Articles | Volume 11, issue 2
https://doi.org/10.5194/cp-11-153-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/cp-11-153-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
05 Feb 2015
Research article |
| 05 Feb 2015
The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference
C. Buizert
CORRESPONDING AUTHOR
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
K. M. Cuffey
Department of Geography, University of California, Berkeley, CA 94720, USA
J. P. Severinghaus
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
D. Baggenstos
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
T. J. Fudge
Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
E. J. Steig
Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
B. R. Markle
Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
M. Winstrup
Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
R. H. Rhodes
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
E. J. Brook
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
T. A. Sowers
Department of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, USA
G. D. Clow
US Geological Survey, Boulder, CO 80309, USA
H. Cheng
Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA
R. L. Edwards
Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA
M. Sigl
Desert Research Institute, Nevada System of Higher Education, Reno, NV 89512, USA
J. R. McConnell
Desert Research Institute, Nevada System of Higher Education, Reno, NV 89512, USA
K. C. Taylor
Desert Research Institute, Nevada System of Higher Education, Reno, NV 89512, USA
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Jai Chowdhry Beeman, Léa Gest, Frédéric Parrenin, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
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Benjamin Birner, Christo Buizert, Till J. W. Wagner, and Jeffrey P. Severinghaus
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Nancy A. N. Bertler, Howard Conway, Dorthe Dahl-Jensen, Daniel B. Emanuelsson, Mai Winstrup, Paul T. Vallelonga, James E. Lee, Ed J. Brook, Jeffrey P. Severinghaus, Taylor J. Fudge, Elizabeth D. Keller, W. Troy Baisden, Richard C. A. Hindmarsh, Peter D. Neff, Thomas Blunier, Ross Edwards, Paul A. Mayewski, Sepp Kipfstuhl, Christo Buizert, Silvia Canessa, Ruzica Dadic, Helle A. Kjær, Andrei Kurbatov, Dongqi Zhang, Edwin D. Waddington, Giovanni Baccolo, Thomas Beers, Hannah J. Brightley, Lionel Carter, David Clemens-Sewall, Viorela G. Ciobanu, Barbara Delmonte, Lukas Eling, Aja Ellis, Shruthi Ganesh, Nicholas R. Golledge, Skylar Haines, Michael Handley, Robert L. Hawley, Chad M. Hogan, Katelyn M. Johnson, Elena Korotkikh, Daniel P. Lowry, Darcy Mandeno, Robert M. McKay, James A. Menking, Timothy R. Naish, Caroline Noerling, Agathe Ollive, Anaïs Orsi, Bernadette C. Proemse, Alexander R. Pyne, Rebecca L. Pyne, James Renwick, Reed P. Scherer, Stefanie Semper, Marius Simonsen, Sharon B. Sneed, Eric J. Steig, Andrea Tuohy, Abhijith Ulayottil Venugopal, Fernando Valero-Delgado, Janani Venkatesh, Feitang Wang, Shimeng Wang, Dominic A. Winski, V. Holly L. Winton, Arran Whiteford, Cunde Xiao, Jiao Yang, and Xin Zhang
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Alan M. Seltzer, Christo Buizert, Daniel Baggenstos, Edward J. Brook, Jinho Ahn, Ji-Woong Yang, and Jeffrey P. Severinghaus
Clim. Past, 13, 1323–1338, https://doi.org/10.5194/cp-13-1323-2017, https://doi.org/10.5194/cp-13-1323-2017, 2017
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Daniel Baggenstos, Thomas K. Bauska, Jeffrey P. Severinghaus, James E. Lee, Hinrich Schaefer, Christo Buizert, Edward J. Brook, Sarah Shackleton, and Vasilii V. Petrenko
Clim. Past, 13, 943–958, https://doi.org/10.5194/cp-13-943-2017, https://doi.org/10.5194/cp-13-943-2017, 2017
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We present measurements of the gas composition in trapped air bubbles in ice samples taken from Taylor Glacier, Antarctica. We can show that ice from the entire last glacial cycle (125 000 years ago to the present) is exposed at the surface of this glacier and that the atmospheric record contained in the air bubbles is well preserved. Taylor Glacier therefore provides an easily accessible archive of ancient ice that allows for studies of trace components that require large ice volumes.
Léa Gest, Frédéric Parrenin, Jai Chowdhry Beeman, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-71, https://doi.org/10.5194/cp-2017-71, 2017
Revised manuscript has not been submitted
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In this manuscript, we place the atmospheric CO2 and Antarctic temperature records onto a common age scale during the last deglaciation. Moreover, we evaluate the phase relationship between those two records in order to discuss possible climatic and carbon cycle scenarios. Indeed, this phase relationship is central to determine the role of the former in past (and therefore future) climatic variations. This scientific problem was even discussed by some policy makers (e.g., in the USA senate).
Christo Buizert and Jeffrey P. Severinghaus
The Cryosphere, 10, 2099–2111, https://doi.org/10.5194/tc-10-2099-2016, https://doi.org/10.5194/tc-10-2099-2016, 2016
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The upper 50–100 m of the world's ice sheets consists of the firn layer, a porous layer of snow that is slowly compacted by overlying snow. Understanding air movement inside the firn is critical for ice core climate reconstructions. Buizert and Severinghaus identify and describe a new mechanism of firn air movement. High- and low-pressure systems force air movement in the firn that drives strong mixing, called dispersion. Dispersion is the main mechanism for air mixing in the deep firn.
Rachael H. Rhodes, Xavier Faïn, Edward J. Brook, Joseph R. McConnell, Olivia J. Maselli, Michael Sigl, Jon Edwards, Christo Buizert, Thomas Blunier, Jérôme Chappellaz, and Johannes Freitag
Clim. Past, 12, 1061–1077, https://doi.org/10.5194/cp-12-1061-2016, https://doi.org/10.5194/cp-12-1061-2016, 2016
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Local artifacts in ice core methane data are superimposed on consistent records of past atmospheric variability. These artifacts are not related to past atmospheric history and care should be taken to avoid interpreting them as such. By investigating five polar ice cores from sites with different conditions, we relate isolated methane spikes to melt layers and decimetre-scale variations as "trapping signal" associated with a difference in timing of air bubble closure in adjacent firn layers.
Michael Sigl, Tyler J. Fudge, Mai Winstrup, Jihong Cole-Dai, David Ferris, Joseph R. McConnell, Ken C. Taylor, Kees C. Welten, Thomas E. Woodruff, Florian Adolphi, Marion Bisiaux, Edward J. Brook, Christo Buizert, Marc W. Caffee, Nelia W. Dunbar, Ross Edwards, Lei Geng, Nels Iverson, Bess Koffman, Lawrence Layman, Olivia J. Maselli, Kenneth McGwire, Raimund Muscheler, Kunihiko Nishiizumi, Daniel R. Pasteris, Rachael H. Rhodes, and Todd A. Sowers
Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, https://doi.org/10.5194/cp-12-769-2016, 2016
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Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide ice core, which is based on layer counting of distinctive annual cycles preserved in the elemental, chemical and electrical conductivity records. We validated the chronology by comparing it to independent high-accuracy, absolutely dated chronologies. Given its demonstrated high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere.
S. O. Rasmussen, P. M. Abbott, T. Blunier, A. J. Bourne, E. Brook, S. L. Buchardt, C. Buizert, J. Chappellaz, H. B. Clausen, E. Cook, D. Dahl-Jensen, S. M. Davies, M. Guillevic, S. Kipfstuhl, T. Laepple, I. K. Seierstad, J. P. Severinghaus, J. P. Steffensen, C. Stowasser, A. Svensson, P. Vallelonga, B. M. Vinther, F. Wilhelms, and M. Winstrup
Clim. Past, 9, 2713–2730, https://doi.org/10.5194/cp-9-2713-2013, https://doi.org/10.5194/cp-9-2713-2013, 2013
Frédéric Parrenin, Marie Bouchet, Christo Buizert, Emilie Capron, Ellen Corrick, Russell Drysdale, Kenji Kawamura, Amaëlle Landais, Robert Mulvaney, Ikumi Oyabu, and Sune Olander Rasmussen
Geosci. Model Dev., 17, 8735–8750, https://doi.org/10.5194/gmd-17-8735-2024, https://doi.org/10.5194/gmd-17-8735-2024, 2024
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The Paleochrono-1.1 probabilistic dating model allows users to derive a common and optimized chronology for several paleoclimatic sites from various archives (ice cores, speleothems, marine cores, lake cores, etc.). It combines prior sedimentation scenarios with chronological information such as dated horizons, dated intervals, stratigraphic links and (for ice cores) Δdepth observations. Paleochrono-1.1 is available under an open-source license.
Helene Hoffmann, Jason Day, Rachael H. Rhodes, Mackenzie Grieman, Jack Humby, Isobel Rowell, Christoph Nehrbass-Ahles, Robert Mulvaney, Sally Gibson, and Eric Wolff
The Cryosphere, 18, 4993–5013, https://doi.org/10.5194/tc-18-4993-2024, https://doi.org/10.5194/tc-18-4993-2024, 2024
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Ice cores are archives of past atmospheric conditions. In deep and old ice, the layers containing this information get thinned to the millimetre scale or below. We installed a setup for high-resolution (182 μm) chemical impurity measurements in ice cores using the laser ablation technique at the University of Cambridge. In a first application to the Skytrain ice core from Antarctica, we discuss the potential to detect fine-layered structures in ice up to an age of 26 000 years.
