Articles | Volume 10, issue 5
https://doi.org/10.5194/tc-10-2317-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/tc-10-2317-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
30 Sep 2016
Research article |
| 30 Sep 2016
Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics
Steven J. Phipps
CORRESPONDING AUTHOR
Climate Change Research Centre, School of Biological, Earth
and Environmental Sciences, UNSW Australia, Sydney, NSW 2052,
Australia
Institute for Marine and Antarctic Studies, University of
Tasmania, Hobart, TAS 7001, Australia
Christopher J. Fogwill
Climate Change Research Centre, School of Biological, Earth
and Environmental Sciences, UNSW Australia, Sydney, NSW 2052,
Australia
PANGEA Research Centre, UNSW Australia, Sydney, NSW 2052,
Australia
Christian S. M. Turney
Climate Change Research Centre, School of Biological, Earth
and Environmental Sciences, UNSW Australia, Sydney, NSW 2052,
Australia
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We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
Chris S. M. Turney, Christopher J. Fogwill, Jonathan G. Palmer, Erik van Sebille, Zoë Thomas, Matt McGlone, Sarah Richardson, Janet M. Wilmshurst, Pavla Fenwick, Violette Zunz, Hugues Goosse, Kerry-Jayne Wilson, Lionel Carter, Mathew Lipson, Richard T. Jones, Melanie Harsch, Graeme Clark, Ezequiel Marzinelli, Tracey Rogers, Eleanor Rainsley, Laura Ciasto, Stephanie Waterman, Elizabeth R. Thomas, and Martin Visbeck
Clim. Past, 13, 231–248, https://doi.org/10.5194/cp-13-231-2017, https://doi.org/10.5194/cp-13-231-2017, 2017
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The Southern Ocean plays a fundamental role in global climate but suffers from a dearth of observational data. As the Australasian Antarctic Expedition 2013–2014 we have developed the first annually resolved temperature record using trees from subantarctic southwest Pacific (52–54˚S) to extend the climate record back to 1870. With modelling we show today's high climate variability became established in the ~1940s and likely driven by a Rossby wave response originating from the tropical Pacific.
Pearse J. Buchanan, Richard J. Matear, Andrew Lenton, Steven J. Phipps, Zanna Chase, and David M. Etheridge
Clim. Past, 12, 2271–2295, https://doi.org/10.5194/cp-12-2271-2016, https://doi.org/10.5194/cp-12-2271-2016, 2016
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We quantify the contributions of physical and biogeochemical changes in the ocean to enhancing ocean carbon storage at the Last Glacial Maximum. We find that simulated circulation and surface conditions cannot explain changes in carbon storage or other major biogeochemical fields that existed during the glacial climate. Key modifications to the functioning of the biological pump are therefore required to explain the glacial climate and improve model–proxy agreement for all fields.
Christopher J. Fogwill, Erik van Sebille, Eva A. Cougnon, Chris S. M. Turney, Steve R. Rintoul, Benjamin K. Galton-Fenzi, Graeme F. Clark, E. M. Marzinelli, Eleanor B. Rainsley, and Lionel Carter
The Cryosphere, 10, 2603–2609, https://doi.org/10.5194/tc-10-2603-2016, https://doi.org/10.5194/tc-10-2603-2016, 2016
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Here we report new data from in situ oceanographic surveys and high-resolution ocean modelling experiments in the Commonwealth Bay region of East Antarctica, where in 2010 there was a major reconfiguration of the regional icescape due to the collision of the 97 km long iceberg B09B with the Mertz Glacier tongue. Here we compare post-calving observations with high-resolution ocean modelling which suggest that this reconfiguration has led to the development of a new polynya off Commonwealth Bay.
Bette L. Otto-Bliesner, Pascale Braconnot, Sandy P. Harrison, Daniel J. Lunt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Emilie Capron, Anders E. Carlson, Andrea Dutton, Hubertus Fischer, Heiko Goelzer, Aline Govin, Alan Haywood, Fortunat Joos, Allegra N. Legrande, William H. Lipscomb, Gerrit Lohmann, Natalie Mahowald, Christoph Nehrbass-Ahles, Jean-Yves Peterschmidt, Francesco S.-R. Pausata, Steven Phipps, and Hans Renssen
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-106, https://doi.org/10.5194/cp-2016-106, 2016
Preprint retracted
C. S. M. Turney, R. T. Jones, C. Fogwill, J. Hatton, A. N. Williams, A. Hogg, Z. A. Thomas, J. Palmer, S. Mooney, and R. W. Reimer
Clim. Past, 12, 189–200, https://doi.org/10.5194/cp-12-189-2016, https://doi.org/10.5194/cp-12-189-2016, 2016
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Southern Hemisphere westerly airflow is considered a major driver of Southern Ocean and global climate. Observational records, however, are limited. Here we present a new Falkland Islands record that exploits "exotic" South America pollen and charcoal to reconstruct changing airflow. We find stronger winds 2000–1000 cal. yr BP, associated with increased burning, and a 250-year periodicity, suggesting solar forcing. Our results have important implications for understanding late Holocene climates.
C. S. M. Turney, C. J. Fogwill, A. R. Klekociuk, T. D. van Ommen, M. A. J. Curran, A. D. Moy, and J. G. Palmer
The Cryosphere, 9, 2405–2415, https://doi.org/10.5194/tc-9-2405-2015, https://doi.org/10.5194/tc-9-2405-2015, 2015
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Recent trends in ocean circulation, sea ice and climate over the Southern Ocean and Antarctica are highly complex. Here we report a new snow core from the South Pole alongside reanalysis of 20th century global atmospheric circulation. We demonstrate for the first time that atmospheric pressure anomalies in the mid-latitudes act as "gatekeepers" to meridional exchange over continental Antarctica, modulated by the tropical Pacific, with potentially significant impacts on surface mass balance.
