Articles | Volume 13, issue 3
https://doi.org/10.5194/tc-13-845-2019
© Author(s) 2019. 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-13-845-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
11 Mar 2019
Research article |
| 11 Mar 2019
| 11 Mar 2019
Firn data compilation reveals widespread decrease of firn air content in western Greenland
Department of Glaciology and Climate, Geological Survey of Denmark
and Greenland, Copenhagen, Denmark
Department of Civil Engineering, Technical University of Denmark,
Kongens Lyngby, Denmark
Michael MacFerrin
Cooperative Institute for Research in Environmental Sciences,
University of Colorado, Boulder, CO, USA
Horst Machguth
Department of Geosciences, University of Fribourg, Fribourg,
Switzerland
Department of Geography, University of Zurich, Zurich, Switzerland
William T. Colgan
Department of Glaciology and Climate, Geological Survey of Denmark
and Greenland, Copenhagen, Denmark
Dirk van As
Department of Glaciology and Climate, Geological Survey of Denmark
and Greenland, Copenhagen, Denmark
Achim Heilig
Department of Earth and Environmental Sciences, Ludwig Maximilian University, Munich, Germany
C. Max Stevens
Department of Earth and Space Sciences, University of Washington, Seattle,
WA, USA
Charalampos Charalampidis
Bavarian Academy of Sciences and Humanities, Munich, Germany
Robert S. Fausto
Department of Glaciology and Climate, Geological Survey of Denmark
and Greenland, Copenhagen, Denmark
Elizabeth M. Morris
Scott Polar Research Institute, Cambridge University, Cambridge, UK
Ellen Mosley-Thompson
Byrd Polar and Climate Research Center and Department of Geography,
Ohio State University, Columbus, OH, USA
Lora Koenig
National Snow and Ice Data Center, University of Colorado, Boulder,
CO, USA
Lynn N. Montgomery
National Snow and Ice Data Center, University of Colorado, Boulder,
CO, USA
Clément Miège
Department of Geography, Rutgers University, Piscataway, NJ, USA
Sebastian B. Simonsen
DTU Space, National Space Institute, Department of Geodynamics,
Technical University of Denmark, Kongens Lyngby, Denmark
Thomas Ingeman-Nielsen
Department of Civil Engineering, Technical University of Denmark,
Kongens Lyngby, Denmark
Jason E. Box
Department of Glaciology and Climate, Geological Survey of Denmark
and Greenland, Copenhagen, Denmark
Related authors
Alamgir Hossan, Andreas Colliander, Baptiste Vandecrux, Nicole-Jeanne Schlegel, Joel Harper, Shawn Marshall, and Julie Z. Miller
EGUsphere, https://doi.org/10.5194/egusphere-2024-2563, https://doi.org/10.5194/egusphere-2024-2563, 2024
Short summary
Short summary
We used L-band observations from the SMAP mission to quantify the surface and subsurface liquid water amounts (LWA) in the percolation zone of the Greenland ice sheet. The algorithm is described, and the validation results are provided. The results demonstrate the potential for creating an LWA data product across GrIS, which will advance our understanding of ice sheet physical processes for better projection of Greenland’s contribution to global sea level rise.
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
Short summary
Short summary
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.
Baptiste Vandecrux, Robert S. Fausto, Jason E. Box, Federico Covi, Regine Hock, Åsa K. Rennermalm, Achim Heilig, Jakob Abermann, Dirk van As, Elisa Bjerre, Xavier Fettweis, Paul C. J. P. Smeets, Peter Kuipers Munneke, Michiel R. van den Broeke, Max Brils, Peter L. Langen, Ruth Mottram, and Andreas P. Ahlstrøm
The Cryosphere, 18, 609–631, https://doi.org/10.5194/tc-18-609-2024, https://doi.org/10.5194/tc-18-609-2024, 2024
Short summary
Short summary
How fast is the Greenland ice sheet warming? In this study, we compiled 4500+ temperature measurements at 10 m below the ice sheet surface (T10m) from 1912 to 2022. We trained a machine learning model on these data and reconstructed T10m for the ice sheet during 1950–2022. After a slight cooling during 1950–1985, the ice sheet warmed at a rate of 0.7 °C per decade until 2022. Climate models showed mixed results compared to our observations and underestimated the warming in key regions.
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
Short summary
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).
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
Short summary
Short summary
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.
Nicolaj Hansen, Peter L. Langen, Fredrik Boberg, Rene Forsberg, Sebastian B. Simonsen, Peter Thejll, Baptiste Vandecrux, and Ruth Mottram
The Cryosphere, 15, 4315–4333, https://doi.org/10.5194/tc-15-4315-2021, https://doi.org/10.5194/tc-15-4315-2021, 2021
Short summary
Short summary
We have used computer models to estimate the Antarctic surface mass balance (SMB) from 1980 to 2017. Our estimates lies between 2473.5 ± 114.4 Gt per year and 2564.8 ± 113.7 Gt per year. To evaluate our models, we compared the modelled snow temperatures and densities to in situ measurements. We also investigated the spatial distribution of the SMB. It is very important to have estimates of the Antarctic SMB because then it is easier to understand global sea level changes.
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
Short summary
Short summary
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.
Baptiste Vandecrux, Ruth Mottram, Peter L. Langen, Robert S. Fausto, Martin Olesen, C. Max Stevens, Vincent Verjans, Amber Leeson, Stefan Ligtenberg, Peter Kuipers Munneke, Sergey Marchenko, Ward van Pelt, Colin R. Meyer, Sebastian B. Simonsen, Achim Heilig, Samira Samimi, Shawn Marshall, Horst Machguth, Michael MacFerrin, Masashi Niwano, Olivia Miller, Clifford I. Voss, and Jason E. Box
The Cryosphere, 14, 3785–3810, https://doi.org/10.5194/tc-14-3785-2020, https://doi.org/10.5194/tc-14-3785-2020, 2020
Short summary
Short summary
In the vast interior of the Greenland ice sheet, snow accumulates into a thick and porous layer called firn. Each summer, the firn retains part of the meltwater generated at the surface and buffers sea-level rise. In this study, we compare nine firn models traditionally used to quantify this retention at four sites and evaluate their performance against a set of in situ observations. We highlight limitations of certain model designs and give perspectives for future model development.
Achim Heilig, Olaf Eisen, Martin Schneebeli, Michael MacFerrin, C. Max Stevens, Baptiste Vandecrux, and Konrad Steffen
The Cryosphere, 14, 385–402, https://doi.org/10.5194/tc-14-385-2020, https://doi.org/10.5194/tc-14-385-2020, 2020
Short summary
Short summary
We investigate the spatial representativeness of point observations of snow accumulation in SW Greenland. Such analyses have rarely been conducted but are necessary to link regional-scale observations from, e.g., remote-sensing data to firn cores and snow pits. The presented data reveal a low regional variability in density but snow depth can vary significantly. It is necessary to combine pits with spatial snow depth data to increase the regional representativeness of accumulation observations.
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, and Javed Hassan
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-348, https://doi.org/10.5194/essd-2024-348, 2024
Preprint under review for ESSD
Short summary
Short summary
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 useful for GIS ice sheet modelling.
Alamgir Hossan, Andreas Colliander, Baptiste Vandecrux, Nicole-Jeanne Schlegel, Joel Harper, Shawn Marshall, and Julie Z. Miller
EGUsphere, https://doi.org/10.5194/egusphere-2024-2563, https://doi.org/10.5194/egusphere-2024-2563, 2024
Short summary
Short summary
We used L-band observations from the SMAP mission to quantify the surface and subsurface liquid water amounts (LWA) in the percolation zone of the Greenland ice sheet. The algorithm is described, and the validation results are provided. The results demonstrate the potential for creating an LWA data product across GrIS, which will advance our understanding of ice sheet physical processes for better projection of Greenland’s contribution to global sea level rise.
Marcus Gastaldello, Enrico Mattea, Martin Hoelzle, and Horst Machguth
EGUsphere, https://doi.org/10.5194/egusphere-2024-2892, https://doi.org/10.5194/egusphere-2024-2892, 2024
Short summary
Short summary
Inside the highest glaciers of the Alps lies an invaluable archive of data revealing the Earth's historic climate. However, as the atmosphere warms due to climate change, so does the glaciers' internal temperature – threatening the future longevity of these records. Using our customised Python model, validated by on-site measurements, we show how a doubling in surface melt has caused a warming of 1.5 °C in the past 21 years and explore the challenges of modelling in complex mountainous terrain.
Kirk M. Scanlan, Anja Rutishauser, and Sebastian B. Simonsen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2832, https://doi.org/10.5194/egusphere-2024-2832, 2024
Short summary
Short summary
In this paper we investigate how to interpret Greenland surface roughness derived from reflected radar altimetry signals. Based on a comparison to conventional laser altimetry results, we 1) define a new mapping between the radar surface echo power strengths and surface roughness and 2) contextualize the horizontal lengths over which this roughness is representative. This work provides critical insight into how these observations integrate into Greenland Ice Sheet mass balance modeling.
Horst Machguth, Andrew Tedstone, Peter Kuipers Munneke, Max Brils, Brice Noël, Nicole Clerx, Nicolas Jullien, Xavier Fettweis, and Michiel van den Broeke
EGUsphere, https://doi.org/10.5194/egusphere-2024-2750, https://doi.org/10.5194/egusphere-2024-2750, 2024
Short summary
Short summary
Due to increasing air temperatures, surface melt expands to higher elevations on the Greenland ice sheet. This is visible on satellite imagery in the form of rivers of meltwater running across the surface of the ice sheet. We compare model results of meltwater at high elevations on the ice sheet to satellite observations. We find that each of the models shows strengths and weaknesses. A detailed look into the model results reveals potential reasons for the differences between models.
Renée M. Fredensborg Hansen, Henriette Skourup, Eero Rinne, Arttu Jutila, Isobel R. Lawrence, Andrew Shepherd, Knut V. Høyland, Jilu Li, Fernando Rodriguez-Morales, Sebastian B. Simonsen, Jeremy Wilkinson, Gaelle Veyssiere, Donghui Yi, René Forsberg, and Taniâ G. D. Casal
EGUsphere, https://doi.org/10.5194/egusphere-2024-2854, https://doi.org/10.5194/egusphere-2024-2854, 2024
Short summary
Short summary
In December 2022, an airborne campaign collected unprecedented coincident multi-frequency radar and lidar data over sea ice along a CryoSat-2 and ICESat-2 (CRYO2ICE) orbit in the Weddell Sea useful for evaluating microwave penetration. We found limited snow penetration at Ka- and Ku-bands, with significant contributions from the air-snow interface, contradicting traditional assumptions. These findings challenge current methods for comparing air- and spaceborne altimeter estimates of sea ice.
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
Short summary
Short summary
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.
Marissa E. Dattler, Brooke Medley, and C. Max Stevens
The Cryosphere, 18, 3613–3631, https://doi.org/10.5194/tc-18-3613-2024, https://doi.org/10.5194/tc-18-3613-2024, 2024
Short summary
Short summary
We developed an algorithm based on combining models and satellite observations to identify the presence of surface melt on the Antarctic Ice Sheet. We find that this method works similarly to previous methods by assessing 13 sites and the Larsen C ice shelf. Unlike previous methods, this algorithm is based on physical parameters, and updates to this method could allow the meltwater present on the Antarctic Ice Sheet to be quantified instead of simply detected.
Michael MacFerrin, Christopher Amante, Kelly Carignan, Matthew Love, and Elliot Lim
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-250, https://doi.org/10.5194/essd-2024-250, 2024
Preprint under review for ESSD
Short summary
Short summary
Here we present Earth TOPOgraphy (ETOPO) 2022, the latest iteration of NOAA’s global, seamless topographic-bathymetric dataset. ETOPO 2022 is a significant upgrade in resolution and accuracy from previous ETOPO releases, freely available in multiple data formats and resolutions for all uses (public or private), excepting navigation.
Nicolaj Hansen, Andrew Orr, Xun Zou, Fredrik Boberg, Thomas J. Bracegirdle, Ella Gilbert, Peter L. Langen, Matthew A. Lazzara, Ruth Mottram, Tony Phillips, Ruth Price, Sebastian B. Simonsen, and Stuart Webster
The Cryosphere, 18, 2897–2916, https://doi.org/10.5194/tc-18-2897-2024, https://doi.org/10.5194/tc-18-2897-2024, 2024
Short summary
Short summary
We investigated a melt event over the Ross Ice Shelf. We use regional climate models and a firn model to simulate the melt and compare the results with satellite data. We find that the firn model aligned well with observed melt days in certain parts of the ice shelf. The firn model had challenges accurately simulating the melt extent in the western sector. We identified potential reasons for these discrepancies, pointing to limitations in the models related to representing the cloud properties.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Horst Machguth, Anja Eichler, Margit Schwikowski, Sabina Brütsch, Enrico Mattea, Stanislav Kutuzov, Martin Heule, Ryskul Usubaliev, Sultan Belekov, Vladimir N. Mikhalenko, Martin Hoelzle, and Marlene Kronenberg
The Cryosphere, 18, 1633–1646, https://doi.org/10.5194/tc-18-1633-2024, https://doi.org/10.5194/tc-18-1633-2024, 2024
Short summary
Short summary
In 2018 we drilled an 18 m ice core on the summit of Grigoriev ice cap, located in the Tien Shan mountains of Kyrgyzstan. The core analysis reveals strong melting since the early 2000s. Regardless of this, we find that the structure and temperature of the ice have changed little since the 1980s. The probable cause of this apparent stability is (i) an increase in snowfall and (ii) the fact that meltwater nowadays leaves the glacier and thereby removes so-called latent heat.
Baptiste Vandecrux, Robert S. Fausto, Jason E. Box, Federico Covi, Regine Hock, Åsa K. Rennermalm, Achim Heilig, Jakob Abermann, Dirk van As, Elisa Bjerre, Xavier Fettweis, Paul C. J. P. Smeets, Peter Kuipers Munneke, Michiel R. van den Broeke, Max Brils, Peter L. Langen, Ruth Mottram, and Andreas P. Ahlstrøm
The Cryosphere, 18, 609–631, https://doi.org/10.5194/tc-18-609-2024, https://doi.org/10.5194/tc-18-609-2024, 2024
Short summary
Short summary
How fast is the Greenland ice sheet warming? In this study, we compiled 4500+ temperature measurements at 10 m below the ice sheet surface (T10m) from 1912 to 2022. We trained a machine learning model on these data and reconstructed T10m for the ice sheet during 1950–2022. After a slight cooling during 1950–1985, the ice sheet warmed at a rate of 0.7 °C per decade until 2022. Climate models showed mixed results compared to our observations and underestimated the warming in key regions.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Soňa Tomaškovičová and Thomas Ingeman-Nielsen
The Cryosphere, 18, 321–340, https://doi.org/10.5194/tc-18-321-2024, https://doi.org/10.5194/tc-18-321-2024, 2024
Short summary
Short summary
We present the results of a fully coupled modeling framework for simulating the ground thermal regime using only surface measurements to calibrate the thermal model. The heat conduction model is forced by surface ground temperature measurements and calibrated using the field measurements of time lapse apparent electrical resistivity. The resistivity-calibrated thermal model achieves a performance comparable to the traditional calibration of borehole temperature measurements.
