Articles | Volume 16, issue 2
https://doi.org/10.5194/tc-16-397-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-16-397-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Weakening of the pinning point buttressing Thwaites Glacier, West Antarctica
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
Karen E. Alley
Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, MB, Canada
Atsuhiro Muto
Department of Earth and Environmental Science, Temple University, Philadelphia, PA, USA
Martin Truffer
Geophysical Institute and Department of Physics, University of Alaska Fairbanks, Fairbanks, AK, USA
Ted A. Scambos
Earth Science and Observation Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
Erin C. Pettit
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
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Distributed optical fibre sensing (DOFS) is a technology that enables continuous, real-time measurements of environmental parameters along a fibre optic cable. Here, we review the recently emerged applications of DOFS in physical oceanography, and offer a perspective on the technology’s potential for future growth in the field.
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Thwaites Glacier is retreating due to warm ocean water melting it from below, but its thick ice shelf makes this heat hard to monitor. Using hot water drilling, we placed sensors beneath the floating ice, revealing how surface freezing in Pine Island Bay influences heat at depth. Alongside gradual warming, we found bursts of heat that could speed up melting at the grounding zone, which may become more common as sea ice declines.
Christian T. Wild, Reinhard Drews, Niklas Neckel, Joohan Lee, Sihyung Kim, Hyangsun Han, Won Sang Lee, Veit Helm, Sebastian Harry Reid Rosier, Oliver J. Marsh, and Wolfgang Rack
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The stability of the Antarctic Ice Sheet depends on how resistance along the sides of large glaciers slows down the flow of ice into the ocean. We present a method to map ice strength using the effect of ocean tides on floating ice shelves. Incorporating weaker ice in shear zones improves the accuracy of model predictions compared to satellite observations. This demonstrates the untapped potential of radar satellites to map ice stiffness in the most critical areas for ice sheet stability.
Gabriela Collao-Barrios, Ted A. Scambos, Christian T. Wild, Martin Truffer, Karen E. Alley, and Erin C. Pettit
EGUsphere, https://doi.org/10.5194/egusphere-2024-1895, https://doi.org/10.5194/egusphere-2024-1895, 2024
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Destabilization of ice shelves frequently leads to significant acceleration and greater mass loss, affecting rates of sea level rise. Our results show a relation between tides, flow direction, and grounding-zone acceleration that result from changing stresses in the ice margins and around a nunatak in Dotson Ice Shelf. The study describes a new way tides can influence ice shelf dynamics, an effect that could become more common as ice shelves thin and weaken around Antarctica.
Karen E. Alley, Christian T. Wild, Adrian Luckman, Ted A. Scambos, Martin Truffer, Erin C. Pettit, Atsuhiro Muto, Bruce Wallin, Marin Klinger, Tyler Sutterley, Sarah F. Child, Cyrus Hulen, Jan T. M. Lenaerts, Michelle Maclennan, Eric Keenan, and Devon Dunmire
The Cryosphere, 15, 5187–5203, https://doi.org/10.5194/tc-15-5187-2021, https://doi.org/10.5194/tc-15-5187-2021, 2021
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We present a 20-year, satellite-based record of velocity and thickness change on the Thwaites Eastern Ice Shelf (TEIS), the largest remaining floating extension of Thwaites Glacier (TG). TG holds the single greatest control on sea-level rise over the next few centuries, so it is important to understand changes on the TEIS, which controls much of TG's flow into the ocean. Our results suggest that the TEIS is progressively destabilizing and is likely to disintegrate over the next few decades.
