Articles | Volume 15, issue 4
https://doi.org/10.5194/tc-15-1787-2021
© Author(s) 2021. 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-15-1787-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
13 Apr 2021
Research article | Highlight paper |
| 13 Apr 2021
| 13 Apr 2021
Pervasive diffusion of climate signals recorded in ice-vein ionic impurities
Department of Geography, University of Sheffield, Sheffield, UK
Related authors
Felix S. L. Ng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1012, https://doi.org/10.5194/egusphere-2024-1012, 2024
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Liquid veins and grain boundaries in ice can accelerate the decay of climate signals in δ18O and δD by short-circuiting the slow isotopic diffusion in crystal grains. This theory for ‘excess diffusion’ has not been confirmed experimentally. We show that if the mechanism occurs, then distinct isotopic patterns must form near grain junctions, offering a testable prediction of the theory. We calculate the patterns and describe an experimental scheme for testing ice-core samples for the mechanism.
Felix S. L. Ng
The Cryosphere, 17, 3063–3082, https://doi.org/10.5194/tc-17-3063-2023, https://doi.org/10.5194/tc-17-3063-2023, 2023
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The stable isotopes of oxygen and hydrogen in ice cores are routinely analysed for the climate signals which they carry. It has long been known that the system of water veins in ice facilitates isotopic diffusion. Here, mathematical modelling shows that water flow in the veins strongly accelerates the diffusion and the decay of climate signals. The process hampers methods using the variations in signal decay with depth to reconstruct past climatic temperature.
Stephen J. Livingstone, Emma L. M. Lewington, Chris D. Clark, Robert D. Storrar, Andrew J. Sole, Isabelle McMartin, Nico Dewald, and Felix Ng
The Cryosphere, 14, 1989–2004, https://doi.org/10.5194/tc-14-1989-2020, https://doi.org/10.5194/tc-14-1989-2020, 2020
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We map series of aligned mounds (esker beads) across central Nunavut, Canada. Mounds are interpreted to have formed roughly annually as sediment carried by subglacial rivers is deposited at the ice margin. Chains of mounds are formed as the ice retreats. This high-resolution (annual) record allows us to constrain the pace of ice retreat, sediment fluxes, and the style of drainage through time. In particular, we suggest that eskers in general record a composite signature of ice-marginal drainage.
Adam J. Hepburn, Tom Holt, Bryn Hubbard, and Felix Ng
Geosci. Instrum. Method. Data Syst., 8, 293–313, https://doi.org/10.5194/gi-8-293-2019, https://doi.org/10.5194/gi-8-293-2019, 2019
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Currently, there exist thousands of unprocessed stereo pairs of satellite imagery which can be used to create models of the surface of Mars. This paper sets out a new open–source and free to use pipeline for creating these models. Our pipeline produces models of comparable quality to the limited number released to date but remains free to use and easily implemented by researchers, who may not necessarily have prior experience of DEM creation.
A. E. Jowett, E. Hanna, F. Ng, P. Huybrechts, and I. Janssens
The Cryosphere Discuss., https://doi.org/10.5194/tcd-9-5327-2015, https://doi.org/10.5194/tcd-9-5327-2015, 2015
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Felix S. L. Ng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1012, https://doi.org/10.5194/egusphere-2024-1012, 2024
Short summary
Short summary
Liquid veins and grain boundaries in ice can accelerate the decay of climate signals in δ18O and δD by short-circuiting the slow isotopic diffusion in crystal grains. This theory for ‘excess diffusion’ has not been confirmed experimentally. We show that if the mechanism occurs, then distinct isotopic patterns must form near grain junctions, offering a testable prediction of the theory. We calculate the patterns and describe an experimental scheme for testing ice-core samples for the mechanism.
Felix S. L. Ng
The Cryosphere, 17, 3063–3082, https://doi.org/10.5194/tc-17-3063-2023, https://doi.org/10.5194/tc-17-3063-2023, 2023
Short summary
Short summary
The stable isotopes of oxygen and hydrogen in ice cores are routinely analysed for the climate signals which they carry. It has long been known that the system of water veins in ice facilitates isotopic diffusion. Here, mathematical modelling shows that water flow in the veins strongly accelerates the diffusion and the decay of climate signals. The process hampers methods using the variations in signal decay with depth to reconstruct past climatic temperature.