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
Short summary
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).
Juditha Aga, Julia Boike, Moritz Langer, Thomas Ingeman-Nielsen, and Sebastian Westermann
The Cryosphere, 17, 4179–4206, https://doi.org/10.5194/tc-17-4179-2023, https://doi.org/10.5194/tc-17-4179-2023, 2023
Short summary
Short summary
This study presents a new model scheme for simulating ice segregation and thaw consolidation in permafrost environments, depending on ground properties and climatic forcing. It is embedded in the CryoGrid community model, a land surface model for the terrestrial cryosphere. We describe the model physics and functionalities, followed by a model validation and a sensitivity study of controlling factors.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
Short summary
Short summary
This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Nicolaj Hansen, Louise Sandberg Sørensen, Giorgio Spada, Daniele Melini, Rene Forsberg, Ruth Mottram, and Sebastian B. Simonsen
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-104, https://doi.org/10.5194/tc-2023-104, 2023
Preprint withdrawn
Short summary
Short summary
We use ICESat-2 to estimate the surface elevation change over Greenland and Antarctica in the period of 2018 to 2021. Numerical models have been used the compute the firn compaction and the vertical bedrock movement so non-mass-related elevation changes can be taken into account. We have made a parameterization of the surface density so we can convert the volume change to mass change. We find that Antarctica has lost 135.7±27.3 Gt per year, and the Greenland ice sheet 237.5±14.0 Gt per year.
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
Short summary
Short summary
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 %.
Mai Winstrup, Heidi Ranndal, Signe Hillerup Larsen, Sebastian Bjerregaard Simonsen, Kenneth David Mankoff, Robert Schjøtt Fausto, and Louise Sandberg Sørensen
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2023-224, https://doi.org/10.5194/essd-2023-224, 2023
Revised manuscript accepted for ESSD
Short summary
Short summary
Surface topography across the marginal zone of the Greenland Ice Sheet is constantly evolving. We here present four 500-meter resolution annual (2019–2022) summer DEMs (PRODEMs) of the Greenland ice sheet marginal zone, capturing all outlet glaciers of the ice sheet. The PRODEMs are based on fusion of CryoSat-2 radar altimetry and ICESat-2 laser altimetry. With their high spatial and temporal resolution, the PRODEMs will enable detailed studies of the changes in marginal ice sheet elevations.
Elizabeth R. Thomas, Diana O. Vladimirova, Dieter R. Tetzner, B. Daniel Emanuelsson, Nathan Chellman, Daniel A. Dixon, Hugues Goosse, Mackenzie M. Grieman, Amy C. F. King, Michael Sigl, Danielle G. Udy, Tessa R. Vance, Dominic A. Winski, V. Holly L. Winton, Nancy A. N. Bertler, Akira Hori, Chavarukonam M. Laluraj, Joseph R. McConnell, Yuko Motizuki, Kazuya Takahashi, Hideaki Motoyama, Yoichi Nakai, Franciéle Schwanck, Jefferson Cardia Simões, Filipe Gaudie Ley Lindau, Mirko Severi, Rita Traversi, Sarah Wauthy, Cunde Xiao, Jiao Yang, Ellen Mosely-Thompson, Tamara V. Khodzher, Ludmila P. Golobokova, and Alexey A. Ekaykin
Earth Syst. Sci. Data, 15, 2517–2532, https://doi.org/10.5194/essd-15-2517-2023, https://doi.org/10.5194/essd-15-2517-2023, 2023
Short summary
Short summary
The concentration of sodium and sulfate measured in Antarctic ice cores is related to changes in both sea ice and winds. Here we have compiled a database of sodium and sulfate records from 105 ice core sites in Antarctica. The records span all, or part, of the past 2000 years. The records will improve our understanding of how winds and sea ice have changed in the past and how they have influenced the climate of Antarctica over the past 2000 years.
Megan Thompson-Munson, Nander Wever, C. Max Stevens, Jan T. M. Lenaerts, and Brooke Medley
The Cryosphere, 17, 2185–2209, https://doi.org/10.5194/tc-17-2185-2023, https://doi.org/10.5194/tc-17-2185-2023, 2023
Short summary
Short summary
To better understand the Greenland Ice Sheet’s firn layer and its ability to buffer sea level rise by storing meltwater, we analyze firn density observations and output from two firn models. We find that both models, one physics-based and one semi-empirical, simulate realistic density and firn air content when compared to observations. The models differ in their representation of firn air content, highlighting the uncertainty in physical processes and the paucity of deep-firn measurements.
Sebastian Westermann, Thomas Ingeman-Nielsen, Johanna Scheer, Kristoffer Aalstad, Juditha Aga, Nitin Chaudhary, Bernd Etzelmüller, Simon Filhol, Andreas Kääb, Cas Renette, Louise Steffensen Schmidt, Thomas Vikhamar Schuler, Robin B. Zweigel, Léo Martin, Sarah Morard, Matan Ben-Asher, Michael Angelopoulos, Julia Boike, Brian Groenke, Frederieke Miesner, Jan Nitzbon, Paul Overduin, Simone M. Stuenzi, and Moritz Langer
Geosci. Model Dev., 16, 2607–2647, https://doi.org/10.5194/gmd-16-2607-2023, https://doi.org/10.5194/gmd-16-2607-2023, 2023
Short summary
Short summary
The CryoGrid community model is a new tool for simulating ground temperatures and the water and ice balance in cold regions. It is a modular design, which makes it possible to test different schemes to simulate, for example, permafrost ground in an efficient way. The model contains tools to simulate frozen and unfrozen ground, snow, glaciers, and other massive ice bodies, as well as water bodies.
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
Short summary
Short summary
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.
Christo Buizert, Sarah Shackleton, Jeffrey P. Severinghaus, William H. G. Roberts, Alan Seltzer, Bernhard Bereiter, Kenji Kawamura, Daniel Baggenstos, Anaïs J. Orsi, Ikumi Oyabu, Benjamin Birner, Jacob D. Morgan, Edward J. Brook, David M. Etheridge, David Thornton, Nancy Bertler, Rebecca L. Pyne, Robert Mulvaney, Ellen Mosley-Thompson, Peter D. Neff, and Vasilii V. Petrenko
Clim. Past, 19, 579–606, https://doi.org/10.5194/cp-19-579-2023, https://doi.org/10.5194/cp-19-579-2023, 2023
Short summary
Short summary
It is unclear how different components of the global atmospheric circulation, such as the El Niño effect, respond to large-scale climate change. We present a new ice core gas proxy, called krypton-86 excess, that reflects past storminess in Antarctica. We present data from 11 ice cores that suggest the new proxy works. We present a reconstruction of changes in West Antarctic storminess over the last 24 000 years and suggest these are caused by north–south movement of the tropical rain belt.
Marlene Kronenberg, Ward van Pelt, Horst Machguth, Joel Fiddes, Martin Hoelzle, and Felix Pertziger
The Cryosphere, 16, 5001–5022, https://doi.org/10.5194/tc-16-5001-2022, https://doi.org/10.5194/tc-16-5001-2022, 2022
Short summary
Short summary
The Pamir Alay is located at the edge of regions with anomalous glacier mass changes. Unique long-term in situ data are available for Abramov Glacier, located in the Pamir Alay. In this study, we use this extraordinary data set in combination with reanalysis data and a coupled surface energy balance–multilayer subsurface model to compute and analyse the distributed climatic mass balance and firn evolution from 1968 to 2020.
Nicole Clerx, Horst Machguth, Andrew Tedstone, Nicolas Jullien, Nander Wever, Rolf Weingartner, and Ole Roessler
The Cryosphere, 16, 4379–4401, https://doi.org/10.5194/tc-16-4379-2022, https://doi.org/10.5194/tc-16-4379-2022, 2022
Short summary
Short summary
Meltwater runoff is one of the main contributors to mass loss on the Greenland Ice Sheet that influences global sea level rise. However, it remains unclear where meltwater runs off and what processes cause this. We measured the velocity of meltwater flow through snow on the ice sheet, which ranged from 0.17–12.8 m h−1 for vertical percolation and from 1.3–15.1 m h−1 for lateral flow. This is an important step towards understanding where, when and why meltwater runoff occurs on the ice sheet.
Brooke Medley, Thomas A. Neumann, H. Jay Zwally, Benjamin E. Smith, and C. Max Stevens
The Cryosphere, 16, 3971–4011, https://doi.org/10.5194/tc-16-3971-2022, https://doi.org/10.5194/tc-16-3971-2022, 2022
Short summary
Short summary
Satellite altimeters measure the height or volume change over Earth's ice sheets, but in order to understand how that change translates into ice mass, we must account for various processes at the surface. Specifically, snowfall events generate large, transient increases in surface height, yet snow fall has a relatively low density, which means much of that height change is composed of air. This air signal must be removed from the observed height changes before we can assess ice mass change.
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, and Michael Studinger
The Cryosphere, 16, 3033–3049, https://doi.org/10.5194/tc-16-3033-2022, https://doi.org/10.5194/tc-16-3033-2022, 2022
Short summary
Short summary
Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known, yet knowing this state is increasingly important to interpret modern changes in ice flow there. We produced a second synthesis of knowledge of the basal thermal state of the ice sheet using airborne and satellite observations and numerical models. About one-third of the ice sheet’s bed is likely thawed; two-fifths is likely frozen; and the remainder is too uncertain to specify.
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
Short summary
Short summary
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.
Rohi Muthyala, Åsa K. Rennermalm, Sasha Z. Leidman, Matthew G. Cooper, Sarah W. Cooley, Laurence C. Smith, and Dirk van As
The Cryosphere, 16, 2245–2263, https://doi.org/10.5194/tc-16-2245-2022, https://doi.org/10.5194/tc-16-2245-2022, 2022
Short summary
Short summary
In situ measurements of meltwater discharge through supraglacial stream networks are rare. The unprecedentedly long record of discharge captures diurnal and seasonal variability. Two major findings are (1) a change in the timing of peak discharge through the melt season that could impact meltwater delivery in the subglacial system and (2) though the primary driver of stream discharge is shortwave radiation, longwave radiation and turbulent heat fluxes play a major role during high-melt episodes.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Nicolaj Hansen, Sebastian B. Simonsen, Fredrik Boberg, Christoph Kittel, Andrew Orr, Niels Souverijns, J. Melchior van Wessem, and Ruth Mottram
The Cryosphere, 16, 711–718, https://doi.org/10.5194/tc-16-711-2022, https://doi.org/10.5194/tc-16-711-2022, 2022
Short summary
Short summary
We investigate the impact of different ice masks when modelling surface mass balance over Antarctica. We used ice masks and data from five of the most used regional climate models and a common mask. We see large disagreement between the ice masks, which has a large impact on the surface mass balance, especially around the Antarctic Peninsula and some of the largest glaciers. We suggest a solution for creating a new, up-to-date, high-resolution ice mask that can be used in Antarctic modelling.
Martin Horwath, Benjamin D. Gutknecht, Anny Cazenave, Hindumathi Kulaiappan Palanisamy, Florence Marti, Ben Marzeion, Frank Paul, Raymond Le Bris, Anna E. Hogg, Inès Otosaka, Andrew Shepherd, Petra Döll, Denise Cáceres, Hannes Müller Schmied, Johnny A. Johannessen, Jan Even Øie Nilsen, Roshin P. Raj, René Forsberg, Louise Sandberg Sørensen, Valentina R. Barletta, Sebastian B. Simonsen, Per Knudsen, Ole Baltazar Andersen, Heidi Ranndal, Stine K. Rose, Christopher J. Merchant, Claire R. Macintosh, Karina von Schuckmann, Kristin Novotny, Andreas Groh, Marco Restano, and Jérôme Benveniste
Earth Syst. Sci. Data, 14, 411–447, https://doi.org/10.5194/essd-14-411-2022, https://doi.org/10.5194/essd-14-411-2022, 2022
Short summary
Short summary
Global mean sea-level change observed from 1993 to 2016 (mean rate of 3.05 mm yr−1) matches the combined effect of changes in water density (thermal expansion) and ocean mass. Ocean-mass change has been assessed through the contributions from glaciers, ice sheets, and land water storage or directly from satellite data since 2003. Our budget assessments of linear trends and monthly anomalies utilise new datasets and uncertainty characterisations developed within ESA's Climate Change Initiative.
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
Short summary
Short summary
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.
Nicolaj Hansen, Peter L. Langen, Fredrik Boberg, Rene Forsberg, Sebastian B. Simonsen, Peter Thejll, Baptiste Vandecrux, and Ruth Mottram
The Cryosphere, 15, 4315–4333, https://doi.org/10.5194/tc-15-4315-2021, https://doi.org/10.5194/tc-15-4315-2021, 2021
Short summary
Short summary
We have used computer models to estimate the Antarctic surface mass balance (SMB) from 1980 to 2017. Our estimates lies between 2473.5 ± 114.4 Gt per year and 2564.8 ± 113.7 Gt per year. To evaluate our models, we compared the modelled snow temperatures and densities to in situ measurements. We also investigated the spatial distribution of the SMB. It is very important to have estimates of the Antarctic SMB because then it is easier to understand global sea level changes.
Ruth Mottram, Nicolaj Hansen, Christoph Kittel, J. Melchior van Wessem, Cécile Agosta, Charles Amory, Fredrik Boberg, Willem Jan van de Berg, Xavier Fettweis, Alexandra Gossart, Nicole P. M. van Lipzig, Erik van Meijgaard, Andrew Orr, Tony Phillips, Stuart Webster, Sebastian B. Simonsen, and Niels Souverijns
The Cryosphere, 15, 3751–3784, https://doi.org/10.5194/tc-15-3751-2021, https://doi.org/10.5194/tc-15-3751-2021, 2021
Short summary
Short summary
We compare the calculated surface mass budget (SMB) of Antarctica in five different regional climate models. On average ~ 2000 Gt of snow accumulates annually, but different models vary by ~ 10 %, a difference equivalent to ± 0.5 mm of global sea level rise. All models reproduce observed weather, but there are large differences in regional patterns of snowfall, especially in areas with very few observations, giving greater uncertainty in Antarctic mass budget than previously identified.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Enrico Mattea, Horst Machguth, Marlene Kronenberg, Ward van Pelt, Manuela Bassi, and Martin Hoelzle
The Cryosphere, 15, 3181–3205, https://doi.org/10.5194/tc-15-3181-2021, https://doi.org/10.5194/tc-15-3181-2021, 2021
Short summary
Short summary
In our study we find that climate change is affecting the high-alpine Colle Gnifetti glacier (Swiss–Italian Alps) with an increase in melt amounts and ice temperatures.
In the near future this trend could threaten the viability of the oldest ice core record in the Alps.
To reach our conclusions, for the first time we used the meteorological data of the highest permanent weather station in Europe (Capanna Margherita, 4560 m), together with an advanced numeric simulation of the glacier.