Mira Berdahl, Gunter R. Leguy, William H. Lipscomb, Bette L. Otto-Bliesner, Esther C. Brady, Robert A. Tomas, Nathan M. Urban, Ian Miller, Harriet Morgan, and Eric J. Steig
Clim. Past, 20, 2349–2371, https://doi.org/10.5194/cp-20-2349-2024, https://doi.org/10.5194/cp-20-2349-2024, 2024
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Studying climate conditions near the Antarctic ice sheet (AIS) during Earth’s past warm periods informs us about how global warming may influence AIS ice loss. Using a global climate model, we investigate climate conditions near the AIS during the Last Interglacial (129 to 116 kyr ago), a period with warmer global temperatures and higher sea level than today. We identify the orbital and freshwater forcings that could cause ice loss and probe the mechanisms that lead to warmer climate conditions.
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. Mackie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Verjan Višnjević, Rodrigo Zamora, and Alexandra Zuhr
EGUsphere, https://doi.org/10.5194/egusphere-2024-2593, https://doi.org/10.5194/egusphere-2024-2593, 2024
This preprint is open for discussion and under review for The Cryosphere (TC).
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The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative to work together on this archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica, and how this will be used to reconstruct past and predict future ice and climate behaviour.
Rachael H. Rhodes, Yvan Bollet-Quivogne, Piers Barnes, Mirko Severi, and Eric W. Wolff
Clim. Past, 20, 2031–2043, https://doi.org/10.5194/cp-20-2031-2024, https://doi.org/10.5194/cp-20-2031-2024, 2024
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Some ionic components slowly move through glacier ice by diffusion, but the rate of this diffusion, its exact mechanism(s), and the factors that might influence it are poorly understood. In this study, we model how peaks in sulfate, deposited at Dome C on the Antarctic ice sheet after volcanic eruptions, change with depth and time. We find that the sulfate diffusion rate in ice is relatively fast in young ice near the surface, but the rate is markedly reduced over time.
Romilly Harris Stuart, Amaëlle Landais, Laurent Arnaud, Christo Buizert, Emilie Capron, Marie Dumont, Quentin Libois, Robert Mulvaney, Anaïs Orsi, Ghislain Picard, Frédéric Prié, Jeffrey Severinghaus, Barbara Stenni, and Patricia Martinerie
The Cryosphere, 18, 3741–3763, https://doi.org/10.5194/tc-18-3741-2024, https://doi.org/10.5194/tc-18-3741-2024, 2024
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Ice core δO2/N2 records are useful dating tools due to their local insolation pacing. A precise understanding of the physical mechanism driving this relationship, however, remain ambiguous. By compiling data from 15 polar sites, we find a strong dependence of mean δO2/N2 on accumulation rate and temperature in addition to the well-documented insolation dependence. Snowpack modelling is used to investigate which physical properties drive the mechanistic dependence on these local parameters.
Vasilii V. Petrenko, Segev BenZvi, Michael Dyonisius, Benjamin Hmiel, Andrew M. Smith, and Christo Buizert
The Cryosphere, 18, 3439–3451, https://doi.org/10.5194/tc-18-3439-2024, https://doi.org/10.5194/tc-18-3439-2024, 2024
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This manuscript presents the concept for a new proxy for past variations in the galactic cosmic ray flux (GCR). Past variations in GCR flux are important to understand for interpretation of records of isotopes produced by cosmic rays; these records are used for reconstructing solar variations and past land ice extent. The proxy involves using measurements of 14CO in ice cores, which should provide an uncomplicated and precise estimate of past GCR flux variations for the past few thousand years.
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
The Cryosphere, 18, 3363–3382, https://doi.org/10.5194/tc-18-3363-2024, https://doi.org/10.5194/tc-18-3363-2024, 2024
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The main aim of this research is to improve understanding of carbon-14 that is produced by cosmic rays in ice sheets. Measurements of carbon-14 in ice cores can provide a range of useful information (age of ice, past atmospheric chemistry, past cosmic ray intensity). Our results show that almost all (>99 %) of carbon-14 that is produced in the upper layer of ice sheets is rapidly lost to the atmosphere. Our results also provide better estimates of carbon-14 production rates in deeper ice.
Piers Larkman, Rachael H. Rhodes, Nicolas Stoll, Carlo Barbante, and Pascal Bohleber
EGUsphere, https://doi.org/10.5194/egusphere-2024-1723, https://doi.org/10.5194/egusphere-2024-1723, 2024
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Impurities in ice cores can be preferentially located at the boundaries between crystals of ice, impacting the interpretation of high-resolution data collected from ice core samples. This work finds that one dimensional signals can be significantly effected by this association, meaning experiments collecting data at high resolution must be carefully designed. Accounting for this effect is important for interpreting ice core data, especially for deep ice samples.
Jessica Ng, Jeffrey Severinghaus, Ryan Bay, and Delia Tosi
Clim. Past, 20, 1437–1449, https://doi.org/10.5194/cp-20-1437-2024, https://doi.org/10.5194/cp-20-1437-2024, 2024
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The pattern of Earth’s ice age cycles shifted around a million years ago, becoming more extreme and longer in duration. Multiple projects are underway to obtain an Antarctic ice core that covers this time period, as ice cores contain important clues to why the transition happened. To make sure the ice is old enough at the bottom, we demonstrate how to use new technology to quickly measure dust patterns in the ice and compare them to dust in deep-ocean sediments whose ages are known.
Chloe A. Brashear, Tyler R. Jones, Valerie Morris, Bruce H. Vaughn, William H. G. Roberts, William B. Skorski, Abigail G. Hughes, Richard Nunn, Sune Olander Rasmussen, Kurt M. Cuffey, Bo M. Vinther, Todd Sowers, Christo Buizert, Vasileios Gkinis, Christian Holme, Mari F. Jensen, Sofia E. Kjellman, Petra M. Langebroek, Florian Mekhaldi, Kevin S. Rozmiarek, Jonathan W. Rheinlænder, Margit Simon, Giulia Sinnl, Silje Smith-Johnsen, and James W. C. White
EGUsphere, https://doi.org/10.5194/egusphere-2024-1003, https://doi.org/10.5194/egusphere-2024-1003, 2024
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We use a series of spectral techniques to quantify the strength of high-frequency climate variability in Northeastern Greenland to 50,000 ka before present. Importantly, we find that variability consistently decreases hundreds of years prior to Dansgaard-Oeschger warming events. Model simulations suggest a change in North Atlantic sea ice behavior contributed to this pattern, thus providing new information on the conditions which proceeded abrupt climate change during the Last Glacial Period.
Qinggang Gao, Emilie Capron, Louise C. Sime, Rachael H. Rhodes, Rahul Sivankutty, Xu Zhang, Bette L. Otto-Bliesner, and Martin Werner
EGUsphere, https://doi.org/10.5194/egusphere-2024-1261, https://doi.org/10.5194/egusphere-2024-1261, 2024
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Marine sediment and ice core records suggest a warmer Southern Ocean and Antarctica at the early last interglacial, ~127 thousand years ago. However, when only forced by orbital parameters and greenhouse gas concentrations during that period, state-of-the-art climate models do not reproduce the magnitude of warming. Here we show that much of the warming at southern mid-to-high latitudes can be reproduced by a UK climate model HadCM3 with a 3000-year freshwater forcing over the North Atlantic.
Susanne Preunkert, Pascal Bohleber, Michel Legrand, Adrien Gilbert, Tobias Erhardt, Roland Purtschert, Lars Zipf, Astrid Waldner, Joseph R. McConnell, and Hubertus Fischer
The Cryosphere, 18, 2177–2194, https://doi.org/10.5194/tc-18-2177-2024, https://doi.org/10.5194/tc-18-2177-2024, 2024
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Ice cores from high-elevation Alpine glaciers are an important tool to reconstruct the past atmosphere. However, since crevasses are common at these glacier sites, rigorous investigations of glaciological conditions upstream of drill sites are needed before interpreting such ice cores. On the basis of three ice cores extracted at Col du Dôme (4250 m a.s.l; French Alps), an overall picture of a dynamic crevasse formation is drawn, which disturbs the depth–age relation of two of the three cores.
Xavier Faïn, Sophie Szopa, Vaishali Naïk, Patricia Martinerie, David M. Etheridge, Rachael H. Rhodes, Cathy M. Trudinger, Vasilii V. Petrenko, Kévin Fourteau, and Phillip Place
EGUsphere, https://doi.org/10.5194/egusphere-2024-653, https://doi.org/10.5194/egusphere-2024-653, 2024
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Carbon monoxide (CO) plays a crucial role in the atmosphere's oxidizing capacity. In this study, we analyse how historical (1850–2014) [CO] outputs from state-of-the-art global chemistry-climate models over Greenland and Antarctica are able to capture both absolute values and trends recorded in multi-site ice archives. A disparity in [CO] growth rates emerges in the Northern Hemisphere between models and observations from 1920–1975 CE, possibly linked to uncertainties in CO emission factors.
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.
Tyler J. Fudge, Raphael Sauvage, Linh Vu, Benjamin H. Hills, Mirko Severi, and Edwin D. Waddington
Clim. Past, 20, 297–312, https://doi.org/10.5194/cp-20-297-2024, https://doi.org/10.5194/cp-20-297-2024, 2024
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We use the oldest Antarctic ice core to estimate the rate of diffusion of sulfuric acid. Sulfuric acid is a marker of past volcanic activity and is critical in developing ice core timescales. The rate of diffusion is uncertain and is important to know, both for selecting future ice core locations and interpreting ice core records. We find the effective diffusivity of sulfate is 10 times smaller than previously estimated, indicating that the sulfuric acid signals will persist for longer.
Laura Melling, Amber Leeson, Malcolm McMillan, Jennifer Maddalena, Jade Bowling, Emily Glen, Louise Sandberg Sørensen, Mai Winstrup, and Rasmus Lørup Arildsen
The Cryosphere, 18, 543–558, https://doi.org/10.5194/tc-18-543-2024, https://doi.org/10.5194/tc-18-543-2024, 2024
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Lakes on glaciers hold large volumes of water which can drain through the ice, influencing estimates of sea level rise. To estimate water volume, we must calculate lake depth. We assessed the accuracy of three satellite-based depth detection methods on a study area in western Greenland and considered the implications for quantifying the volume of water within lakes. We found that the most popular method of detecting depth on the ice sheet scale has higher uncertainty than previously assumed.
