikainen, J., Liakka, J., Fausto, R. S., Dahl-Jensen, D., Bjørk, A., Naslund, J.-O., Mørk, F., Martos, Y., Balling, N., Funck, T., Kjeldsen, K. K., Petersen, D., Gregersen, U., Dam, G., Nielsen, T., Khan, S. A., and Løkkegaard, A.: Greenland Geothermal Heat Flow Database and Map (Version 1), Earth Syst. Sci. Data, 14, 2209–2238, https://doi.org/10.5194/essd-14-2209-2022, 2022.
Cooper, M. A., Jordan, T. M., Schroeder, D. M., Siegert, M. J., Williams, C. N., and Bamber, J. L.: Subglacial roughness of the Greenland Ice Sheet: relationship with contemporary ice velocity and geology, The Cryosphere, 13, 3093–3115, https://doi.org/10.5194/tc-13-3093-2019, 2019a.
Cooper, M. A., Jordan, T. M., Siegert, M. J., and Bamber, J. L.: Surface
Expression of Basal and Englacial Features, Properties, and Processes of the
Greenland Ice Sheet, Geophys. Res. Lett., 46, 783–793,
https://doi.org/10.1029/2018gl080620, 2019b.
Cuffey, K. M. and Kavanaugh, J. L.: How nonlinear is the creep deformation
of polar ice? A new field assessment, Geology, 39, 1027–2030,
https://doi.org/10.1130/G32259.1, 2011.
Cuffey, K. M. and Paterson, W. S. B.: The Physics of Glaciers, 4th ed.,
Butterworth-Heinemann, ISBN 9780080919126, 2010.
Doyle, S. H., Hubbard, B., Christoffersen, P., Young, T. J., Hofstede, C.,
Bougamont, M., Box, J. E., and Hubbard, A.: Physical conditions of fast
glacier flow: 1. Measurements from boreholes drilled to the bed of Store
Glacier, West Greenland, 123, 324–348, https://doi.org/10.1002/2017JF004529, 2018.
Dahl-Jensen, D., Gundestrup, N. S., Gogineni, S. P., and Millar, D: Basal
melt at NorthGRIP modeled from borehole, ice-core and radio-echo sounder
observations, Ann. Glaciol., 37, 207–212, https://doi.org/10.3189/172756403781815492, 2003.
Dansgaard, W. and Johnsen, S.: A flow model and a time scale for the ice
core from Camp Century, Greenland, J. Glaciol., 8, 215–223,
https://doi.org/10.3189/S0022143000031208, 1969.
De Rydt, J., Gudmundsson, G. H., Corr, H. F. J., and Christoffersen, P.: Surface undulations of Antarctic ice streams tightly controlled by bedrock topography, The Cryosphere, 7, 407–417, https://doi.org/10.5194/tc-7-407-2013, 2013.
Dow, C. F., Karlsson, N. B., and Werder, M. A.: Limited Impact of Subglacial
Supercooling Freeze-on for Greenland Ice Sheet Stratigraphy, Geophys. Res. Lett., 45, 1481–1489, https://doi.org/10.1002/2017gl076251, 2018.
Fahnestock, M. A., Abdalati, W., Joughin, I. R., Brozena, J., and Gogineni,
S. P.: High geothermal heat flow, basal melt, and the origin of rapid ice
flow in central Greenland, Science, 294, 2338–2342,
https://doi.org/10.1126/science.1065370, 2001.
Goelzer, H., Nowicki, S., Payne, A., Larour, E., Seroussi, H., Lipscomb, W. H., Gregory, J., Abe-Ouchi, A., Shepherd, A., Simon, E., Agosta, C., Alexander, P., Aschwanden, A., Barthel, A., Calov, R., Chambers, C., Choi, Y., Cuzzone, J., Dumas, C., Edwards, T., Felikson, D., Fettweis, X., Golledge, N. R., Greve, R., Humbert, A., Huybrechts, P., Le clec'h, S., Lee, V., Leguy, G., Little, C., Lowry, D. P., Morlighem, M., Nias, I., Quiquet, A., Rückamp, M., Schlegel, N.-J., Slater, D. A., Smith, R. S., Straneo, F., Tarasov, L., van de Wal, R., and van den Broeke, M.: The future sea-level contribution of the Greenland ice sheet: a multi-model ensemble study of ISMIP6, The Cryosphere, 14, 3071–3096, https://doi.org/10.5194/tc-14-3071-2020, 2020.