Thomas Schneider von Deimling, Hanna Lee, Thomas Ingeman-Nielsen, Sebastian Westermann, Vladimir Romanovsky, Scott Lamoureux, Donald A. Walker, Sarah Chadburn, Erin Trochim, Lei Cai, Jan Nitzbon, Stephan Jacobi, and Moritz Langer
The Cryosphere, 15, 2451–2471, https://doi.org/10.5194/tc-15-2451-2021, https://doi.org/10.5194/tc-15-2451-2021, 2021
Short summary
Short summary
Climate warming puts infrastructure built on permafrost at risk of failure. There is a growing need for appropriate model-based risk assessments. Here we present a modelling study and show an exemplary case of how a gravel road in a cold permafrost environment in Alaska might suffer from degrading permafrost under a scenario of intense climate warming. We use this case study to discuss the broader-scale applicability of our model for simulating future Arctic infrastructure failure.
Stefan Kowalewski, Veit Helm, Elizabeth Mary Morris, and Olaf Eisen
The Cryosphere, 15, 1285–1305, https://doi.org/10.5194/tc-15-1285-2021, https://doi.org/10.5194/tc-15-1285-2021, 2021
Short summary
Short summary
This study presents estimates of total mass input for the Pine Island Glacier (PIG) over the period 2005–2014 from airborne radar measurements. Our analysis reveals a total mass input similar to an earlier estimate for the period 1985–2009 and same area. This suggests a stationary total mass input contrary to the accelerated mass loss of PIG over the past decades. However, we also find that its uncertainty is highly sensitive to the geostatistical assumptions required for its calculation.
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
Short summary
Short summary
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.
Ethan Welty, Michael Zemp, Francisco Navarro, Matthias Huss, Johannes J. Fürst, Isabelle Gärtner-Roer, Johannes Landmann, Horst Machguth, Kathrin Naegeli, Liss M. Andreassen, Daniel Farinotti, Huilin Li, and GlaThiDa Contributors
Earth Syst. Sci. Data, 12, 3039–3055, https://doi.org/10.5194/essd-12-3039-2020, https://doi.org/10.5194/essd-12-3039-2020, 2020
Short summary
Short summary
Knowing the thickness of glacier ice is critical for predicting the rate of glacier loss and the myriad downstream impacts. To facilitate forecasts of future change, we have added 3 million measurements to our worldwide database of glacier thickness: 14 % of global glacier area is now within 1 km of a thickness measurement (up from 6 %). To make it easier to update and monitor the quality of our database, we have used automated tools to check and track changes to the data over time.
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
Short summary
Short summary
This work partitions regional climate model (RCM) runoff from the MAR and RACMO RCMs to hydrologic outlets at the ice margin and coast. Temporal resolution is daily from 1959 through 2019. Spatial grid is ~ 100 m, resolving individual streams. In addition to discharge at outlets, we also provide the streams, outlets, and basin geospatial data, as well as a script to query and access the geospatial or time series discharge data from the data files.
Xavier Fettweis, Stefan Hofer, Uta Krebs-Kanzow, Charles Amory, Teruo Aoki, Constantijn J. Berends, Andreas Born, Jason E. Box, Alison Delhasse, Koji Fujita, Paul Gierz, Heiko Goelzer, Edward Hanna, Akihiro Hashimoto, Philippe Huybrechts, Marie-Luise Kapsch, Michalea D. King, Christoph Kittel, Charlotte Lang, Peter L. Langen, Jan T. M. Lenaerts, Glen E. Liston, Gerrit Lohmann, Sebastian H. Mernild, Uwe Mikolajewicz, Kameswarrao Modali, Ruth H. Mottram, Masashi Niwano, Brice Noël, Jonathan C. Ryan, Amy Smith, Jan Streffing, Marco Tedesco, Willem Jan van de Berg, Michiel van den Broeke, Roderik S. W. van de Wal, Leo van Kampenhout, David Wilton, Bert Wouters, Florian Ziemen, and Tobias Zolles
The Cryosphere, 14, 3935–3958, https://doi.org/10.5194/tc-14-3935-2020, https://doi.org/10.5194/tc-14-3935-2020, 2020
Short summary
Short summary
We evaluated simulated Greenland Ice Sheet surface mass balance from 5 kinds of models. While the most complex (but expensive to compute) models remain the best, the faster/simpler models also compare reliably with observations and have biases of the same order as the regional models. Discrepancies in the trend over 2000–2012, however, suggest that large uncertainties remain in the modelled future SMB changes as they are highly impacted by the meltwater runoff biases over the current climate.
Baptiste Vandecrux, Ruth Mottram, Peter L. Langen, Robert S. Fausto, Martin Olesen, C. Max Stevens, Vincent Verjans, Amber Leeson, Stefan Ligtenberg, Peter Kuipers Munneke, Sergey Marchenko, Ward van Pelt, Colin R. Meyer, Sebastian B. Simonsen, Achim Heilig, Samira Samimi, Shawn Marshall, Horst Machguth, Michael MacFerrin, Masashi Niwano, Olivia Miller, Clifford I. Voss, and Jason E. Box
The Cryosphere, 14, 3785–3810, https://doi.org/10.5194/tc-14-3785-2020, https://doi.org/10.5194/tc-14-3785-2020, 2020
Short summary
Short summary
In the vast interior of the Greenland ice sheet, snow accumulates into a thick and porous layer called firn. Each summer, the firn retains part of the meltwater generated at the surface and buffers sea-level rise. In this study, we compare nine firn models traditionally used to quantify this retention at four sites and evaluate their performance against a set of in situ observations. We highlight limitations of certain model designs and give perspectives for future model development.
C. Max Stevens, Vincent Verjans, Jessica M. D. Lundin, Emma C. Kahle, Annika N. Horlings, Brita I. Horlings, and Edwin D. Waddington
Geosci. Model Dev., 13, 4355–4377, https://doi.org/10.5194/gmd-13-4355-2020, https://doi.org/10.5194/gmd-13-4355-2020, 2020
Short summary
Short summary
Understanding processes in snow (firn), including compaction and airflow, is important for calculating how much mass the ice sheets are losing and for interpreting climate records from ice cores. We have developed the open-source Community Firn Model to simulate these processes. We used it to compare 13 different firn compaction equations and found that they do not agree within 10 %. We also show that including firn compaction in a firn-air model improves the match with data from ice cores.
Vincent Verjans, Amber A. Leeson, Christopher Nemeth, C. Max Stevens, Peter Kuipers Munneke, Brice Noël, and Jan Melchior van Wessem
The Cryosphere, 14, 3017–3032, https://doi.org/10.5194/tc-14-3017-2020, https://doi.org/10.5194/tc-14-3017-2020, 2020
Short summary
Short summary
Ice sheets are covered by a firn layer, which is the transition stage between fresh snow and ice. Accurate modelling of firn density properties is important in many glaciological aspects. Current models show disagreements, are mostly calibrated to match specific observations of firn density and lack thorough uncertainty analysis. We use a novel calibration method for firn models based on a Bayesian statistical framework, which results in improved model accuracy and in uncertainty evaluation.
Abigail G. Hughes, Tyler R. Jones, Bo M. Vinther, Vasileios Gkinis, C. Max Stevens, Valerie Morris, Bruce H. Vaughn, Christian Holme, Bradley R. Markle, and James W. C. White
Clim. Past, 16, 1369–1386, https://doi.org/10.5194/cp-16-1369-2020, https://doi.org/10.5194/cp-16-1369-2020, 2020
Short summary
Short summary
An ice core drilled on the Renland ice cap (RECAP) in east-central Greenland contains a continuous climate record dating through the last glacial period. Here we present the water isotope record for the Holocene, in which high-resolution climate information is retained for the last 8 kyr. We find that the RECAP water isotope record exhibits seasonal and decadal variability which may reflect sea surface conditions and regional climate variability.
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
Short summary
Short summary
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.
Kristine M. Larson, Michael MacFerrin, and Thomas Nylen
The Cryosphere, 14, 1985–1988, https://doi.org/10.5194/tc-14-1985-2020, https://doi.org/10.5194/tc-14-1985-2020, 2020
Short summary
Short summary
Reflected GPS signals can be used to measure snow accumulation. The GPS method is accurate and has a footprint that is larger than that of many other methods. This short note makes available 9 years of daily snow accumulation measurements from Greenland that were derived from reflected GPS signals. It also provides information about open-source software that the cryosphere community can use to analyze other datasets.
Marco Meloni, Jerome Bouffard, Tommaso Parrinello, Geoffrey Dawson, Florent Garnier, Veit Helm, Alessandro Di Bella, Stefan Hendricks, Robert Ricker, Erica Webb, Ben Wright, Karina Nielsen, Sanggyun Lee, Marcello Passaro, Michele Scagliola, Sebastian Bjerregaard Simonsen, Louise Sandberg Sørensen, David Brockley, Steven Baker, Sara Fleury, Jonathan Bamber, Luca Maestri, Henriette Skourup, René Forsberg, and Loretta Mizzi
The Cryosphere, 14, 1889–1907, https://doi.org/10.5194/tc-14-1889-2020, https://doi.org/10.5194/tc-14-1889-2020, 2020
Short summary
Short summary
This manuscript aims to describe the evolutions which have been implemented in the new CryoSat Ice processing chain Baseline-D and the validation activities carried out in different domains such as sea ice, land ice and hydrology.
This new CryoSat processing Baseline-D will maximise the uptake and use of CryoSat data by scientific users since it offers improved capability for monitoring the complex and multiscale changes over the cryosphere.
Tyler J. Fudge, David A. Lilien, Michelle Koutnik, Howard Conway, C. Max Stevens, Edwin D. Waddington, Eric J. Steig, Andrew J. Schauer, and Nicholas Holschuh
Clim. Past, 16, 819–832, https://doi.org/10.5194/cp-16-819-2020, https://doi.org/10.5194/cp-16-819-2020, 2020
Short summary
Short summary
A 1750 m ice core at the South Pole was recently drilled. The oldest ice is ~55 000 years old. Since ice at the South Pole flows at 10 m per year, the ice in the core originated upstream, where the climate is different. We made measurements of the ice flow, snow accumulation, and temperature upstream. We determined the ice came from ~150 km away near the Titan Dome where the accumulation rate was similar but the temperature was colder. Our measurements improve the interpretation of the ice core.
Alison Delhasse, Christoph Kittel, Charles Amory, Stefan Hofer, Dirk van As, Robert S. Fausto, and Xavier Fettweis
The Cryosphere, 14, 957–965, https://doi.org/10.5194/tc-14-957-2020, https://doi.org/10.5194/tc-14-957-2020, 2020
Short summary
Short summary
The ERA5 reanalysis of the ECMWF replaced the ERA-Interim in August 2019 and has never been evaluated over Greenland. The aim was to evaluate the performance of ERA5 to simulate the near-surface climate of the Greenland Ice sheet (GrIS) against ERA-Interim and regional climate models with the help of in situ observations from the PROMICE dataset. We also highlighted that polar regional climate models are still a useful tool to study the GrIS climate compared to ERA5.
Achim Heilig, Olaf Eisen, Martin Schneebeli, Michael MacFerrin, C. Max Stevens, Baptiste Vandecrux, and Konrad Steffen
The Cryosphere, 14, 385–402, https://doi.org/10.5194/tc-14-385-2020, https://doi.org/10.5194/tc-14-385-2020, 2020
Short summary
Short summary
We investigate the spatial representativeness of point observations of snow accumulation in SW Greenland. Such analyses have rarely been conducted but are necessary to link regional-scale observations from, e.g., remote-sensing data to firn cores and snow pits. The presented data reveal a low regional variability in density but snow depth can vary significantly. It is necessary to combine pits with spatial snow depth data to increase the regional representativeness of accumulation observations.
Joseph M. Cook, Andrew J. Tedstone, Christopher Williamson, Jenine McCutcheon, Andrew J. Hodson, Archana Dayal, McKenzie Skiles, Stefan Hofer, Robert Bryant, Owen McAree, Andrew McGonigle, Jonathan Ryan, Alexandre M. Anesio, Tristram D. L. Irvine-Fynn, Alun Hubbard, Edward Hanna, Mark Flanner, Sathish Mayanna, Liane G. Benning, Dirk van As, Marian Yallop, James B. McQuaid, Thomas Gribbin, and Martyn Tranter
The Cryosphere, 14, 309–330, https://doi.org/10.5194/tc-14-309-2020, https://doi.org/10.5194/tc-14-309-2020, 2020
Short summary
Short summary
Melting of the Greenland Ice Sheet (GrIS) is a major source of uncertainty for sea level rise projections. Ice-darkening due to the growth of algae has been recognized as a potential accelerator of melting. This paper measures and models the algae-driven ice melting and maps the algae over the ice sheet for the first time. We estimate that as much as 13 % total runoff from the south-western GrIS can be attributed to these algae, showing that they must be included in future mass balance models.
Thomas J. Ballinger, Thomas L. Mote, Kyle Mattingly, Angela C. Bliss, Edward Hanna, Dirk van As, Melissa Prieto, Saeideh Gharehchahi, Xavier Fettweis, Brice Noël, Paul C. J. P. Smeets, Carleen H. Reijmer, Mads H. Ribergaard, and John Cappelen
The Cryosphere, 13, 2241–2257, https://doi.org/10.5194/tc-13-2241-2019, https://doi.org/10.5194/tc-13-2241-2019, 2019
Short summary
Short summary
Arctic sea ice and the Greenland Ice Sheet (GrIS) are melting later in the year due to a warming climate. Through analyses of weather station, climate model, and reanalysis data, physical links are evaluated between Baffin Bay open water duration and western GrIS melt conditions. We show that sub-Arctic air mass movement across this portion of the GrIS strongly influences late summer and autumn melt, while near-surface, off-ice winds inhibit westerly atmospheric heat transfer from Baffin Bay.
Vincent Verjans, Amber A. Leeson, C. Max Stevens, Michael MacFerrin, Brice Noël, and Michiel R. van den Broeke
The Cryosphere, 13, 1819–1842, https://doi.org/10.5194/tc-13-1819-2019, https://doi.org/10.5194/tc-13-1819-2019, 2019
Short summary
Short summary
Firn models rely on empirical approaches for representing the percolation and refreezing of meltwater through the firn column. We develop liquid water schemes of different levels of complexity for firn models and compare their performances with respect to observations of density profiles from Greenland. Our results demonstrate that physically advanced water schemes do not lead to better agreement with density observations. Uncertainties in other processes contribute more to model discrepancy.
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
Short summary
Short summary
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.
Kang Yang, Laurence C. Smith, Leif Karlstrom, Matthew G. Cooper, Marco Tedesco, Dirk van As, Xiao Cheng, Zhuoqi Chen, and Manchun Li
The Cryosphere, 12, 3791–3811, https://doi.org/10.5194/tc-12-3791-2018, https://doi.org/10.5194/tc-12-3791-2018, 2018
Short summary
Short summary
A high-resolution spatially lumped hydrologic surface routing model is proposed to simulate meltwater transport over bare ice surfaces. In an ice-covered catchment, meltwater is routed by slow interfluve flow (~10−3–10−4 m s−1) followed by fast open-channel flow (~10−1 m s−1). Seasonal evolution of supraglacial stream-river networks substantially alters the magnitude and timing of moulin discharge with implications for subglacial hydrology and ice dynamics.