Z. A. Thomas, F. Kwasniok, C. A. Boulton, P. M. Cox, R. T. Jones, T. M. Lenton, and C. S. M. Turney
Clim. Past, 11, 1621–1633, https://doi.org/10.5194/cp-11-1621-2015, https://doi.org/10.5194/cp-11-1621-2015, 2015
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Using a combination of speleothem records and model simulations of the East Asian Monsoon over the penultimate glacial cycle, we search for early warning signals of past tipping points. We detect a characteristic slower response to perturbations prior to an abrupt monsoon shift at the glacial termination; however, we do not detect these signals in the preceding shifts. Our results have important implications for detecting tipping points in palaeoclimate records outside glacial terminations.
B. Kravitz, A. Robock, S. Tilmes, O. Boucher, J. M. English, P. J. Irvine, A. Jones, M. G. Lawrence, M. MacCracken, H. Muri, J. C. Moore, U. Niemeier, S. J. Phipps, J. Sillmann, T. Storelvmo, H. Wang, and S. Watanabe
Geosci. Model Dev., 8, 3379–3392, https://doi.org/10.5194/gmd-8-3379-2015, https://doi.org/10.5194/gmd-8-3379-2015, 2015
A. Rouillard, G. Skrzypek, S. Dogramaci, C. Turney, and P. F. Grierson
Hydrol. Earth Syst. Sci., 19, 2057–2078, https://doi.org/10.5194/hess-19-2057-2015, https://doi.org/10.5194/hess-19-2057-2015, 2015
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We reconstructed a 100-year monthly history of flooding and drought of a large wetland in arid northwest Australia, using hydroclimatic data calibrated against 25 years of satellite images. Severe and intense regional rainfall, as well as the sequence of events, determined surface water expression on the floodplain. While inter-annual variability was high, changes to the flood regime over the last 20 years suggest the wetland may become more persistent in response to the observed rainfall trend.
R. J. Matear, A. Lenton, D. Etheridge, and S. J. Phipps
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-1093-2015, https://doi.org/10.5194/cpd-11-1093-2015, 2015
Revised manuscript has not been submitted
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Global climate models provide an important tool for simulating the earth's climate. Here we present a simulation of the climate of the Last Glacial Maximum, which was obtained by setting atmospheric greenhouse gas concentrations and the earth's orbital parameters to the 21 000 years before present values. We simulate an ocean behaviour that agrees with paleoclimate reconstructions supporting our ability to model the climate system and use the model to explore the impacts on the carbon cycle.
U. Heikkilä, X. Shi, S. J. Phipps, and A. M. Smith
Clim. Past, 10, 687–696, https://doi.org/10.5194/cp-10-687-2014, https://doi.org/10.5194/cp-10-687-2014, 2014
U. Heikkilä, S. J. Phipps, and A. M. Smith
Clim. Past, 9, 2641–2649, https://doi.org/10.5194/cp-9-2641-2013, https://doi.org/10.5194/cp-9-2641-2013, 2013
Related subject area
Antarctic
Assessing the sensitivity of the Vanderford Glacier, East Antarctica, to basal melt and calving
A history-matching analysis of the Antarctic Ice Sheet since the Last Interglacial – Part 1: Ice sheet evolution
Extreme precipitation associated with atmospheric rivers over West Antarctic ice shelves: insights from kilometre-scale regional climate modelling
ISMIP6-based Antarctic projections to 2100: simulations with the BISICLES ice sheet model
Assessing the suitability of sites near Pine Island Glacier for subglacial bedrock drilling aimed at detecting Holocene retreat–readvance
Surface processes and drivers of the snow water stable isotopic composition at Dome C, East Antarctica – a multi-dataset and modelling analysis
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM)
A fast and simplified subglacial hydrological model for the Antarctic Ice Sheet and outlet glaciers
Dual-frequency radar observations of snowmelt processes on Antarctic perennial sea ice by CFOSCAT and ASCAT
Brief communication: New perspectives on the skill of modelled sea ice trends in light of recent Antarctic sea ice loss
Using deep learning and multi-source remote sensing images to map landlocked lakes in Antarctica
How do extreme ENSO events affect Antarctic surface mass balance?
Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone
Contribution of blowing-snow sublimation to the surface mass balance of Antarctica
Melt sensitivity of irreversible retreat of Pine Island Glacier
A model framework for atmosphere–snow water vapor exchange and the associated isotope effects at Dome Argus, Antarctica – Part 1: The diurnal changes
The long-term sea-level commitment from Antarctica
The influence of present-day regional surface mass balance uncertainties on the future evolution of the Antarctic Ice Sheet
Quantifying the influence of snow over sea ice morphology on L-band passive microwave satellite observations in the Southern Ocean
How well can satellite altimetry and firn models resolve Antarctic firn thickness variations?