Harrington, J. A., Humphrey, N. F., and Harper, J. T.: Temperature
distribution and thermal anomalies along a flowline of the Greenland Ice
Sheet, Ann. Glaciol., 56, 98–104, https://doi.org/10.3189/2015AoG70A945,
2015.
Howat, I. M., Negrete, A., and Smith, B. E.: The Greenland Ice Mapping Project (GIMP) land classification and surface elevation data sets, The Cryosphere, 8, 1509–1518, https://doi.org/10.5194/tc-8-1509-2014, 2014.
Ignéczi, Á., Sole, A. J., Livingstone, S. J., Ng, F. S. L., and Yang,
K.: Greenland Ice Sheet Surface Topography and Drainage Structure Controlled
by the Transfer of Basal Variability, Front. Earth Sci., 6, 101,
https://doi.org/10.3389/feart.2018.00101, 2018.
Jordan, T. M., Cooper, M. A., Schroeder, D. M., Williams, C. N., Paden, J. D., Siegert, M. J., and Bamber, J. L.: Self-affine subglacial roughness: consequences for radar scattering and basal water discrimination in northern Greenland, The Cryosphere, 11, 1247–1264, https://doi.org/10.5194/tc-11-1247-2017, 2017.
Jordan, T. M., Williams, C. N., Schroeder, D. M., Martos, Y. M., Cooper, M. A., Siegert, M. J., Paden, J. D., Huybrechts, P., and Bamber, J. L.: A constraint upon the basal water distribution and thermal state of the Greenland Ice Sheet from radar bed echoes, The Cryosphere, 12, 2831–2854, https://doi.org/10.5194/tc-12-2831-2018, 2018.
Joughin, I. R., Smith, B. E., Howat, I. M., and Scambos, T. A.: MEaSUREs
Multi-year Greenland Ice Sheet Velocity Mosaic, Version 1, NASA National
Snow and Ice Data Center Distributed Active Archive Center,
https://doi.org/10.5067/QUA5Q9SVMSJG, 2016.
Joughin, I. R., Smith, B. E., and Howat, I. M.: A complete map of Greenland
ice velocity derived from satellite data collected over 20 years, J. Glaciol., 56, 1–11, https://doi.org/10.1017/jog.2017.73, 2017.
Karlsson, N. B., Solgaard, A. M., Mankoff, K. D., Gillet-Chaulet, F.,
MacGregor, J. A., Box, J. E., Citterio, M., Colgan, W. T., Larsen, S. H.,
Kjeldsen, K. K., Korsgaard, N. J., Benn, D. I, Hewitt, I. J., and Fausto, R.
S.: A first constraint on basal melt-water production of the Greenland Ice
Sheet, Nat. Commun., 12, 3461, https://doi.org/10.1038/s41467-021-23739-z, 2021.
Kjær, K. H., Larsen, N. K., Binder, T., Bjørk, A. A., Eisen, O.,
Fahnestock, M. A., Funder, S., Garde, A. A., Haack, H., Helm, V.,
Houmark-Nielsen, M., Kjeldsen, K. K., Khan, S. A., Machguth, H., McDonald,
I., Morlighem, M., Mouginot, J., Paden, J. D., Waight, T. E., Weikusat, C.,
Willerslev, E., and MacGregor, J. A.: A large impact crater beneath Hiawatha
Glacier in northwest Greenland, Sci. Adv., 4, aar8173,
https://doi.org/10.1126/sciadv.aar8173, 2018.
Law, R., Christoffersen, P., Hubbard, B., Doyle, S. H., Chudley, T. R.,
Schoonman, C. M., Bougamont, M., des Tombe, B., Schilperoort, B.,
Kechavarzi, C., Booth, A., and Young, T. J.: Thermodynamics of a fast-moving
Greenlandic outlet glacier revealed by fiber-optic distributed temperature
sensing, Sci, Adv,, 7, eabe7136, https://doi.org/10.1126/sciadv.abe7136, 2021.
Leysinger-Vieli, G. J. M. C., Martin, C., Hindmarsh, R. C. A., and Lüthi,
M. P.: Basal freeze-on generates complex ice-sheet stratigraphy, Nat. Commun., 9, 4669, https://doi.org/10.1038/s41467-018-07083-3, 2018.