Lynn Montgomery, Lora Koenig, and Patrick Alexander
Earth Syst. Sci. Data, 10, 1959–1985, https://doi.org/10.5194/essd-10-1959-2018, https://doi.org/10.5194/essd-10-1959-2018, 2018
Short summary
Short summary
The SUMup dataset is a standardized, expandable, community dataset of Arctic and Antarctic observations of surface mass balance components, including snow/firn density, snow accumulation on land ice, and snow depth on sea ice. The measurements in this dataset were compiled from field notes, papers, technical reports, and digital files. We use these observations to monitor change in the polar regions and evaluate model output as well as remote sensing measurements.
Denis Cohen, Fabien Gillet-Chaulet, Wilfried Haeberli, Horst Machguth, and Urs H. Fischer
The Cryosphere, 12, 2515–2544, https://doi.org/10.5194/tc-12-2515-2018, https://doi.org/10.5194/tc-12-2515-2018, 2018
Short summary
Short summary
As part of an integrative study about the safety of repositories for radioactive waste under ice age conditions in Switzerland, we modeled the flow of ice of the Rhine glacier at the Last Glacial Maximum to determine conditions at the ice–bed interface. Results indicate that portions of the ice lobes were at the melting temperature and ice was sliding, two conditions necessary for erosion by glacier. Conditions at the bed of the ice lobes were affected by climate and also by topography.
Alexander Kokhanovsky, Maxim Lamare, Biagio Di Mauro, Ghislain Picard, Laurent Arnaud, Marie Dumont, François Tuzet, Carsten Brockmann, and Jason E. Box
The Cryosphere, 12, 2371–2382, https://doi.org/10.5194/tc-12-2371-2018, https://doi.org/10.5194/tc-12-2371-2018, 2018
Short summary
Short summary
This work presents a new technique with which to derive the snow microphysical and optical properties from snow spectral reflectance measurements. The technique is robust and easy to use, and it does not require the extraction of snow samples from a given snowpack. It can be used in processing satellite imagery over extended fresh dry, wet and polluted snowfields.
Achim Heilig, Olaf Eisen, Michael MacFerrin, Marco Tedesco, and Xavier Fettweis
The Cryosphere, 12, 1851–1866, https://doi.org/10.5194/tc-12-1851-2018, https://doi.org/10.5194/tc-12-1851-2018, 2018
Short summary
Short summary
This paper presents data on temporal changes in snow and firn, which were not available before. We present data on water infiltration in the percolation zone of the Greenland Ice Sheet that improve our understanding of liquid water retention in snow and firn and mass transfer. We compare those findings with model simulations. It appears that simulated accumulation in terms of SWE is fairly accurate, while modeling of the individual parameters density and liquid water content is incorrect.
Konstanze Haubner, Jason E. Box, Nicole J. Schlegel, Eric Y. Larour, Mathieu Morlighem, Anne M. Solgaard, Kristian K. Kjeldsen, Signe H. Larsen, Eric Rignot, Todd K. Dupont, and Kurt H. Kjær
The Cryosphere, 12, 1511–1522, https://doi.org/10.5194/tc-12-1511-2018, https://doi.org/10.5194/tc-12-1511-2018, 2018
Short summary
Short summary
We investigate the effect of neglecting calving on Upernavik Isstrøm, West Greenland, between 1849 and 2012.
Our simulation is forced with observed terminus positions in discrete time steps and is responsive to the prescribed ice front changes.
Simulated frontal retreat is needed to obtain a realistic ice surface elevation and velocity evolution of Upernavik.
Using the prescribed terminus position change we gain insight to mass loss partitioning during different time periods.
Matthew G. Cooper, Laurence C. Smith, Asa K. Rennermalm, Clément Miège, Lincoln H. Pitcher, Jonathan C. Ryan, Kang Yang, and Sarah W. Cooley
The Cryosphere, 12, 955–970, https://doi.org/10.5194/tc-12-955-2018, https://doi.org/10.5194/tc-12-955-2018, 2018
Short summary
Short summary
We present measurements of ice density that show the melting bare-ice surface of the Greenland ice sheet study site is porous and saturated with meltwater. The data suggest up to 18 cm of meltwater is temporarily stored within porous, low-density ice. The findings imply meltwater drainage off the ice sheet surface is delayed and that the surface mass balance of the ice sheet during summer cannot be estimated solely from ice surface elevation change measurements.
Brice Noël, Willem Jan van de Berg, J. Melchior van Wessem, Erik van Meijgaard, Dirk van As, Jan T. M. Lenaerts, Stef Lhermitte, Peter Kuipers Munneke, C. J. P. Paul Smeets, Lambertus H. van Ulft, Roderik S. W. van de Wal, and Michiel R. van den Broeke
The Cryosphere, 12, 811–831, https://doi.org/10.5194/tc-12-811-2018, https://doi.org/10.5194/tc-12-811-2018, 2018
Short summary
Short summary
We present a detailed evaluation of the latest version of the regional climate model RACMO2.3p2 at 11 km resolution (1958–2016) over the Greenland ice sheet (GrIS). The model successfully reproduces the present-day climate and surface mass balance, i.e. snowfall minus meltwater run-off, of the GrIS compared to in situ observations. Since run-off from marginal narrow glaciers is poorly resolved at 11 km, further statistical downscaling to 1 km resolution is required for mass balance studies.
David E. Shean, Knut Christianson, Kristine M. Larson, Stefan R. M. Ligtenberg, Ian R. Joughin, Ben E. Smith, C. Max Stevens, Mitchell Bushuk, and David M. Holland
The Cryosphere, 11, 2655–2674, https://doi.org/10.5194/tc-11-2655-2017, https://doi.org/10.5194/tc-11-2655-2017, 2017
Short summary
Short summary
We used long-term GPS data and interferometric reflectometry (GPS-IR) to measure velocity, strain rate and surface elevation for the PIG ice shelf – a site of significant mass loss in recent decades. We combined these observations with high-res DEMs and firn model output to constrain surface mass balance and basal melt rates. We document notable spatial variability in basal melt rates but limited temporal variability from 2012 to 2014 despite significant changes in sub-shelf ocean heat content.
Vassiliy Kapitsa, Maria Shahgedanova, Horst Machguth, Igor Severskiy, and Akhmetkal Medeu
Nat. Hazards Earth Syst. Sci., 17, 1837–1856, https://doi.org/10.5194/nhess-17-1837-2017, https://doi.org/10.5194/nhess-17-1837-2017, 2017
Short summary
Short summary
Changes in lake count and area in the region of Djungarskiy Alatau were assessed, showing that both increased by 6 % in 2002–2014 due to glacier melt. A total of 50 lakes were identified as potentially dangerous. GlabTop2 was used to simulate location and size of overdeepenings in the subglacier beds which present sites where lakes can develop in the future. The model predicted 67 % of lakes would form in the area de-glacierized in 2002–2014, correctly proving a useful tool in hazard management.
Martin Hoelzle, Erlan Azisov, Martina Barandun, Matthias Huss, Daniel Farinotti, Abror Gafurov, Wilfried Hagg, Ruslan Kenzhebaev, Marlene Kronenberg, Horst Machguth, Alexandr Merkushkin, Bolot Moldobekov, Maxim Petrov, Tomas Saks, Nadine Salzmann, Tilo Schöne, Yuri Tarasov, Ryskul Usubaliev, Sergiy Vorogushyn, Andrey Yakovlev, and Michael Zemp
Geosci. Instrum. Method. Data Syst., 6, 397–418, https://doi.org/10.5194/gi-6-397-2017, https://doi.org/10.5194/gi-6-397-2017, 2017
Dirk van As, Andreas Bech Mikkelsen, Morten Holtegaard Nielsen, Jason E. Box, Lillemor Claesson Liljedahl, Katrin Lindbäck, Lincoln Pitcher, and Bent Hasholt
The Cryosphere, 11, 1371–1386, https://doi.org/10.5194/tc-11-1371-2017, https://doi.org/10.5194/tc-11-1371-2017, 2017
Short summary
Short summary
The Greenland ice sheet melts faster in a warmer climate. The ice sheet is flatter at high elevation, therefore atmospheric warming increases the melt area exponentially. For current climate conditions, we find that the ice sheet shape amplifies the total meltwater generation by roughly 60 %. Meltwater is not stored underneath the ice sheet, as previously found, but it does take multiple days for it to pass through the seasonally developing subglacial drainage channels, moderating discharge.
Xavier Fettweis, Jason E. Box, Cécile Agosta, Charles Amory, Christoph Kittel, Charlotte Lang, Dirk van As, Horst Machguth, and Hubert Gallée
The Cryosphere, 11, 1015–1033, https://doi.org/10.5194/tc-11-1015-2017, https://doi.org/10.5194/tc-11-1015-2017, 2017
Short summary
Short summary
This paper shows that the surface melt increase over the Greenland ice sheet since the end of the 1990s has been unprecedented, with respect to the last 120 years, using a regional climate model. These simulations also suggest an increase of the snowfall accumulation through the last century before a surface mass decrease in the 2000s. Such a mass gain could have impacted the ice sheet's dynamic stability and could explain the recent observed increase of the glaciers' velocity.
Daniel Farinotti, Douglas J. Brinkerhoff, Garry K. C. Clarke, Johannes J. Fürst, Holger Frey, Prateek Gantayat, Fabien Gillet-Chaulet, Claire Girard, Matthias Huss, Paul W. Leclercq, Andreas Linsbauer, Horst Machguth, Carlos Martin, Fabien Maussion, Mathieu Morlighem, Cyrille Mosbeux, Ankur Pandit, Andrea Portmann, Antoine Rabatel, RAAJ Ramsankaran, Thomas J. Reerink, Olivier Sanchez, Peter A. Stentoft, Sangita Singh Kumari, Ward J. J. van Pelt, Brian Anderson, Toby Benham, Daniel Binder, Julian A. Dowdeswell, Andrea Fischer, Kay Helfricht, Stanislav Kutuzov, Ivan Lavrentiev, Robert McNabb, G. Hilmar Gudmundsson, Huilin Li, and Liss M. Andreassen
The Cryosphere, 11, 949–970, https://doi.org/10.5194/tc-11-949-2017, https://doi.org/10.5194/tc-11-949-2017, 2017
Short summary
Short summary
ITMIX – the Ice Thickness Models Intercomparison eXperiment – was the first coordinated performance assessment for models inferring glacier ice thickness from surface characteristics. Considering 17 different models and 21 different test cases, we show that although solutions of individual models can differ considerably, an ensemble average can yield uncertainties in the order of 10 ± 24 % the mean ice thickness. Ways forward for improving such estimates are sketched.
Gabriel Lewis, Erich Osterberg, Robert Hawley, Brian Whitmore, Hans Peter Marshall, and Jason Box
The Cryosphere, 11, 773–788, https://doi.org/10.5194/tc-11-773-2017, https://doi.org/10.5194/tc-11-773-2017, 2017
Short summary
Short summary
We analyze 25 flight lines from NASA's Operation IceBridge Accumulation Radar totaling to determine snow accumulation throughout the dry snow and percolation zone of the Greenland Ice Sheet. Our results indicate that regional differences between IceBridge and model accumulation are large enough to significantly alter the Greenland Ice Sheet surface mass balance, with implications for future global sea-level rise.
Brice Noël, Willem Jan van de Berg, Horst Machguth, Stef Lhermitte, Ian Howat, Xavier Fettweis, and Michiel R. van den Broeke
The Cryosphere, 10, 2361–2377, https://doi.org/10.5194/tc-10-2361-2016, https://doi.org/10.5194/tc-10-2361-2016, 2016
Short summary
Short summary
We present a 1 km resolution data set (1958–2015) of daily Greenland ice sheet surface mass balance (SMB), statistically downscaled from the data of RACMO2.3 at 11 km using elevation dependence, precipitation and bare ice albedo corrections. The data set resolves Greenland narrow ablation zones and local outlet glaciers, and shows more realistic SMB patterns, owing to enhanced runoff at the ice sheet margins. An evaluation of the product against SMB measurements shows improved agreement.
Jonathan C. Ryan, Alun Hubbard, Marek Stibal, Jason E. Box, and the Dark Snow Project team
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-204, https://doi.org/10.5194/tc-2016-204, 2016
Preprint withdrawn
Short summary
Short summary
Using digital imagery and broadband albedo acquired by a fixed-wing UAS we classified and measured the albedo of six surface types that dominate the Greenland ablation area and its dark region. We found that the primary control on ablation area albedo is the fractional area of distributed impurities. Although not the darkest surface type observed, the distributed impurities dominate the albedo signal because of their extensive coverage.
Nicole-Jeanne Schlegel, David N. Wiese, Eric Y. Larour, Michael M. Watkins, Jason E. Box, Xavier Fettweis, and Michiel R. van den Broeke
The Cryosphere, 10, 1965–1989, https://doi.org/10.5194/tc-10-1965-2016, https://doi.org/10.5194/tc-10-1965-2016, 2016
Short summary
Short summary
We investigate Greenland Ice Sheet mass change from 2003–2012 by comparing observations from GRACE with state-of-the-art atmospheric and ice sheet model simulations. We find that the largest discrepancies (in the northwest and southeast) are likely controlled by errors in modeled surface climate as well as ice–ocean interaction and hydrological processes (not included in the models). Models should consider such processes at monthly to seasonal resolutions in order to improve future projections.
Thomas B. Overly, Robert L. Hawley, Veit Helm, Elizabeth M. Morris, and Rohan N. Chaudhary
The Cryosphere, 10, 1679–1694, https://doi.org/10.5194/tc-10-1679-2016, https://doi.org/10.5194/tc-10-1679-2016, 2016
Short summary
Short summary
We demonstrate that snow accumulation rates across the Greenland Ice Sheet, determined from RADAR layers and modeled snow density profiles, are identical to ground-based measurements of snow accumulation. Three regional climate models underestimate snow accumulation compared to RADAR layer estimates. Using RADAR increases spatial coverage and improves accuracy of snow accumulation estimates. Incorporating our results into climate models may reduce uncertainty of sea-level rise estimates.
Andreas Bech Mikkelsen, Alun Hubbard, Mike MacFerrin, Jason Eric Box, Sam H. Doyle, Andrew Fitzpatrick, Bent Hasholt, Hannah L. Bailey, Katrin Lindbäck, and Rickard Pettersson
The Cryosphere, 10, 1147–1159, https://doi.org/10.5194/tc-10-1147-2016, https://doi.org/10.5194/tc-10-1147-2016, 2016
Wenshan Wang, Charles S. Zender, Dirk van As, Paul C. J. P. Smeets, and Michiel R. van den Broeke
The Cryosphere, 10, 727–741, https://doi.org/10.5194/tc-10-727-2016, https://doi.org/10.5194/tc-10-727-2016, 2016
Short summary
Short summary
We identify and correct station-tilt-induced biases in insolation observed by automatic weather stations on the Greenland Ice Sheet. Without tilt correction, only 40 % of clear days have the correct solar noon time (±0.5 h). The largest hourly bias exceeds 20 %. We estimate the tilt angles based on solar geometric relationship between insolation observed on horizontal surfaces and that on tilted surfaces, and produce shortwave radiation and albedo that agree better with independent data sets.