John D. Patterson, Murat Aydin, Andrew M. Crotwell, Gabrielle Pétron, Jeffery P. Severinghaus, Paul B. Krummel, Ray L. Langenfelds, Vasilii V. Petrenko, and Eric S. Saltzman
Clim. Past, 19, 2535–2550, https://doi.org/10.5194/cp-19-2535-2023, https://doi.org/10.5194/cp-19-2535-2023, 2023
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Atmospheric levels of molecular hydrogen (H2) can impact climate and air quality. Constraining past changes to atmospheric H2 is useful for understanding how H2 cycles through the Earth system and predicting the impacts of increasing anthropogenic emissions under the
hydrogen economy. Here, we use the aging air found in the polar snowpack to reconstruct H2 levels over the past 100 years. We find that H2 levels increased by 30 % over Greenland and 60 % over Antarctica during the 20th century.
Xavier Faïn, David M. Etheridge, Kévin Fourteau, Patricia Martinerie, Cathy M. Trudinger, Rachael H. Rhodes, Nathan J. Chellman, Ray L. Langenfelds, Joseph R. McConnell, Mark A. J. Curran, Edward J. Brook, Thomas Blunier, Grégory Teste, Roberto Grilli, Anthony Lemoine, William T. Sturges, Boris Vannière, Johannes Freitag, and Jérôme Chappellaz
Clim. Past, 19, 2287–2311, https://doi.org/10.5194/cp-19-2287-2023, https://doi.org/10.5194/cp-19-2287-2023, 2023
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We report on a 3000-year record of carbon monoxide (CO) levels in the Southern Hemisphere's high latitudes by combining ice core and firn air measurements with modern direct atmospheric samples. Antarctica [CO] remained stable (–835 to 1500 CE), decreased during the Little Ice Age, and peaked around 1985 CE. Such evolution reflects stable biomass burning CO emissions before industrialization, followed by growth from CO anthropogenic sources, which decline after 1985 due to improved combustion.
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.
Gemma K. O'Connor, Paul R. Holland, Eric J. Steig, Pierre Dutrieux, and Gregory J. Hakim
The Cryosphere, 17, 4399–4420, https://doi.org/10.5194/tc-17-4399-2023, https://doi.org/10.5194/tc-17-4399-2023, 2023
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Glaciers in West Antarctica are rapidly melting, but the causes are unknown due to limited observations. A leading hypothesis is that an unusually large wind event in the 1940s initiated the ocean-driven melting. Using proxy reconstructions (e.g., using ice cores) and climate model simulations, we find that wind events similar to the 1940s event are relatively common on millennial timescales, implying that ocean variability or climate trends are also necessary to explain the start of ice loss.
Anja Løkkegaard, Kenneth D. Mankoff, Christian Zdanowicz, Gary D. Clow, Martin P. Lüthi, Samuel H. Doyle, Henrik H. Thomsen, David Fisher, Joel Harper, Andy Aschwanden, Bo M. Vinther, Dorthe Dahl-Jensen, Harry Zekollari, Toby Meierbachtol, Ian McDowell, Neil Humphrey, Anne Solgaard, Nanna B. Karlsson, Shfaqat A. Khan, Benjamin Hills, Robert Law, Bryn Hubbard, Poul Christoffersen, Mylène Jacquemart, Julien Seguinot, Robert S. Fausto, and William T. Colgan
The Cryosphere, 17, 3829–3845, https://doi.org/10.5194/tc-17-3829-2023, https://doi.org/10.5194/tc-17-3829-2023, 2023
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This study presents a database compiling 95 ice temperature profiles from the Greenland ice sheet and peripheral ice caps. Ice viscosity and hence ice flow are highly sensitive to ice temperature. To highlight the value of the database in evaluating ice flow simulations, profiles from the Greenland ice sheet are compared to a modeled temperature field. Reoccurring discrepancies between modeled and observed temperatures provide insight on the difficulties faced when simulating ice temperatures.
Benoit S. Lecavalier, Lev Tarasov, Greg Balco, Perry Spector, Claus-Dieter Hillenbrand, Christo Buizert, Catherine Ritz, Marion Leduc-Leballeur, Robert Mulvaney, Pippa L. Whitehouse, Michael J. Bentley, and Jonathan Bamber
Earth Syst. Sci. Data, 15, 3573–3596, https://doi.org/10.5194/essd-15-3573-2023, https://doi.org/10.5194/essd-15-3573-2023, 2023
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The Antarctic Ice Sheet Evolution constraint database version 2 (AntICE2) consists of a large variety of observations that constrain the evolution of the Antarctic Ice Sheet over the last glacial cycle. This includes observations of past ice sheet extent, past ice thickness, past relative sea level, borehole temperature profiles, and present-day bedrock displacement rates. The database is intended to improve our understanding of past Antarctic changes and for ice sheet model calibrations.
Elizabeth R. Thomas, Diana O. Vladimirova, Dieter R. Tetzner, B. Daniel Emanuelsson, Nathan Chellman, Daniel A. Dixon, Hugues Goosse, Mackenzie M. Grieman, Amy C. F. King, Michael Sigl, Danielle G. Udy, Tessa R. Vance, Dominic A. Winski, V. Holly L. Winton, Nancy A. N. Bertler, Akira Hori, Chavarukonam M. Laluraj, Joseph R. McConnell, Yuko Motizuki, Kazuya Takahashi, Hideaki Motoyama, Yoichi Nakai, Franciéle Schwanck, Jefferson Cardia Simões, Filipe Gaudie Ley Lindau, Mirko Severi, Rita Traversi, Sarah Wauthy, Cunde Xiao, Jiao Yang, Ellen Mosely-Thompson, Tamara V. Khodzher, Ludmila P. Golobokova, and Alexey A. Ekaykin
Earth Syst. Sci. Data, 15, 2517–2532, https://doi.org/10.5194/essd-15-2517-2023, https://doi.org/10.5194/essd-15-2517-2023, 2023
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The concentration of sodium and sulfate measured in Antarctic ice cores is related to changes in both sea ice and winds. Here we have compiled a database of sodium and sulfate records from 105 ice core sites in Antarctica. The records span all, or part, of the past 2000 years. The records will improve our understanding of how winds and sea ice have changed in the past and how they have influenced the climate of Antarctica over the past 2000 years.
Aymeric P. M. Servettaz, Anaïs J. Orsi, Mark A. J. Curran, Andrew D. Moy, Amaelle Landais, Joseph R. McConnell, Trevor J. Popp, Emmanuel Le Meur, Xavier Faïn, and Jérôme Chappellaz
Clim. Past, 19, 1125–1152, https://doi.org/10.5194/cp-19-1125-2023, https://doi.org/10.5194/cp-19-1125-2023, 2023
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The temperature of the past 2000 years is still poorly known in vast parts of the East Antarctic plateau. In this study, we present temperature reconstructions based on water and gas stable isotopes from the Aurora Basin North ice core. Spatial and temporal significance of each proxy differs, and we can identify some cold periods in the snow temperature up to 2°C cooler in the 1000–1400 CE period, which could not be determined with water isotopes only.
Michaela Mühl, Jochen Schmitt, Barbara Seth, James E. Lee, Jon S. Edwards, Edward J. Brook, Thomas Blunier, and Hubertus Fischer
Clim. Past, 19, 999–1025, https://doi.org/10.5194/cp-19-999-2023, https://doi.org/10.5194/cp-19-999-2023, 2023
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Our ice core measurements show that methane, ethane, and propane concentrations are significantly elevated above their past atmospheric background for Greenland ice samples containing mineral dust. The underlying co-production process happens during the classical discrete wet extraction of air from the ice sample and affects previous reconstructions of the inter-polar difference of methane as well as methane stable isotope records derived from dust-rich Greenland ice.
Robert Mulvaney, Eric W. Wolff, Mackenzie M. Grieman, Helene H. Hoffmann, Jack D. Humby, Christoph Nehrbass-Ahles, Rachael H. Rhodes, Isobel F. Rowell, Frédéric Parrenin, Loïc Schmidely, Hubertus Fischer, Thomas F. Stocker, Marcus Christl, Raimund Muscheler, Amaelle Landais, and Frédéric Prié
Clim. Past, 19, 851–864, https://doi.org/10.5194/cp-19-851-2023, https://doi.org/10.5194/cp-19-851-2023, 2023
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We present an age scale for a new ice core drilled at Skytrain Ice Rise, an ice rise facing the Ronne Ice Shelf in Antarctica. Various measurements in the ice and air phases are used to match the ice core to other Antarctic cores that have already been dated, and a new age scale is constructed. The 651 m ice core includes ice that is confidently dated to 117 000–126 000 years ago, in the last interglacial. Older ice is found deeper down, but there are flow disturbances in the deeper ice.
Christo Buizert, Sarah Shackleton, Jeffrey P. Severinghaus, William H. G. Roberts, Alan Seltzer, Bernhard Bereiter, Kenji Kawamura, Daniel Baggenstos, Anaïs J. Orsi, Ikumi Oyabu, Benjamin Birner, Jacob D. Morgan, Edward J. Brook, David M. Etheridge, David Thornton, Nancy Bertler, Rebecca L. Pyne, Robert Mulvaney, Ellen Mosley-Thompson, Peter D. Neff, and Vasilii V. Petrenko
Clim. Past, 19, 579–606, https://doi.org/10.5194/cp-19-579-2023, https://doi.org/10.5194/cp-19-579-2023, 2023
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It is unclear how different components of the global atmospheric circulation, such as the El Niño effect, respond to large-scale climate change. We present a new ice core gas proxy, called krypton-86 excess, that reflects past storminess in Antarctica. We present data from 11 ice cores that suggest the new proxy works. We present a reconstruction of changes in West Antarctic storminess over the last 24 000 years and suggest these are caused by north–south movement of the tropical rain belt.
