Articles | Volume 7, issue 6
https://doi.org/10.5194/tc-7-1901-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/tc-7-1901-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
17 Dec 2013
Research article |
| 17 Dec 2013
Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas
W. Colgan
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
Geological Survey of Denmark and Greenland, Copenhagen, Denmark
S. Luthcke
Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, USA
W. Abdalati
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
M. Citterio
Geological Survey of Denmark and Greenland, Copenhagen, Denmark
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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
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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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Kenneth D. Mankoff, Anne Solgaard, William Colgan, Andreas P. Ahlstrøm, Shfaqat Abbas Khan, and Robert S. Fausto
Earth Syst. Sci. Data, 12, 1367–1383, https://doi.org/10.5194/essd-12-1367-2020, https://doi.org/10.5194/essd-12-1367-2020, 2020
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We have produced an open and reproducible estimate of Greenland Ice Sheet solid ice discharge from 1986 to 2020. Our results show three modes at the the total ice sheet scale: steady discharge from 1986 through 2000, increasing discharge from 2000 through 2005, and steady discharge from 2005 through 2019. The behavior of individual sectors and glaciers is more complicated. This work was done to provide a 100 % reproducible estimate to help constrain mass balance and sea-level-rise estimates.
Kenneth D. Mankoff, William Colgan, Anne Solgaard, Nanna B. Karlsson, Andreas P. Ahlstrøm, Dirk van As, Jason E. Box, Shfaqat Abbas Khan, Kristian K. Kjeldsen, Jeremie Mouginot, and Robert S. Fausto
Earth Syst. Sci. Data, 11, 769–786, https://doi.org/10.5194/essd-11-769-2019, https://doi.org/10.5194/essd-11-769-2019, 2019
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We have produced an open and reproducible estimate of Greenland Ice Sheet solid ice discharge from 1986 through 2017. Our results show three modes at the total ice-sheet scale: steady discharge from 1986 through 2000, increasing discharge from 2000 through 2005, and steady discharge from 2005 through 2017. The behavior of individual sectors and glaciers is more complicated. This work was done to provide a 100 % reproducible estimate to help constrain mass balance and sea-level rise estimates.
Baptiste Vandecrux, Michael MacFerrin, Horst Machguth, William T. Colgan, Dirk van As, Achim Heilig, C. Max Stevens, Charalampos Charalampidis, Robert S. Fausto, Elizabeth M. Morris, Ellen Mosley-Thompson, Lora Koenig, Lynn N. Montgomery, Clément Miège, Sebastian B. Simonsen, Thomas Ingeman-Nielsen, and Jason E. Box
The Cryosphere, 13, 845–859, https://doi.org/10.5194/tc-13-845-2019, https://doi.org/10.5194/tc-13-845-2019, 2019
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The perennial snow, or firn, on the Greenland ice sheet each summer stores part of the meltwater formed at the surface, buffering the ice sheet’s contribution to sea level. We gathered observations of firn air content, indicative of the space available in the firn to retain meltwater, and find that this air content remained stable in cold regions of the firn over the last 65 years but recently decreased significantly in western Greenland.
Shfaqat A. Khan, Helene Seroussi, Mathieu Morlighem, William Colgan, Veit Helm, Gong Cheng, Danjal Berg, Valentina R. Barletta, Nicolaj K. Larsen, William Kochtitzky, Michiel van den Broeke, Kurt H. Kjær, Andy Aschwanden, Brice Noël, Jason E. Box, Joseph A. MacGregor, Robert S. Fausto, Kenneth D. Mankoff, Ian M. Howat, Kuba Oniszk, Dominik Fahrner, Anja Løkkegaard, Eigil Y. H. Lippert, Alicia Bråtner, and Javed Hassan
Earth Syst. Sci. Data, 17, 3047–3071, https://doi.org/10.5194/essd-17-3047-2025, https://doi.org/10.5194/essd-17-3047-2025, 2025
Short summary
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The surface elevation of the Greenland Ice Sheet is changing due to surface mass balance processes and ice dynamics, each exhibiting distinct spatiotemporal patterns. Here, we employ satellite and airborne altimetry data with fine spatial (1 km) and temporal (monthly) resolutions to document this spatiotemporal evolution from 2003 to 2023. This dataset of fine-resolution altimetry data in both space and time will support studies of ice mass loss and be useful for GIS ice sheet modeling.
Andrea Securo, Costanza Del Gobbo, Giovanni Baccolo, Carlo Barbante, Michele Citterio, Fabrizio De Blasi, Marco Marcer, Mauro Valt, and Renato R. Colucci
The Cryosphere, 19, 1335–1352, https://doi.org/10.5194/tc-19-1335-2025, https://doi.org/10.5194/tc-19-1335-2025, 2025
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We have reconstructed the multi-decadal (1980s–2023) ice mass changes for all the current mountain glaciers in the Dolomites. We used historical aerial photographs, drone surveys, and lidar to fill the glaciological data gap for the region. We observed an alarming decline in both glacier area and volume, with some of the glaciers showing smaller losses due to local topography and debris cover feedback. We strongly recommend more specific monitoring of these glaciers.
Bernhard Hynek, Daniel Binder, Michele Citterio, Signe Hillerup Larsen, Jakob Abermann, Geert Verhoeven, Elke Ludewig, and Wolfgang Schöner
The Cryosphere, 18, 5481–5494, https://doi.org/10.5194/tc-18-5481-2024, https://doi.org/10.5194/tc-18-5481-2024, 2024
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An avalanche event in February 2018 caused thick snow deposits on Freya Glacier, a peripheral mountain glacier in northeastern Greenland. The avalanche deposits contributed significantly to the mass balance, leaving a strong imprint in the elevation changes in 2013–2021. The 8-year geodetic mass balance (2013–2021) of the glacier is positive, whereas previous estimates by direct measurements were negative and now turned out to have a negative bias.
Signe Hillerup Larsen, Daniel Binder, Anja Rutishauser, Bernhard Hynek, Robert Schjøtt Fausto, and Michele Citterio
Earth Syst. Sci. Data, 16, 4103–4118, https://doi.org/10.5194/essd-16-4103-2024, https://doi.org/10.5194/essd-16-4103-2024, 2024
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The Greenland Ecosystem Monitoring programme has been running since 1995. In 2008, the Glaciological monitoring sub-program GlacioBasis was initiated at the Zackenberg site in northeast Greenland, with a transect of three weather stations on the A. P. Olsen Ice Cap. In 2022, the weather stations were replaced with a more standardized set up. Here, we provide the reprocessed and quality-checked data from 2008 to 2022, i.e., the first 15 years of continued monitoring.
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.
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
Short summary
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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).
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.
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.
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, and Michael Studinger
The Cryosphere, 16, 3033–3049, https://doi.org/10.5194/tc-16-3033-2022, https://doi.org/10.5194/tc-16-3033-2022, 2022
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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.
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.