Jacob C. Yde, Niels T. Knudsen, Jørgen P. Steffensen, Jonathan L. Carrivick, Bent Hasholt, Thomas Ingeman-Nielsen, Christian Kronborg, Nicolaj K. Larsen, Sebastian H. Mernild, Hans Oerter, David H. Roberts, and Andrew J. Russell
Hydrol. Earth Syst. Sci., 20, 1197–1210, https://doi.org/10.5194/hess-20-1197-2016, https://doi.org/10.5194/hess-20-1197-2016, 2016
N. Wever, L. Schmid, A. Heilig, O. Eisen, C. Fierz, and M. Lehning
The Cryosphere, 9, 2271–2293, https://doi.org/10.5194/tc-9-2271-2015, https://doi.org/10.5194/tc-9-2271-2015, 2015
Short summary
Short summary
A verification of the physics based SNOWPACK model with field observations showed that typical snowpack properties like density and temperature are adequately simulated. Also two water transport schemes were verified, showing that although Richards equation improves snowpack runoff and several aspects of the internal snowpack structure, the bucket scheme appeared to have a higher agreement with the snow microstructure. The choice of water transport scheme may depend on the intended application.
C. Charalampidis, D. van As, J. E. Box, M. R. van den Broeke, W. T. Colgan, S. H. Doyle, A. L. Hubbard, M. MacFerrin, H. Machguth, and C. J. P. P. Smeets
The Cryosphere, 9, 2163–2181, https://doi.org/10.5194/tc-9-2163-2015, https://doi.org/10.5194/tc-9-2163-2015, 2015
P. Kuipers Munneke, S. R. M. Ligtenberg, B. P. Y. Noël, I. M. Howat, J. E. Box, E. Mosley-Thompson, J. R. McConnell, K. Steffen, J. T. Harper, S. B. Das, and M. R. van den Broeke
The Cryosphere, 9, 2009–2025, https://doi.org/10.5194/tc-9-2009-2015, https://doi.org/10.5194/tc-9-2009-2015, 2015
Short summary
Short summary
The snow layer on top of the Greenland Ice Sheet is changing: it is thickening in the high and cold interior due to increased snowfall, while it is thinning around the margins. The marginal thinning is caused by compaction, and by more melt.
This knowledge is important: there are satellites that measure volume change of the ice sheet. It can be caused by increased ice discharge, or by compaction of the snow layer. Here, we quantify the latter, so that we can translate volume to mass change.
V. Masson-Delmotte, H. C. Steen-Larsen, P. Ortega, D. Swingedouw, T. Popp, B. M. Vinther, H. Oerter, A. E. Sveinbjornsdottir, H. Gudlaugsdottir, J. E. Box, S. Falourd, X. Fettweis, H. Gallée, E. Garnier, V. Gkinis, J. Jouzel, A. Landais, B. Minster, N. Paradis, A. Orsi, C. Risi, M. Werner, and J. W. C. White
The Cryosphere, 9, 1481–1504, https://doi.org/10.5194/tc-9-1481-2015, https://doi.org/10.5194/tc-9-1481-2015, 2015
Short summary
Short summary
The deep NEEM ice core provides the oldest Greenland ice core record, enabling improved understanding of the response of ice core records to local climate. Here, we focus on shallow ice cores providing a stack record of accumulation and water-stable isotopes spanning the past centuries. For the first time, we document the ongoing warming in a Greenland ice core. By combining our data with other Greenland ice cores and model results, we characterise the spatio-temporal patterns of variability.
S. de la Peña, I. M. Howat, P. W. Nienow, M. R. van den Broeke, E. Mosley-Thompson, S. F. Price, D. Mair, B. Noël, and A. J. Sole
The Cryosphere, 9, 1203–1211, https://doi.org/10.5194/tc-9-1203-2015, https://doi.org/10.5194/tc-9-1203-2015, 2015
Short summary
Short summary
This paper presents an assessment of changes in the near-surface structure of the accumulation zone of the Greenland Ice Sheet caused by an increase of melt at higher elevations in the last decade, especially during the unusually warm years of 2010 and 2012. The increase in melt and firn densification complicate the interpretation of changes in the ice volume, and the observed increase in firn ice content may reduce the important meltwater buffering capacity of the Greenland Ice Sheet.
E. Johansson, S. Berglund, T. Lindborg, J. Petrone, D. van As, L.-G. Gustafsson, J.-O. Näslund, and H. Laudon
Earth Syst. Sci. Data, 7, 93–108, https://doi.org/10.5194/essd-7-93-2015, https://doi.org/10.5194/essd-7-93-2015, 2015
Short summary
Short summary
This paper presents a hydrological and meteorological data set from the Kangerlussuaq region, western Greenland. The data set is used to conceptualize and model the hydrological system and constitutes an important platform in order to describe the exchange of water between the surface, active layer, the lake, and the underlying talik. The resulting hydrological model will be used as a basis for biogeochemical mass-balance and transport calculations of the terrestrial and limnic ecosystems.
J. C. Ryan, A. L. Hubbard, J. E. Box, J. Todd, P. Christoffersen, J. R. Carr, T. O. Holt, and N. Snooke
The Cryosphere, 9, 1–11, https://doi.org/10.5194/tc-9-1-2015, https://doi.org/10.5194/tc-9-1-2015, 2015
Short summary
Short summary
An unmanned aerial vehicle (UAV) equipped with a commercial digital camera enabled us to obtain high-resolution digital images of the calving front of Store glacier, Greenland. The three sorties flown enabled key glaciological parameters to be quantified in sufficient detail to reveal that the terminus of Store glacier is a complex system with large variations in crevasse patterns surface velocities, calving processes, surface elevations and front positions at a daily and seasonal timescale.
M. Schaefer, H. Machguth, M. Falvey, G. Casassa, and E. Rignot
The Cryosphere, 9, 25–35, https://doi.org/10.5194/tc-9-25-2015, https://doi.org/10.5194/tc-9-25-2015, 2015
Short summary
Short summary
We use a meteorological-glaciological multi-model approach to quantify, for the first time, melt and accumulation of snow on the Southern Patagonia Icefield (SPI). We were able to reproduce the high measured accumulation of snow of up to 15.4 m water equivalent per year as well as the high measured ablation of up to 11 m water equivalent per year. Mass losses of the SPI due to calving of icebergs strongly increased from 1975-2000 to 2000-2011 and were higher than losses due to surface melt.
H. Frey, H. Machguth, M. Huss, C. Huggel, S. Bajracharya, T. Bolch, A. Kulkarni, A. Linsbauer, N. Salzmann, and M. Stoffel
The Cryosphere, 8, 2313–2333, https://doi.org/10.5194/tc-8-2313-2014, https://doi.org/10.5194/tc-8-2313-2014, 2014
Short summary
Short summary
Existing methods (area–volume relations, a slope-dependent volume estimation method, and two ice-thickness distribution models) are used to estimate the ice reserves stored in Himalayan–Karakoram glaciers. Resulting volumes range from 2955–4737km³. Results from the ice-thickness distribution models agree well with local measurements; volume estimates from area-related relations exceed the estimates from the other approaches. Evidence on the effect of the selected method on results is provided.
J. M. Lea, D. W. F. Mair, F. M. Nick, B. R. Rea, D. van As, M. Morlighem, P. W. Nienow, and A. Weidick
The Cryosphere, 8, 2031–2045, https://doi.org/10.5194/tc-8-2031-2014, https://doi.org/10.5194/tc-8-2031-2014, 2014
S. A. Khan, K. K. Kjeldsen, K. H. Kjær, S. Bevan, A. Luckman, A. Aschwanden, A. A. Bjørk, N. J. Korsgaard, J. E. Box, M. van den Broeke, T. M. van Dam, and A. Fitzner
The Cryosphere, 8, 1497–1507, https://doi.org/10.5194/tc-8-1497-2014, https://doi.org/10.5194/tc-8-1497-2014, 2014
N. Chauché, A. Hubbard, J.-C. Gascard, J. E. Box, R. Bates, M. Koppes, A. Sole, P. Christoffersen, and H. Patton
The Cryosphere, 8, 1457–1468, https://doi.org/10.5194/tc-8-1457-2014, https://doi.org/10.5194/tc-8-1457-2014, 2014
A. A. W. Fitzpatrick, A. L. Hubbard, J. E. Box, D. J. Quincey, D. van As, A. P. B. Mikkelsen, S. H. Doyle, C. F. Dow, B. Hasholt, and G. A. Jones
The Cryosphere, 8, 107–121, https://doi.org/10.5194/tc-8-107-2014, https://doi.org/10.5194/tc-8-107-2014, 2014
K. Helfricht, M. Kuhn, M. Keuschnig, and A. Heilig
The Cryosphere, 8, 41–57, https://doi.org/10.5194/tc-8-41-2014, https://doi.org/10.5194/tc-8-41-2014, 2014
W. Colgan, S. Luthcke, W. Abdalati, and M. Citterio
The Cryosphere, 7, 1901–1914, https://doi.org/10.5194/tc-7-1901-2013, https://doi.org/10.5194/tc-7-1901-2013, 2013
T. Kobashi, K. Goto-Azuma, J. E. Box, C.-C. Gao, and T. Nakaegawa
Clim. Past, 9, 2299–2317, https://doi.org/10.5194/cp-9-2299-2013, https://doi.org/10.5194/cp-9-2299-2013, 2013
A. K. Rennermalm, L. C. Smith, V. W. Chu, J. E. Box, R. R. Forster, M. R. Van den Broeke, D. Van As, and S. E. Moustafa
The Cryosphere, 7, 1433–1445, https://doi.org/10.5194/tc-7-1433-2013, https://doi.org/10.5194/tc-7-1433-2013, 2013
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
H. C. Steen-Larsen, S. J. Johnsen, V. Masson-Delmotte, B. Stenni, C. Risi, H. Sodemann, D. Balslev-Clausen, T. Blunier, D. Dahl-Jensen, M. D. Ellehøj, S. Falourd, A. Grindsted, V. Gkinis, J. Jouzel, T. Popp, S. Sheldon, S. B. Simonsen, J. Sjolte, J. P. Steffensen, P. Sperlich, A. E. Sveinbjörnsdóttir, B. M. Vinther, and J. W. C. White
Atmos. Chem. Phys., 13, 4815–4828, https://doi.org/10.5194/acp-13-4815-2013, https://doi.org/10.5194/acp-13-4815-2013, 2013
M. Tedesco, X. Fettweis, T. Mote, J. Wahr, P. Alexander, J. E. Box, and B. Wouters
The Cryosphere, 7, 615–630, https://doi.org/10.5194/tc-7-615-2013, https://doi.org/10.5194/tc-7-615-2013, 2013
T. Kobashi, D. T. Shindell, K. Kodera, J. E. Box, T. Nakaegawa, and K. Kawamura
Clim. Past, 9, 583–596, https://doi.org/10.5194/cp-9-583-2013, https://doi.org/10.5194/cp-9-583-2013, 2013
P. Rastner, T. Bolch, N. Mölg, H. Machguth, R. Le Bris, and F. Paul
The Cryosphere, 6, 1483–1495, https://doi.org/10.5194/tc-6-1483-2012, https://doi.org/10.5194/tc-6-1483-2012, 2012
Related subject area
Discipline: Ice sheets | Subject: Greenland
Firn seismic anisotropy in the Northeast Greenland Ice Stream from ambient-noise surface waves
First results of the polar regional climate model RACMO2.4
Calving front monitoring at a subseasonal resolution: a deep learning application for Greenland glaciers
Projections of Precipitation and Temperatures in Greenland and the Impact of Spatially Uniform Anomalies on the Evolution of the Ice Sheet
Impacts of Differing Melt Regimes on Satellite Radar Waveforms and Elevation Retrievals
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry
The future of Upernavik Isstrøm through ISMIP6 framework: Sensitivity analysis and Bayesian calibration of ensemble prediction
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
A topographically-controlled tipping point for complete Greenland ice-sheet melt
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
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
Sources of uncertainty in Greenland surface mass balance in the 21st century
Proper orthogonal decomposition of ice velocity identifies drivers of flow variability at Sermeq Kujalleq (Jakobshavn Isbræ)
Brief communication: A roadmap towards credible projections of ice sheet contribution to sea level
Automated detection and analysis of surface calving waves with a terrestrial radar interferometer at the front of Eqip Sermia, Greenland
Generation and fate of basal meltwater during winter, western Greenland Ice Sheet
Modeling the Greenland englacial stratigraphy
Upstream flow effects revealed in the EastGRIP ice core using Monte Carlo inversion of a two-dimensional ice-flow model
Indication of high basal melting at the EastGRIP drill site on the Northeast Greenland Ice Stream
Brief communication: Reduction in the future Greenland ice sheet surface melt with the help of solar geoengineering
Contrasting regional variability of buried meltwater extent over 2 years across the Greenland Ice Sheet
Sensitivity of the Greenland surface mass and energy balance to uncertainties in key model parameters
Surface melting over the Greenland ice sheet derived from enhanced resolution passive microwave brightness temperatures (1979–2019)
Impact of updated radiative transfer scheme in snow and ice in RACMO2.3p3 on the surface mass and energy budget of the Greenland ice sheet
Winter drainage of surface lakes on the Greenland Ice Sheet from Sentinel-1 SAR imagery
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland
The GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for phase 6 of the Coupled Model Intercomparison Project (ISMIP6) – Part 1: Projections of the Greenland ice sheet evolution by the end of the 21st century
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Nils Bochow, Anna Poltronieri, and Niklas Boers
EGUsphere, https://doi.org/10.5194/egusphere-2024-1597, https://doi.org/10.5194/egusphere-2024-1597, 2024
Short summary
Short summary
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.
Alexander Ronan, Robert Hawley, and Jonathan Chipman
EGUsphere, https://doi.org/10.5194/egusphere-2024-1152, https://doi.org/10.5194/egusphere-2024-1152, 2024
Short summary
Short summary
We generate a 2010–2021 time series of CryoSat-2 waveform shape metrics on the Greenland Ice Sheet, and 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.
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
Short summary
Short summary
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.
Eliot Jager, Fabien Gillet-Chaulet, Nicolas Champollion, Romain Millan, Heiko Goelzer, and Jérémie Mouginot
EGUsphere, https://doi.org/10.5194/egusphere-2024-862, https://doi.org/10.5194/egusphere-2024-862, 2024
Short summary
Short summary
Our study projects uncertainties through ISMIP6 framework for Upernavik Isstrøm, a tidewater Greenlandic glacier. We validate our ice sheet model against past data and quantify uncertainties in SSPs, climate models, ice-ocean interactions, and parameters. We highlight that future CO2 emissions via SSPs is the major uncertainty source at the end of the century. Finally, we show how uncertainties can be reduced using Bayesian calibration, the robustness of which is verified by cross-validation.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Michele Petrini, Meike Scherrenberg, Laura Muntjewerf, Miren Vizcaino, Raymond Sellevold, Gunter Leguy, William Lipscomb, and Heiko Goelzer
The Cryosphere Discuss., https://doi.org/10.5194/tc-2023-154, https://doi.org/10.5194/tc-2023-154, 2023
Revised manuscript accepted for TC
Short summary
Short summary
In this study, we investigate with a numerical model the stability of the Greenland ice-sheet under prolonged sustained warming and ice melt. We show that there is a threshold beyond which the ice-sheet will lose more than 80 % of its mass over tens of thousand of years. The point of no return is reached when the ice-sheet disconnects from a region of high topography in western Greenland. This threshold is determined by the interaction of surface and solid-Earth processes.