Michael N. Dyonisius, Vasilii V. Petrenko, Andrew M. Smith, Benjamin Hmiel, Peter D. Neff, Bin Yang, Quan Hua, Jochen Schmitt, Sarah A. Shackleton, Christo Buizert, Philip F. Place, James A. Menking, Ross Beaudette, Christina Harth, Michael Kalk, Heidi A. Roop, Bernhard Bereiter, Casey Armanetti, Isaac Vimont, Sylvia Englund Michel, Edward J. Brook, Jeffrey P. Severinghaus, Ray F. Weiss, and Joseph R. McConnell
The Cryosphere, 17, 843–863, https://doi.org/10.5194/tc-17-843-2023, https://doi.org/10.5194/tc-17-843-2023, 2023
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Cosmic rays that enter the atmosphere produce secondary particles which react with surface minerals to produce radioactive nuclides. These nuclides are often used to constrain Earth's surface processes. However, the production rates from muons are not well constrained. We measured 14C in ice with a well-known exposure history to constrain the production rates from muons. 14C production in ice is analogous to quartz, but we obtain different production rates compared to commonly used estimates.
François Burgay, Rafael Pedro Fernández, Delia Segato, Clara Turetta, Christopher S. Blaszczak-Boxe, Rachael H. Rhodes, Claudio Scarchilli, Virginia Ciardini, Carlo Barbante, Alfonso Saiz-Lopez, and Andrea Spolaor
The Cryosphere, 17, 391–405, https://doi.org/10.5194/tc-17-391-2023, https://doi.org/10.5194/tc-17-391-2023, 2023
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The paper presents the first ice-core record of bromine (Br) in the Antarctic plateau. By the observation of the ice core and the application of atmospheric chemical models, we investigate the behaviour of bromine after its deposition into the snowpack, with interest in the effect of UV radiation change connected to the formation of the ozone hole, the role of volcanic deposition, and the possible use of Br to reconstruct past sea ice changes from ice core collect in the inner Antarctic plateau.
Lindsey Davidge, Eric J. Steig, and Andrew J. Schauer
Atmos. Meas. Tech., 15, 7337–7351, https://doi.org/10.5194/amt-15-7337-2022, https://doi.org/10.5194/amt-15-7337-2022, 2022
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We describe a continuous-flow analysis (CFA) method to measure Δ17O by laser spectroscopy, and we show that centimeter-scale information can be measured reliably in ice cores by this method. We present seasonally resolved Δ17O data from Greenland and demonstrate that the measurement precision is not reduced by the CFA process. Our results encourage the development and use of CFA methods for Δ17O, and they identify calibration strategies as a target for method improvement.
Paul R. Holland, Gemma K. O'Connor, Thomas J. Bracegirdle, Pierre Dutrieux, Kaitlin A. Naughten, Eric J. Steig, David P. Schneider, Adrian Jenkins, and James A. Smith
The Cryosphere, 16, 5085–5105, https://doi.org/10.5194/tc-16-5085-2022, https://doi.org/10.5194/tc-16-5085-2022, 2022
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The Antarctic Ice Sheet is losing ice, causing sea-level rise. However, it is not known whether human-induced climate change has contributed to this ice loss. In this study, we use evidence from climate models and palaeoclimate measurements (e.g. ice cores) to suggest that the ice loss was triggered by natural climate variations but is now sustained by human-forced climate change. This implies that future greenhouse-gas emissions may influence sea-level rise from Antarctica.
Jinhwa Shin, Jinho Ahn, Jai Chowdhry Beeman, Hun-Gyu Lee, Jaemyeong Mango Seo, and Edward J. Brook
Clim. Past, 18, 2063–2075, https://doi.org/10.5194/cp-18-2063-2022, https://doi.org/10.5194/cp-18-2063-2022, 2022
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We present a new and highly resolved atmospheric CO2 record from the Siple Dome ice core, Antarctica, over the early Holocene (11.7–7.4 ka). Atmospheric CO2 decreased by ~10 ppm from 10.9 to 7.3 ka, but the decrease was punctuated by local minima at 11.1, 10.1, 9.1, and 8.3 ka. We found millennial CO2 variability of 2–6 ppm, and the millennial CO2 variations correlate with proxies for solar forcing and local climate in the Southern Ocean, North Atlantic, and eastern equatorial Pacific.
Xavier Crosta, Karen E. Kohfeld, Helen C. Bostock, Matthew Chadwick, Alice Du Vivier, Oliver Esper, Johan Etourneau, Jacob Jones, Amy Leventer, Juliane Müller, Rachael H. Rhodes, Claire S. Allen, Pooja Ghadi, Nele Lamping, Carina B. Lange, Kelly-Anne Lawler, David Lund, Alice Marzocchi, Katrin J. Meissner, Laurie Menviel, Abhilash Nair, Molly Patterson, Jennifer Pike, Joseph G. Prebble, Christina Riesselman, Henrik Sadatzki, Louise C. Sime, Sunil K. Shukla, Lena Thöle, Maria-Elena Vorrath, Wenshen Xiao, and Jiao Yang
Clim. Past, 18, 1729–1756, https://doi.org/10.5194/cp-18-1729-2022, https://doi.org/10.5194/cp-18-1729-2022, 2022
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Despite its importance in the global climate, our knowledge of Antarctic sea-ice changes throughout the last glacial–interglacial cycle is extremely limited. As part of the Cycles of Sea Ice Dynamics in the Earth system (C-SIDE) Working Group, we review marine- and ice-core-based sea-ice proxies to provide insights into their applicability and limitations. By compiling published records, we provide information on Antarctic sea-ice dynamics over the past 130 000 years.
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.
Michael Sigl, Matthew Toohey, Joseph R. McConnell, Jihong Cole-Dai, and Mirko Severi
Earth Syst. Sci. Data, 14, 3167–3196, https://doi.org/10.5194/essd-14-3167-2022, https://doi.org/10.5194/essd-14-3167-2022, 2022
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Volcanism is a key driver of climate. Based on ice cores from Greenland and Antarctica, we reconstruct its climate impact potential over the Holocene. By aligning records on a well-dated chronology from Antarctica, we resolve long-standing inconsistencies in the dating of past volcanic eruptions. We reconstruct 850 eruptions (which, in total, injected 7410 Tg of sulfur in the stratosphere) and estimate how they changed the opacity of the atmosphere, a prerequisite for climate model simulations.
Bradley R. Markle and Eric J. Steig
Clim. Past, 18, 1321–1368, https://doi.org/10.5194/cp-18-1321-2022, https://doi.org/10.5194/cp-18-1321-2022, 2022
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The geochemistry preserved in polar ice can provide detailed histories of Earth’s climate over millennia. Here we use the stable isotope ratios of ice from many Antarctic ice cores to reconstruct temperature variability of Antarctica and the midlatitude Southern Hemisphere over tens of thousands of years. We improve upon existing methods to estimate temperature from the geochemical measurements and investigate the patterns of climate change in the past.
Giyoon Lee, Jinho Ahn, Hyeontae Ju, Florian Ritterbusch, Ikumi Oyabu, Christo Buizert, Songyi Kim, Jangil Moon, Sambit Ghosh, Kenji Kawamura, Zheng-Tian Lu, Sangbum Hong, Chang Hee Han, Soon Do Hur, Wei Jiang, and Guo-Min Yang
The Cryosphere, 16, 2301–2324, https://doi.org/10.5194/tc-16-2301-2022, https://doi.org/10.5194/tc-16-2301-2022, 2022
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Blue-ice areas (BIAs) have several advantages for reconstructing past climate. However, the complicated ice flow in the area hinders constraining the age. We applied state-of-the-art techniques and found that the ages cover the last deglaciation period. Our study demonstrates that the BIA in northern Victoria Land may help reconstruct the past climate during the termination of the last glacial period.
Giulia Sinnl, Mai Winstrup, Tobias Erhardt, Eliza Cook, Camilla Marie Jensen, Anders Svensson, Bo Møllesøe Vinther, Raimund Muscheler, and Sune Olander Rasmussen
Clim. Past, 18, 1125–1150, https://doi.org/10.5194/cp-18-1125-2022, https://doi.org/10.5194/cp-18-1125-2022, 2022
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A new Greenland ice-core timescale, covering the last 3800 years, was produced using the machine learning algorithm StratiCounter. We synchronized the ice cores using volcanic eruptions and wildfires. We compared the new timescale to the tree-ring timescale, finding good alignment both between the common signatures of volcanic eruptions and of solar activity. Our Greenlandic timescales is safe to use for the Late Holocene, provided one uses our uncertainty estimate.
Markus Stoffel, Christophe Corona, Francis Ludlow, Michael Sigl, Heli Huhtamaa, Emmanuel Garnier, Samuli Helama, Sébastien Guillet, Arlene Crampsie, Katrin Kleemann, Chantal Camenisch, Joseph McConnell, and Chaochao Gao
Clim. Past, 18, 1083–1108, https://doi.org/10.5194/cp-18-1083-2022, https://doi.org/10.5194/cp-18-1083-2022, 2022
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The mid-17th century saw several volcanic eruptions, deteriorating climate, political instability, and famine in Europe, China, and Japan. We analyze impacts of the eruptions on climate but also study their socio-political context. We show that an unambiguous distinction of volcanic cooling or wetting from natural climate variability is not straightforward. It also shows that political instability, poor harvest, and famine cannot only be attributed to volcanic climatic impacts.