Stephen J. Livingstone, Emma L. M. Lewington, Chris D. Clark, Robert D. Storrar, Andrew J. Sole, Isabelle McMartin, Nico Dewald, and Felix Ng
The Cryosphere, 14, 1989–2004, https://doi.org/10.5194/tc-14-1989-2020, https://doi.org/10.5194/tc-14-1989-2020, 2020
Short summary
Short summary
We map series of aligned mounds (esker beads) across central Nunavut, Canada. Mounds are interpreted to have formed roughly annually as sediment carried by subglacial rivers is deposited at the ice margin. Chains of mounds are formed as the ice retreats. This high-resolution (annual) record allows us to constrain the pace of ice retreat, sediment fluxes, and the style of drainage through time. In particular, we suggest that eskers in general record a composite signature of ice-marginal drainage.
Adam J. Hepburn, Tom Holt, Bryn Hubbard, and Felix Ng
Geosci. Instrum. Method. Data Syst., 8, 293–313, https://doi.org/10.5194/gi-8-293-2019, https://doi.org/10.5194/gi-8-293-2019, 2019
Short summary
Short summary
Currently, there exist thousands of unprocessed stereo pairs of satellite imagery which can be used to create models of the surface of Mars. This paper sets out a new open–source and free to use pipeline for creating these models. Our pipeline produces models of comparable quality to the limited number released to date but remains free to use and easily implemented by researchers, who may not necessarily have prior experience of DEM creation.
A. E. Jowett, E. Hanna, F. Ng, P. Huybrechts, and I. Janssens
The Cryosphere Discuss., https://doi.org/10.5194/tcd-9-5327-2015, https://doi.org/10.5194/tcd-9-5327-2015, 2015
Revised manuscript has not been submitted
Related subject area
Discipline: Ice sheets | Subject: Ice Cores
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Benjamin Hmiel, Vasilii V. Petrenko, Christo Buizert, Andrew M. Smith, Michael N. Dyonisius, Philip Place, Bin Yang, Quan Hua, Ross Beaudette, Jeffrey P. Severinghaus, Christina Harth, Ray F. Weiss, Lindsey Davidge, Melisa Diaz, Matthew Pacicco, James A. Menking, Michael Kalk, Xavier Faïn, Alden Adolph, Isaac Vimont, and Lee T. Murray
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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
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Felix S. L. Ng
The Cryosphere, 17, 3063–3082, https://doi.org/10.5194/tc-17-3063-2023, https://doi.org/10.5194/tc-17-3063-2023, 2023
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The stable isotopes of oxygen and hydrogen in ice cores are routinely analysed for the climate signals which they carry. It has long been known that the system of water veins in ice facilitates isotopic diffusion. Here, mathematical modelling shows that water flow in the veins strongly accelerates the diffusion and the decay of climate signals. The process hampers methods using the variations in signal decay with depth to reconstruct past climatic temperature.
Takashi Obase, Ayako Abe-Ouchi, Fuyuki Saito, Shun Tsutaki, Shuji Fujita, Kenji Kawamura, and Hideaki Motoyama
The Cryosphere, 17, 2543–2562, https://doi.org/10.5194/tc-17-2543-2023, https://doi.org/10.5194/tc-17-2543-2023, 2023
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We use a one-dimensional ice-flow model to examine the most suitable core location near Dome Fuji (DF), Antarctica. This model computes the temporal evolution of age and temperature from past to present. We investigate the influence of different parameters of climate and ice sheet on the ice's basal age and compare the results with ground radar surveys. We find that the local ice thickness primarily controls the age because it is critical to the basal melting, which can eliminate the old ice.
Nicolas Stoll, Julien Westhoff, Pascal Bohleber, Anders Svensson, Dorthe Dahl-Jensen, Carlo Barbante, and Ilka Weikusat
The Cryosphere, 17, 2021–2043, https://doi.org/10.5194/tc-17-2021-2023, https://doi.org/10.5194/tc-17-2021-2023, 2023
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Impurities in polar ice play a role regarding its climate signal and internal deformation. We bridge different scales using different methods to investigate ice from the Last Glacial Period derived from the EGRIP ice core in Greenland. We characterise different types of cloudy bands, i.e. frequently occurring milky layers in the ice, and analyse their chemistry with Raman spectroscopy and 2D imaging. We derive new insights into impurity localisation and deposition conditions.