Alberto C. Naveira Garabato, Carl P. Spingys, Andrew J. Lucas, Tiago S. Dotto, Christian T. Wild, Scott W. Tyler, Ted A. Scambos, Christopher B. Kratt, Ethan F. Williams, Mariona Claret, Hannah E. Glover, Meagan E. Wengrove, Madison M. Smith, Michael G. Baker, Giuseppe Marra, Max Tamussino, Zitong Feng, David Lloyd, Liam Taylor, Mikael Mazur, Maria-Daphne Mangriotis, Aaron Micallef, Jennifer Ward Neale, Oleg A. Godin, Matthew H. Alford, Emma P. M. Gregory, Michael A. Clare, Angel Ruiz Angulo, Kathryn L. Gunn, Ben I. Moat, Isobel A. Yeo, Alessandro Silvano, Arthur Hartog, and Mohammad Belal
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Douglas J. Brinkerhoff, Brandon S. Tober, Michael Daniel, Victor Devaux-Chupin, Michael S. Christoffersen, John W. Holt, Christopher F. Larsen, Mark Fahnestock, Michael G. Loso, Kristin M. F. Timm, Russell C. Mitchell, and Martin Truffer
The Cryosphere, 19, 2321–2353, https://doi.org/10.5194/tc-19-2321-2025, https://doi.org/10.5194/tc-19-2321-2025, 2025
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Sít' Tlein is one of the largest glaciers in the world outside of the polar regions, and we know that it has been rapidly thinning. To forecast how this glacier will change in the future, we combine a computer model of ice flow with measurements from many different sources. Our model tells us that with high probability, Sít' Tlein's lower reaches are going to disappear in the next century and a half, creating a new bay or lake along Alaska's coastline.
Laurel A. Sindewald, Ryan Lagerquist, Matthew D. Cross, Theodore A. Scambos, Peter J. Anthamatten, and Diana F. Tomback
EGUsphere, https://doi.org/10.5194/egusphere-2025-970, https://doi.org/10.5194/egusphere-2025-970, 2025
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We used high-resolution satellite imagery and artificial intelligence models to identify six tree and shrub species commonly found at alpine treeline in the Rocky Mountains with accuracies from 44.1% to 86.2%. We are the first to attempt species identification using satellite imagery in treeline systems, where trees are small and difficult to identify remotely. Our work provides a method to identify species with satellite imagery over a broader geographic range than can be achieved with drones.
Christian T. Wild, Tasha Snow, Tiago S. Dotto, Peter E. D. Davis, Scott Tyler, Ted A. Scambos, Erin C. Pettit, and Karen J. Heywood
EGUsphere, https://doi.org/10.5194/egusphere-2025-1675, https://doi.org/10.5194/egusphere-2025-1675, 2025
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Thwaites Glacier is retreating due to warm ocean water melting it from below, but its thick ice shelf makes this heat hard to monitor. Using hot water drilling, we placed sensors beneath the floating ice, revealing how surface freezing in Pine Island Bay influences heat at depth. Alongside gradual warming, we found bursts of heat that could speed up melting at the grounding zone, which may become more common as sea ice declines.
Natalie Lützow, Bretwood Higman, Martin Truffer, Bodo Bookhagen, Friedrich Knuth, Oliver Korup, Katie E. Hughes, Marten Geertsema, John J. Clague, and Georg Veh
The Cryosphere, 19, 1085–1102, https://doi.org/10.5194/tc-19-1085-2025, https://doi.org/10.5194/tc-19-1085-2025, 2025
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As the atmosphere warms, thinning glacier dams impound smaller lakes at their margins. Yet, some lakes deviate from this trend and have instead grown over time, increasing the risk of glacier floods to downstream populations and infrastructure. In this article, we examine the mechanisms behind the growth of an ice-dammed lake in Alaska. We find that the growth in size and outburst volumes is more controlled by glacier front downwaste than by overall mass loss over the entire glacier surface.
Alex S. Gardner, Chad A. Greene, Joseph H. Kennedy, Mark A. Fahnestock, Maria Liukis, Luis A. López, Yang Lei, Ted A. Scambos, and Amaury Dehecq
EGUsphere, https://doi.org/10.5194/egusphere-2025-392, https://doi.org/10.5194/egusphere-2025-392, 2025
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The NASA MEaSUREs Inter-mission Time Series of Land Ice Velocity and Elevation (ITS_LIVE) project provides glacier and ice sheet velocity products for the full Landsat, Sentinel-1 and Sentinel-2 satellite archives, and will soon include data from Sentinel 1C and NISAR satellites. This paper describes the ITS_LIVE processing chain and provides guidance for working with the cloud-optimized velocity data it produces.