Xavier Faïn, Rachael H. Rhodes, Philip Place, Vasilii V. Petrenko, Kévin Fourteau, Nathan Chellman, Edward Crosier, Joseph R. McConnell, Edward J. Brook, Thomas Blunier, Michel Legrand, and Jérôme Chappellaz
Clim. Past, 18, 631–647, https://doi.org/10.5194/cp-18-631-2022, https://doi.org/10.5194/cp-18-631-2022, 2022
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Carbon monoxide (CO) is a regulated pollutant and one of the key components determining the oxidizing capacity of the atmosphere. In this study, we analyzed five ice cores from Greenland at high resolution for CO concentrations by coupling laser spectrometry with continuous melting. By combining these new datasets, we produced an upper-bound estimate of past atmospheric CO abundance since preindustrial times for the Northern Hemisphere high latitudes, covering the period from 1700 to 1957 CE.
Paolo Gabrielli, Theo Manuel Jenk, Michele Bertó, Giuliano Dreossi, Daniela Festi, Werner Kofler, Mai Winstrup, Klaus Oeggl, Margit Schwikowski, Barbara Stenni, and Carlo Barbante
Clim. Past Discuss., https://doi.org/10.5194/cp-2022-20, https://doi.org/10.5194/cp-2022-20, 2022
Revised manuscript not accepted
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We present a methodology that reduces the chronological uncertainty of an Alpine ice core record from the glacier Alto dell’Ortles, Italy. This chronology will allow the constraint of the Holocene climatic and environmental histories emerging from this archive of Central Europe. This method will allow to obtain accurate chronologies also from other ice cores from-low latitude/high-altitude glaciers that typically suffer from larger dating uncertainties compared with well dated polar records.
Gill Plunkett, Michael Sigl, Hans F. Schwaiger, Emma L. Tomlinson, Matthew Toohey, Joseph R. McConnell, Jonathan R. Pilcher, Takeshi Hasegawa, and Claus Siebe
Clim. Past, 18, 45–65, https://doi.org/10.5194/cp-18-45-2022, https://doi.org/10.5194/cp-18-45-2022, 2022
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We report the identification of volcanic ash associated with a sulfate layer in Greenland ice cores previously thought to have been from the Vesuvius 79 CE eruption and which had been used to confirm the precise dating of the Greenland ice-core chronology. We find that the tephra was probably produced by an eruption in Alaska. We show the importance of verifying sources of volcanic signals in ice cores through ash analysis to avoid errors in dating ice cores and interpreting volcanic impacts.
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.
Sarah Shackleton, James A. Menking, Edward Brook, Christo Buizert, Michael N. Dyonisius, Vasilii V. Petrenko, Daniel Baggenstos, and Jeffrey P. Severinghaus
Clim. Past, 17, 2273–2289, https://doi.org/10.5194/cp-17-2273-2021, https://doi.org/10.5194/cp-17-2273-2021, 2021
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In this study, we measure atmospheric noble gases trapped in ice cores to reconstruct ocean temperature during the last glaciation. Comparing the new reconstruction to other climate records, we show that the ocean reached its coldest temperatures before ice sheets reached maximum volumes and atmospheric CO2 reached its lowest concentrations. Ocean cooling played a major role in lowering atmospheric CO2 early in the glaciation, but it only played a minor role later.
Yuzhen Yan, Nicole E. Spaulding, Michael L. Bender, Edward J. Brook, John A. Higgins, Andrei V. Kurbatov, and Paul A. Mayewski
Clim. Past, 17, 1841–1855, https://doi.org/10.5194/cp-17-1841-2021, https://doi.org/10.5194/cp-17-1841-2021, 2021
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Here we reconstruct the rate of snow accumulation during the Last Interglacial period in an East Antarctic ice core located near the present-day northern edge of the Ross Ice Shelf. We find an order-of-magnitude increase in the accumulation rate during the peak warming in the Last Interglacial. This large increase in mass accumulation is compatible with less ice cover in the Ross Sea, perhaps created by a partly collapsed West Antarctic Ice Sheet, whose stability in a warming world is uncertain.
Benjamin Birner, William Paplawsky, Jeffrey Severinghaus, and Ralph F. Keeling
Atmos. Meas. Tech., 14, 2515–2527, https://doi.org/10.5194/amt-14-2515-2021, https://doi.org/10.5194/amt-14-2515-2021, 2021
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The atmospheric helium-to-nitrogen ratio is a promising indicator for circulation changes in the upper atmosphere and fossil fuel burning by humans. We present a very precise analysis method to determine changes in the helium-to-nitrogen ratio of air samples. The method relies on stabilizing the gas flow to a mass spectrometer and continuous removal of reactive gases. These advances enable new insights and monitoring possibilities for anthropogenic and natural processes.
Peter M. Abbott, Gill Plunkett, Christophe Corona, Nathan J. Chellman, Joseph R. McConnell, John R. Pilcher, Markus Stoffel, and Michael Sigl
Clim. Past, 17, 565–585, https://doi.org/10.5194/cp-17-565-2021, https://doi.org/10.5194/cp-17-565-2021, 2021
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Volcanic eruptions are a key source of climatic variability, and greater understanding of their past influence will increase the accuracy of future projections. We use volcanic ash from a 1477 CE Icelandic eruption in a Greenlandic ice core as a temporal fix point to constrain the timing of two eruptions in the 1450s CE and their climatic impact. Despite being the most explosive Icelandic eruption in the last 1200 years, the 1477 CE event had a limited impact on Northern Hemisphere climate.
Elizabeth Ruth Thomas, Guisella Gacitúa, Joel B. Pedro, Amy Constance Faith King, Bradley Markle, Mariusz Potocki, and Dorothea Elisabeth Moser
The Cryosphere, 15, 1173–1186, https://doi.org/10.5194/tc-15-1173-2021, https://doi.org/10.5194/tc-15-1173-2021, 2021
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Here we present the first-ever radar and ice core data from the sub-Antarctic islands of Bouvet Island, Peter I Island, and Young Island. These islands have the potential to record past climate in one of the most data-sparse regions on earth. Despite their northerly location, surface melting is generally low, and the upper layer of the ice at most sites is undisturbed. We estimate that a 100 m ice core drilled on these islands could capture climate over the past 100–200 years.
Lu Zhou, Julienne Stroeve, Shiming Xu, Alek Petty, Rachel Tilling, Mai Winstrup, Philip Rostosky, Isobel R. Lawrence, Glen E. Liston, Andy Ridout, Michel Tsamados, and Vishnu Nandan
The Cryosphere, 15, 345–367, https://doi.org/10.5194/tc-15-345-2021, https://doi.org/10.5194/tc-15-345-2021, 2021
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Snow on sea ice plays an important role in the Arctic climate system. Large spatial and temporal discrepancies among the eight snow depth products are analyzed together with their seasonal variability and long-term trends. These snow products are further compared against various ground-truth observations. More analyses on representation error of sea ice parameters are needed for systematic comparison and fusion of airborne, in situ and remote sensing observations.
Ikumi Oyabu, Kenji Kawamura, Kyotaro Kitamura, Remi Dallmayr, Akihiro Kitamura, Chikako Sawada, Jeffrey P. Severinghaus, Ross Beaudette, Anaïs Orsi, Satoshi Sugawara, Shigeyuki Ishidoya, Dorthe Dahl-Jensen, Kumiko Goto-Azuma, Shuji Aoki, and Takakiyo Nakazawa
Atmos. Meas. Tech., 13, 6703–6731, https://doi.org/10.5194/amt-13-6703-2020, https://doi.org/10.5194/amt-13-6703-2020, 2020
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Air in polar ice cores provides information on past atmosphere and climate. We present a new method for simultaneously measuring eight gases (CH4, N2O and CO2 concentrations; isotopic ratios of N2 and O2; elemental ratios between N2, O2 and Ar; and total air content) from single ice-core samples with high precision.
Jenna A. Epifanio, Edward J. Brook, Christo Buizert, Jon S. Edwards, Todd A. Sowers, Emma C. Kahle, Jeffrey P. Severinghaus, Eric J. Steig, Dominic A. Winski, Erich C. Osterberg, Tyler J. Fudge, Murat Aydin, Ekaterina Hood, Michael Kalk, Karl J. Kreutz, David G. Ferris, and Joshua A. Kennedy
Clim. Past, 16, 2431–2444, https://doi.org/10.5194/cp-16-2431-2020, https://doi.org/10.5194/cp-16-2431-2020, 2020
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A new ice core drilled at the South Pole provides a 54 000-year paleo-environmental record including the composition of the past atmosphere. This paper describes the gas chronology for the South Pole ice core, based on a high-resolution methane record. The new gas chronology, in combination with the existing ice age scale from Winski et al. (2019), allows a model-independent reconstruction of the delta age record.
Pavel Talalay, Yazhou Li, Laurent Augustin, Gary D. Clow, Jialin Hong, Eric Lefebvre, Alexey Markov, Hideaki Motoyama, and Catherine Ritz
The Cryosphere, 14, 4021–4037, https://doi.org/10.5194/tc-14-4021-2020, https://doi.org/10.5194/tc-14-4021-2020, 2020
James W. Kirchner, Sarah E. Godsey, Madeline Solomon, Randall Osterhuber, Joseph R. McConnell, and Daniele Penna
Hydrol. Earth Syst. Sci., 24, 5095–5123, https://doi.org/10.5194/hess-24-5095-2020, https://doi.org/10.5194/hess-24-5095-2020, 2020
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Streams and groundwaters often show daily cycles in response to snowmelt and evapotranspiration. These typically have a roughly 6 h time lag, which is often interpreted as a travel-time lag. Here we show that it is instead primarily a phase lag that arises because aquifers integrate their inputs over time. We further show how these cycles shift seasonally, mirroring the springtime retreat of snow cover to higher elevations and the seasonal advance and retreat of photosynthetic activity.