Michael J. MacFerrin, C. Max Stevens, Baptiste Vandecrux, Edwin D. Waddington, and Waleed Abdalati
Earth Syst. Sci. Data, 14, 955–971, https://doi.org/10.5194/essd-14-955-2022, https://doi.org/10.5194/essd-14-955-2022, 2022
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The vast majority of the Greenland ice sheet's surface is covered by pluriannual snow, also called firn, that accumulates year after year and is compressed into glacial ice. The thickness of the firn layer changes through time and responds to the surface climate. We present continuous measurement of the firn compaction at various depths for eight sites. The dataset will help to evaluate firn models, interpret ice cores, and convert remotely sensed ice sheet surface height change to mass loss.
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.
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.
Kenneth D. Mankoff, Anne Solgaard, William Colgan, Andreas P. Ahlstrøm, Shfaqat Abbas Khan, and Robert S. Fausto
Earth Syst. Sci. Data, 12, 1367–1383, https://doi.org/10.5194/essd-12-1367-2020, https://doi.org/10.5194/essd-12-1367-2020, 2020
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We have produced an open and reproducible estimate of Greenland Ice Sheet solid ice discharge from 1986 to 2020. Our results show three modes at the the total ice sheet scale: steady discharge from 1986 through 2000, increasing discharge from 2000 through 2005, and steady discharge from 2005 through 2019. The behavior of individual sectors and glaciers is more complicated. This work was done to provide a 100 % reproducible estimate to help constrain mass balance and sea-level-rise estimates.
Kenneth D. Mankoff, William Colgan, Anne Solgaard, Nanna B. Karlsson, Andreas P. Ahlstrøm, Dirk van As, Jason E. Box, Shfaqat Abbas Khan, Kristian K. Kjeldsen, Jeremie Mouginot, and Robert S. Fausto
Earth Syst. Sci. Data, 11, 769–786, https://doi.org/10.5194/essd-11-769-2019, https://doi.org/10.5194/essd-11-769-2019, 2019
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We have produced an open and reproducible estimate of Greenland Ice Sheet solid ice discharge from 1986 through 2017. Our results show three modes at the total ice-sheet scale: steady discharge from 1986 through 2000, increasing discharge from 2000 through 2005, and steady discharge from 2005 through 2017. The behavior of individual sectors and glaciers is more complicated. This work was done to provide a 100 % reproducible estimate to help constrain mass balance and sea-level rise estimates.
Baptiste Vandecrux, Michael MacFerrin, Horst Machguth, William T. Colgan, Dirk van As, Achim Heilig, C. Max Stevens, Charalampos Charalampidis, Robert S. Fausto, Elizabeth M. Morris, Ellen Mosley-Thompson, Lora Koenig, Lynn N. Montgomery, Clément Miège, Sebastian B. Simonsen, Thomas Ingeman-Nielsen, and Jason E. Box
The Cryosphere, 13, 845–859, https://doi.org/10.5194/tc-13-845-2019, https://doi.org/10.5194/tc-13-845-2019, 2019
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The perennial snow, or firn, on the Greenland ice sheet each summer stores part of the meltwater formed at the surface, buffering the ice sheet’s contribution to sea level. We gathered observations of firn air content, indicative of the space available in the firn to retain meltwater, and find that this air content remained stable in cold regions of the firn over the last 65 years but recently decreased significantly in western Greenland.
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
A. P. Ahlstrøm, S. B. Andersen, M. L. Andersen, H. Machguth, F. M. Nick, I. Joughin, C. H. Reijmer, R. S. W. van de Wal, J. P. Merryman Boncori, J. E. Box, M. Citterio, D. van As, R. S. Fausto, and A. Hubbard
Earth Syst. Sci. Data, 5, 277–287, https://doi.org/10.5194/essd-5-277-2013, https://doi.org/10.5194/essd-5-277-2013, 2013
M. Citterio and A. P. Ahlstrøm
The Cryosphere, 7, 445–449, https://doi.org/10.5194/tc-7-445-2013, https://doi.org/10.5194/tc-7-445-2013, 2013
Related subject area
Greenland
The system of atmosphere, land, ice and ocean in the region near the 79N Glacier in northeast Greenland: synthesis and key findings from the Greenland Ice Sheet–Ocean Interaction (GROCE) experiment
Brief communication: Storstrømmen Glacier, northeastern Greenland, primed for end-of-decade surge
Historically consistent mass loss projections of the Greenland ice sheet
A comparison of supraglacial meltwater features throughout contrasting melt seasons: southwest Greenland
Enhanced MOIDS-derived ice physical properties within CoLM revealing bare ice-snow-albedo feedback over Greenland
Ice speed of a Greenlandic tidewater glacier modulated by tide, melt, and rain
The Greenland Ice Sheet Large Ensemble (GrISLENS): Simulating the future of Greenland under climate variability
Seasonal and interannual variability of freshwater sources for Greenland's fjords
A topographically controlled tipping point for complete Greenland ice sheet melt
Projections of precipitation and temperatures in Greenland and the impact of spatially uniform anomalies on the evolution of the ice sheet
Seasonal snow cover indicators in coastal Greenland from in situ observations, a climate model, and reanalysis
Impacts of differing melt regimes on satellite radar waveforms and elevation retrievals
The future of Upernavik Isstrøm through the ISMIP6 framework: sensitivity analysis and Bayesian calibration of ensemble prediction
Firn seismic anisotropy in the Northeast Greenland Ice Stream from ambient-noise surface waves
Factors influencing lake surface water temperature variability in West Greenland and the role of the ice sheet
First results of the polar regional climate model RACMO2.4
Advancing interpretation of incoherent scattering in ice penetrating radar data used for ice core site selection
Post-depositional modification on seasonal-to-interannual timescales alters the deuterium-excess signals in summer snow layers in Greenland
Calving front monitoring at a subseasonal resolution: a deep learning application for Greenland glaciers
Modeled Greenland Ice Sheet evolution constrained by ice-core-derived Holocene elevation histories
Bias in modeled Greenland ice sheet melt revealed by ASCAT
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry
Modelling present and future rock wall permafrost distribution in the Sisimiut mountain area, West Greenland
Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates
Coupling MAR (Modèle Atmosphérique Régional) with PISM (Parallel Ice Sheet Model) mitigates the positive melt–elevation feedback
Cloud- and ice-albedo feedbacks drive greater Greenland Ice Sheet sensitivity to warming in CMIP6 than in CMIP5
Evaluating different geothermal heat-flow maps as basal boundary conditions during spin-up of the Greenland ice sheet
Seasonal evolution of the supraglacial drainage network at Humboldt Glacier, northern Greenland, between 2016 and 2020
Choice of observation type affects Bayesian calibration of Greenland Ice Sheet model simulations
Effects of extreme melt events on ice flow and sea level rise of the Greenland Ice Sheet
Precursor of disintegration of Greenland's largest floating ice tongue
An evaluation of a physics-based firn model and a semi-empirical firn model across the Greenland Ice Sheet (1980–2020)
Subglacial lake activity beneath the ablation zone of the Greenland Ice Sheet
Exploring the role of snow metamorphism on the isotopic composition of the surface snow at EastGRIP