Johanna Beckmann and Ricarda Winkelmann
The Cryosphere, 17, 3083–3099, https://doi.org/10.5194/tc-17-3083-2023, https://doi.org/10.5194/tc-17-3083-2023, 2023
Short summary
Short summary
Over the past decade, Greenland has experienced several extreme melt events.
With progressing climate change, such extreme melt events can be expected to occur more frequently and potentially become more severe and persistent.
Strong melt events may considerably contribute to Greenland's mass loss, which in turn strongly determines future sea level rise. How important these extreme melt events could be in the future is assessed in this study for the first time.
Angelika Humbert, Veit Helm, Niklas Neckel, Ole Zeising, Martin Rückamp, Shfaqat Abbas Khan, Erik Loebel, Jörg Brauchle, Karsten Stebner, Dietmar Gross, Rabea Sondershaus, and Ralf Müller
The Cryosphere, 17, 2851–2870, https://doi.org/10.5194/tc-17-2851-2023, https://doi.org/10.5194/tc-17-2851-2023, 2023
Short summary
Short summary
The largest floating glacier mass in Greenland, the 79° N Glacier, is showing signs of instability. We investigate how crack formation at the glacier's calving front has changed over the last decades by using satellite imagery and airborne data. The calving front is about to lose contact to stabilizing ice islands. Simulations show that the glacier will accelerate as a result of this, leading to an increase in ice discharge of more than 5.1 % if its calving front retreats by 46 %.
Megan Thompson-Munson, Nander Wever, C. Max Stevens, Jan T. M. Lenaerts, and Brooke Medley
The Cryosphere, 17, 2185–2209, https://doi.org/10.5194/tc-17-2185-2023, https://doi.org/10.5194/tc-17-2185-2023, 2023
Short summary
Short summary
To better understand the Greenland Ice Sheet’s firn layer and its ability to buffer sea level rise by storing meltwater, we analyze firn density observations and output from two firn models. We find that both models, one physics-based and one semi-empirical, simulate realistic density and firn air content when compared to observations. The models differ in their representation of firn air content, highlighting the uncertainty in physical processes and the paucity of deep-firn measurements.
Yubin Fan, Chang-Qing Ke, Xiaoyi Shen, Yao Xiao, Stephen J. Livingstone, and Andrew J. Sole
The Cryosphere, 17, 1775–1786, https://doi.org/10.5194/tc-17-1775-2023, https://doi.org/10.5194/tc-17-1775-2023, 2023
Short summary
Short summary
We used the new-generation ICESat-2 altimeter to detect and monitor active subglacial lakes in unprecedented spatiotemporal detail. We created a new inventory of 18 active subglacial lakes as well as their elevation and volume changes during 2019–2020, which provides an improved understanding of how the Greenland subglacial water system operates and how these lakes are fed by water from the ice surface.
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
Short summary
Short summary
We characterized short-lived episodes of ice mélange weakening (IMW) at the front of three major Greenland outlet glaciers. Through a continuous detection at the front of Kangerdlugssuaq Glacier during the June-to-September period from 2018 to 2021, we found that 87 % of the IMW episodes occurred prior to a large-scale calving event. Using a simple model for ice mélange motion, we further characterized the IMW process as self-sustained through the existence of an IMW–calving feedback.
Taryn E. Black and Ian Joughin
The Cryosphere, 17, 1–13, https://doi.org/10.5194/tc-17-1-2023, https://doi.org/10.5194/tc-17-1-2023, 2023
Short summary
Short summary
The frontal positions of most ice-sheet-based glaciers in Greenland vary seasonally. On average, these glaciers begin retreating in May and begin advancing in October, and the difference between their most advanced and most retreated positions is 220 m. The timing may be related to the timing of melt on the ice sheet, and the seasonal length variation may be related to glacier speed. These seasonal variations can affect glacier behavior and, consequently, how much ice is lost from the ice sheet.
Trevor R. Hillebrand, Matthew J. Hoffman, Mauro Perego, Stephen F. Price, and Ian M. Howat
The Cryosphere, 16, 4679–4700, https://doi.org/10.5194/tc-16-4679-2022, https://doi.org/10.5194/tc-16-4679-2022, 2022
Short summary
Short summary
We estimate that Humboldt Glacier, northern Greenland, will contribute 5.2–8.7 mm to global sea level in 2007–2100, using an ensemble of model simulations constrained by observations of glacier retreat and speedup. This is a significant fraction of the 40–140 mm from the whole Greenland Ice Sheet predicted by the recent ISMIP6 multi-model ensemble, suggesting that calibrating models against observed velocity changes could result in higher estimates of 21st century sea-level rise from Greenland.
Evan Carnahan, Ginny Catania, and Timothy C. Bartholomaus
The Cryosphere, 16, 4305–4317, https://doi.org/10.5194/tc-16-4305-2022, https://doi.org/10.5194/tc-16-4305-2022, 2022
Short summary
Short summary
The Greenland Ice Sheet primarily loses mass through increased ice discharge. We find changes in discharge from outlet glaciers are initiated by ocean warming, which causes a change in the balance of forces resisting gravity and leads to acceleration. Vulnerable conditions for sustained retreat and acceleration are predetermined by the glacier-fjord geometry and exist around Greenland, suggesting increases in ice discharge may be sustained into the future despite a pause in ocean warming.
Raf M. Antwerpen, Marco Tedesco, Xavier Fettweis, Patrick Alexander, and Willem Jan van de Berg
The Cryosphere, 16, 4185–4199, https://doi.org/10.5194/tc-16-4185-2022, https://doi.org/10.5194/tc-16-4185-2022, 2022
Short summary
Short summary
The ice on Greenland has been melting more rapidly over the last few years. Most of this melt comes from the exposure of ice when the overlying snow melts. This ice is darker than snow and absorbs more sunlight, leading to more melt. It remains challenging to accurately simulate the brightness of the ice. We show that the color of ice simulated by Modèle Atmosphérique Régional (MAR) is too bright. We then show that this means that MAR may underestimate how fast the Greenland ice is melting.
Jason P. Briner, Caleb K. Walcott, Joerg M. Schaefer, Nicolás E. Young, Joseph A. MacGregor, Kristin Poinar, Benjamin A. Keisling, Sridhar Anandakrishnan, Mary R. Albert, Tanner Kuhl, and Grant Boeckmann
The Cryosphere, 16, 3933–3948, https://doi.org/10.5194/tc-16-3933-2022, https://doi.org/10.5194/tc-16-3933-2022, 2022
Short summary
Short summary
The 7.4 m of sea level equivalent stored as Greenland ice is getting smaller every year. The uncertain trajectory of ice loss could be better understood with knowledge of the ice sheet's response to past climate change. Within the bedrock below the present-day ice sheet is an archive of past ice-sheet history. We analyze all available data from Greenland to create maps showing where on the ice sheet scientists can drill, using currently available drills, to obtain sub-ice materials.
Ioanna Karagali, Magnus Barfod Suhr, Ruth Mottram, Pia Nielsen-Englyst, Gorm Dybkjær, Darren Ghent, and Jacob L. Høyer
The Cryosphere, 16, 3703–3721, https://doi.org/10.5194/tc-16-3703-2022, https://doi.org/10.5194/tc-16-3703-2022, 2022
Short summary
Short summary
Ice surface temperature (IST) products were used to develop the first multi-sensor, gap-free Level 4 (L4) IST product of the Greenland Ice Sheet (GIS) for 2012, when a significant melt event occurred. For the melt season, mean IST was −15 to −1 °C, and almost the entire GIS experienced at least 1 to 5 melt days. Inclusion of the L4 IST to a surface mass budget (SMB) model improved simulated surface temperatures during the key onset of the melt season, where biases are typically large.
Michael Studinger, Serdar S. Manizade, Matthew A. Linkswiler, and James K. Yungel
The Cryosphere, 16, 3649–3668, https://doi.org/10.5194/tc-16-3649-2022, https://doi.org/10.5194/tc-16-3649-2022, 2022
Short summary
Short summary
The footprint density and high-resolution imagery of airborne surveys reveal details in supraglacial hydrological features that are currently not obtainable from spaceborne data. The accuracy and resolution of airborne measurements complement spaceborne measurements, can support calibration and validation of spaceborne methods, and provide information necessary for process studies of the hydrological system on ice sheets that currently cannot be achieved from spaceborne observations alone.
Tiago Silva, Jakob Abermann, Brice Noël, Sonika Shahi, Willem Jan van de Berg, and Wolfgang Schöner
The Cryosphere, 16, 3375–3391, https://doi.org/10.5194/tc-16-3375-2022, https://doi.org/10.5194/tc-16-3375-2022, 2022
Short summary
Short summary
To overcome internal climate variability, this study uses k-means clustering to combine NAO, GBI and IWV over the Greenland Ice Sheet (GrIS) and names the approach as the North Atlantic influence on Greenland (NAG). With the support of a polar-adapted RCM, spatio-temporal changes on SEB components within NAG phases are investigated. We report atmospheric warming and moistening across all NAG phases as well as large-scale and regional-scale contributions to GrIS mass loss and their interactions.
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, and Michael Studinger
The Cryosphere, 16, 3033–3049, https://doi.org/10.5194/tc-16-3033-2022, https://doi.org/10.5194/tc-16-3033-2022, 2022
Short summary
Short summary
Where the bottom of the Greenland Ice Sheet is frozen and where it is thawed is not well known, yet knowing this state is increasingly important to interpret modern changes in ice flow there. We produced a second synthesis of knowledge of the basal thermal state of the ice sheet using airborne and satellite observations and numerical models. About one-third of the ice sheet’s bed is likely thawed; two-fifths is likely frozen; and the remainder is too uncertain to specify.
Michael A. Cooper, Paulina Lewińska, William A. P. Smith, Edwin R. Hancock, Julian A. Dowdeswell, and David M. Rippin
The Cryosphere, 16, 2449–2470, https://doi.org/10.5194/tc-16-2449-2022, https://doi.org/10.5194/tc-16-2449-2022, 2022
Short summary
Short summary
Here we use old photographs gathered several decades ago to expand the temporal record of glacier change in part of East Greenland. This is important because the longer the record of past glacier change, the better we are at predicting future glacier behaviour. Our work also shows that despite all these glaciers retreating, the rate at which they do this varies markedly. It is therefore important to consider outlet glaciers from Greenland individually to take account of this differing behaviour.
Joshua K. Cuzzone, Nicolás E. Young, Mathieu Morlighem, Jason P. Briner, and Nicole-Jeanne Schlegel
The Cryosphere, 16, 2355–2372, https://doi.org/10.5194/tc-16-2355-2022, https://doi.org/10.5194/tc-16-2355-2022, 2022
Short summary
Short summary
We use an ice sheet model to determine what influenced the Greenland Ice Sheet to retreat across a portion of southwestern Greenland during the Holocene (about the last 12 000 years). Our simulations, constrained by observations from geologic markers, show that atmospheric warming and ice melt primarily caused the ice sheet to retreat rapidly across this domain. We find, however, that iceberg calving at the interface where the ice meets the ocean significantly influenced ice mass change.
Martin Rückamp, Thomas Kleiner, and Angelika Humbert
The Cryosphere, 16, 1675–1696, https://doi.org/10.5194/tc-16-1675-2022, https://doi.org/10.5194/tc-16-1675-2022, 2022
Short summary
Short summary
We present a comparative modelling study between the full-Stokes (FS) and Blatter–Pattyn (BP) approximation applied to the Northeast Greenland Ice Stream. Both stress regimes are implemented in one single ice sheet code to eliminate numerical issues. The simulations unveil minor differences in the upper ice stream but become considerable at the grounding line of the 79° North Glacier. Model differences are stronger for a power-law friction than a linear friction law.
Daniel Clarkson, Emma Eastoe, and Amber Leeson
The Cryosphere, 16, 1597–1607, https://doi.org/10.5194/tc-16-1597-2022, https://doi.org/10.5194/tc-16-1597-2022, 2022
Short summary
Short summary
The Greenland ice sheet has seen large amounts of melt in recent years, and accurately modelling temperatures is vital to understand how much of the ice sheet is melting. We estimate the probability of melt from ice surface temperature data to identify which areas of the ice sheet have experienced melt and estimate temperature quantiles. Our results suggest that for large areas of the ice sheet, melt has become more likely over the past 2 decades and high temperatures are also becoming warmer.
Benjamin Joseph Davison, Tom Cowton, Andrew Sole, Finlo Cottier, and Pete Nienow
The Cryosphere, 16, 1181–1196, https://doi.org/10.5194/tc-16-1181-2022, https://doi.org/10.5194/tc-16-1181-2022, 2022
Short summary
Short summary
The ocean is an important driver of Greenland glacier retreat. Icebergs influence ocean temperature in the vicinity of glaciers, which will affect glacier retreat rates, but the effect of icebergs on water temperature is poorly understood. In this study, we use a model to show that icebergs cause large changes to water properties next to Greenland's glaciers, which could influence ocean-driven glacier retreat around Greenland.
Taryn E. Black and Ian Joughin
The Cryosphere, 16, 807–824, https://doi.org/10.5194/tc-16-807-2022, https://doi.org/10.5194/tc-16-807-2022, 2022
Short summary
Short summary
We used satellite images to create a comprehensive record of annual glacier change in northwest Greenland from 1972 through 2021. We found that nearly all glaciers in our study area have retreated and glacier retreat accelerated from around 1996. Comparing these results with climate data, we found that glacier retreat is most sensitive to water runoff and moderately sensitive to ocean temperatures. These can affect glacier fronts in several ways, so no process clearly dominates glacier retreat.
Katharina M. Holube, Tobias Zolles, and Andreas Born
The Cryosphere, 16, 315–331, https://doi.org/10.5194/tc-16-315-2022, https://doi.org/10.5194/tc-16-315-2022, 2022
Short summary
Short summary
We simulated the surface mass balance of the Greenland Ice Sheet in the 21st century by forcing a snow model with the output of many Earth system models and four greenhouse gas emission scenarios. We quantify the contribution to uncertainty in surface mass balance of these two factors and the choice of parameters of the snow model. The results show that the differences between Earth system models are the main source of uncertainty. This effect is localised mostly near the equilibrium line.
David W. Ashmore, Douglas W. F. Mair, Jonathan E. Higham, Stephen Brough, James M. Lea, and Isabel J. Nias
The Cryosphere, 16, 219–236, https://doi.org/10.5194/tc-16-219-2022, https://doi.org/10.5194/tc-16-219-2022, 2022
Short summary
Short summary
In this paper we explore the use of a transferrable and flexible statistical technique to try and untangle the multiple influences on marine-terminating glacier dynamics, as measured from space. We decompose a satellite-derived ice velocity record into ranked sets of static maps and temporal coefficients. We present evidence that the approach can identify velocity variability mainly driven by changes in terminus position and velocity variation mainly driven by subglacial hydrological processes.