Feedback mechanisms controlling Antarctic glacial-cycle dynamics simulated with a coupled ice sheet–solid Earth model
Employing automated electrical resistivity tomography for detecting short- and long-term changes in permafrost and active-layer dynamics in the maritime Antarctic
The effect of ice shelf rheology on shelf edge bending
Hysteresis of idealized, instability-prone outlet glaciers in response to pinning-point buttressing variation
Age-depth distribution in western Dronning Maud Land, East Antarctica, from three decades of radar surveys
A decade (2008–2017) of water stable isotope composition of precipitation at Concordia Station, East Antarctica
The role of atmospheric conditions in the Antarctic sea ice extent summer minima
A physics-based Antarctic melt detection technique: combining Advanced Microwave Scanning Radiometer 2, radiative-transfer modeling, and firn modeling
Brief communication: Precision measurement of the index of refraction of deep glacial ice at radio frequencies at Summit Station, Greenland
A reconstruction of the ice thickness of the Antarctic Peninsula Ice Sheet north of 70º S
Widespread increase in discharge from west Antarctic Peninsula glaciers since 2018
Surface dynamics and history of the calving cycle of Astrolabe Glacier (Adélie Coast, Antarctica) derived from satellite imagery
Current reversal leads to regime change in Amery Ice Shelf cavity in the twenty-first century
Inferring the seasonality of sea ice floes in the Weddell Sea using ICESat-2
A facet based numerical model to retrieve ice sheet topography from Sentinel-3 altimetry
Weak relationship between remotely detected crevasses and inferred ice rheological parameters on Antarctic ice shelves
Speed-up, slowdown, and redirection of ice flow on neighbouring ice streams in the Pope, Smith and Kohler region of West Antarctica
Extensive palaeo-surfaces beneath the Evans–Rutford region of the West Antarctic Ice Sheet control modern and past ice flow
Sources of low-frequency variability in observed Antarctic sea ice
Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 1: Event detection for cryoseismology
Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 2: Unsupervised learning for source process characterization
Firn air content changes on Antarctic ice shelves under three future warming scenarios
Geometric amplification and suppression of ice-shelf basal melt in West Antarctica
Alpine topography of the Gamburtsev Subglacial Mountains, Antarctica, mapped from ice sheet surface morphology
Impact of boundary conditions on the modeled thermal regime of the Antarctic ice sheet
The staggered retreat of grounded ice in the Ross Sea, Antarctica, since the Last Glacial Maximum (LGM)
The effect of landfast sea ice buttressing on ice dynamic speedup in the Larsen B embayment, Antarctica
Meteoric water and glacial melt in the southeastern Amundsen Sea: a time series from 1994 to 2020
Evaporative controls on Antarctic precipitation: an ECHAM6 model study using innovative water tracer diagnostics
Extreme events of snow grain size increase in East Antarctica and their relationship with meteorological conditions
Lawrence A. Bird, Felicity S. McCormack, Johanna Beckmann, Richard S. Jones, and Andrew N. Mackintosh
The Cryosphere, 19, 955–973, https://doi.org/10.5194/tc-19-955-2025, https://doi.org/10.5194/tc-19-955-2025, 2025
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Vanderford Glacier is the fastest-retreating glacier in East Antarctica and may have important implications for future ice loss from the Aurora Subglacial Basin. Our ice sheet model simulations suggest that grounding line retreat is driven by sub-ice-shelf basal melting, in which warm ocean waters melt ice close to the grounding line. We show that current estimates of basal melt are likely too low, highlighting the need for improved estimates and direct measurements of basal melt in the region.
Benoit S. Lecavalier and Lev Tarasov
The Cryosphere, 19, 919–953, https://doi.org/10.5194/tc-19-919-2025, https://doi.org/10.5194/tc-19-919-2025, 2025
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We present the evolution of the Antarctic Ice Sheet (AIS) over the last 200 kyr by means of a history-matching analysis where an updated observational database constrained ~ 10 000 model simulations. During peak glaciation at the Last Glacial Maximum (LGM), the best-fitting sub-ensemble of AIS simulations reached an excess grounded ice volume relative to the present of 9.2 to 26.5 m equivalent sea level relative to the present. The LGM AIS volume can help resolve the LGM missing-ice problem.
Ella Gilbert, Denis Pishniak, José Abraham Torres, Andrew Orr, Michelle Maclennan, Nander Wever, and Kristiina Verro
The Cryosphere, 19, 597–618, https://doi.org/10.5194/tc-19-597-2025, https://doi.org/10.5194/tc-19-597-2025, 2025
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We use three sophisticated climate models to examine extreme precipitation in a critical region of West Antarctica. We found that rainfall probably occurred during the two cases we examined and that it was generated by the interaction of air with steep topography. Our results show that kilometre-scale models are useful tools for exploring extreme precipitation in this region and that more observations of rainfall are needed.
James F. O'Neill, Tamsin L. Edwards, Daniel F. Martin, Courtney Shafer, Stephen L. Cornford, Hélène L. Seroussi, Sophie Nowicki, Mira Adhikari, and Lauren J. Gregoire
The Cryosphere, 19, 541–563, https://doi.org/10.5194/tc-19-541-2025, https://doi.org/10.5194/tc-19-541-2025, 2025
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We use an ice sheet model to simulate the Antarctic contribution to sea level over the 21st century under a range of future climates and varying how sensitive the ice sheet is to different processes. We find that ocean temperatures increase and more snow falls on the ice sheet under stronger warming scenarios. When the ice sheet is sensitive to ocean warming, ocean melt-driven loss exceeds snowfall-driven gains, meaning that the sea level contribution is greater with more climate warming.
Joanne S. Johnson, John Woodward, Ian Nesbitt, Kate Winter, Seth Campbell, Keir A. Nichols, Ryan A. Venturelli, Scott Braddock, Brent M. Goehring, Brenda Hall, Dylan H. Rood, and Greg Balco
The Cryosphere, 19, 303–324, https://doi.org/10.5194/tc-19-303-2025, https://doi.org/10.5194/tc-19-303-2025, 2025
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Determining where and when the Antarctic ice sheet was smaller than present requires recovery and exposure dating of subglacial bedrock. Here we use ice sheet model outputs and field data (geological and glaciological observations, bedrock samples, and ground-penetrating radar) to assess the suitability for subglacial drilling of sites in the Hudson Mountains, West Antarctica. We find that no sites are perfect, but two are feasible, with the most suitable being Winkie Nunatak (74.86°S, 99.77°W).
Inès Ollivier, Hans Christian Steen-Larsen, Barbara Stenni, Laurent Arnaud, Mathieu Casado, Alexandre Cauquoin, Giuliano Dreossi, Christophe Genthon, Bénédicte Minster, Ghislain Picard, Martin Werner, and Amaëlle Landais
The Cryosphere, 19, 173–200, https://doi.org/10.5194/tc-19-173-2025, https://doi.org/10.5194/tc-19-173-2025, 2025
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The role of post-depositional processes taking place at the ice sheet's surface on the water stable isotope signal measured in polar ice cores is not fully understood. Using field observations and modelling results, we show that the original precipitation isotopic signal at Dome C, East Antarctica, is modified by post-depositional processes and provide the first quantitative estimation of their mean impact on the isotopic signal observed in the snow.