The control of short-term ice mélange weakening episodes on calving activity at major Greenland outlet glaciers
Weekly to monthly terminus variability of Greenland's marine-terminating outlet glaciers
The contribution of Humboldt Glacier, northern Greenland, to sea-level rise through 2100 constrained by recent observations of speedup and retreat
Observed mechanism for sustained glacier retreat and acceleration in response to ocean warming around Greenland
Assessing bare-ice albedo simulated by MAR over the Greenland ice sheet (2000–2021) and implications for meltwater production estimates
Drill-site selection for cosmogenic-nuclide exposure dating of the bed of the Greenland Ice Sheet
A new Level 4 multi-sensor ice surface temperature product for the Greenland Ice Sheet
High-resolution imaging of supraglacial hydrological features on the Greenland Ice Sheet with NASA's Airborne Topographic Mapper (ATM) instrument suite
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate
GBaTSv2: a revised synthesis of the likely basal thermal state of the Greenland Ice Sheet
Unravelling the long-term, locally heterogenous response of Greenland glaciers observed in archival photography
Simulating the Holocene deglaciation across a marine-terminating portion of southwestern Greenland in response to marine and atmospheric forcings
Comparison of ice dynamics using full-Stokes and Blatter–Pattyn approximation: application to the Northeast Greenland Ice Stream
Melt probabilities and surface temperature trends on the Greenland ice sheet using a Gaussian mixture model
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties
Multi-decadal retreat of marine-terminating outlet glaciers in northwest and central-west Greenland
Torsten Kanzow, Angelika Humbert, Thomas Mölg, Mirko Scheinert, Matthias Braun, Hans Burchard, Francesca Doglioni, Philipp Hochreuther, Martin Horwath, Oliver Huhn, Maria Kappelsberger, Jürgen Kusche, Erik Loebel, Katrina Lutz, Ben Marzeion, Rebecca McPherson, Mahdi Mohammadi-Aragh, Marco Möller, Carolyne Pickler, Markus Reinert, Monika Rhein, Martin Rückamp, Janin Schaffer, Muhammad Shafeeque, Sophie Stolzenberger, Ralph Timmermann, Jenny Turton, Claudia Wekerle, and Ole Zeising
The Cryosphere, 19, 1789–1824, https://doi.org/10.5194/tc-19-1789-2025, https://doi.org/10.5194/tc-19-1789-2025, 2025
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The Greenland Ice Sheet represents the second-largest contributor to global sea-level rise. We quantify atmosphere, ice and ocean processes related to the mass balance of glaciers in northeast Greenland, focusing on Greenland’s largest floating ice tongue, the 79° N Glacier. We find that together, the different in situ and remote sensing observations and model simulations reveal a consistent picture of a coupled atmosphere–ice sheet–ocean system that has entered a phase of major change.
Jonas K. Andersen, Rasmus P. Meyer, Flora S. Huiban, Mads L. Dømgaard, Romain Millan, and Anders A. Bjørk
The Cryosphere, 19, 1717–1724, https://doi.org/10.5194/tc-19-1717-2025, https://doi.org/10.5194/tc-19-1717-2025, 2025
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Storstrømmen Glacier in northeastern Greenland goes through cycles of sudden flow speed-ups (known as surges) followed by long quiet phases. It is currently in its quiet phase, but recent measurements suggest it may be nearing conditions for a new surge, possibly between 2027 and 2040. We also observed several lake drainages that caused brief increases in glacier flow but did not trigger a surge. Continued monitoring is essential to understand how these processes influence glacier behavior.
Charlotte Rahlves, Heiko Goelzer, Andreas Born, and Petra M. Langebroek
The Cryosphere, 19, 1205–1220, https://doi.org/10.5194/tc-19-1205-2025, https://doi.org/10.5194/tc-19-1205-2025, 2025
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Mass loss from the Greenland ice sheet significantly contributes to rising sea levels, threatening coastal communities globally. To improve future sea-level projections, we simulated ice sheet behavior until 2100, initializing the model with observed geometry and using various climate models. Predictions indicate a sea-level rise of 32 to 228 mm by 2100, with climate model uncertainty being the main source of variability in projections.
Emily Glen, Amber Leeson, Alison F. Banwell, Jennifer Maddalena, Diarmuid Corr, Olivia Atkins, Brice Noël, and Malcolm McMillan
The Cryosphere, 19, 1047–1066, https://doi.org/10.5194/tc-19-1047-2025, https://doi.org/10.5194/tc-19-1047-2025, 2025
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We compare surface meltwater features from optical satellite imagery in the Russell–Leverett glacier catchment during high (2019) and low (2018) melt years. In the high melt year, features appear at higher elevations, meltwater systems are more connected, small lakes are more frequent, and slush is more widespread. These findings provide insights into how a warming climate, where high melt years become common, could alter meltwater distribution and dynamics on the Greenland Ice Sheet.
Shuyang Guo, Yongjiu Dai, Hua Yuan, and Hongbin Liang
EGUsphere, https://doi.org/10.5194/egusphere-2025-230, https://doi.org/10.5194/egusphere-2025-230, 2025
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The Snow, Ice, and Aerosol Radiation Model Version 4 has only been used to evaluate bare ice albedo in land surface models, with necessary ice property data lacking quality control. We integrated this model into our land surface model and improved bare ice properties using quality-controlled satellite data. Our findings show regional warming and reduced snow cover in Greenland’s bare ice region, driven by changes in bare ice properties through the bare ice-snow-albedo feedback.
Shin Sugiyama, Shun Tsutaki, Daiki Sakakibara, Izumi Asaji, Ken Kondo, Yefan Wang, Evgeny Podolskiy, Guillaume Jouvet, and Martin Funk
The Cryosphere, 19, 525–540, https://doi.org/10.5194/tc-19-525-2025, https://doi.org/10.5194/tc-19-525-2025, 2025
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We report flow speed variations near the front of a tidewater glacier in Greenland. Ice flow near the glacier front is crucial for the mass loss of the Greenland ice sheet, but in situ data are hard to obtain. Our unique in situ GPS data revealed fine details of short-term speed variations associated with melting, ocean tides, and rain. The results are important for understanding the response of tidewater glaciers to changing environments, such as warming, more frequent rain, and ice thinning.
Vincent Verjans, Alexander A. Robel, Lizz Ultee, Helene Seroussi, Andrew F. Thompson, Lars Ackerman, Youngmin Choi, and Uta Krebs-Kanzow
EGUsphere, https://doi.org/10.5194/egusphere-2024-4067, https://doi.org/10.5194/egusphere-2024-4067, 2025
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This study examines how random variations in climate may influence future ice loss from the Greenland Ice Sheet. We find that random climate variations are important for predicting future ice loss from the entire Greenland Ice Sheet over the next 20–30 years, but relatively unimportant after that period. Thus, uncertainty in sea level projections from the effect of climate variability on Greenland may play a role in coastal decision-making about sea level rise over the next few decades.