Andy Aschwanden, Timothy C. Bartholomaus, Douglas J. Brinkerhoff, and Martin Truffer
The Cryosphere, 15, 5705–5715, https://doi.org/10.5194/tc-15-5705-2021, https://doi.org/10.5194/tc-15-5705-2021, 2021
Short summary
Short summary
Estimating how much ice loss from Greenland and Antarctica will contribute to sea level rise is of critical societal importance. However, our analysis shows that recent efforts are not trustworthy because the models fail at reproducing contemporary ice melt. Here we present a roadmap towards making more credible estimates of ice sheet melt.
Adrien Wehrlé, Martin P. Lüthi, Andrea Walter, Guillaume Jouvet, and Andreas Vieli
The Cryosphere, 15, 5659–5674, https://doi.org/10.5194/tc-15-5659-2021, https://doi.org/10.5194/tc-15-5659-2021, 2021
Short summary
Short summary
We developed a novel automated method for the detection and the quantification of ocean waves generated by glacier calving. This method was applied to data recorded with a terrestrial radar interferometer at Eqip Sermia, Greenland. Results show a high calving activity at the glacier front sector ending in deep water linked with more frequent meltwater plumes. This suggests that rising subglacial meltwater plumes strongly affect glacier calving in deep water, but weakly in shallow water.
Joel Harper, Toby Meierbachtol, Neil Humphrey, Jun Saito, and Aidan Stansberry
The Cryosphere, 15, 5409–5421, https://doi.org/10.5194/tc-15-5409-2021, https://doi.org/10.5194/tc-15-5409-2021, 2021
Short summary
Short summary
We use surface and borehole measurements to investigate the generation and fate of basal meltwater in the ablation zone of western Greenland. The rate of basal meltwater generation at borehole study sites increases by up to 20 % over the winter period. Accommodation of all basal meltwater by expansion of isolated subglacial cavities is implausible. Other sinks for water do not likely balance basal meltwater generation, implying water evacuation through a connected drainage system in winter.
Andreas Born and Alexander Robinson
The Cryosphere, 15, 4539–4556, https://doi.org/10.5194/tc-15-4539-2021, https://doi.org/10.5194/tc-15-4539-2021, 2021
Short summary
Short summary
Ice penetrating radar reflections from the Greenland ice sheet are the best available record of past accumulation and how these layers have been deformed over time by the flow of ice. Direct simulations of this archive hold great promise for improving our models and for uncovering details of ice sheet dynamics that neither models nor data could achieve alone. We present the first three-dimensional ice sheet model that explicitly simulates individual layers of accumulation and how they deform.
Tamara Annina Gerber, Christine Schøtt Hvidberg, Sune Olander Rasmussen, Steven Franke, Giulia Sinnl, Aslak Grinsted, Daniela Jansen, and Dorthe Dahl-Jensen
The Cryosphere, 15, 3655–3679, https://doi.org/10.5194/tc-15-3655-2021, https://doi.org/10.5194/tc-15-3655-2021, 2021
Short summary
Short summary
We simulate the ice flow in the onset region of the Northeast Greenland Ice Stream to determine the source area and past accumulation rates of ice found in the EastGRIP ice core. This information is required to correct for bias in ice-core records introduced by the upstream flow effects. Our results reveal that the increasing accumulation rate with increasing upstream distance is predominantly responsible for the constant annual layer thicknesses observed in the upper 900 m of the ice core.
Ole Zeising and Angelika Humbert
The Cryosphere, 15, 3119–3128, https://doi.org/10.5194/tc-15-3119-2021, https://doi.org/10.5194/tc-15-3119-2021, 2021
Short summary
Short summary
Greenland’s largest ice stream – the Northeast Greenland Ice Stream (NEGIS) – extends far into the interior of the ice sheet. Basal meltwater acts as a lubricant for glaciers and sustains sliding. Hence, observations of basal melt rates are of high interest. We performed two time series of precise ground-based radar measurements in the upstream region of NEGIS and found high melt rates of 0.19 ± 0.04 m per year.
Xavier Fettweis, Stefan Hofer, Roland Séférian, Charles Amory, Alison Delhasse, Sébastien Doutreloup, Christoph Kittel, Charlotte Lang, Joris Van Bever, Florent Veillon, and Peter Irvine
The Cryosphere, 15, 3013–3019, https://doi.org/10.5194/tc-15-3013-2021, https://doi.org/10.5194/tc-15-3013-2021, 2021
Short summary
Short summary
Without any reduction in our greenhouse gas emissions, the Greenland ice sheet surface mass loss can be brought in line with a medium-mitigation emissions scenario by reducing the solar downward flux at the top of the atmosphere by 1.5 %. In addition to reducing global warming, these solar geoengineering measures also dampen the well-known positive melt–albedo feedback over the ice sheet by 6 %. However, only stronger reductions in solar radiation could maintain a stable ice sheet in 2100.
Devon Dunmire, Alison F. Banwell, Nander Wever, Jan T. M. Lenaerts, and Rajashree Tri Datta
The Cryosphere, 15, 2983–3005, https://doi.org/10.5194/tc-15-2983-2021, https://doi.org/10.5194/tc-15-2983-2021, 2021
Short summary
Short summary
Here, we automatically detect buried lakes (meltwater lakes buried below layers of snow) across the Greenland Ice Sheet, providing insight into a poorly studied meltwater feature. For 2018 and 2019, we compare areal extent of buried lakes. We find greater buried lake extent in 2019, especially in northern Greenland, which we attribute to late-summer surface melt and high autumn temperatures. We also provide evidence that buried lakes form via different processes across Greenland.
Tobias Zolles and Andreas Born
The Cryosphere, 15, 2917–2938, https://doi.org/10.5194/tc-15-2917-2021, https://doi.org/10.5194/tc-15-2917-2021, 2021
Short summary
Short summary
We investigate the sensitivity of a glacier surface mass and the energy balance model of the Greenland ice sheet for the cold period of the Last Glacial Maximum (LGM) and the present-day climate. The results show that the model sensitivity changes with climate. While for present-day simulations inclusions of sublimation and hoar formation are of minor importance, they cannot be neglected during the LGM. To simulate the surface mass balance over long timescales, a water vapor scheme is necessary.
Paolo Colosio, Marco Tedesco, Roberto Ranzi, and Xavier Fettweis
The Cryosphere, 15, 2623–2646, https://doi.org/10.5194/tc-15-2623-2021, https://doi.org/10.5194/tc-15-2623-2021, 2021
Short summary
Short summary
We use a new satellite dataset to study the spatiotemporal evolution of surface melting over Greenland at an enhanced resolution of 3.125 km. Using meteorological data and the MAR model, we observe that a dynamic algorithm can best detect surface melting. We found that the melting season is elongating, the melt extent is increasing and that high-resolution data better describe the spatiotemporal evolution of the melting season, which is crucial to improve estimates of sea level rise.
Christiaan T. van Dalum, Willem Jan van de Berg, and Michiel R. van den Broeke
The Cryosphere, 15, 1823–1844, https://doi.org/10.5194/tc-15-1823-2021, https://doi.org/10.5194/tc-15-1823-2021, 2021
Short summary
Short summary
Absorption of solar radiation is often limited to the surface in regional climate models. Therefore, we have implemented a new radiative transfer scheme in the model RACMO2, which allows for internal heating and improves the surface reflectivity. Here, we evaluate its impact on the surface mass and energy budget and (sub)surface temperature, by using observations and the previous model version for the Greenland ice sheet. New results match better with observations and introduce subsurface melt.
Corinne L. Benedek and Ian C. Willis
The Cryosphere, 15, 1587–1606, https://doi.org/10.5194/tc-15-1587-2021, https://doi.org/10.5194/tc-15-1587-2021, 2021
Short summary
Short summary
The surface of the Greenland Ice Sheet contains thousands of surface lakes. These lakes can deliver water through cracks to the ice sheet base and influence the speed of ice flow. Here we look at instances of lakes draining in the middle of winter using the Sentinel-1 radar satellites. Winter-draining lakes can help us understand the mechanisms for lake drainages throughout the year and can point to winter movement of water that will impact our understanding of ice sheet hydrology.
Nathan Maier, Florent Gimbert, Fabien Gillet-Chaulet, and Adrien Gilbert
The Cryosphere, 15, 1435–1451, https://doi.org/10.5194/tc-15-1435-2021, https://doi.org/10.5194/tc-15-1435-2021, 2021
Short summary
Short summary
In Greenland, ice motion and the surface geometry depend on the friction at the bed. We use satellite measurements and modeling to determine how ice speeds and friction are related across the ice sheet. The relationships indicate that ice flowing over bed bumps sets the friction across most of the ice sheet's on-land regions. This result helps simplify and improve our understanding of how ice motion will change in the future.
Aurélien Quiquet and Christophe Dumas
The Cryosphere, 15, 1015–1030, https://doi.org/10.5194/tc-15-1015-2021, https://doi.org/10.5194/tc-15-1015-2021, 2021
Short summary
Short summary
We present here the GRISLI-LSCE contribution to the Ice Sheet Model Intercomparison Project for CMIP6 for Greenland. The project aims to quantify the ice sheet contribution to global sea level rise for the next century. We show an important spread in the simulated Greenland ice loss in the future depending on the climate forcing used. Mass loss is primarily driven by atmospheric warming, while oceanic forcing contributes to a relatively smaller uncertainty in our simulations.
Cited articles
Albert, M. and Shultz, E.: Snow and firn properties and air–snow transport
processes at Summit, Greenland, Atmos. Environ., 36, 2789–2797,
https://doi.org/10.1016/S1352-2310(02)00119-X, 2002.
Alley, R.: Transformations in Polar Firn, PhD Thesis, University of
Wisconsin, Madison, WI, USA, 1987.
Bader, H.: Sorge's law of densification of snow on high polar glaciers, J.
Glaciol., 2, 15, 319–411, https://doi.org/10.3189/S0022143000025144, 1954.
Baker, I.: Density and permeability measurements with depth for the NEEM
2009S2 firn core, ACADIS Gateway, https://doi.org/10.18739/A2Q88G, 2012.
Benson, C. S.: Stratigraphic Studies in the Snow and Firn of the Greenland
Ice Sheet, U.S. Army Snow, Ice and Permafrost Research Establishment
(SIPRE–CRREL), Research Report 70, reprinted with revisions by CRREL, 1996,
1962.
Bindoff, N. L., Stott, P. A., AchutaRao, K. M., Allen, M. R., Gillett, N.,
Gutzler, D., Hansingo, K., Hegerl, G., Hu, Y., Jain, S., Mokhov, I. I.,
Overland, J., Perlwitz, J., Sebbari, R., and Zhang, X.: Detection and
Attribution of Climate Change: from Global to Regional, in: Climate Change
2013: The Physical Science Basis, Contribution of Working Group I to the
Fifth Assessment Report of the Intergovernmental Panel on Climate Change,
edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S.
K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge
University Press, Cambridge, UK, New York, NY, USA, 867–952,
https://doi.org/10.1017/CBO9781107415324.022, 2013.
Bolzan, J. F. and Strobel, M.: Oxygen isotope data from snowpit at GISP2 Site
15, PANGAEA, https://doi.org/10.1594/PANGAEA.55511, 1999.
Box, J.: Greenland ice sheet mass balance reconstruction. Part II: Surface
mass balance (1840–2010), J. Climate, 26, 6974–6989,
https://doi.org/10.1175/JCLI-D-12-00518.1, 2013.
Box, J., Cressie, N., Bromwich, D. H., Jung, J.-H., van den Broeke, M. R.,
van Angelen, J., Forster, R. R., Miège, C., Mosley-Thompson, E., Vinther,
B., and McConnell, J. R.: Greenland ice sheet mass balance reconstruction.
Part I: Net snow accumulation (1600–2009), J. Climate, 26, 3919–3934,
https://doi.org/10.1175/JCLI-D-12-00373.1, 2013.
Braithwaite, R., Laternser, M., and Pfeffer, W. T.: Variation of near-surface
firn density in the lower accumulation area of the Greenland ice sheet,
Pâkitsoq, West Greenland, J. Glaciol., 40, 477–485,
https://doi.org/10.3189/S002214300001234X, 1994.
Buchardt, S. L., Clausen, H. B., Vinther, B. M., and Dahl-Jensen, D.:
Investigating the past and recent δ18O-accumulation relationship
seen in Greenland ice cores, Clim. Past, 8, 2053–2059,
https://doi.org/10.5194/cp-8-2053-2012, 2012.
Charalampidis, C., van As, D., Box, J. E., van den Broeke, M. R., Colgan, W.
T., Doyle, S. H., Hubbard, A. L., MacFerrin, M., Machguth, H., and Smeets, C.
J. P. P.: Changing surface–atmosphere energy exchange and refreezing
capacity of the lower accumulation area, West Greenland, The Cryosphere, 9,
2163–2181, https://doi.org/10.5194/tc-9-2163-2015, 2015.
Clausen, H., Gundestrup, N. S., Johnsen, S. J., Bindschadler, R., and Zwally,
J.: Glaciological investigations in the Crete area, Central Greenland: a
search for a new deep-drilling Site, Ann. Glaciol., 10, 10–15,
https://doi.org/10.3189/S0260305500004080, 1988.
Colgan, W., Pedersen, A., Binder, D., Machguth, H., Abermann, J., and Jayred,
M.: Initial field activities of the Camp Century Climate Monitoring Programme
in Greenland, Geol. Surv. Denmark Greenland Bull., 41, 75–78, 2018.
de la Peña, S., Howat, I. M., Nienow, P. W., van den Broeke, M. R.,
Mosley-Thompson, E., Price, S. F., Mair, D., Noël, B., and Sole, A. J.:
Changes in the firn structure of the western Greenland Ice Sheet caused by
recent warming, The Cryosphere, 9, 1203–1211,
https://doi.org/10.5194/tc-9-1203-2015, 2015.
Fausto, R., Mayer, C., and Ahlstrøm, A.: Satellite-derived surface type
and melt area of the Greenland ice sheet using MODIS data from 2000 to 2005,
Ann. Glaciol., 46, 35–42, https://doi.org/10.3189/172756407782871422, 2007.
Fausto, R. S, Andersen, S. B., Ahlstrøm, A. P., van As, D., Box, J. E.,
Binder, D., Citterio, M., Colgan, W., Haubner, K., Hansen, K., Karlsson, N.
B., Mankoff, K. D., Pedersen, A. Ø., Solgaard, A., and Vandecrux, B.: The
Greenland ice sheet – snowline elevations at the end of the melt seasons
from 2000 to 2017, Geol. Surv. Denmark Greenland Bull., 41, 71–74, 2018a.
Fausto, R. S., Box, J. E., Vandecrux, B., van As, D., Steffen, K., MacFerrin,
M., Machguth H., Colgan W., Koenig L. S., McGrath D., Charalampidis, C., and
Braithwaite, R. J.: A Snow Density Dataset for Improving Surface Boundary
Conditions in Greenland Ice Sheet Firn Modeling, Front. Earth Sci., 6,
51 pp., https://doi.org/10.3389/feart.2018.00051, 2018b.