Francesca Baldacchino, Nicholas R. Golledge, Mathieu Morlighem, Huw Horgan, Alanna V. Alevropoulos-Borrill, Alena Malyarenko, Alexandra Gossart, Daniel P. Lowry, and Laurine van Haastrecht
The Cryosphere, 19, 107–127, https://doi.org/10.5194/tc-19-107-2025, https://doi.org/10.5194/tc-19-107-2025, 2025
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Understanding how the Ross Ice Shelf flow is changing in a warming world is important for predicting ice sheet change. Field measurements show clear intra-annual variations in ice flow; however, it is unclear what mechanisms drive this variability. We show that local perturbations in basal melt can have a significant impact on ice flow speed, but a combination of forcings is likely driving the observed variability in ice flow.
Elise Kazmierczak, Thomas Gregov, Violaine Coulon, and Frank Pattyn
The Cryosphere, 18, 5887–5911, https://doi.org/10.5194/tc-18-5887-2024, https://doi.org/10.5194/tc-18-5887-2024, 2024
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We introduce a new fast model for water flow beneath the ice sheet capable of handling various hydrological and bed conditions in a unified way. Applying this model to Thwaites Glacier, we show that accounting for this water flow in ice sheet model projections has the potential to greatly increase the contribution to future sea level rise. We also demonstrate that the sensitivity of the ice sheet in response to external changes depends on the efficiency of the drainage and the bed type.
Rui Xu, Chaofang Zhao, Stefanie Arndt, and Christian Haas
The Cryosphere, 18, 5769–5788, https://doi.org/10.5194/tc-18-5769-2024, https://doi.org/10.5194/tc-18-5769-2024, 2024
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The onset of snowmelt on Antarctic sea ice is an important indicator of sea ice change. In this study, we used two radar scatterometers to detect the onset of snowmelt on perennial Antarctic sea ice. Results show that since 2007, snowmelt onset has demonstrated strong interannual and regional variabilities. We also found that the difference in snowmelt onsets between the two scatterometers is closely related to snow metamorphism.
Caroline R. Holmes, Thomas J. Bracegirdle, Paul R. Holland, Julienne Stroeve, and Jeremy Wilkinson
The Cryosphere, 18, 5641–5652, https://doi.org/10.5194/tc-18-5641-2024, https://doi.org/10.5194/tc-18-5641-2024, 2024
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Until recently, satellite data showed an increase in Antarctic sea ice area since 1979, but climate models simulated a decrease over this period. This mismatch was one reason for low confidence in model projections of 21st-century sea ice loss. We show that following low Antarctic sea ice in 2022 and 2023, we can no longer conclude that modelled and observed trends differ. However, differences in the manner of the decline mean that model sea ice projections should still be viewed with caution.
Anyao Jiang, Xin Meng, Yan Huang, and Guitao Shi
The Cryosphere, 18, 5347–5364, https://doi.org/10.5194/tc-18-5347-2024, https://doi.org/10.5194/tc-18-5347-2024, 2024
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Landlocked lakes are crucial to the Antarctic ecosystem and sensitive to climate change. Limited research on their distribution prompted us to develop an automated detection process using deep learning and multi-source satellite imagery. This allowed us to accurately determine the landlocked lake open water (LLOW) area in Antarctica, generating high-resolution time series data. We find that the changes in positive and negative degree days predominantly drive variations in the LLOW area.
Jessica M. A. Macha, Andrew N. Mackintosh, Felicity S. Mccormack, Benjamin J. Henley, Helen V. McGregor, Christiaan T. van Dalum, and Ariaan Purich
EGUsphere, https://doi.org/10.5194/egusphere-2024-3425, https://doi.org/10.5194/egusphere-2024-3425, 2024
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Extreme El Niño-Southern Oscillation (ENSO) events have global impacts but their Antarctic impacts are poorly understood. Examining Antarctic snow accumulation impacts of past observed extreme ENSO events, we show that accumulation changes differ between events & are unsignificant during most events. Remarkable changes occur during 2015/16 & in Enderby Land during all extreme El Niños. Historical data limits conclusions but future greater extremes could cause Antarctic accumulation changes.
Allison M. Chartrand, Ian M. Howat, Ian R. Joughin, and Benjamin E. Smith
The Cryosphere, 18, 4971–4992, https://doi.org/10.5194/tc-18-4971-2024, https://doi.org/10.5194/tc-18-4971-2024, 2024
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This study uses high-resolution remote-sensing data to show that shrinking of the West Antarctic Thwaites Glacier’s ice shelf (floating extension) is exacerbated by several sub-ice-shelf meltwater channels that form as the glacier transitions from full contact with the seafloor to fully floating. In mapping these channels, the position of the transition zone, and thinning rates of the Thwaites Glacier, this work elucidates important processes driving its rapid contribution to sea level rise.
Srinidhi Gadde and Willem Jan van de Berg
The Cryosphere, 18, 4933–4953, https://doi.org/10.5194/tc-18-4933-2024, https://doi.org/10.5194/tc-18-4933-2024, 2024
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Blowing-snow sublimation is the major loss term in the mass balance of Antarctica. In this study we update the blowing-snow representation in the Regional Atmospheric Climate Model (RACMO). With the updates, results compare well with observations from East Antarctica. Also, the continent-wide variation of blowing snow compares well with satellite observations. Hence, the updates provide a clear step forward in producing a physically sound and reliable estimate of the mass balance of Antarctica.
Brad Reed, J. A. Mattias Green, Adrian Jenkins, and G. Hilmar Gudmundsson
The Cryosphere, 18, 4567–4587, https://doi.org/10.5194/tc-18-4567-2024, https://doi.org/10.5194/tc-18-4567-2024, 2024
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We use a numerical ice-flow model to simulate the response of a 1940s Pine Island Glacier to changes in melting beneath its ice shelf. A decadal period of warm forcing is sufficient to push the glacier into an unstable, irreversible retreat from its long-term position on a subglacial ridge to an upstream ice plain. This retreat can only be stopped when unrealistic cold forcing is applied. These results show that short warm anomalies can lead to quick and substantial increases in ice flux.