Anneke Louise Vries, Willem Jan van de Berg, Brice Noël, Lorenz Meire, and Michiel R. van den Broeke
EGUsphere, https://doi.org/10.5194/egusphere-2024-3735, https://doi.org/10.5194/egusphere-2024-3735, 2025
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Freshwater enters Greenland's fjords from various sources. Solid ice discharge dominates freshwater input into fjords in the southeast and northwest. In contrast, in the southwest, runoff from the ice sheet and tundra are most significant. Seasonally resolved data revealed that fjord precipitation and tundra runoff contribute up to 11 % and 35 % of the total freshwater influx, respectively. Our results provide valuable input for ocean models and for researchers studying fjord ecosystems.
Michele Petrini, Meike D. W. Scherrenberg, Laura Muntjewerf, Miren Vizcaino, Raymond Sellevold, Gunter R. Leguy, William H. Lipscomb, and Heiko Goelzer
The Cryosphere, 19, 63–81, https://doi.org/10.5194/tc-19-63-2025, https://doi.org/10.5194/tc-19-63-2025, 2025
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Anthropogenic warming is causing accelerated Greenland ice sheet melt. Here, we use a computer model to understand how prolonged warming and ice melt could threaten ice sheet stability. We find a threshold beyond which Greenland will lose more than 80 % of its ice over several thousand years, due to the interaction of surface and solid-Earth processes. Nearly complete Greenland ice sheet melt occurs when the ice margin disconnects from a region of high elevation in western Greenland.
Nils Bochow, Anna Poltronieri, and Niklas Boers
The Cryosphere, 18, 5825–5863, https://doi.org/10.5194/tc-18-5825-2024, https://doi.org/10.5194/tc-18-5825-2024, 2024
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Using the latest climate models, we update the understanding of how the Greenland ice sheet responds to climate changes. We found that precipitation and temperature changes in Greenland vary across different regions. Our findings suggest that using uniform estimates for temperature and precipitation for modelling the response of the ice sheet can overestimate ice loss in Greenland. Therefore, this study highlights the need for spatially resolved data in predicting the ice sheet's future.
Jorrit van der Schot, Jakob Abermann, Tiago Silva, Kerstin Rasmussen, Michael Winkler, Kirsty Langley, and Wolfgang Schöner
The Cryosphere, 18, 5803–5823, https://doi.org/10.5194/tc-18-5803-2024, https://doi.org/10.5194/tc-18-5803-2024, 2024
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We present snow data from nine locations in coastal Greenland. We show that a reanalysis product (CARRA) simulates seasonal snow characteristics better than a regional climate model (RACMO). CARRA output matches particularly well with our reference dataset when we look at the maximum snow water equivalent and the snow cover end date. We show that seasonal snow in coastal Greenland has large spatial and temporal variability and find little evidence of trends in snow cover characteristics.
Alexander C. Ronan, Robert L. Hawley, and Jonathan W. Chipman
The Cryosphere, 18, 5673–5683, https://doi.org/10.5194/tc-18-5673-2024, https://doi.org/10.5194/tc-18-5673-2024, 2024
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We generate a 2010–2021 time series of CryoSat-2 waveform shape metrics on the Greenland Ice Sheet, and we compare it to CryoSat-2 elevation data to investigate the reliability of two algorithms used to derive elevations from the SIRAL radar altimeter. Retracked elevations are found to depend on a waveform's leading-edge width in the dry-snow zone. The study indicates that retracking algorithms must consider significant climate events and snow conditions when assessing elevation change.
Eliot Jager, Fabien Gillet-Chaulet, Nicolas Champollion, Romain Millan, Heiko Goelzer, and Jérémie Mouginot
The Cryosphere, 18, 5519–5550, https://doi.org/10.5194/tc-18-5519-2024, https://doi.org/10.5194/tc-18-5519-2024, 2024
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Inspired by a previous intercomparison framework, our study better constrains uncertainties in glacier evolution using an innovative method to validate Bayesian calibration. Upernavik Isstrøm, one of Greenland's largest glaciers, has lost significant mass since 1985. By integrating observational data, climate models, human emissions, and internal model parameters, we project its evolution until 2100. We show that future human emissions are the main source of uncertainty in 2100, making up half.
Emma Pearce, Dimitri Zigone, Coen Hofstede, Andreas Fichtner, Joachim Rimpot, Sune Olander Rasmussen, Johannes Freitag, and Olaf Eisen
The Cryosphere, 18, 4917–4932, https://doi.org/10.5194/tc-18-4917-2024, https://doi.org/10.5194/tc-18-4917-2024, 2024
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Our study near EastGRIP camp in Greenland shows varying firn properties by direction (crucial for studying ice stream stability, structure, surface mass balance, and past climate conditions). We used dispersion curve analysis of Love and Rayleigh waves to show firn is nonuniform along and across the flow of an ice stream due to wind patterns, seasonal variability, and the proximity to the edge of the ice stream. This method better informs firn structure, advancing ice stream understanding.
Laura Carrea, Christopher J. Merchant, Richard I. Woolway, and Niall McCarroll
EGUsphere, https://doi.org/10.5194/egusphere-2024-2926, https://doi.org/10.5194/egusphere-2024-2926, 2024
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Lakes in Greenland serve as sentinel of climate change. Satellites can be used to monitor water temperature and ice. Using 28 years measurements from satellite, we conclude that lakes are overall warmer than previously thought. The lakes connected to the ice sheet are cooler than the rest because of cold glacial meltwater inflow. Change in water temperature can impact light availability, nutrient cycling, and oxygen levels crucial for lake ecosystem but can also have influence on the ice sheet.
Christiaan T. van Dalum, Willem Jan van de Berg, Srinidhi N. Gadde, Maurice van Tiggelen, Tijmen van der Drift, Erik van Meijgaard, Lambertus H. van Ulft, and Michiel R. van den Broeke
The Cryosphere, 18, 4065–4088, https://doi.org/10.5194/tc-18-4065-2024, https://doi.org/10.5194/tc-18-4065-2024, 2024
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We present a new version of the polar Regional Atmospheric Climate Model (RACMO), version 2.4p1, and show first results for Greenland, Antarctica and the Arctic. We provide an overview of all changes and investigate the impact that they have on the climate of polar regions. By comparing the results with observations and the output from the previous model version, we show that the model performs well regarding the surface mass balance of the ice sheets and near-surface climate.
Ellen Lucinda Mutter and Nicholas Holschuh
EGUsphere, https://doi.org/10.5194/egusphere-2024-2450, https://doi.org/10.5194/egusphere-2024-2450, 2024
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“Ice Penetrating Radar” is a technology that lets us see through ice sheets, capturing their organized, layered structure. But near the ice bottom, radar data are much more complicated, with signals that are disordered and often ignored. Here, we work to better understand these complex signals by comparing radar data to measurements of ice structure from ice cores. We show these signals reflect structural changes in the ice itself, and can inform our search for ancient climate records.