Niccolò Maffezzoli, Eliza Cook, Willem G. M. van der Bilt, Eivind N. Støren, Daniela Festi, Florian Muthreich, Alistair W. R. Seddon, François Burgay, Giovanni Baccolo, Amalie R. F. Mygind, Troels Petersen, Andrea Spolaor, Sebastiano Vascon, Marcello Pelillo, Patrizia Ferretti, Rafael S. dos Reis, Jefferson C. Simões, Yuval Ronen, Barbara Delmonte, Marco Viccaro, Jørgen Peder Steffensen, Dorthe Dahl-Jensen, Kerim H. Nisancioglu, and Carlo Barbante
The Cryosphere, 17, 539–565, https://doi.org/10.5194/tc-17-539-2023, https://doi.org/10.5194/tc-17-539-2023, 2023
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Multiple lines of research in ice core science are limited by manually intensive and time-consuming optical microscopy investigations for the detection of insoluble particles, from pollen grains to volcanic shards. To help overcome these limitations and support researchers, we present a novel methodology for the identification and autonomous classification of ice core insoluble particles based on flow image microscopy and neural networks.
Tomotaka Saruya, Shuji Fujita, Yoshinori Iizuka, Atsushi Miyamoto, Hiroshi Ohno, Akira Hori, Wataru Shigeyama, Motohiro Hirabayashi, and Kumiko Goto-Azuma
The Cryosphere, 16, 2985–3003, https://doi.org/10.5194/tc-16-2985-2022, https://doi.org/10.5194/tc-16-2985-2022, 2022
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Crystal orientation fabrics (COF) of the Dome Fuji ice core were investigated with an innovative method with unprecedentedly high statistical significance and dense depth coverage. The COF profile and its fluctuation were found to be highly dependent on concentrations of chloride ion and dust. The data suggest deformation of ice at the deepest zone is highly influenced by COF fluctuations that progressively develop from the near-surface firn toward the deepest zone within ice sheets.
Jacob D. Morgan, Christo Buizert, Tyler J. Fudge, Kenji Kawamura, Jeffrey P. Severinghaus, and Cathy M. Trudinger
The Cryosphere, 16, 2947–2966, https://doi.org/10.5194/tc-16-2947-2022, https://doi.org/10.5194/tc-16-2947-2022, 2022
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The composition of air bubbles in Antarctic ice cores records information about past changes in properties of the snowpack. We find that, near the South Pole, thinner snowpack in the past is often due to steeper surface topography, in which faster winds erode the snow and deposit it in flatter areas. The slope and wind seem to also cause a seasonal bias in the composition of air bubbles in the ice core. These findings will improve interpretation of other ice cores from places with steep slopes.
Nicolas Stoll, Maria Hörhold, Tobias Erhardt, Jan Eichler, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 16, 667–688, https://doi.org/10.5194/tc-16-667-2022, https://doi.org/10.5194/tc-16-667-2022, 2022
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We mapped and analysed solid inclusion in the upper 1340 m of the EGRIP ice core with Raman spectroscopy and microstructure mapping, based on bulk dust content derived via continuous flow analysis. We observe a large variety in mineralogy throughout the core and samples. The main minerals are sulfates, especially gypsum, and terrestrial dust minerals, such as quartz, mica, and feldspar. A change in mineralogy occurs around 900 m depth indicating a climate-related imprint.
Nicolas Stoll, Jan Eichler, Maria Hörhold, Tobias Erhardt, Camilla Jensen, and Ilka Weikusat
The Cryosphere, 15, 5717–5737, https://doi.org/10.5194/tc-15-5717-2021, https://doi.org/10.5194/tc-15-5717-2021, 2021
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We did a systematic analysis of the location of inclusions in the EGRIP ice core, the first ice core from an ice stream. We combine this with crystal orientation and grain size data, enabling the first overview about the microstructure of this unique ice core. Micro-inclusions show a strong spatial variability and patterns (clusters or horizontal layers); roughly one-third is located at grain boundaries. More holistic approaches are needed to understand deformation processes in the ice better.
Ikumi Oyabu, Kenji Kawamura, Tsutomu Uchida, Shuji Fujita, Kyotaro Kitamura, Motohiro Hirabayashi, Shuji Aoki, Shinji Morimoto, Takakiyo Nakazawa, Jeffrey P. Severinghaus, and Jacob D. Morgan
The Cryosphere, 15, 5529–5555, https://doi.org/10.5194/tc-15-5529-2021, https://doi.org/10.5194/tc-15-5529-2021, 2021
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We present O2/N2 and Ar/N2 records from the Dome Fuji ice core through the bubbly ice, bubble–clathrate transition, and clathrate ice zones without gas-loss fractionation. The insolation signal is preserved through the clathrate formation. The relationship between Ar/Ν2 and Ο2/Ν2 suggests that the fractionation for the bubble–clathrate transition is mass independent, while the bubble close-off process involves a combination of mass-independent and mass-dependent fractionation for O2 and Ar.