Shenjie Zhou, Pierre Dutrieux, Claudia F. Giulivi, Adrian Jenkins, Alessandro Silvano, Christopher Auckland, E. Povl Abrahamsen, Michael P. Meredith, Irena Vaňková, Keith W. Nicholls, Peter E. D. Davis, Svein Østerhus, Arnold L. Gordon, Christopher J. Zappa, Tiago S. Dotto, Theodore A. Scambos, Kathyrn L. Gunn, Stephen R. Rintoul, Shigeru Aoki, Craig Stevens, Chengyan Liu, Sukyoung Yun, Tae-Wan Kim, Won Sang Lee, Markus Janout, Tore Hattermann, Julius Lauber, Elin Darelius, Anna Wåhlin, Leo Middleton, Pasquale Castagno, Giorgio Budillon, Karen J. Heywood, Jennifer Graham, Stephen Dye, Daisuke Hirano, and Una Kim Miller
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-54, https://doi.org/10.5194/essd-2025-54, 2025
Revised manuscript under review for ESSD
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We created the first standardised dataset of in-situ ocean measurements time series from around Antarctica collected since 1970s. This includes temperature, salinity, pressure, and currents recorded by instruments deployed in icy, challenging conditions. Our analysis highlights the dominance of tidal currents and separates these from other patterns to study regional energy distribution. This unique dataset offers a foundation for future research on Antarctic ocean dynamics and ice interactions.
Christian T. Wild, Reinhard Drews, Niklas Neckel, Joohan Lee, Sihyung Kim, Hyangsun Han, Won Sang Lee, Veit Helm, Sebastian Harry Reid Rosier, Oliver J. Marsh, and Wolfgang Rack
EGUsphere, https://doi.org/10.5194/egusphere-2024-3593, https://doi.org/10.5194/egusphere-2024-3593, 2024
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The stability of the Antarctic Ice Sheet depends on how resistance along the sides of large glaciers slows down the flow of ice into the ocean. We present a method to map ice strength using the effect of ocean tides on floating ice shelves. Incorporating weaker ice in shear zones improves the accuracy of model predictions compared to satellite observations. This demonstrates the untapped potential of radar satellites to map ice stiffness in the most critical areas for ice sheet stability.
Amy Jenson, Mark Skidmore, Lucas Beem, Martin Truffer, and Scott McCalla
The Cryosphere, 18, 5451–5464, https://doi.org/10.5194/tc-18-5451-2024, https://doi.org/10.5194/tc-18-5451-2024, 2024
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Water in some glacier environments contains salt, which increases its density and lowers its freezing point, allowing saline water to exist where freshwater cannot. Previous subglacial hydrology models do not consider saline fluid. We model the flow of saline fluid from a subglacial lake through a circular channel at the glacier bed, finding that higher salinities lead to less melting at the channel walls and lower discharge rates. We also observe the impact of increased fluid density on flow.
Gabriela Collao-Barrios, Ted A. Scambos, Christian T. Wild, Martin Truffer, Karen E. Alley, and Erin C. Pettit
EGUsphere, https://doi.org/10.5194/egusphere-2024-1895, https://doi.org/10.5194/egusphere-2024-1895, 2024
Preprint archived
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Destabilization of ice shelves frequently leads to significant acceleration and greater mass loss, affecting rates of sea level rise. Our results show a relation between tides, flow direction, and grounding-zone acceleration that result from changing stresses in the ice margins and around a nunatak in Dotson Ice Shelf. The study describes a new way tides can influence ice shelf dynamics, an effect that could become more common as ice shelves thin and weaken around Antarctica.