Michael S. Town, Hans Christian Steen-Larsen, Sonja Wahl, Anne-Katrine Faber, Melanie Behrens, Tyler R. Jones, and Arny Sveinbjornsdottir
The Cryosphere, 18, 3653–3683, https://doi.org/10.5194/tc-18-3653-2024, https://doi.org/10.5194/tc-18-3653-2024, 2024
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A polar snow isotope dataset from northeast Greenland shows that snow changes isotopically after deposition. Summer snow sometimes enriches in oxygen-18, making it seem warmer than it actually was when the snow fell. Deuterium excess sometimes changes after deposition, making the snow seem to come from warmer, closer, or more humid places. After a year of aging, deuterium excess of summer snow layers always increases. Reinterpretation of deuterium excess used in climate models is necessary.
Erik Loebel, Mirko Scheinert, Martin Horwath, Angelika Humbert, Julia Sohn, Konrad Heidler, Charlotte Liebezeit, and Xiao Xiang Zhu
The Cryosphere, 18, 3315–3332, https://doi.org/10.5194/tc-18-3315-2024, https://doi.org/10.5194/tc-18-3315-2024, 2024
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Comprehensive datasets of calving-front changes are essential for studying and modeling outlet glaciers. Current records are limited in temporal resolution due to manual delineation. We use deep learning to automatically delineate calving fronts for 23 glaciers in Greenland. Resulting time series resolve long-term, seasonal, and subseasonal patterns. We discuss the implications of our results and provide the cryosphere community with a data product and an implementation of our processing system.
Mikkel Langgaard Lauritzen, Anne Munck Solgaard, Nicholas Mossor Rathmann, Bo Møllesøe Vinther, Aslak Grindsted, Brice Noël, Guðfinna Aðalgeirsdóttir, and Christine Schøtt Hvidberg
EGUsphere, https://doi.org/10.5194/egusphere-2024-2223, https://doi.org/10.5194/egusphere-2024-2223, 2024
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We study the Holocene period, which started about 11,700 years ago, through 841 computer simulations to better understand the history of the Greenland Ice Sheet. We accurately match historical surface elevation records, verifying our model. The simulations show that an ice bridge that used to connect the Greenland ice sheet to Canada collapsed around 4,900 years ago and still influences the ice sheet. Over the past 500 years, the Greenland ice sheet has contributed 12 millimeters to sea levels.
Anna Puggaard, Nicolaj Hansen, Ruth Mottram, Thomas Nagler, Stefan Scheiblauer, Sebastian B. Simonsen, Louise S. Sørensen, Jan Wuite, and Anne M. Solgaard
EGUsphere, https://doi.org/10.5194/egusphere-2024-1108, https://doi.org/10.5194/egusphere-2024-1108, 2024
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Regional climate models are currently the only source for assessing the melt volume on a global scale of the Greenland Ice Sheet. This study compares the modeled melt volume with observations from weather stations and melt extent observed from ASCAT to assess the performance of the models. It highlights the importance of critically evaluating model outputs with high-quality satellite measurements to improve the understanding of variability among models.
Anja Rutishauser, Kirk M. Scanlan, Baptiste Vandecrux, Nanna B. Karlsson, Nicolas Jullien, Andreas P. Ahlstrøm, Robert S. Fausto, and Penelope How
The Cryosphere, 18, 2455–2472, https://doi.org/10.5194/tc-18-2455-2024, https://doi.org/10.5194/tc-18-2455-2024, 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.
Marco Marcer, Pierre-Allain Duvillard, Soňa Tomaškovičová, Steffen Ringsø Nielsen, André Revil, and Thomas Ingeman-Nielsen
The Cryosphere, 18, 1753–1771, https://doi.org/10.5194/tc-18-1753-2024, https://doi.org/10.5194/tc-18-1753-2024, 2024
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This study models present and future rock wall temperatures in the mountains near Sisimiut, creating knowledge on mountain permafrost in Greenland for the first time. Bedrock is mostly frozen but also has temperatures near 0 oC, making it very sensitive to climate changes. Future climatic scenarios indicate a reduction in frozen rock wall areas. Since mountain permafrost thaw is linked to an increase in landslides, these results call for more efforts addressing mountain permafrost in Greenland.
Guy J. G. Paxman, Stewart S. R. Jamieson, Aisling M. Dolan, and Michael J. Bentley
The Cryosphere, 18, 1467–1493, https://doi.org/10.5194/tc-18-1467-2024, https://doi.org/10.5194/tc-18-1467-2024, 2024
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This study uses airborne radar data and satellite imagery to map mountainous topography hidden beneath the Greenland Ice Sheet. We find that the landscape records the former extent and configuration of ice masses that were restricted to areas of high topography. Computer models of ice flow indicate that valley glaciers eroded this landscape millions of years ago when local air temperatures were at least 4 °C higher than today and Greenland’s ice volume was < 10 % of that of the modern ice sheet.
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.
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.
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.
Lauren D. Rawlins, David M. Rippin, Andrew J. Sole, Stephen J. Livingstone, and Kang Yang
The Cryosphere, 17, 4729–4750, https://doi.org/10.5194/tc-17-4729-2023, https://doi.org/10.5194/tc-17-4729-2023, 2023
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We map and quantify surface rivers and lakes at Humboldt Glacier to examine seasonal evolution and provide new insights of network configuration and behaviour. A widespread supraglacial drainage network exists, expanding up the glacier as seasonal runoff increases. Large interannual variability affects the areal extent of this network, controlled by high- vs. low-melt years, with late summer network persistence likely preconditioning the surface for earlier drainage activity the following year.
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.
Johanna Beckmann and Ricarda Winkelmann
The Cryosphere, 17, 3083–3099, https://doi.org/10.5194/tc-17-3083-2023, https://doi.org/10.5194/tc-17-3083-2023, 2023
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Over the past decade, Greenland has experienced several extreme melt events.
With progressing climate change, such extreme melt events can be expected to occur more frequently and potentially become more severe and persistent.
Strong melt events may considerably contribute to Greenland's mass loss, which in turn strongly determines future sea level rise. How important these extreme melt events could be in the future is assessed in this study for the first time.
Angelika Humbert, Veit Helm, Niklas Neckel, Ole Zeising, Martin Rückamp, Shfaqat Abbas Khan, Erik Loebel, Jörg Brauchle, Karsten Stebner, Dietmar Gross, Rabea Sondershaus, and Ralf Müller
The Cryosphere, 17, 2851–2870, https://doi.org/10.5194/tc-17-2851-2023, https://doi.org/10.5194/tc-17-2851-2023, 2023
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The largest floating glacier mass in Greenland, the 79° N Glacier, is showing signs of instability. We investigate how crack formation at the glacier's calving front has changed over the last decades by using satellite imagery and airborne data. The calving front is about to lose contact to stabilizing ice islands. Simulations show that the glacier will accelerate as a result of this, leading to an increase in ice discharge of more than 5.1 % if its calving front retreats by 46 %.
Megan Thompson-Munson, Nander Wever, C. Max Stevens, Jan T. M. Lenaerts, and Brooke Medley
The Cryosphere, 17, 2185–2209, https://doi.org/10.5194/tc-17-2185-2023, https://doi.org/10.5194/tc-17-2185-2023, 2023
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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.