Lüthi, M. P., Funk, M., Iken, A., Gogineni, S. P., and Truffer, M.:
Mechanisms of fast flow in Jakobshavn Isbrae, West Greenland: Part III.
Measurements of ice deformation, temperature and cross-borehole conductivity
in boreholes to the bedrock, J. Glaciol., 48, 369–385,
https://doi.org/10.3189/172756502781831322, 2002.
MacGregor, J.: joemacgregor/GBaTSv2: Greenland Ice Sheet Likely Basal Thermal State version 2 FINAL, Zenodo [data set/code], https://doi.org/10.5281/zenodo.6759384, 2022.
MacGregor, J. A., Li, J., Paden, J. D., Catania, G. A., Clow, G. D.,
Fahnestock, M. A., Gogineni, S. P., Grimm, R., Morlighem, M., Nandi, S.,
Seroussi, H., and Stillman, D. E.: Radar attenuation and temperature within
the Greenland Ice Sheet, J. Geophys. Res.-Ea. Surf.,
120-, 983–1008, https://doi.org/10.1002/2014jf003418, 2015a.
MacGregor, J. A., Fahnestock, M. A., Catania, G. A., Paden, J. D., Gogineni,
S. P., Young, S. K., Rybarski, S. C., Mabrey, A. N., Wagman, B. M., and
Morlighem, M.: Radiostratigraphy and age structure of the Greenland Ice
Sheet, J. Geophys. Res.-Ea. Surf., 120, 212–241,
https://doi.org/10.1002/2014jf003215, 2015b.
MacGregor, J. A., Fahnestock, M. A., Catania, G. A., Aschwanden, A., Clow,
G. D., Colgan, W. T., Gogineni, S. P., Morlighem, M., Nowicki, S. M. J.,
Paden, J. D., Price, S. F., and Seroussi, H.: A synthesis of the basal
thermal state of the Greenland Ice Sheet, J. Geophys. Res.-Ea. Surf., 121, 1328–1350, https://doi.org/10.1002/2015jf003803, 2016.
MacGregor, J. A., Bottke, W. F., Fahnestock, M. A., Harbeck, J. P.,
Kjær, K. H., Paden, J. D., Stillman, D. E., and Studinger, M.: A Possible
Second Large Subglacial Impact Crater in Northwest Greenland, Geophys. Res. Lett., 46, 1496–1504, https://doi.org/10.1029/2018gl078126, 2019.
MacGregor, J. A., Fahnestock, M. A., Colgan, W. T., Larsen, N. K., Kjeldsen,
K. K., and Welker, J. M.: The age of surface-exposed ice along the northern
margin of the Greenland Ice Sheet, J. Glaciol., 66, 667–684,
https://doi.org/10.1017/jog.2020.62, 2020.
MacGregor, J. A., Boisvert, L. N., Medley, B., Petty, A. A., Harbeck, J. P.,
Bell, R. E., Blair, J. B., Blanchard-Wrigglesworth, E., Buckley, E. M.,
Christoffersen, M. S., Cochran, J. R., Csathó, B. M., De Marco, E. L.,
Dominguez, R. T., Fahnestock, M. A., Farrell, S. L., Gogineni, S. P.,
Greenbaum, J. S., Hansen, C. M., Hofton, M. A., Holt, J. W., Jezek, K. C.,
Koenig, L. S., Kurtz, N. T., Kwok, R., Larsen, C. F., Leuschen, C. J.,
Locke, C. D., Manizade, S. S., Martin, S., Neumann, T. A., Nowicki, S. M. J.,
Paden, J. D., Richter-Menge, J. A., Rignot, E. J., Rodríguez-Morales,
F., Siegfried, M. R., Smith, B. E., Sonntag, J. G., Studinger, M.,
Tinto, K. J., Truffer, M., Wagner, T. P., Woods, J. E., Young, D. A., and
Yungel, J. K.: The scientific legacy of NASA's Operation IceBridge, Rev.
Geophys., 59, e2020RG000712, https://doi.org/10.1029/2020RG000712, 2021.
Maier, N., Humphrey, N., Harper, J., and Meierbachtol, T.: Sliding dominates
slow-flowing margin regions, Greenland Ice Sheet, Sci. Adv., 5, aaw5406,
https://doi.org/10.1126/sciadv.aaw5406, 2019.