Naomi E. Ochwat, Ted A. Scambos, Alison F. Banwell, Robert S. Anderson, Michelle L. Maclennan, Ghislain Picard, Julia A. Shates, Sebastian Marinsek, Liliana Margonari, Martin Truffer, and Erin C. Pettit
The Cryosphere, 18, 1709–1731, https://doi.org/10.5194/tc-18-1709-2024, https://doi.org/10.5194/tc-18-1709-2024, 2024
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On the Antarctic Peninsula, there is a small bay that had sea ice fastened to the shoreline (
fast ice) for over a decade. The fast ice stabilized the glaciers that fed into the ocean. In January 2022, the fast ice broke away. Using satellite data we found that this was because of low sea ice concentrations and a high long-period ocean wave swell. We find that the glaciers have responded to this event by thinning, speeding up, and retreating by breaking off lots of icebergs at remarkable rates.
Jenna A. Epifanio, Edward J. Brook, Christo Buizert, Erin C. Pettit, Jon S. Edwards, John M. Fegyveresi, Todd A. Sowers, Jeffrey P. Severinghaus, and Emma C. Kahle
The Cryosphere, 17, 4837–4851, https://doi.org/10.5194/tc-17-4837-2023, https://doi.org/10.5194/tc-17-4837-2023, 2023
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The total air content (TAC) of polar ice cores has long been considered a potential proxy for past ice sheet elevation. This study presents a high-resolution record of TAC from the South Pole ice core. The record reveals orbital- and millennial-scale variability that cannot be explained by elevation changes. The orbital- and millennial-scale changes are likely a product of firn grain metamorphism near the surface of the ice sheet, due to summer insolation changes or local accumulation changes.
Inès N. Otosaka, Andrew Shepherd, Erik R. Ivins, Nicole-Jeanne Schlegel, Charles Amory, Michiel R. van den Broeke, Martin Horwath, Ian Joughin, Michalea D. King, Gerhard Krinner, Sophie Nowicki, Anthony J. Payne, Eric Rignot, Ted Scambos, Karen M. Simon, Benjamin E. Smith, Louise S. Sørensen, Isabella Velicogna, Pippa L. Whitehouse, Geruo A, Cécile Agosta, Andreas P. Ahlstrøm, Alejandro Blazquez, William Colgan, Marcus E. Engdahl, Xavier Fettweis, Rene Forsberg, Hubert Gallée, Alex Gardner, Lin Gilbert, Noel Gourmelen, Andreas Groh, Brian C. Gunter, Christopher Harig, Veit Helm, Shfaqat Abbas Khan, Christoph Kittel, Hannes Konrad, Peter L. Langen, Benoit S. Lecavalier, Chia-Chun Liang, Bryant D. Loomis, Malcolm McMillan, Daniele Melini, Sebastian H. Mernild, Ruth Mottram, Jeremie Mouginot, Johan Nilsson, Brice Noël, Mark E. Pattle, William R. Peltier, Nadege Pie, Mònica Roca, Ingo Sasgen, Himanshu V. Save, Ki-Weon Seo, Bernd Scheuchl, Ernst J. O. Schrama, Ludwig Schröder, Sebastian B. Simonsen, Thomas Slater, Giorgio Spada, Tyler C. Sutterley, Bramha Dutt Vishwakarma, Jan Melchior van Wessem, David Wiese, Wouter van der Wal, and Bert Wouters
Earth Syst. Sci. Data, 15, 1597–1616, https://doi.org/10.5194/essd-15-1597-2023, https://doi.org/10.5194/essd-15-1597-2023, 2023
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By measuring changes in the volume, gravitational attraction, and ice flow of Greenland and Antarctica from space, we can monitor their mass gain and loss over time. Here, we present a new record of the Earth’s polar ice sheet mass balance produced by aggregating 50 satellite-based estimates of ice sheet mass change. This new assessment shows that the ice sheets have lost (7.5 x 1012) t of ice between 1992 and 2020, contributing 21 mm to sea level rise.