Yubin Fan, Chang-Qing Ke, Xiaoyi Shen, Yao Xiao, Stephen J. Livingstone, and Andrew J. Sole
The Cryosphere, 17, 1775–1786, https://doi.org/10.5194/tc-17-1775-2023, https://doi.org/10.5194/tc-17-1775-2023, 2023
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We used the new-generation ICESat-2 altimeter to detect and monitor active subglacial lakes in unprecedented spatiotemporal detail. We created a new inventory of 18 active subglacial lakes as well as their elevation and volume changes during 2019–2020, which provides an improved understanding of how the Greenland subglacial water system operates and how these lakes are fed by water from the ice surface.
Romilly Harris Stuart, Anne-Katrine Faber, Sonja Wahl, Maria Hörhold, Sepp Kipfstuhl, Kristian Vasskog, Melanie Behrens, Alexandra M. Zuhr, and Hans Christian Steen-Larsen
The Cryosphere, 17, 1185–1204, https://doi.org/10.5194/tc-17-1185-2023, https://doi.org/10.5194/tc-17-1185-2023, 2023
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This empirical study uses continuous daily measurements from the Greenland Ice Sheet to document changes in surface snow properties. Consistent changes in snow isotopic composition are observed in the absence of deposition due to surface processes, indicating the isotopic signal of deposited precipitation is not always preserved. Our observations have potential implications for the interpretation of water isotopes in ice cores – historically assumed to reflect isotopic composition at deposition.
Adrien Wehrlé, Martin P. Lüthi, and Andreas Vieli
The Cryosphere, 17, 309–326, https://doi.org/10.5194/tc-17-309-2023, https://doi.org/10.5194/tc-17-309-2023, 2023
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We characterized short-lived episodes of ice mélange weakening (IMW) at the front of three major Greenland outlet glaciers. Through a continuous detection at the front of Kangerdlugssuaq Glacier during the June-to-September period from 2018 to 2021, we found that 87 % of the IMW episodes occurred prior to a large-scale calving event. Using a simple model for ice mélange motion, we further characterized the IMW process as self-sustained through the existence of an IMW–calving feedback.
Taryn E. Black and Ian Joughin
The Cryosphere, 17, 1–13, https://doi.org/10.5194/tc-17-1-2023, https://doi.org/10.5194/tc-17-1-2023, 2023
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The frontal positions of most ice-sheet-based glaciers in Greenland vary seasonally. On average, these glaciers begin retreating in May and begin advancing in October, and the difference between their most advanced and most retreated positions is 220 m. The timing may be related to the timing of melt on the ice sheet, and the seasonal length variation may be related to glacier speed. These seasonal variations can affect glacier behavior and, consequently, how much ice is lost from the ice sheet.
Trevor R. Hillebrand, Matthew J. Hoffman, Mauro Perego, Stephen F. Price, and Ian M. Howat
The Cryosphere, 16, 4679–4700, https://doi.org/10.5194/tc-16-4679-2022, https://doi.org/10.5194/tc-16-4679-2022, 2022
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We estimate that Humboldt Glacier, northern Greenland, will contribute 5.2–8.7 mm to global sea level in 2007–2100, using an ensemble of model simulations constrained by observations of glacier retreat and speedup. This is a significant fraction of the 40–140 mm from the whole Greenland Ice Sheet predicted by the recent ISMIP6 multi-model ensemble, suggesting that calibrating models against observed velocity changes could result in higher estimates of 21st century sea-level rise from Greenland.
Evan Carnahan, Ginny Catania, and Timothy C. Bartholomaus
The Cryosphere, 16, 4305–4317, https://doi.org/10.5194/tc-16-4305-2022, https://doi.org/10.5194/tc-16-4305-2022, 2022
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The Greenland Ice Sheet primarily loses mass through increased ice discharge. We find changes in discharge from outlet glaciers are initiated by ocean warming, which causes a change in the balance of forces resisting gravity and leads to acceleration. Vulnerable conditions for sustained retreat and acceleration are predetermined by the glacier-fjord geometry and exist around Greenland, suggesting increases in ice discharge may be sustained into the future despite a pause in ocean warming.
Raf M. Antwerpen, Marco Tedesco, Xavier Fettweis, Patrick Alexander, and Willem Jan van de Berg
The Cryosphere, 16, 4185–4199, https://doi.org/10.5194/tc-16-4185-2022, https://doi.org/10.5194/tc-16-4185-2022, 2022
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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.
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.
Ioanna Karagali, Magnus Barfod Suhr, Ruth Mottram, Pia Nielsen-Englyst, Gorm Dybkjær, Darren Ghent, and Jacob L. Høyer
The Cryosphere, 16, 3703–3721, https://doi.org/10.5194/tc-16-3703-2022, https://doi.org/10.5194/tc-16-3703-2022, 2022
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Ice surface temperature (IST) products were used to develop the first multi-sensor, gap-free Level 4 (L4) IST product of the Greenland Ice Sheet (GIS) for 2012, when a significant melt event occurred. For the melt season, mean IST was −15 to −1 °C, and almost the entire GIS experienced at least 1 to 5 melt days. Inclusion of the L4 IST to a surface mass budget (SMB) model improved simulated surface temperatures during the key onset of the melt season, where biases are typically large.
Michael Studinger, Serdar S. Manizade, Matthew A. Linkswiler, and James K. Yungel
The Cryosphere, 16, 3649–3668, https://doi.org/10.5194/tc-16-3649-2022, https://doi.org/10.5194/tc-16-3649-2022, 2022
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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.
Tiago Silva, Jakob Abermann, Brice Noël, Sonika Shahi, Willem Jan van de Berg, and Wolfgang Schöner
The Cryosphere, 16, 3375–3391, https://doi.org/10.5194/tc-16-3375-2022, https://doi.org/10.5194/tc-16-3375-2022, 2022
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To overcome internal climate variability, this study uses k-means clustering to combine NAO, GBI and IWV over the Greenland Ice Sheet (GrIS) and names the approach as the North Atlantic influence on Greenland (NAG). With the support of a polar-adapted RCM, spatio-temporal changes on SEB components within NAG phases are investigated. We report atmospheric warming and moistening across all NAG phases as well as large-scale and regional-scale contributions to GrIS mass loss and their interactions.
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, and Michael Studinger
The Cryosphere, 16, 3033–3049, https://doi.org/10.5194/tc-16-3033-2022, https://doi.org/10.5194/tc-16-3033-2022, 2022
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Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known, yet knowing this state is increasingly important to interpret modern changes in ice flow there. We produced a second synthesis of knowledge of the basal thermal state of the ice sheet using airborne and satellite observations and numerical models. About one-third of the ice sheet’s bed is likely thawed; two-fifths is likely frozen; and the remainder is too uncertain to specify.