Maier, N., Gimbert, F., Gillet-Chaulet, F., and Gilbert, A.: Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland, The Cryosphere, 15, 1435–1451, https://doi.org/10.5194/tc-15-1435-2021, 2021.
Martos, Y. M., Jordan, T. A., Catalán, M., Jordan, T. M., Bamber, J. L.,
and Vaughan, D. G.: Geothermal heat flux reveals the Iceland hotspot track
underneath Greenland, Geophys. Res. Lett., 45, 8214–8222,
https://doi.org/10.1029/2018GL078289, 2018.
McCormack, F. S., Roberts, J. L., Jong, L. M., Young, D. A., and Beem, L. H.:
A note on digital elevation model smoothing and driving stresses, Polar
Res., 38, https://doi.org/10.33265/polar.v38.3498, 2019.
Menzies, J., van der Meer, J. J. M., and Shilts, W. W.: Subglacial processes
and sediments, in: Past Glacial Environments 2nd ed., 105–158, ISBN 978-0-08-100524-8,
https://doi.org/10.1016/b978-0-08-100524-8.00004-x, 2018.
Millstein, J. D., Minchew, B. M., and Pegler, S. S.: Ice viscosity is more
sensitive to stress than commonly assumed, Communications Earth &
Environment, 3, 57, https://doi.org/10.1038/s43247-022-00385-x, 2022.
Morlighem, M., Rignot, Mouginot, J., Seroussi, H., and Larour, E.: Deeply
incised submarine glacial valleys beneath the Greenland Ice Sheet, Nat.
Geosci., 7, 418–422, https://doi.org/10.1038/ngeo2167, 2014.
Morlighem, M., Williams, C. N., Rignot, E. J., An, L., Arndt, J. E., Bamber,
J. L., Catania, G. A., Chauché, N., Dowdeswell, J. A., Dorschel, B.,
Fenty, I., Hogan, K., Howat, I. M., Hubbard, A. L., Jakobsson, M., Jordan,
T. M., Kjeldsen, K. K., Millan, R., Mayer, L., Mouginot, J., Noël, B. P.
Y., O'Cofaigh, C., Palmer, S. J., Rysgaard, S., Seroussi, H., Siegert, M.
J., Slabon, P., Straneo, F., Broeke, M. R. van den, Weinrebe, W., Wood, M.,
and Zinglersen, K. B.: BedMachine v3: Complete Bed Topography and Ocean
Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With
Mass Conservation, Geophys. Res. Lett., 44, 11051–11061,
https://doi.org/10.1002/2017gl074954, 2017.
Morlighem, M., Williams, C. N., Rignot, E. J., An, L., Arndt, J. E., Bamber,
J. L., Catania, G. A., Chauché, N., Dowdeswell, J. A., Dorschel, B.,
Fenty, I., Hogan, K., Howat, I. M., Hubbard, A. L., Jakobsson, M., Jordan,
T. M., Kjeldsen, K. K., Millan, R., Mayer, L., Mouginot, J., Noël, B. P.
Y., O'Cofaigh, C., Palmer, S. J., Rysgaard, S., Seroussi, H., Siegert, M.
J., Slabon, P., Straneo, F., Broeke, M. R. van den, Weinrebe, W., Wood, M.,
and Zinglersen, K. B.: IceBridge BedMachine Greenland, Version 4, NASA
National Snow and Ice Data Center Distributed Active Archive Center,
https://doi.org/10.5067/VLJ5YXKCNGXO, 2021.
Mouginot, J., Rignot, E., Bjørk, A. A., van den Broeke, M., Millan, R.,
Morlighem, M., Noël, B., Scheuchl, B., and Wood, M.: Forty-fix years of
Greenland Ice Sheet mass balance from 1972 to 2018, P.
Natl. Acad. Sci., 116, 9239–9244,
https://doi.org/10.1073/pnas.1904242116, 2019.
Ng, F. S. L., Ignéczi, Á., Sole, A. J., and Livingstone, S. J.:
Response of Surface Topography to Basal Variability Along Glacial Flowlines,
J. Geophys. Res.-Ea. Surf., 123, 2319–2340,
https://doi.org/10.1029/2017jf004555, 2018.