Michelle L. Maclennan, Jan T. M. Lenaerts, Christine A. Shields, Andrew O. Hoffman, Nander Wever, Megan Thompson-Munson, Andrew C. Winters, Erin C. Pettit, Theodore A. Scambos, and Jonathan D. Wille
The Cryosphere, 17, 865–881, https://doi.org/10.5194/tc-17-865-2023, https://doi.org/10.5194/tc-17-865-2023, 2023
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Atmospheric rivers are air masses that transport large amounts of moisture and heat towards the poles. Here, we use a combination of weather observations and models to quantify the amount of snowfall caused by atmospheric rivers in West Antarctica which is about 10 % of the total snowfall each year. We then examine a unique event that occurred in early February 2020, when three atmospheric rivers made landfall over West Antarctica in rapid succession, leading to heavy snowfall and surface melt.
Marin Kneib, Evan S. Miles, Pascal Buri, Stefan Fugger, Michael McCarthy, Thomas E. Shaw, Zhao Chuanxi, Martin Truffer, Matthew J. Westoby, Wei Yang, and Francesca Pellicciotti
The Cryosphere, 16, 4701–4725, https://doi.org/10.5194/tc-16-4701-2022, https://doi.org/10.5194/tc-16-4701-2022, 2022
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Ice cliffs are believed to be important contributors to the melt of debris-covered glaciers, but this has rarely been quantified as the cliffs can disappear or rapidly expand within a few weeks. We used photogrammetry techniques to quantify the weekly evolution and melt of four cliffs. We found that their behaviour and melt during the monsoon is strongly controlled by supraglacial debris, streams and ponds, thus providing valuable insights on the melt and evolution of debris-covered glaciers.
Douglas I. Benn, Adrian Luckman, Jan A. Åström, Anna J. Crawford, Stephen L. Cornford, Suzanne L. Bevan, Thomas Zwinger, Rupert Gladstone, Karen Alley, Erin Pettit, and Jeremy Bassis
The Cryosphere, 16, 2545–2564, https://doi.org/10.5194/tc-16-2545-2022, https://doi.org/10.5194/tc-16-2545-2022, 2022
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Thwaites Glacier (TG), in West Antarctica, is potentially unstable and may contribute significantly to sea-level rise as global warming continues. Using satellite data, we show that Thwaites Eastern Ice Shelf, the largest remaining floating extension of TG, has started to accelerate as it fragments along a shear zone. Computer modelling does not indicate that fragmentation will lead to imminent glacier collapse, but it is clear that major, rapid, and unpredictable changes are underway.
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
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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.
Karen E. Alley, Christian T. Wild, Adrian Luckman, Ted A. Scambos, Martin Truffer, Erin C. Pettit, Atsuhiro Muto, Bruce Wallin, Marin Klinger, Tyler Sutterley, Sarah F. Child, Cyrus Hulen, Jan T. M. Lenaerts, Michelle Maclennan, Eric Keenan, and Devon Dunmire
The Cryosphere, 15, 5187–5203, https://doi.org/10.5194/tc-15-5187-2021, https://doi.org/10.5194/tc-15-5187-2021, 2021
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We present a 20-year, satellite-based record of velocity and thickness change on the Thwaites Eastern Ice Shelf (TEIS), the largest remaining floating extension of Thwaites Glacier (TG). TG holds the single greatest control on sea-level rise over the next few centuries, so it is important to understand changes on the TEIS, which controls much of TG's flow into the ocean. Our results suggest that the TEIS is progressively destabilizing and is likely to disintegrate over the next few decades.
Ross Maguire, Nicholas Schmerr, Erin Pettit, Kiya Riverman, Christyna Gardner, Daniella N. DellaGiustina, Brad Avenson, Natalie Wagner, Angela G. Marusiak, Namrah Habib, Juliette I. Broadbeck, Veronica J. Bray, and Samuel H. Bailey
The Cryosphere, 15, 3279–3291, https://doi.org/10.5194/tc-15-3279-2021, https://doi.org/10.5194/tc-15-3279-2021, 2021
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In the last decade, airborne radar surveys have revealed the presence of lakes below the Greenland ice sheet. However, little is known about their properties, including their depth and the volume of water they store. We performed a ground-based geophysics survey in northwestern Greenland and, for the first time, were able to image the depth of a subglacial lake and estimate its volume. Our findings have implications for the thermal state and stability of the ice sheet in northwest Greenland.