Michael A. Cooper, Paulina Lewińska, William A. P. Smith, Edwin R. Hancock, Julian A. Dowdeswell, and David M. Rippin
The Cryosphere, 16, 2449–2470, https://doi.org/10.5194/tc-16-2449-2022, https://doi.org/10.5194/tc-16-2449-2022, 2022
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Here we use old photographs gathered several decades ago to expand the temporal record of glacier change in part of East Greenland. This is important because the longer the record of past glacier change, the better we are at predicting future glacier behaviour. Our work also shows that despite all these glaciers retreating, the rate at which they do this varies markedly. It is therefore important to consider outlet glaciers from Greenland individually to take account of this differing behaviour.
Joshua K. Cuzzone, Nicolás E. Young, Mathieu Morlighem, Jason P. Briner, and Nicole-Jeanne Schlegel
The Cryosphere, 16, 2355–2372, https://doi.org/10.5194/tc-16-2355-2022, https://doi.org/10.5194/tc-16-2355-2022, 2022
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We use an ice sheet model to determine what influenced the Greenland Ice Sheet to retreat across a portion of southwestern Greenland during the Holocene (about the last 12 000 years). Our simulations, constrained by observations from geologic markers, show that atmospheric warming and ice melt primarily caused the ice sheet to retreat rapidly across this domain. We find, however, that iceberg calving at the interface where the ice meets the ocean significantly influenced ice mass change.
Martin Rückamp, Thomas Kleiner, and Angelika Humbert
The Cryosphere, 16, 1675–1696, https://doi.org/10.5194/tc-16-1675-2022, https://doi.org/10.5194/tc-16-1675-2022, 2022
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We present a comparative modelling study between the full-Stokes (FS) and Blatter–Pattyn (BP) approximation applied to the Northeast Greenland Ice Stream. Both stress regimes are implemented in one single ice sheet code to eliminate numerical issues. The simulations unveil minor differences in the upper ice stream but become considerable at the grounding line of the 79° North Glacier. Model differences are stronger for a power-law friction than a linear friction law.
Daniel Clarkson, Emma Eastoe, and Amber Leeson
The Cryosphere, 16, 1597–1607, https://doi.org/10.5194/tc-16-1597-2022, https://doi.org/10.5194/tc-16-1597-2022, 2022
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The Greenland ice sheet has seen large amounts of melt in recent years, and accurately modelling temperatures is vital to understand how much of the ice sheet is melting. We estimate the probability of melt from ice surface temperature data to identify which areas of the ice sheet have experienced melt and estimate temperature quantiles. Our results suggest that for large areas of the ice sheet, melt has become more likely over the past 2 decades and high temperatures are also becoming warmer.
Benjamin Joseph Davison, Tom Cowton, Andrew Sole, Finlo Cottier, and Pete Nienow
The Cryosphere, 16, 1181–1196, https://doi.org/10.5194/tc-16-1181-2022, https://doi.org/10.5194/tc-16-1181-2022, 2022
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The ocean is an important driver of Greenland glacier retreat. Icebergs influence ocean temperature in the vicinity of glaciers, which will affect glacier retreat rates, but the effect of icebergs on water temperature is poorly understood. In this study, we use a model to show that icebergs cause large changes to water properties next to Greenland's glaciers, which could influence ocean-driven glacier retreat around Greenland.
Taryn E. Black and Ian Joughin
The Cryosphere, 16, 807–824, https://doi.org/10.5194/tc-16-807-2022, https://doi.org/10.5194/tc-16-807-2022, 2022
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We used satellite images to create a comprehensive record of annual glacier change in northwest Greenland from 1972 through 2021. We found that nearly all glaciers in our study area have retreated and glacier retreat accelerated from around 1996. Comparing these results with climate data, we found that glacier retreat is most sensitive to water runoff and moderately sensitive to ocean temperatures. These can affect glacier fronts in several ways, so no process clearly dominates glacier retreat.
Cited articles
Alley, R., Spencer, M., and Anandakrishnan, S.: Ice-sheet mass balance: assessment, attribution and prognosis, Ann. Glaciol., 46, 1–7, 2007.
Arendt, A., Bolch, T., Cogley, J. G., Gardner, A., Hagen, J.-O., Hock, R., Kaser, G., Pfeffer, W. T., Moholdt, G., Paul, F., V. Radic, Andreassen, L., Bajracharya, S., Beedle, M., Berthier, E., Bhambri, R., Bliss, A., Brown, I., Burgess, E., Burgess, D., Cawkwell, F., Chinn, T., Copland, L., Davies, B., De Angelis, H., Dolgova, E., Filbert, K., Forester, R., Fountain, A., Frey, H., Giffen, B., Glasser, N., Gurney, S., Hagg, W., Hall, D., Haritashya, U. K., Hartmann, G., Helm, C., Herreid, S., Howat, I., Kapustin, G., Khromova, T., Kienholz, C., Koenig, M., Kohler, J., Kriegel, D., Kutuzov, S., Lavrentiev, I., LeBris, R., Lund, J., Manley, W., Mayer, C., Miles, E., Li, X., Menounos, B., Mercer, A., Moelg, N., Mool, P., Nosenko, G., Negrete, A., Nuth, C., Pettersson, R., and Racoviteanu, A., Randolph Glacier Inventory version 2.0: A Dataset of Global Glacier Outlines. Global Land Ice Measurements from Space, Boulder Colorado, USA. Digital Media, 2012.
Barletta, V. R., Sørensen, L. S., and Forsberg, R.: Scatter of mass changes estimates at basin scale for Greenland and Antarctica, The Cryosphere, 7, 1411–1432, https://doi.org/10.5194/tc-7-1411-2013, 2013.
Bolch, T., Sandberg Sørensen, L., Simonsen, S., Mölg, N., Machguth, H., Rastner, P., and Paul, F.: Mass loss of Greenland's glaciers and ice caps 2003–2008 revealed from ICESat laser altimetry data, Geophys. Res. Lett., 40, 875–881, https://doi.org/10.1002/grl.50270, 2013.
Chandler, D., Hubbard, A., Hubbard, B., and Nienow, P.: A Monte Carlo error analysis for basal sliding velocity calculations, J. Geophys. Res., 111, F04005, https://doi.org/10.1029/2006JF000476, 2006.
Chao, B., O'Connor, W., Chang, A., Hall, D., and Foster, J.: Snow load effect on the Earth's rotation and gravitational field, 1979–1985, J. Geophys. Res., 92, 9415–9422, 1987.
Citterio, M. and Ahlstrøm, A. P.: Brief communication "The aerophotogrammetric map of Greenland ice masses", The Cryosphere, 7, 445–449, https://doi.org/10.5194/tc-7-445-2013, 2013.
Colgan, W., Pfeffer, W. T., Rajaram, H., Abdalati, W., and Balog, J.: Monte Carlo ice flow modeling projects a new stable configuration for Columbia Glacier, Alaska, c. 2020, The Cryosphere, 6, 1395–1409, https://doi.org/10.5194/tc-6-1395-2012, 2012.
Colgan, W., Luthcke, S., Abdalati, W., and Citterio, M.: Interactive comment on "Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas", The Cryosphere Discuss., 7, C1191–C1201, https://doi.org/10.5194/tcd-7-3417-2013, 2013.