Nowicki, S. M. J., Bindschadler, R. A., Abe-Ouchi, A. Aschwanden, A.,
Bueler, E., Choi, H., Fastook, J., Granzow, G., Greve, R., Gutowski, G.,
Herzfeld, U., Jackson, C., Johnson, J., Khroulev, C., Larour, E., Levermann,
A., Lipscomb, W. H., Martin, M. A., Morlighem, M., Parizek, B. R., Pollard,
D., Price, S. F., Ren, D., Rignot, E., Saito, F., Sato, T., Seddik, H.,
Seroussi, H., Takahashi, K., Walker, R., and Wang, W. L.: Insights into
spatial sensitivities of ice mass response to environmental change from the
SeaRISE ice sheet modeling project II: Greenland, J. Geophys. Res.-Ea. Surf., 118, 1025–1044, https://doi.org/10.1002/jgrf.20076, 2013.
Nowicki, S., Goelzer, H., Seroussi, H., Payne, A. J., Lipscomb, W. H., Abe-Ouchi, A., Agosta, C., Alexander, P., Asay-Davis, X. S., Barthel, A., Bracegirdle, T. J., Cullather, R., Felikson, D., Fettweis, X., Gregory, J. M., Hattermann, T., Jourdain, N. C., Kuipers Munneke, P., Larour, E., Little, C. M., Morlighem, M., Nias, I., Shepherd, A., Simon, E., Slater, D., Smith, R. S., Straneo, F., Trusel, L. D., van den Broeke, M. R., and van de Wal, R.: Experimental protocol for sea level projections from ISMIP6 stand-alone ice sheet models, The Cryosphere, 14, 2331–2368, https://doi.org/10.5194/tc-14-2331-2020, 2020.
Oswald, G. K. A., Rezvanbehbahani, S., and Stearns, L. A.: Radar evidence of
ponded subglacial water in Greenland, J. Glaciol., 64,
711–729, https://doi.org/10.1017/jog.2018.60, 2018.
Palmer, S. J., Dowdeswell, J. A., Christoffersen, P., Young, D. A.,
Blankenship, D. D., Greenbaum, J. S., Benham, T., Bamber, J., and Siegert, M.
J.: Greenland subglacial lakes detected by radar, Geophys. Res. Lett., 40, 6154–6159, https://doi.org/10.1002/2013GL058383, 2013.
Panton, C. and Karlsson, N. B.: Automated mapping of near bed radio-echo
layer disruptions in the Greenland Ice Sheet, Earth Planet. Sci.
Lett., 432, 323–331, https://doi.org/10.1016/j.epsl.2015.10.024, 2015.
Poinar, K., Joughin, I. R., Das, S. B., Behn, M. D., Lenaerts, J. T. M., and van
den Broeke, M. R.: Limits to future expansion of surface-melt-enhanced ice
flow into the interior of western Greenland, Geophys. Res. Lett.,
42, 1800–1807, https://doi.org/10.1002/2015gl063192, 2015.
Reeh, N., Olesen, O. B., Thomsen, H. H., Starzer, W., and Bøgglid, C. E.:
Mass balance parameterisation for Hans Tausen Iskappe, Peary Land, North
Greenland, Meddelelser om Grønland, 39, 57–69, 2001.
Shapiro, N. M. and Ritzwoller, M. H.: Inferring surface heat flux
distributions guided by a global seismic model: particular application to
Antarctica, Earth Planet. Sci. Lett., 223, 213–224,
https://doi.org/10.1016/j.epsl.2004.04.011, 2004.
Thomsen, H., Olesen, O., Braithwaite, R., and Bøggild, C.: Ice drilling
and mass balance at Pâkitsoq, Jakobshavn, central West Greenland,
Rapport Grønlands Geologiske Undersøgelse, 152, 80–84,
https://doi.org/10.34194/rapggu.v152.8160, 1991.
Willcocks, S., Hasterok, D., and Jennings, S.: Thermal refraction:
implications for subglacial heat flux, J. Glaciol., 875–884,
https://doi.org/10.1017/jog.2021.38, 2021.
Zeising, O. and Humbert, A.: Indication of high basal melting at the EastGRIP drill site on the Northeast Greenland Ice Stream, The Cryosphere, 15, 3119–3128, https://doi.org/10.5194/tc-15-3119-2021, 2021.
Short summary
Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known, yet knowing this state is increasingly important to interpret modern changes in ice flow there. We produced a second synthesis of knowledge of the basal thermal state of the ice sheet using airborne and satellite observations and numerical models. About one-third of the ice sheet’s bed is likely thawed; two-fifths is likely frozen; and the remainder is too uncertain to specify.
Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known,...