Tianming Ma, Zhuang Jiang, Minghu Ding, Pengzhen He, Yuansheng Li, Wenqian Zhang, and Lei Geng
The Cryosphere, 18, 4547–4565, https://doi.org/10.5194/tc-18-4547-2024, https://doi.org/10.5194/tc-18-4547-2024, 2024
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We constructed a box model to evaluate the isotope effects of atmosphere–snow water vapor exchange at Dome A, Antarctica. The results show clear and invisible diurnal changes in surface snow isotopes under summer and winter conditions, respectively. The model also predicts that the annual net effects of atmosphere–snow water vapor exchange would be overall enrichments in snow isotopes since the effects in summer appear to be greater than those in winter at the study site.
Ann Kristin Klose, Violaine Coulon, Frank Pattyn, and Ricarda Winkelmann
The Cryosphere, 18, 4463–4492, https://doi.org/10.5194/tc-18-4463-2024, https://doi.org/10.5194/tc-18-4463-2024, 2024
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We systematically assess the long-term sea-level response from Antarctica to warming projected over the next centuries, using two ice-sheet models. We show that this committed Antarctic sea-level contribution is substantially higher than the transient sea-level change projected for the coming decades. A low-emission scenario already poses considerable risk of multi-meter sea-level increase over the next millennia, while additional East Antarctic ice loss unfolds under the high-emission pathway.
Christian Wirths, Thomas F. Stocker, and Johannes C. R. Sutter
The Cryosphere, 18, 4435–4462, https://doi.org/10.5194/tc-18-4435-2024, https://doi.org/10.5194/tc-18-4435-2024, 2024
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We investigated the influence of several regional climate models on the Antarctic Ice Sheet when applied as forcing for the Parallel Ice Sheet Model (PISM). Our study shows that the choice of regional climate model forcing results in uncertainties of around a tenth of those in future sea level rise projections and also affects the extent of grounding line retreat in West Antarctica.
Lu Zhou, Julienne Stroeve, Vishnu Nandan, Rosemary Willatt, Shiming Xu, Weixin Zhu, Sahra Kacimi, Stefanie Arndt, and Zifan Yang
The Cryosphere, 18, 4399–4434, https://doi.org/10.5194/tc-18-4399-2024, https://doi.org/10.5194/tc-18-4399-2024, 2024
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Snow over Antarctic sea ice, influenced by highly variable meteorological conditions and heavy snowfall, has a complex stratigraphy and profound impact on the microwave signature. We employ advanced radiation transfer models to analyse the effects of complex snow properties on brightness temperatures over the sea ice in the Southern Ocean. Great potential lies in the understanding of snow processes and the application to satellite retrievals.
Maria T. Kappelsberger, Martin Horwath, Eric Buchta, Matthias O. Willen, Ludwig Schröder, Sanne B. M. Veldhuijsen, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 18, 4355–4378, https://doi.org/10.5194/tc-18-4355-2024, https://doi.org/10.5194/tc-18-4355-2024, 2024
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The interannual variations in the height of the Antarctic Ice Sheet (AIS) are mainly due to natural variations in snowfall. Precise knowledge of these variations is important for the detection of any long-term climatic trends in AIS surface elevation. We present a new product that spatially resolves these height variations over the period 1992–2017. The product combines the strengths of atmospheric modeling results and satellite altimetry measurements.
Torsten Albrecht, Meike Bagge, and Volker Klemann
The Cryosphere, 18, 4233–4255, https://doi.org/10.5194/tc-18-4233-2024, https://doi.org/10.5194/tc-18-4233-2024, 2024
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We performed coupled ice sheet–solid Earth simulations and discovered a positive (forebulge) feedback mechanism for advancing grounding lines, supporting a larger West Antarctic Ice Sheet during the Last Glacial Maximum. During deglaciation we found that the stabilizing glacial isostatic adjustment feedback dominates grounding-line retreat in the Ross Sea, with a weak Earth structure. This may have consequences for present and future ice sheet stability and potential rates of sea-level rise.
Mohammad Farzamian, Teddi Herring, Gonçalo Vieira, Miguel Angel de Pablo, Borhan Yaghoobi Tabar, and Christian Hauck
The Cryosphere, 18, 4197–4213, https://doi.org/10.5194/tc-18-4197-2024, https://doi.org/10.5194/tc-18-4197-2024, 2024
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An automated electrical resistivity tomography (A-ERT) system was developed and deployed in Antarctica to monitor permafrost and active-layer dynamics. The A-ERT, coupled with an efficient processing workflow, demonstrated its capability to monitor real-time thaw depth progression, detect seasonal and surficial freezing–thawing events, and assess permafrost stability. Our study showcased the potential of A-ERT to contribute to global permafrost monitoring networks.
W. Roger Buck
The Cryosphere, 18, 4165–4176, https://doi.org/10.5194/tc-18-4165-2024, https://doi.org/10.5194/tc-18-4165-2024, 2024
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Standard theory predicts that the edge of an ice shelf should bend downward. Satellite observations show that the edges of many ice shelves bend upward. A new theory for ice shelf bending is developed that, for the first time, includes the kind of vertical variations in ice flow properties expected for ice shelves. Upward bending of shelf edges is predicted as long as the ice surface is very cold and the ice flow properties depend strongly on temperature.
Johannes Feldmann, Anders Levermann, and Ricarda Winkelmann
The Cryosphere, 18, 4011–4028, https://doi.org/10.5194/tc-18-4011-2024, https://doi.org/10.5194/tc-18-4011-2024, 2024
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Here we show in simplified simulations that the (ir)reversibility of the retreat of instability-prone, Antarctica-type glaciers can strongly depend on the depth of the bed depression they rest on. If it is sufficiently deep, then the destabilized glacier does not recover from its collapsed state. Our results suggest that glaciers resting on a wide and deep bed depression, such as Antarctica's Thwaites Glacier, are particularly susceptible to irreversible retreat.