Gardner, A., Moholdt, G., Wouters, B., Wolken, G., Burgess, D., Sharp, M., Cogley, J., Braun, C., and Labine, C: Sharply increased mass loss from glaciers and ice caps in the Canadian Arctic Archipelago, Nature, 473, 357–360, https://doi.org/10.1038/nature10089, 2011.
Gardner, A., Moholdt, G., Cogley, J., Wouters, B., Arendt, A., Wahr, J., Berthier, E., Hock, R., Pfeffer, W., Kaser, G., Ligtenberg, S., Bolch, T., Sharp, M., Hagen, J., van den Broeke, M., and Paul, F.: A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009, Science, 340, 852–857, https://doi.org/10.1126/science.1234532, 2013.
Guo, J., Duan, X., and Shum, C.: Non-isotropic Gaussian smoothing and leakage reduction for determining mass changes over land and ocean using GRACE data, Geophys. J. Int., 181, 290–302, 2010.
Horwath, M. and Dietrich, R.: Signal and error in mass change inferences from GRACE: the case of Antarctica, Geophys. J. Int., 177, 849–864, https://doi.org/10.1111/j.1365-246X.2009.04139.x, 2009.
Jacob, T., Wahr, J., Pfeffer, W., and Swenson, S.: Recent contributions of glaciers and ice caps to sea level rise, Nature, 482, 514–518, 2012.
Jóhannesson, T., Raymond, C., and Waddington, E.: A Simple Method for Determining the Response Time of Glaciers, in: Glacier Fluctuations and Climatic Change, edited by: Oerlemans, J., 343–352, ISBN 978-90-481-4040-4, 1989.
Longuevergne, L., Scanlon, B., and Wilson, C.: GRACE Hydrological estimates for small basins: Evaluating processing approaches on the High Plains Aquifer, USA, Water Resour. Res., 46, W11517, https://doi.org/10.1029/2009WR008564, 2010.
Luthcke, S., Zwally, H., Abdalati, W., Rowlands, D., Ray, R., Nerem, R., Lemoine, F., McCarthy, J., and Chinn, D.: Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations, Science, 314, 1286–1289, 2006.
Luthcke, S., Sabaka, T., Loomis, B., Arendt, A., McCarthy, J., and Camp, J.: Antarctica, Greenland and Gulf of Alaska land-ice evolution from an iterated GRACE global mascon solution, J. Glaciol., 59, 613–631, https://doi.org/10.3189/2013JoG12J147, 2013.
McGrath, D., Colgan, W., Bayou, N., Muto, A., and Steffen, K.: Recent warming at Summit, Greenland: Global context and implications, Geophys. Res. Lett., 40, 2091–2096, https://doi.org/10.1002/grl.50456, 2013.
Meehl, G., Stocker, T. F., Collins, W. D., Friedlingstein, P., Gaye, A. T., Gregory, J. M., Kitoh, A., Knutti, R., Murphy, J. M., Noda, A., Raper, S. C. B., Watterson, I. G., Weaver A. J., and Zhao, Z.-C.: Global Climate Projections, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, 2007.
Muto, A., Scambos, T., Steffen, K., Slater, A., and Clow, G.: Recent surface temperature trends in the interior of East Antarctica from borehole firn temperature measurements and geophysical inverse methods Geophys. Res. Lett., 38, L15502, https://doi.org/10.1029/2011GL048086, 2011.
Nye, J.: The response of glaciers and ice-sheets to seasonal and climatic changes, P. Roy. Soc. A, 256, 559–584, https://doi.org/10.1098/rspa.1960.0127, 1960.
Pritchard, H., Lutchke, S., and Fleming, A.: Understanding ice-sheet mass balance: progress in satellite altimetry and gravimetry J. Glaciol., 56, 1151–1161, 2010.
Rastner, P., Bolch, T., Mölg, N., Machguth, H., Le Bris, R., and Paul, F.: The first complete inventory of the local glaciers and ice caps on Greenland, The Cryosphere, 6, 1483–1495, https://doi.org/10.5194/tc-6-1483-2012, 2012.
Rignot, E., Box, J., Burgess, E., and Hanna, E.: Mass balance of the Greenland ice sheet from 1958 to 2007, Geophys. Res. Lett., 35, L20502, https://doi.org/10.1029/2008GL035417, 2008.
Sasgen, I., van den Broeke, M., Bamber, J., Rignot, E., Sørensen, L., Wouters, B., Martinec, Z., Velicogna, I., and Simonsen, S.: Timing and origin of recent regional ice-mass loss in Greenland, Earth Planet. Sc. Lett., 334, 293–303, 2012.
Schrama, E. and Wouters, B.: Revisiting Greenland ice sheet mass loss observed by GRACE, J. Geophys. Res., 116, B02407, https://doi.org/10.1029/2009JB006847, 2011.
Shepherd, A., Ivins, E., Geruo, A., Barletta, V., Bentley, M., Bettadpur, S., Briggs, K., Bromwich, D., Forsberg, R., Galin, N., Horwath, M., Jacobs, S., Joughin, I., King, M., Lenaerts, J., Li, J., Ligtenberg, S., Luckman, A., Luthcke, S., McMillan, M., Meister, R., Milne, G., Mouginot, J., Muir, A., Nicolas, J., Paden, J., Payne, A., Pritchard, H., Rignot, E., Rott, H., Sørensen, L., Scambos, T., Scheuchl, B., Schrama, E., Smith, B., Sundal, A., van Angelen, J., van de Berg, W., van den Broeke, M., Vaughan, D., Velicogna, I., Wahr, J., Whitehouse, P., Wingham, D., Yi, D., Young, D., and Zwally, H.: A Reconciled Estimate of Ice-Sheet Mass Balance, Science, 338, 1183–119, 2012.
Simons, F., Dahlen, F., and Wieczorek, M.: Spatiospectral concentration on a sphere, J. Soc. Ind. Appl. Math., 48, 504–536, https://doi.org/10.1137/S0036144504445765, 2006.
Velicogna, I. and Wahr, J.: Greenland mass balance from GRACE, Geophys. Res. Lett., 32, L18505, https://doi.org/10.1029/2005GL023955, 2005.
Velicogna, I. and Wahr, J.: Acceleration of Greenland ice mass loss in spring 2004, Nature, 443, 329–331, https://doi.org/10.1038/nature05168, 2006.
Vernon, C. L., Bamber, J. L., Box, J. E., van den Broeke, M. R., Fettweis, X., Hanna, E., and Huybrechts, P.: Surface mass balance model intercomparison for the Greenland ice sheet, The Cryosphere, 7, 599–614, https://doi.org/10.5194/tc-7-599-2013, 2013.
Zwally, H., Li, J., Brenner, A., Beckley, M., Cornejo, H., DiMarzio, J., Giovinetto, M., Neumann, T., Robbins, J., Saba, J., Yi, D., and Wang, W.: Greenland ice sheet mass balance: distribution of increased mass loss with climate warming; 2003–07 versus 1992–2002, J. Glaciol., 57, 88–102, 2011.
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