Pascal Bohleber, Marco Roman, Martin Šala, Barbara Delmonte, Barbara Stenni, and Carlo Barbante
The Cryosphere, 15, 3523–3538, https://doi.org/10.5194/tc-15-3523-2021, https://doi.org/10.5194/tc-15-3523-2021, 2021
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Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers micro-destructive, micrometer-scale impurity analysis of ice cores. For improved understanding of the LA-ICP-MS signals, novel 2D impurity imaging is applied to selected glacial and interglacial samples of Antarctic deep ice cores. This allows evaluating the 2D impurity distribution in relation to ice crystal features and assessing implications for investigating highly thinned climate proxy signals in deep polar ice.
David A. Lilien, Daniel Steinhage, Drew Taylor, Frédéric Parrenin, Catherine Ritz, Robert Mulvaney, Carlos Martín, Jie-Bang Yan, Charles O'Neill, Massimo Frezzotti, Heinrich Miller, Prasad Gogineni, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 15, 1881–1888, https://doi.org/10.5194/tc-15-1881-2021, https://doi.org/10.5194/tc-15-1881-2021, 2021
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We collected radar data between EDC, an ice core spanning ~800 000 years, and BELDC, the site chosen for a new
oldest icecore at nearby Little Dome C. These data allow us to identify 50 % older internal horizons than previously traced in the area. We fit a model to the ages of those horizons at BELDC to determine the age of deep ice there. We find that there is likely to be 1.5 Myr old ice ~265 m above the bed, with sufficient resolution to preserve desired climatic information.
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Christoph F. Schaller, Rebecca J. Tuckwell, Henning Löwe, Laurent Arnaud, Olivier Magand, Elizabeth R. Thomas, Johannes Freitag, Robert Mulvaney, Martin Schneebeli, and Vladimir Ya. Lipenkov
The Cryosphere, 13, 3383–3403, https://doi.org/10.5194/tc-13-3383-2019, https://doi.org/10.5194/tc-13-3383-2019, 2019
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Understanding gas trapping in polar ice is essential to study the relationship between greenhouse gases and past climates. New data of bubble closure, used in a simple gas-trapping model, show inconsistency with the final air content in ice. This suggests gas trapping is not fully understood. We also use a combination of high-resolution measurements to investigate the effect of polar snow stratification on gas trapping and find that all strata have similar pores, but that some close in advance.
Youngjoon Jang, Sang Bum Hong, Christo Buizert, Hun-Gyu Lee, Sang-Young Han, Ji-Woong Yang, Yoshinori Iizuka, Akira Hori, Yeongcheol Han, Seong Joon Jun, Pieter Tans, Taejin Choi, Seong-Joong Kim, Soon Do Hur, and Jinho Ahn
The Cryosphere, 13, 2407–2419, https://doi.org/10.5194/tc-13-2407-2019, https://doi.org/10.5194/tc-13-2407-2019, 2019
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We can learn how human activity altered atmospheric air from the interstitial air in the porous snow layer (firn) on top of glaciers. However, old firn air (> 55 years) was observed only at sites where surface temperatures and snow accumulation rates are very low, such as the South Pole. In this study, we report an unusually old firn air with CO2 age of 93 years from Styx Glacier, near the Ross Sea coast in Antarctica. We hypothesize that the large snow density variations increase firn air ages.
Nanna B. Karlsson, Tobias Binder, Graeme Eagles, Veit Helm, Frank Pattyn, Brice Van Liefferinge, and Olaf Eisen
The Cryosphere, 12, 2413–2424, https://doi.org/10.5194/tc-12-2413-2018, https://doi.org/10.5194/tc-12-2413-2018, 2018
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In this study, we investigate the probability that the Dome Fuji region in East Antarctica contains ice more than 1.5 Ma old. The retrieval of a continuous ice-core record extending beyond 1 Ma is imperative to understand why the frequency of ice ages changed from 40 to 100 ka approximately 1 Ma ago.
We use a new radar dataset to improve the ice thickness maps, and apply a thermokinematic model to predict basal temperature and age of the ice. Our results indicate several areas of interest.
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Short summary
Current theory predicts climate signals in the vein chemistry of ice cores to migrate, hampering their dating. I show that the Gibbs–Thomson effect, which has been overlooked, causes fast diffusion that prevents signals from surviving into deep ice. Hence the deep climatic peaks in Antarctic and Greenlandic ice must be due to impurities in the ice matrix (outside veins) and safe from migration. These findings reset our understanding of postdepositional changes of ice-core climate signals.
Current theory predicts climate signals in the vein chemistry of ice cores to migrate, hampering...