Benjamin Birner, Martyn P. Chipperfield, Eric J. Morgan, Britton B. Stephens, Marianna Linz, Wuhu Feng, Chris Wilson, Jonathan D. Bent, Steven C. Wofsy, Jeffrey Severinghaus, and Ralph F. Keeling
Atmos. Chem. Phys., 20, 12391–12408, https://doi.org/10.5194/acp-20-12391-2020, https://doi.org/10.5194/acp-20-12391-2020, 2020
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With new high-precision observations from nine aircraft campaigns and 3-D chemical transport modeling, we show that the argon-to-nitrogen ratio (Ar / N2) in the lowermost stratosphere provides a useful constraint on the “age of air” (the time elapsed since entry of an air parcel into the stratosphere). Therefore, Ar / N2 in combination with traditional age-of-air indicators, such as CO2 and N2O, could provide new insights into atmospheric mixing and transport.
James E. Lee, Edward J. Brook, Nancy A. N. Bertler, Christo Buizert, Troy Baisden, Thomas Blunier, V. Gabriela Ciobanu, Howard Conway, Dorthe Dahl-Jensen, Tyler J. Fudge, Richard Hindmarsh, Elizabeth D. Keller, Frédéric Parrenin, Jeffrey P. Severinghaus, Paul Vallelonga, Edwin D. Waddington, and Mai Winstrup
Clim. Past, 16, 1691–1713, https://doi.org/10.5194/cp-16-1691-2020, https://doi.org/10.5194/cp-16-1691-2020, 2020
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The Roosevelt Island ice core was drilled to investigate climate from the eastern Ross Sea, West Antarctica. We describe the ice age-scale and gas age-scale of the ice core for 0–763 m (83 000 years BP). Old ice near the bottom of the core implies the ice dome existed throughout the last glacial period and that ice streaming was active in the region. Variations in methane, similar to those used as evidence of early human influence on climate, were observed prior to significant human populations.
Anders Svensson, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Thomas Blunier, Sune O. Rasmussen, Bo M. Vinther, Paul Vallelonga, Emilie Capron, Vasileios Gkinis, Eliza Cook, Helle Astrid Kjær, Raimund Muscheler, Sepp Kipfstuhl, Frank Wilhelms, Thomas F. Stocker, Hubertus Fischer, Florian Adolphi, Tobias Erhardt, Michael Sigl, Amaelle Landais, Frédéric Parrenin, Christo Buizert, Joseph R. McConnell, Mirko Severi, Robert Mulvaney, and Matthias Bigler
Clim. Past, 16, 1565–1580, https://doi.org/10.5194/cp-16-1565-2020, https://doi.org/10.5194/cp-16-1565-2020, 2020
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We identify signatures of large bipolar volcanic eruptions in Greenland and Antarctic ice cores during the last glacial period, which allows for a precise temporal alignment of the ice cores. Thereby the exact timing of unexplained, abrupt climatic changes occurring during the last glacial period can be determined in a global context. The study thus provides a step towards a full understanding of elements of the climate system that may also play an important role in the future.
Abigail G. Hughes, Tyler R. Jones, Bo M. Vinther, Vasileios Gkinis, C. Max Stevens, Valerie Morris, Bruce H. Vaughn, Christian Holme, Bradley R. Markle, and James W. C. White
Clim. Past, 16, 1369–1386, https://doi.org/10.5194/cp-16-1369-2020, https://doi.org/10.5194/cp-16-1369-2020, 2020
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An ice core drilled on the Renland ice cap (RECAP) in east-central Greenland contains a continuous climate record dating through the last glacial period. Here we present the water isotope record for the Holocene, in which high-resolution climate information is retained for the last 8 kyr. We find that the RECAP water isotope record exhibits seasonal and decadal variability which may reflect sea surface conditions and regional climate variability.
Jessica A. Badgeley, Eric J. Steig, Gregory J. Hakim, and Tyler J. Fudge
Clim. Past, 16, 1325–1346, https://doi.org/10.5194/cp-16-1325-2020, https://doi.org/10.5194/cp-16-1325-2020, 2020
Tyler J. Fudge, David A. Lilien, Michelle Koutnik, Howard Conway, C. Max Stevens, Edwin D. Waddington, Eric J. Steig, Andrew J. Schauer, and Nicholas Holschuh
Clim. Past, 16, 819–832, https://doi.org/10.5194/cp-16-819-2020, https://doi.org/10.5194/cp-16-819-2020, 2020
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A 1750 m ice core at the South Pole was recently drilled. The oldest ice is ~55 000 years old. Since ice at the South Pole flows at 10 m per year, the ice in the core originated upstream, where the climate is different. We made measurements of the ice flow, snow accumulation, and temperature upstream. We determined the ice came from ~150 km away near the Titan Dome where the accumulation rate was similar but the temperature was colder. Our measurements improve the interpretation of the ice core.
Kirstin Hoffmann, Francisco Fernandoy, Hanno Meyer, Elizabeth R. Thomas, Marcelo Aliaga, Dieter Tetzner, Johannes Freitag, Thomas Opel, Jorge Arigony-Neto, Christian Florian Göbel, Ricardo Jaña, Delia Rodríguez Oroz, Rebecca Tuckwell, Emily Ludlow, Joseph R. McConnell, and Christoph Schneider
The Cryosphere, 14, 881–904, https://doi.org/10.5194/tc-14-881-2020, https://doi.org/10.5194/tc-14-881-2020, 2020
Hubertus Fischer, Jochen Schmitt, Michael Bock, Barbara Seth, Fortunat Joos, Renato Spahni, Sebastian Lienert, Gianna Battaglia, Benjamin D. Stocker, Adrian Schilt, and Edward J. Brook
Biogeosciences, 16, 3997–4021, https://doi.org/10.5194/bg-16-3997-2019, https://doi.org/10.5194/bg-16-3997-2019, 2019
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N2O concentrations were subject to strong variations accompanying glacial–interglacial but also rapid climate changes over the last 21 kyr. The sources of these N2O changes can be identified by measuring the isotopic composition of N2O in ice cores and using the distinct isotopic composition of terrestrial and marine N2O. We show that both marine and terrestrial sources increased from the last glacial to the Holocene but that only terrestrial emissions responded quickly to rapid climate changes.
Dominic A. Winski, Tyler J. Fudge, David G. Ferris, Erich C. Osterberg, John M. Fegyveresi, Jihong Cole-Dai, Zayta Thundercloud, Thomas S. Cox, Karl J. Kreutz, Nikolas Ortman, Christo Buizert, Jenna Epifanio, Edward J. Brook, Ross Beaudette, Jeffrey Severinghaus, Todd Sowers, Eric J. Steig, Emma C. Kahle, Tyler R. Jones, Valerie Morris, Murat Aydin, Melinda R. Nicewonger, Kimberly A. Casey, Richard B. Alley, Edwin D. Waddington, Nels A. Iverson, Nelia W. Dunbar, Ryan C. Bay, Joseph M. Souney, Michael Sigl, and Joseph R. McConnell
Clim. Past, 15, 1793–1808, https://doi.org/10.5194/cp-15-1793-2019, https://doi.org/10.5194/cp-15-1793-2019, 2019
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A deep ice core was recently drilled at the South Pole to understand past variations in the Earth's climate. To understand the information contained within the ice, we present the relationship between the depth and age of the ice in the South Pole Ice Core. We found that the oldest ice in our record is from 54 302 ± 519 years ago. Our results show that, on average, 7.4 cm of snow falls at the South Pole each year.
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.
Jens Mühle, Cathy M. Trudinger, Luke M. Western, Matthew Rigby, Martin K. Vollmer, Sunyoung Park, Alistair J. Manning, Daniel Say, Anita Ganesan, L. Paul Steele, Diane J. Ivy, Tim Arnold, Shanlan Li, Andreas Stohl, Christina M. Harth, Peter K. Salameh, Archie McCulloch, Simon O'Doherty, Mi-Kyung Park, Chun Ok Jo, Dickon Young, Kieran M. Stanley, Paul B. Krummel, Blagoj Mitrevski, Ove Hermansen, Chris Lunder, Nikolaos Evangeliou, Bo Yao, Jooil Kim, Benjamin Hmiel, Christo Buizert, Vasilii V. Petrenko, Jgor Arduini, Michela Maione, David M. Etheridge, Eleni Michalopoulou, Mike Czerniak, Jeffrey P. Severinghaus, Stefan Reimann, Peter G. Simmonds, Paul J. Fraser, Ronald G. Prinn, and Ray F. Weiss
Atmos. Chem. Phys., 19, 10335–10359, https://doi.org/10.5194/acp-19-10335-2019, https://doi.org/10.5194/acp-19-10335-2019, 2019
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We discuss atmospheric concentrations and emissions of the strong greenhouse gas perfluorocyclobutane. A large fraction of recent emissions stem from China, India, and Russia, probably as a by-product from the production of fluoropolymers and fluorochemicals. Most historic emissions likely stem from developed countries. Total emissions are higher than what is being reported. Clearly, more measurements and better reporting are needed to understand emissions of this and other greenhouse gases.
James A. Menking, Edward J. Brook, Sarah A. Shackleton, Jeffrey P. Severinghaus, Michael N. Dyonisius, Vasilii Petrenko, Joseph R. McConnell, Rachael H. Rhodes, Thomas K. Bauska, Daniel Baggenstos, Shaun Marcott, and Stephen Barker
Clim. Past, 15, 1537–1556, https://doi.org/10.5194/cp-15-1537-2019, https://doi.org/10.5194/cp-15-1537-2019, 2019
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An ice core from Taylor Glacier, Antarctica, spans a period ~ 70 000 years ago when Earth entered the last ice age. Chemical analyses of the ice and air bubbles allow for an independent determination of the ages of the ice and gas bubbles. The difference between the age of the ice and the bubbles at any given depth, called ∆age, is unusually high in the Taylor Glacier core compared to the Taylor Dome ice core situated to the south. This implies a dramatic accumulation gradient between the sites.