Steven Franke, Daniel Steinhage, Veit Helm, Alexandra M. Zuhr, Julien A. Bodart, Olaf Eisen, and Paul Bons
EGUsphere, https://doi.org/10.5194/egusphere-2024-2349, https://doi.org/10.5194/egusphere-2024-2349, 2024
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We use radar technology to study the internal architecture of the ice sheet in western DML, East Antarctica. We identified and dated nine internal reflection horizons (IRHs), revealing important information about the ice sheet's history and dynamics. Some IRHs can be linked to past volcanic eruptions and are of similar age to IRHs detected in other parts of Antarctica. Our findings enhance our understanding of ice sheet behaviour and aid in developing better models for predicting future changes.
Giuliano Dreossi, Mauro Masiol, Barbara Stenni, Daniele Zannoni, Claudio Scarchilli, Virginia Ciardini, Mathieu Casado, Amaëlle Landais, Martin Werner, Alexandre Cauquoin, Giampietro Casasanta, Massimo Del Guasta, Vittoria Posocco, and Carlo Barbante
The Cryosphere, 18, 3911–3931, https://doi.org/10.5194/tc-18-3911-2024, https://doi.org/10.5194/tc-18-3911-2024, 2024
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Oxygen and hydrogen stable isotopes have been extensively used to reconstruct past temperatures, with precipitation representing the input signal of the isotopic records in ice cores. We present a 10-year record of stable isotopes in daily precipitation at Concordia Station: this is the longest record for inland Antarctica and represents a benchmark for quantifying post-depositional processes and improving the paleoclimate interpretation of ice cores.
Bianca Mezzina, Hugues Goosse, François Klein, Antoine Barthélemy, and François Massonnet
The Cryosphere, 18, 3825–3839, https://doi.org/10.5194/tc-18-3825-2024, https://doi.org/10.5194/tc-18-3825-2024, 2024
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We analyze years with extraordinarily low sea ice extent in Antarctica during summer, until the striking record in 2022. We highlight common aspects among these events, such as the fact that the exceptional melting usually occurs in two key regions and that it is related to winds with a similar direction. We also investigate whether the summer conditions are preceded by an unusual state of the sea ice during the previous winter, as well as the physical processes involved.
Marissa E. Dattler, Brooke Medley, and C. Max Stevens
The Cryosphere, 18, 3613–3631, https://doi.org/10.5194/tc-18-3613-2024, https://doi.org/10.5194/tc-18-3613-2024, 2024
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We developed an algorithm based on combining models and satellite observations to identify the presence of surface melt on the Antarctic Ice Sheet. We find that this method works similarly to previous methods by assessing 13 sites and the Larsen C ice shelf. Unlike previous methods, this algorithm is based on physical parameters, and updates to this method could allow the meltwater present on the Antarctic Ice Sheet to be quantified instead of simply detected.
Christoph Welling and The RNO-G Collaboration
The Cryosphere, 18, 3433–3437, https://doi.org/10.5194/tc-18-3433-2024, https://doi.org/10.5194/tc-18-3433-2024, 2024
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We report on the measurement of the index of refraction in glacial ice at radio frequencies. We show that radio echoes from within the ice can be associated with specific features of the ice conductivity and use this to determine the wave velocity. This measurement is especially relevant for the Radio Neutrino Observatory Greenland (RNO-G), a neutrino detection experiment currently under construction at Summit Station, Greenland.
Kaian Shahateet, Johannes J. Fürst, Francisco Navarro, Thorsten Seehaus, Daniel Farinotti, and Matthias Braun
EGUsphere, https://doi.org/10.5194/egusphere-2024-1571, https://doi.org/10.5194/egusphere-2024-1571, 2024
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In the present work, we provide a new ice-thickness reconstruction of the Antarctic Peninsula Ice Sheet north of 70º S by using inversion modeling. This model consists of two steps; the first takes basic assumptions of the rheology of the glacier, and the second uses mass conservation to improve the reconstruction where the previously made assumptions are expected to fail. Validation with independent data showed that our reconstruction improved compared to other reconstruction available.
Benjamin J. Davison, Anna E. Hogg, Carlos Moffat, Michael P. Meredith, and Benjamin J. Wallis
The Cryosphere, 18, 3237–3251, https://doi.org/10.5194/tc-18-3237-2024, https://doi.org/10.5194/tc-18-3237-2024, 2024
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Using a new dataset of ice motion, we observed glacier acceleration on the west coast of the Antarctic Peninsula. The speed-up began around January 2021, but some glaciers sped up earlier or later. Using a combination of ship-based ocean temperature observations and climate models, we show that the speed-up coincided with a period of unusually warm air and ocean temperatures in the region.
Floriane Provost, Dimitri Zigone, Emmanuel Le Meur, Jean-Philippe Malet, and Clément Hibert
The Cryosphere, 18, 3067–3079, https://doi.org/10.5194/tc-18-3067-2024, https://doi.org/10.5194/tc-18-3067-2024, 2024
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The recent calving of Astrolabe Glacier in November 2021 presents an opportunity to better understand the processes leading to ice fracturing. Optical-satellite imagery is used to retrieve the calving cycle of the glacier ice tongue and to measure the ice velocity and strain rates in order to document fracture evolution. We observed that the presence of sea ice for consecutive years has favoured the glacier extension but failed to inhibit the growth of fractures that accelerated in June 2021.
Jing Jin, Antony J. Payne, and Christopher Y. S. Bull
EGUsphere, https://doi.org/10.5194/egusphere-2024-1287, https://doi.org/10.5194/egusphere-2024-1287, 2024
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The Amery Ice Shelf cavity is one of the largest cold cavities filled by relatively cold Dense Shelf Water. However, in this study, we show that warm intrusion of modified Circumpolar Deep Water flushes the Amery cavity, which changes it from a cold cavity to a warm cavity and leads to an abrupt increase in basal melt rate in the 2060s. The shift to the warm cavity is attributed to a freshening-driven current reversal in front of the ice shelf.