Huw J. Horgan, Laurine van Haastrecht, Richard B. Alley, Sridhar Anandakrishnan, Lucas H. Beem, Knut Christianson, Atsuhiro Muto, and Matthew R. Siegfried
The Cryosphere, 15, 1863–1880, https://doi.org/10.5194/tc-15-1863-2021, https://doi.org/10.5194/tc-15-1863-2021, 2021
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The grounding zone marks the transition from a grounded ice sheet to a floating ice shelf. Like Earth's coastlines, the grounding zone is home to interactions between the ocean, fresh water, and geology but also has added complexity and importance due to the overriding ice. Here we use seismic surveying – sending sound waves down through the ice – to image the grounding zone of Whillans Ice Stream in West Antarctica and learn more about the nature of this important transition zone.
Alan Huston, Nicholas Siler, Gerard H. Roe, Erin Pettit, and Nathan J. Steiger
The Cryosphere, 15, 1645–1662, https://doi.org/10.5194/tc-15-1645-2021, https://doi.org/10.5194/tc-15-1645-2021, 2021
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We simulate the past 1000 years of glacier length variability using a simple glacier model and an ensemble of global climate model simulations. Glaciers with long response times are more likely to record global climate changes caused by events like volcanic eruptions and greenhouse gas emissions, while glaciers with short response times are more likely to record natural variability. This difference stems from differences in the frequency spectra of natural and forced temperature variability.
Alia L. Khan, Heidi M. Dierssen, Ted A. Scambos, Juan Höfer, and Raul R. Cordero
The Cryosphere, 15, 133–148, https://doi.org/10.5194/tc-15-133-2021, https://doi.org/10.5194/tc-15-133-2021, 2021
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We present radiative forcing (RF) estimates by snow algae in the Antarctic Peninsula (AP) region from multi-year measurements of solar radiation and ground-based hyperspectral characterization of red and green snow algae collected during a brief field expedition in austral summer 2018. Mean daily RF was double for green (~26 W m−2) vs. red (~13 W m−2) snow algae during the peak growing season, which is on par with midlatitude dust attributions capable of advancing snowmelt.
Tom A. Jordan, David Porter, Kirsty Tinto, Romain Millan, Atsuhiro Muto, Kelly Hogan, Robert D. Larter, Alastair G. C. Graham, and John D. Paden
The Cryosphere, 14, 2869–2882, https://doi.org/10.5194/tc-14-2869-2020, https://doi.org/10.5194/tc-14-2869-2020, 2020
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Linking ocean and ice sheet processes allows prediction of sea level change. Ice shelves form a floating buffer between the ice–ocean systems, but the water depth beneath is often a mystery, leaving a critical blind spot in our understanding of how these systems interact. Here, we use airborne measurements of gravity to reveal the bathymetry under the ice shelves flanking the rapidly changing Thwaites Glacier and adjacent glacier systems, providing new insights and data for future models.
Julie Z. Miller, David G. Long, Kenneth C. Jezek, Joel T. Johnson, Mary J. Brodzik, Christopher A. Shuman, Lora S. Koenig, and Ted A. Scambos
The Cryosphere, 14, 2809–2817, https://doi.org/10.5194/tc-14-2809-2020, https://doi.org/10.5194/tc-14-2809-2020, 2020
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Short summary
Thwaites Glacier has the potential to significantly raise Antarctica's contribution to global sea-level rise by the end of this century. Here, we use satellite measurements of surface elevation to show that its floating part is close to losing contact with an underwater ridge that currently acts to stabilize. We then use computer models of ice flow to simulate the predicted unpinning, which show that accelerated ice discharge into the ocean follows the breakup of the floating part.
Thwaites Glacier has the potential to significantly raise Antarctica's contribution to global...