Robert Tardif, Gregory J. Hakim, Walter A. Perkins, Kaleb A. Horlick, Michael P. Erb, Julien Emile-Geay, David M. Anderson, Eric J. Steig, and David Noone
Clim. Past, 15, 1251–1273, https://doi.org/10.5194/cp-15-1251-2019, https://doi.org/10.5194/cp-15-1251-2019, 2019
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An updated Last Millennium Reanalysis is presented, using an expanded multi-proxy database, and proxy models representing the seasonal characteristics of proxy records, in addition to the dual sensitivity to temperature and moisture of tree-ring-width chronologies. We show enhanced skill in spatial reconstructions of key climate variables in the updated reanalysis, compared to an earlier version, resulting from the combined influences of the enhanced proxy network and improved proxy modeling.
Xin Yang, Markus M. Frey, Rachael H. Rhodes, Sarah J. Norris, Ian M. Brooks, Philip S. Anderson, Kouichi Nishimura, Anna E. Jones, and Eric W. Wolff
Atmos. Chem. Phys., 19, 8407–8424, https://doi.org/10.5194/acp-19-8407-2019, https://doi.org/10.5194/acp-19-8407-2019, 2019
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This is a comprehensive model–data comparison aiming to evaluate the proposed mechanism of sea salt aerosol (SSA) production from blowing snow on sea ice. Some key parameters such as snow salinity and blowing-snow size distribution were constrained by data collected in the Weddell Sea. The good agreement between modelled SSA and the cruise data strongly indicates that sea ice surface is a large SSA source in polar regions, a process which has not been considered in current climate models.
Jai Chowdhry Beeman, Léa Gest, Frédéric Parrenin, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past, 15, 913–926, https://doi.org/10.5194/cp-15-913-2019, https://doi.org/10.5194/cp-15-913-2019, 2019
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Atmospheric CO2 was likely an important amplifier of global-scale orbitally-driven warming during the last deglaciation. However, the mechanisms responsible for the rise in CO2, and the coherent rise in Antarctic isotopic temperature records, are under debate. Using a stochastic method, we detect variable lags between coherent changes in Antarctic temperature and CO2. This implies that the climate mechanisms linking the two records changed or experienced modulations during the deglaciation.
Mai Winstrup, Paul Vallelonga, Helle A. Kjær, Tyler J. Fudge, James E. Lee, Marie H. Riis, Ross Edwards, Nancy A. N. Bertler, Thomas Blunier, Ed J. Brook, Christo Buizert, Gabriela Ciobanu, Howard Conway, Dorthe Dahl-Jensen, Aja Ellis, B. Daniel Emanuelsson, Richard C. A. Hindmarsh, Elizabeth D. Keller, Andrei V. Kurbatov, Paul A. Mayewski, Peter D. Neff, Rebecca L. Pyne, Marius F. Simonsen, Anders Svensson, Andrea Tuohy, Edwin D. Waddington, and Sarah Wheatley
Clim. Past, 15, 751–779, https://doi.org/10.5194/cp-15-751-2019, https://doi.org/10.5194/cp-15-751-2019, 2019
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We present a 2700-year timescale and snow accumulation history for an ice core from Roosevelt Island, Ross Ice Shelf, Antarctica. We observe a long-term slightly decreasing trend in accumulation during most of the period but a rapid decline since the mid-1960s. The latter is linked to a recent strengthening of the Amundsen Sea Low and the expansion of regional sea ice. The year 1965 CE may thus mark the onset of significant increases in sea-ice extent in the eastern Ross Sea.
Kang Wang, Elchin Jafarov, Irina Overeem, Vladimir Romanovsky, Kevin Schaefer, Gary Clow, Frank Urban, William Cable, Mark Piper, Christopher Schwalm, Tingjun Zhang, Alexander Kholodov, Pamela Sousanes, Michael Loso, and Kenneth Hill
Earth Syst. Sci. Data, 10, 2311–2328, https://doi.org/10.5194/essd-10-2311-2018, https://doi.org/10.5194/essd-10-2311-2018, 2018
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Ground thermal and moisture data are important indicators of the rapid permafrost changes in the Arctic. To better understand the changes, we need a comprehensive dataset across various sites. We synthesize permafrost-related data in the state of Alaska. It should be a valuable permafrost dataset that is worth maintaining in the future. On a wider level, it also provides a prototype of basic data collection and management for permafrost regions in general.
Gary D. Clow
Geosci. Model Dev., 11, 4889–4908, https://doi.org/10.5194/gmd-11-4889-2018, https://doi.org/10.5194/gmd-11-4889-2018, 2018
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CVPM is a modular heat-transfer modeling system designed for scientific and engineering studies in permafrost terrain, and as an educational tool. CVPM implements the heat-transfer equations in both Cartesian and cylindrical coordinates. To accommodate a diversity of geologic settings, a variety of materials can be specified within the model domain. CVPM can be used over a broad range of depth, temperature, porosity, water saturation, and solute conditions on either Earth or Mars.
Mackenzie M. Grieman, Murat Aydin, Joseph R. McConnell, and Eric S. Saltzman
Clim. Past, 14, 1625–1637, https://doi.org/10.5194/cp-14-1625-2018, https://doi.org/10.5194/cp-14-1625-2018, 2018
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Vanillic acid is reported in the Tunu ice core from northeastern Greenland. It is an aerosol-borne acid produced by biomass burning. North American boreal forests are likely the source regions of the vanillic acid deposited at the ice core site. Vanillic acid levels were elevated during warm climate periods and lower during cooler climate periods. There is a positive correlation between the vanillic acid ice core record and ammonium and black carbon in the NEEM ice core from northern Greenland.
Amaëlle Landais, Emilie Capron, Valérie Masson-Delmotte, Samuel Toucanne, Rachael Rhodes, Trevor Popp, Bo Vinther, Bénédicte Minster, and Frédéric Prié
Clim. Past, 14, 1405–1415, https://doi.org/10.5194/cp-14-1405-2018, https://doi.org/10.5194/cp-14-1405-2018, 2018
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During the last glacial–interglacial climate transition (120 000 to 10 000 years before present), Greenland climate and midlatitude North Atlantic climate and water cycle vary in phase over the succession of millennial events. We identify here one notable exception to this behavior with a decoupling unambiguously identified through a combination of water isotopic tracers measured in a Greenland ice core. The midlatitude moisture source becomes warmer and wetter at 16 200 years before present.
Frazer D. W. Christie, Robert G. Bingham, Noel Gourmelen, Eric J. Steig, Rosie R. Bisset, Hamish D. Pritchard, Kate Snow, and Simon F. B. Tett
The Cryosphere, 12, 2461–2479, https://doi.org/10.5194/tc-12-2461-2018, https://doi.org/10.5194/tc-12-2461-2018, 2018
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With a focus on the hitherto little-studied Marie Byrd Land coastline linking Antarctica's more comprehensively studied Amundsen and Ross Sea Embayments, this paper uses both satellite remote sensing (Landsat, ASTER, ICESat, and CryoSat2) and climate and ocean records (i.e. ERA-Interim, Met Office EN4 data) to examine links between ice recession, inter-decadal atmosphere-ocean forcing and other influences acting upon the Pacific-facing coastline of West Antarctica.
Benjamin Birner, Christo Buizert, Till J. W. Wagner, and Jeffrey P. Severinghaus
The Cryosphere, 12, 2021–2037, https://doi.org/10.5194/tc-12-2021-2018, https://doi.org/10.5194/tc-12-2021-2018, 2018
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Ancient air enclosed in bubbles of the Antarctic ice sheet is a key source of information about the Earth's past climate. However, a range of physical processes in the snow layer atop an ice sheet may change the trapped air's chemical composition before it is occluded in the ice. We developed the first detailed 2-D computer simulation of these processes and found a new method to improve the reconstruction of past climate from air in ice cores bubbles.
Katrina M. Macdonald, Sangeeta Sharma, Desiree Toom, Alina Chivulescu, Andrew Platt, Mike Elsasser, Lin Huang, Richard Leaitch, Nathan Chellman, Joseph R. McConnell, Heiko Bozem, Daniel Kunkel, Ying Duan Lei, Cheol-Heon Jeong, Jonathan P. D. Abbatt, and Greg J. Evans
Atmos. Chem. Phys., 18, 3485–3503, https://doi.org/10.5194/acp-18-3485-2018, https://doi.org/10.5194/acp-18-3485-2018, 2018
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The sources of key contaminants in Arctic snow may be an important factor in understanding the rapid climate changes observed in the Arctic. Fresh snow samples collected frequently through the winter season were analyzed for major constituents. Temporally refined source apportionment via positive matrix factorization in conjunction with FLEXPART suggested potential source characteristics and locations. The identity of these sources and their relative contribution to key analytes is discussed.