Mukund Gupta, Heather Regan, Young Hyun Koo, Sean Minhui Tashi Chua, Xueke Li, and Petra Heil
EGUsphere, https://doi.org/10.5194/egusphere-2024-1329, https://doi.org/10.5194/egusphere-2024-1329, 2024
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The sea ice cover is composed of floes, whose shapes set the material properties of the pack. Here, we use a satellite product (ICESat-2) to investigate these floe shapes within the Weddell Sea. We find that floes tend to become smaller during the melt season, while their thickness distribution exhibits different behavior between the western and southern regions of the pack. These metrics will help calibrate models, and improve our understanding of sea ice physics across scales.
Jérémie Aublanc, François Boy, Franck Borde, and Pierre Féménias
EGUsphere, https://doi.org/10.5194/egusphere-2024-1323, https://doi.org/10.5194/egusphere-2024-1323, 2024
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In this study we developed an innovative algorithm to derive the ice sheet topography from Sentinel-3 altimetry measurements. The processing chain is named the “Altimeter data Modelling and Processing for Land Ice” (AMPLI). The performance improvement is substantial compared to the official data generated by the ESA ground segment. With AMPLI, we show that Sentinel-3 is able to estimate the Surface Elevation Change of the Antarctic ice sheet with a high level of agreement to ICESat-2.
Cristina Gerli, Sebastian Rosier, G. Hilmar Gudmundsson, and Sainan Sun
The Cryosphere, 18, 2677–2689, https://doi.org/10.5194/tc-18-2677-2024, https://doi.org/10.5194/tc-18-2677-2024, 2024
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Recent efforts have focused on using AI and satellite imagery to track crevasses for assessing ice shelf damage and informing ice flow models. Our study reveals a weak connection between these observed products and damage maps inferred from ice flow models. While there is some improvement in crevasse-dense regions, this association remains limited. Directly mapping ice damage from satellite observations may not significantly improve the representation of these processes within ice flow models.
Heather Louise Selley, Anna E. Hogg, Benjamin J. Davison, Pierre Dutrieux, and Thomas Slater
EGUsphere, https://doi.org/10.5194/egusphere-2024-1442, https://doi.org/10.5194/egusphere-2024-1442, 2024
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We used satellite observations to measure recent changes in ice speed and flow direction in the Pope, Smith and Kohler Region of West Antarctica (2005–2022). We found substantial speed up on seven ice streams of up to 87 %. However, Kohler West Glacier has slowed by 10%, due to the redirection of ice flow into its rapidly thinning neighbour. This process of ‘ice piracy’ hasn’t previously been directly observed on this rapid timescale and may influence future ice shelf and sheet mass changes.
Charlotte M. Carter, Michael J. Bentley, Stewart S. R. Jamieson, Guy J. G. Paxman, Tom A. Jordan, Julien A. Bodart, Neil Ross, and Felipe Napoleoni
The Cryosphere, 18, 2277–2296, https://doi.org/10.5194/tc-18-2277-2024, https://doi.org/10.5194/tc-18-2277-2024, 2024
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We use radio-echo sounding data to investigate the presence of flat surfaces beneath the Evans–Rutford region in West Antarctica. These surfaces may be what remains of laterally continuous surfaces, formed before the inception of the West Antarctic Ice Sheet, and we assess two hypotheses for their formation. Tectonic structures in the region may have also had a control on the growth of the ice sheet by focusing ice flow into troughs adjoining these surfaces.
David B. Bonan, Jakob Dörr, Robert C. J. Wills, Andrew F. Thompson, and Marius Årthun
The Cryosphere, 18, 2141–2159, https://doi.org/10.5194/tc-18-2141-2024, https://doi.org/10.5194/tc-18-2141-2024, 2024
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Antarctic sea ice has exhibited variability over satellite records, including a period of gradual expansion and a period of sudden decline. We use a novel statistical method to identify sources of variability in observed Antarctic sea ice changes. We find that the gradual increase in sea ice is likely related to large-scale temperature trends, and periods of abrupt sea ice decline are related to specific flavors of equatorial tropical variability known as the El Niño–Southern Oscillation.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, and J. Paul Winberry
The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, https://doi.org/10.5194/tc-18-2061-2024, 2024
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The study of icequakes allows for investigation of many glacier processes that are unseen by typical reconnaissance methods. However, detection of such seismic signals is challenging due to low signal-to-noise levels and diverse source mechanisms. Here we present a novel algorithm that is optimized to detect signals from a glacier environment. We apply the algorithm to seismic data recorded in the 2010–2011 austral summer from the Whillans Ice Stream and evaluate the resulting event catalogue.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, Sue Cook, Bernd Kulessa, and J. Paul Winberry
The Cryosphere, 18, 2081–2101, https://doi.org/10.5194/tc-18-2081-2024, https://doi.org/10.5194/tc-18-2081-2024, 2024
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Seismic catalogues are potentially rich sources of information on glacier processes. In a companion study, we constructed an event catalogue for seismic data from the Whillans Ice Stream. Here, we provide a semi-automated workflow for consistent catalogue analysis using an unsupervised cluster analysis. We discuss the defining characteristics of identified signal types found in this catalogue and possible mechanisms for the underlying glacier processes and noise sources.
Sanne B. M. Veldhuijsen, Willem Jan van de Berg, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 18, 1983–1999, https://doi.org/10.5194/tc-18-1983-2024, https://doi.org/10.5194/tc-18-1983-2024, 2024
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We use the IMAU firn densification model to simulate the 21st-century evolution of Antarctic firn air content. Ice shelves on the Antarctic Peninsula and the Roi Baudouin Ice Shelf in Dronning Maud Land are particularly vulnerable to total firn air content (FAC) depletion. Our results also underline the potentially large vulnerability of low-accumulation ice shelves to firn air depletion through ice slab formation.