Fettweis, X., Box, J. E., Agosta, C., Amory, C., Kittel, C., Lang, C., van
As, D., Machguth, H., and Gallée, H.: Reconstructions of the 1900–2015
Greenland ice sheet surface mass balance using the regional climate MAR
model, The Cryosphere, 11, 1015–1033,
https://doi.org/10.5194/tc-11-1015-2017, 2017.
Fischer, H., Wagenbach, D., Laternser, M., and Haeberli, W.:
Glacio-meteorological and isotopic studies along the EGIG line, central
Greenland, J. Glaciol., 41, 139, 515–527, https://doi.org/10.3189/S0022143000034857,
1995.
Forster, R. R., Box, J. E., van den Broeke, M. R., Miège, C., Burgess, E.
W., Angelen, J. H., Lenaerts, J. T. M., Koenig, L. S., Paden, J., Lewis, C.,
Gogineni, S. P., Leuschen, C., and McConnell, J. R.: Extensive liquid
meltwater storage in firn within the Greenland ice sheet, Nat. Geosci., 7,
95–98, 2014.
Graeter, K. A., Osterberg, E., Ferris, D. G., Hawley, R. L., Marshall, H. P.,
Lewis, G., Meehan, T., McCarthy, F., Overly, T., and Birkel, S. D.: Ice Core
Records of West Greenland Melt and Climate Forcing, Geophys. Res. Lett., 45,
3164–3182, https://doi.org/10.1002/2017GL076641, 2018.
Harper, J., Humphrey, N., Pfeffer, W. T., Brown, J., and Fettweis, X.:
Greenland ice-sheet contribution to sea-level rise buffered by meltwater
storage in firn, Nature, 491, 240–243, https://doi.org/10.1038/nature11566, 2012.
Hawley, R. L., Courville, Z. R., Kehrl, L., Lutz, E., Osterberg, E., Overly,
T. B., and Wong, G.: Recent accumulation variability in northwest Greenland
from ground-penetrating radar and shallow cores along the Greenland Inland
Traverse, J. Glaciol., 60, 375–382, https://doi.org/10.3189/2014JoG13J141, 2014.
Heilig, A., Eisen, O., MacFerrin, M., Tedesco, M., and Fettweis, X.: Seasonal
monitoring of melt and accumulation within the deep percolation zone of the
Greenland Ice Sheet and comparison with simulations of regional climate
modeling, The Cryosphere, 12, 1851–1866,
https://doi.org/10.5194/tc-12-1851-2018, 2018.
Humphrey, N. F., Harper, J. T., and Pfeffer, W. T.: Thermal tracking of
meltwater retention in Greenland's accumulation area, J. Geophys. Res., 117,
F01010, https://doi.org/10.1029/2011JF002083, 2012.
Jezek, K. C.: Surface Elevation and Velocity Changes on the South Central
Greenland Ice Sheet: 1980–2011 – Data Summary, BPRC Technical Report No.
2012-01, Byrd Polar Research Center, The Ohio State University, Columbus,
Ohio, 2012.
Kameda, T., Narita, H., Shoji, H., Nishio, F., Fuji, Y., and Watanabe, O.:
Melt features in ice cores from Site J, southern Greenland: some implication
for summer climate since AD 1550, Ann. Glaciol., 21, 51–58,
https://doi.org/10.3189/S0260305500015597, 1995.
Koenig, L. and Montgomery, L.: Surface Mass Balance and Snow Depth on Sea
Ice Working Group (SUMup) snow density subdataset, Greenland and Antartica,
1950–2018, Arctic Data Center, https://doi.org/10.18739/A2JH3D23R, 2018.
Koenig, L. S., Miège, C., Forster, R. R., and Brucker, L.: Initial in
situ measurements of perennial meltwater storage in the Greenland firn
aquifer, Geophys. Res. Lett., 41, 81–85, https://doi.org/10.1002/2013GL058083, 2014.
Kovacs, A., Weeks, W. F., and Michitti, F.: Variation of Some Mechanical
Properties of Polar Snow, Camp Century, Greenland, CRREL Res. Rpt. 276, 1969.
Kuipers Munneke, P., Ligtenberg, S. R. M., Noël, B. P. Y., Howat, I. M.,
Box, J. E., Mosley-Thompson, E., McConnell, J. R., Steffen, K., Harper, J.
T., Das, S. B., and van den Broeke, M. R.: Elevation change of the Greenland
Ice Sheet due to surface mass balance and firn processes, 1960–2014, The
Cryosphere, 9, 2009–2025, https://doi.org/10.5194/tc-9-2009-2015, 2015a.
Kuipers Munneke, P., Ligtenberg, S. R., Suder, E. A., and van den Broeke, M.
R.: A model study of the response of dry and wet firn to climate change, Ann.
Glaciol., 56, 1–8, https://doi.org/10.3189/2015AoG70A994, 2015b.
Langen, P., Fausto, R. S., Vandecrux, B., Mottram, R., and Box, J.: Liquid
Water Flow and Retention on the Greenland Ice Sheet in the Regional Climate
Model HIRHAM5: Local and Large-Scale Impacts, Front. Earth Sci., 4, 110 pp.,
https://doi.org/10.3389/feart.2016.00110, 2017.
Langway, C. C.: Stratigraphic analysis of a deep ice core from Greenland,
CRREL Res. Rpt. 77, 1967.
Ligtenberg, S. R. M., Kuipers Munneke, P., Noël, B. P. Y., and van den
Broeke, M. R.: Brief communication: Improved simulation of the present-day
Greenland firn layer (1960–2016), The Cryosphere, 12, 1643–1649,
https://doi.org/10.5194/tc-12-1643-2018, 2018.
Lomonaco, R., Albert, M., and Baker, I.: Microstructural evolution of
fine-grained layers through the firn column at Summit, Greenland, J.
Glaciol., 57, 204 pp., https://doi.org/10.3189/002214311797409730, 2011.
Lucas-Picher, P., Wulff-Nielsen, M., Christensen, J. H.,
Aðalgeirsdóttir, G., Mottram, R., and Simonsen, S. B.: Very high
resolution in regional climate model simulations for Greenland: Identifying
added value, J. Geophys. Res., 117, D02108, https://doi.org/10.1029/2011JD016267, 2012.
Machguth, H., MacFerrin, M., van As, D., Box, J., Charalampidis, C., Colgan,
W., Fausto, R. S., Meijer, H. A., Mosley-Thompson, E., and van de Wal, R. S.:
Greenland meltwater storage in firn limited by near-surface ice formation,
Nat. Clim. Change, 6, 390–395, https://doi.org/10.1038/NCLIMATE2899, 2016.
Mayewski, P. and Whitlow, S.: Snow Pit and Ice Core Data from Southern
Greenland, 1984, NSF Arctic Data Center https://doi.org/10.5065/D6S180MH, 2016a.
Mayewski, P. and Whitlow S.: Snow Pit Data from Greenland Summit, 1989 to
1993, NSF Arctic Data Center, https://doi.org/10.5065/D6NP22KX, 2016b.
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.
Miège, C., Forster, R. R., Box, J. E., Burgess, E., McConnell, J.,
Pasteris, D., and Spikes, V. B.: Southeast Greenland high accumulation rates
derived from firn cores and ground-penetrating radar, Ann. Glaciol., 54,
322–332, https://doi.org/10.3189/2013AoG63A358, 2013.
Miège, C., Forster, R. R., Brucker, L., Koenig, L. S., Solomon, D. K.,
Paden, J. D., Box, J. E., Burgess, E. W., Miller, J. Z., McNerney, L.,
Brautigam, N., Fausto, R. S., and Gogineni, S.: Spatial extent and temporal
variability of Greenland firn aquifers detected by ground and airborne
radars, J. Geophys. Res.-Earth, 121, 2381–2398, https://doi.org/10.1002/2016JF003869,
2016.
Morris, E. M. and Wingham, D. J.: Densification of polar snow: Measurements,
modeling and implication for altimetry, J. Geophys. Res.-Earth, 119,
349–365, https://doi.org/10.1002/2013JF002898, 2014.
Mosley-Thompson, E., McConnell, J., Bales, R., Li, Z., Lin, P.-N., Steffen,
K., Thompson, L. G., Edwards, R., and Bathke, D.: Local to regional-scale
variability of annual net accumulation on the Greenland ice sheet from PARCA
cores, J. Geophys. Res., 106, 33839–33851, https://doi.org/10.1029/2001JD900067, 2001.
Mote, T. L.: Greenland surface melt trends 1973–2007: Evidence of a large
increase in 2007, Geophys. Res. Lett., 34, L22507, https://doi.org/10.1029/2007GL031976,
2007.
Nerem, R. S., Beckley, B. D., Fasullo, J. T., Hamlington, B. D., Masters, D.,
and Mitchum, G. T.: Climate-change-driven accelerated sea-level rise detected
in the altimeter era, P. Natl. Acad. Sci. USA, 7, 201717312,
https://doi.org/10.1073/pnas.1717312115, 2018.
Nghiem, S. V., Hall, D. K., Mote, T. L., Tedesco, M., Albert, M. R., Keegan,
K., Shuman, C. A., DiGirolamo, N. E., and Neumann, G.: The extreme melt
across the Greenland ice sheet in 2012, Geophys. Res. Lett., 39, L20502,
https://doi.org/10.1029/2012GL053611, 2012.
Noël, B., van de Berg, W. J., van Wessem, J. M., van Meijgaard, E., van
As, D., Lenaerts, J. T. M., Lhermitte, S., Kuipers Munneke, P., Smeets, C. J.
P. P., van Ulft, L. H., van de Wal, R. S. W., and van den Broeke, M. R.:
Modelling the climate and surface mass balance of polar ice sheets using
RACMO2 – Part 1: Greenland (1958–2016), The Cryosphere, 12, 811–831,
https://doi.org/10.5194/tc-12-811-2018, 2018.
Porter, S. and Mosley-Thompson, E.: Exploring seasonal accumulation bias in a
west central Greenland ice core with observed and reanalyzed data, J.
Glaciol., 60, 1065–1074, https://doi.org/10.3189/2014JoG13J233, 2014.
Reed, S.: Performance Study of the Dewline Ice Cap Stations, 1963, CRREL
Special Report 72, 1966.
Renaud, A.: Etude physiques et chimiques sur la glace de l'inlandsis du
Groenland, Medd. Groenland, 2, 100–107, 1959.
Shumskii, P. A.: Principles of structural glaciology: the petrography of
fresh-water ice as a method of glaciological investigation, Dover
Publications Inc., 1964.
Simonsen, S. B., Stenseng, L., Ađalgeirsdóttir, G., Fausto, R. S.,
Hvidberg, C. S., and Lucas-Picher, P.: Assessing a multilayered dynamic
firn-compaction model for Greenland with ASIRAS radar measurements, J.
Glaciol., 59, 545–558, https://doi.org/10.3189/2013JoG12J158, 2013.
Spencer, M. K., Alley, R. B., and Creyts, T. T.: Preliminary
firn-densification model with 38-site dataset, J. Glaciol., 47, 671–676,
https://doi.org/10.3189/172756501781831765, 2001.
Steen-Larsen, H. C., Masson-Delmotte, V., Sjolte, J., Johnsen, S. J.,
Vinther, B. M., Bréon, F. M., Clausen, H. B., Dahl-Jensen, D., Falourd,
S., Fettweis, X., Gallée, H., Jouzel, J., Kageyama, M., Lerche, H.,
Minster, B., Picard, G., Punge, H. J., Risi, C., Salas, D., Schwander, J.,
Steffen, K., Sveinbjörnsdóttir, A. E., Svensson, A., and White, J.:
Understanding the climatic signal in the water stable isotope records from
the NEEM cores, J. Geophys. Res., 116, D06108, https://doi.org/10.1029/2010JD014311,
2011.
Sørensen, L. S., Simonsen, S. B., Nielsen, K., Lucas-Picher, P., Spada,
G., Adalgeirsdottir, G., Forsberg, R., and Hvidberg, C. S.: Mass balance of
the Greenland ice sheet (2003–2008) from ICESat data – the impact of
interpolation, sampling and firn density, The Cryosphere, 5, 173–186,
https://doi.org/10.5194/tc-5-173-2011, 2011.
Vallelonga, P., Christianson, K., Alley, R. B., Anandakrishnan, S.,
Christian, J. E. M., Dahl-Jensen, D., Gkinis, V., Holme, C., Jacobel, R. W.,
Karlsson, N. B., Keisling, B. A., Kipfstuhl, S., Kjær, H. A., Kristensen,
M. E. L., Muto, A., Peters, L. E., Popp, T., Riverman, K. L., Svensson, A.
M., Tibuleac, C., Vinther, B. M., Weng, Y., and Winstrup, M.: Initial results
from geophysical surveys and shallow coring of the Northeast Greenland Ice
Stream (NEGIS), The Cryosphere, 8, 1275–1287,
https://doi.org/10.5194/tc-8-1275-2014, 2014.
van Angelen, J., Lenaerts, J. T., van den Broeke, M. R., Fettweis, X., and
van Meijgaard, E.: Rapid loss of firn pore space accelerates 21st century
Greenland mass loss, Geophys. Res. Lett., 40, 2109–2113,
https://doi.org/10.1002/grl.50490, 2013.
Vandecrux, B., Fausto, R. S., Langen, P. L., Van As, D., MacFerrin, M.,
Colgan, W. T., Ingeman-Nielsen, T., Steffen, K., Jensen, N. S., Møller, M.
T., and Box, J. E.: Drivers of Firn Density on the Greenland Ice Sheet
Revealed by Weather Station Observations and Modeling, J. Geophys.
Res.-Earth, 123, 2563–2576, https://doi.org/10.1029/2017JF004597, 2018.
Vandecrux, B.: Firn air content and firn area delineation on the Greenland
ice sheet, Arctic Data Center, https://doi.org/10.18739/A2V40JZ6C, 2019a.
Vandecrux, B.: Greenland ice sheet firn air content analysis scripts
(Version v1.0.1), Zenodo, https://doi.org/10.5281/zenodo.2578788, 2019b.
van den Broeke, M. R., Enderlin, E. M., Howat, I. M., Kuipers Munneke, P.,
Noël, B. P. Y., van de Berg, W. J., van Meijgaard, E., and Wouters, B.:
On the recent contribution of the Greenland ice sheet to sea level change,
The Cryosphere, 10, 1933–1946, https://doi.org/10.5194/tc-10-1933-2016,
2016.
van der Veen, C. J., Mosley-Thompson, E., Jezek, K. C., Whillans, I. M., and
Bolzan, J. F.: Accumulation rates in South and Central Greenland, Polar
Geography, 25, 79–162, https://doi.org/10.1080/10889370109377709, 2001.
Wilhelms, F.: Measuring the Conductivity and Density of Ice Cores, Ber.
Polarforsch., 191 pp., 1996.
Short summary
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.
The perennial snow, or firn, on the Greenland ice sheet each summer stores part of the meltwater...