Jan De Rydt and Kaitlin Naughten
The Cryosphere, 18, 1863–1888, https://doi.org/10.5194/tc-18-1863-2024, https://doi.org/10.5194/tc-18-1863-2024, 2024
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The West Antarctic Ice Sheet is losing ice at an accelerating pace. This is largely due to the presence of warm ocean water around the periphery of the Antarctic continent, which melts the ice. It is generally assumed that the strength of this process is controlled by the temperature of the ocean. However, in this study we show that an equally important role is played by the changing geometry of the ice sheet, which affects the strength of the ocean currents and thereby the melt rates.
Edmund J. Lea, Stewart S. R. Jamieson, and Michael J. Bentley
The Cryosphere, 18, 1733–1751, https://doi.org/10.5194/tc-18-1733-2024, https://doi.org/10.5194/tc-18-1733-2024, 2024
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We use the ice surface expression of the Gamburtsev Subglacial Mountains in East Antarctica to map the horizontal pattern of valleys and ridges in finer detail than possible from previous methods. In upland areas, valleys are spaced much less than 5 km apart, with consequences for the distribution of melting at the bed and hence the likelihood of ancient ice being preserved. Automated mapping techniques were tested alongside manual approaches, with a hybrid approach recommended for future work.
In-Woo Park, Emilia Kyung Jin, Mathieu Morlighem, and Kang-Kun Lee
The Cryosphere, 18, 1139–1155, https://doi.org/10.5194/tc-18-1139-2024, https://doi.org/10.5194/tc-18-1139-2024, 2024
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This study conducted 3D thermodynamic ice sheet model experiments, and modeled temperatures were compared with 15 observed borehole temperature profiles. We found that using incompressibility of ice without sliding agrees well with observed temperature profiles in slow-flow regions, while incorporating sliding in fast-flow regions captures observed temperature profiles. Also, the choice of vertical velocity scheme has a greater impact on the shape of the modeled temperature profile.
Matthew A. Danielson and Philip J. Bart
The Cryosphere, 18, 1125–1138, https://doi.org/10.5194/tc-18-1125-2024, https://doi.org/10.5194/tc-18-1125-2024, 2024
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The post-Last Glacial Maximum (LGM) retreat of the West Antarctic Ice Sheet in the Ross Sea was more significant than for any other Antarctic sector. Here we combined the available dates of retreat with new mapping of sediment deposited by the ice sheet during overall retreat. Our work shows that the post-LGM retreat through the Ross Sea was not uniform. This uneven retreat can cause instability in the present-day Antarctic ice sheet configuration and lead to future runaway retreat.
Trystan Surawy-Stepney, Anna E. Hogg, Stephen L. Cornford, Benjamin J. Wallis, Benjamin J. Davison, Heather L. Selley, Ross A. W. Slater, Elise K. Lie, Livia Jakob, Andrew Ridout, Noel Gourmelen, Bryony I. D. Freer, Sally F. Wilson, and Andrew Shepherd
The Cryosphere, 18, 977–993, https://doi.org/10.5194/tc-18-977-2024, https://doi.org/10.5194/tc-18-977-2024, 2024
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Here, we use satellite observations and an ice flow model to quantify the impact of sea ice buttressing on ice streams on the Antarctic Peninsula. The evacuation of 11-year-old landfast sea ice in the Larsen B embayment on the East Antarctic Peninsula in January 2022 was closely followed by major changes in the calving behaviour and acceleration (30 %) of the ocean-terminating glaciers. Our results show that sea ice buttressing had a negligible direct role in the observed dynamic changes.
Andrew N. Hennig, David A. Mucciarone, Stanley S. Jacobs, Richard A. Mortlock, and Robert B. Dunbar
The Cryosphere, 18, 791–818, https://doi.org/10.5194/tc-18-791-2024, https://doi.org/10.5194/tc-18-791-2024, 2024
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A total of 937 seawater paired oxygen isotope (δ18O)–salinity samples collected during seven cruises on the SE Amundsen Sea between 1994 and 2020 reveal a deep freshwater source with δ18O − 29.4±1.0‰, consistent with the signature of local ice shelf melt. Local mean meteoric water content – comprised primarily of glacial meltwater – increased between 1994 and 2020 but exhibited greater interannual variability than increasing trend.
Qinggang Gao, Louise C. Sime, Alison J. McLaren, Thomas J. Bracegirdle, Emilie Capron, Rachael H. Rhodes, Hans Christian Steen-Larsen, Xiaoxu Shi, and Martin Werner
The Cryosphere, 18, 683–703, https://doi.org/10.5194/tc-18-683-2024, https://doi.org/10.5194/tc-18-683-2024, 2024
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Antarctic precipitation is a crucial component of the climate system. Its spatio-temporal variability impacts sea level changes and the interpretation of water isotope measurements in ice cores. To better understand its climatic drivers, we developed water tracers in an atmospheric model to identify moisture source conditions from which precipitation originates. We find that mid-latitude surface winds exert an important control on moisture availability for Antarctic precipitation.
Claudio Stefanini, Giovanni Macelloni, Marion Leduc-Leballeur, Vincent Favier, Benjamin Pohl, and Ghislain Picard
The Cryosphere, 18, 593–608, https://doi.org/10.5194/tc-18-593-2024, https://doi.org/10.5194/tc-18-593-2024, 2024
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Local and large-scale meteorological conditions have been considered in order to explain some peculiar changes of snow grains on the East Antarctic Plateau from 2000 to 2022, by using remote sensing observations and reanalysis. We identified some extreme grain size events on the highest ice divide, resulting from a combination of conditions of low wind speed and low temperature. Moreover, the beginning of seasonal grain growth has been linked to the occurrence of atmospheric rivers.
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Short summary
We explore the effects of melting of the East Antarctic Ice Sheet on the Southern Ocean. Using a climate model, we find that melting changes the ocean circulation and causes warming of more than 1 °C at depth. We also discover the potential existence of a "domino effect", whereby the initial warming spreads westwards around the Antarctic continent. Melting of just one sector could therefore destabilise the wider Antarctic Ice Sheet, leading to substantial increases in global sea level.
We explore the effects of melting of the East Antarctic Ice Sheet on the Southern Ocean. Using a...