Nancy A. N. Bertler, Howard Conway, Dorthe Dahl-Jensen, Daniel B. Emanuelsson, Mai Winstrup, Paul T. Vallelonga, James E. Lee, Ed J. Brook, Jeffrey P. Severinghaus, Taylor J. Fudge, Elizabeth D. Keller, W. Troy Baisden, Richard C. A. Hindmarsh, Peter D. Neff, Thomas Blunier, Ross Edwards, Paul A. Mayewski, Sepp Kipfstuhl, Christo Buizert, Silvia Canessa, Ruzica Dadic, Helle A. Kjær, Andrei Kurbatov, Dongqi Zhang, Edwin D. Waddington, Giovanni Baccolo, Thomas Beers, Hannah J. Brightley, Lionel Carter, David Clemens-Sewall, Viorela G. Ciobanu, Barbara Delmonte, Lukas Eling, Aja Ellis, Shruthi Ganesh, Nicholas R. Golledge, Skylar Haines, Michael Handley, Robert L. Hawley, Chad M. Hogan, Katelyn M. Johnson, Elena Korotkikh, Daniel P. Lowry, Darcy Mandeno, Robert M. McKay, James A. Menking, Timothy R. Naish, Caroline Noerling, Agathe Ollive, Anaïs Orsi, Bernadette C. Proemse, Alexander R. Pyne, Rebecca L. Pyne, James Renwick, Reed P. Scherer, Stefanie Semper, Marius Simonsen, Sharon B. Sneed, Eric J. Steig, Andrea Tuohy, Abhijith Ulayottil Venugopal, Fernando Valero-Delgado, Janani Venkatesh, Feitang Wang, Shimeng Wang, Dominic A. Winski, V. Holly L. Winton, Arran Whiteford, Cunde Xiao, Jiao Yang, and Xin Zhang
Clim. Past, 14, 193–214, https://doi.org/10.5194/cp-14-193-2018, https://doi.org/10.5194/cp-14-193-2018, 2018
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Temperature and snow accumulation records from the annually dated Roosevelt Island Climate Evolution (RICE) ice core show that for the past 2 700 years, the eastern Ross Sea warmed, while the western Ross Sea showed no trend and West Antarctica cooled. From the 17th century onwards, this dipole relationship changed. Now all three regions show concurrent warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea.
Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elizabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Martin Werner, and Massimo Frezzotti
Clim. Past, 13, 1609–1634, https://doi.org/10.5194/cp-13-1609-2017, https://doi.org/10.5194/cp-13-1609-2017, 2017
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Within PAGES Antarctica2k, we build an enlarged database of ice core water stable isotope records. We produce isotopic composites and temperature reconstructions since 0 CE for seven distinct Antarctic regions. We find a significant cooling trend from 0 to 1900 CE across all regions. Since 1900 CE, significant warming trends are identified for three regions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of last-2000-year natural variability.
Elizabeth R. Thomas, J. Melchior van Wessem, Jason Roberts, Elisabeth Isaksson, Elisabeth Schlosser, Tyler J. Fudge, Paul Vallelonga, Brooke Medley, Jan Lenaerts, Nancy Bertler, Michiel R. van den Broeke, Daniel A. Dixon, Massimo Frezzotti, Barbara Stenni, Mark Curran, and Alexey A. Ekaykin
Clim. Past, 13, 1491–1513, https://doi.org/10.5194/cp-13-1491-2017, https://doi.org/10.5194/cp-13-1491-2017, 2017
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Regional Antarctic snow accumulation derived from 79 ice core records is evaluated as part of the PAGES Antarctica 2k working group. Our results show that surface mass balance for the total Antarctic ice sheet has increased at a rate of 7 ± 0.13 Gt dec-1 since 1800 AD, representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~ 0.04 mm dec-1 since 1900 AD. The largest contribution is from the Antarctic Peninsula.
Alan M. Seltzer, Christo Buizert, Daniel Baggenstos, Edward J. Brook, Jinho Ahn, Ji-Woong Yang, and Jeffrey P. Severinghaus
Clim. Past, 13, 1323–1338, https://doi.org/10.5194/cp-13-1323-2017, https://doi.org/10.5194/cp-13-1323-2017, 2017
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To explore whether the oxygen-18 to oxygen-16 ratio of atmospheric O2 is sensitive to the position of the tropical rain belts, we (1) present a record of ice core bubble oxygen isotope measurements from two Antarctic ice cores, and (2) examine the sensitivity of oxygen isotopes in precipitation, weighted by photosynthesis, to the location of oxygen production over the modern-day seasonal cycle. We find a strong modern relationship and discuss implications for past shifts in tropical rainfall.
Ji-Woong Yang, Jinho Ahn, Edward J. Brook, and Yeongjun Ryu
Clim. Past, 13, 1227–1242, https://doi.org/10.5194/cp-13-1227-2017, https://doi.org/10.5194/cp-13-1227-2017, 2017
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The early Holocene climate is characterized as an interglacial boundary condition without substantial human influence. Here we present a high-resolution CH4 record covering the early Holocene. The results show that abrupt cooling in Greenland and southward migration of ITCZ were able to induce an ~20 ppb CH4 decrease on a millennial timescale. The inter-polar difference exhibits a gradual increase during the early Holocene, implying the strengthening of northern extratropical emission.
Rachael H. Rhodes, Xin Yang, Eric W. Wolff, Joseph R. McConnell, and Markus M. Frey
Atmos. Chem. Phys., 17, 9417–9433, https://doi.org/10.5194/acp-17-9417-2017, https://doi.org/10.5194/acp-17-9417-2017, 2017
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Sea salt aerosol comes from the open ocean or the sea ice surface. In the polar regions, this opens up the possibility of reconstructing sea ice history using sea salt recorded in ice cores. We use a chemical transport model to demonstrate that the sea ice source of aerosol is important in the Arctic. For the first time, we simulate realistic Greenland ice core sea salt in a process-based model. The importance of the sea ice source increases from south to north across the Greenland ice sheet.
Daniel Baggenstos, Thomas K. Bauska, Jeffrey P. Severinghaus, James E. Lee, Hinrich Schaefer, Christo Buizert, Edward J. Brook, Sarah Shackleton, and Vasilii V. Petrenko
Clim. Past, 13, 943–958, https://doi.org/10.5194/cp-13-943-2017, https://doi.org/10.5194/cp-13-943-2017, 2017
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We present measurements of the gas composition in trapped air bubbles in ice samples taken from Taylor Glacier, Antarctica. We can show that ice from the entire last glacial cycle (125 000 years ago to the present) is exposed at the surface of this glacier and that the atmospheric record contained in the air bubbles is well preserved. Taylor Glacier therefore provides an easily accessible archive of ancient ice that allows for studies of trace components that require large ice volumes.
Dennis L. Nielson, Chris Delahunty, John W. Goodge, and Jeffery P. Severinghaus
Sci. Dril., 22, 29–33, https://doi.org/10.5194/sd-22-29-2017, https://doi.org/10.5194/sd-22-29-2017, 2017
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The North American Testing (NAT) was designed to test critical functions of a Rapid Access Ice Drill (RAID) at a site in northern Utah. The RAID was designed to rapidly drill in Antarctica through over 2500 m of ice and then take a core sample of the bedrock. The system has many innovative features that required field testing before the system was shipped to Antarcitca. The NAT facility consisted of a borehole where we froze a column of ice to test drilling and fluid circulation functions.
Léa Gest, Frédéric Parrenin, Jai Chowdhry Beeman, Dominique Raynaud, Tyler J. Fudge, Christo Buizert, and Edward J. Brook
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-71, https://doi.org/10.5194/cp-2017-71, 2017
Revised manuscript has not been submitted
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In this manuscript, we place the atmospheric CO2 and Antarctic temperature records onto a common age scale during the last deglaciation. Moreover, we evaluate the phase relationship between those two records in order to discuss possible climatic and carbon cycle scenarios. Indeed, this phase relationship is central to determine the role of the former in past (and therefore future) climatic variations. This scientific problem was even discussed by some policy makers (e.g., in the USA senate).
Juliana D'Andrilli, Christine M. Foreman, Michael Sigl, John C. Priscu, and Joseph R. McConnell
Clim. Past, 13, 533–544, https://doi.org/10.5194/cp-13-533-2017, https://doi.org/10.5194/cp-13-533-2017, 2017
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Climate-driven trends in fluorescent organic matter (OM) markers from Antarctic ice cores revealed fluctuations over 21.0 kyr, reflecting environmental shifts as a result of global ecosystem response in a warming climate. Precursors of lignin-like fluorescent chemical species were detected as OM markers from the Last Glacial Maximum to the mid-Holocene. Holocene ice contained the most complex lignin-like fluorescent OM markers. Thus, ice cores contain paleoecological OM markers of Earth’s past.
Katrina M. Macdonald, Sangeeta Sharma, Desiree Toom, Alina Chivulescu, Sarah Hanna, Allan K. Bertram, Andrew Platt, Mike Elsasser, Lin Huang, David Tarasick, Nathan Chellman, Joseph R. McConnell, Heiko Bozem, Daniel Kunkel, Ying Duan Lei, Greg J. Evans, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 17, 5775–5788, https://doi.org/10.5194/acp-17-5775-2017, https://doi.org/10.5194/acp-17-5775-2017, 2017
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Rapid climate changes within the Arctic have highlighted existing uncertainties in the transport of contaminants to Arctic snow. Fresh snow samples collected frequently through the winter season were analyzed for major constituents creating a unique record of Arctic snow. Comparison with simultaneous atmospheric measurements provides insight into the driving processes in the transfer of contaminants from air to snow. The relative importance of deposition mechanisms over the season is proposed.
Mackenzie M. Grieman, Murat Aydin, Diedrich Fritzsche, Joseph R. McConnell, Thomas Opel, Michael Sigl, and Eric S. Saltzman
Clim. Past, 13, 395–410, https://doi.org/10.5194/cp-13-395-2017, https://doi.org/10.5194/cp-13-395-2017, 2017
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Wildfires impact ecosystems, climate, and atmospheric chemistry. Records that predate instrumental records and industrialization are needed to study the climatic controls on biomass burning. In this study, we analyzed organic chemicals produced from burning of plant matter that were preserved in an ice core from the Eurasian Arctic. These chemicals are elevated during three periods that have similar timing to climate variability. This is the first millennial-scale record of these chemicals.
Markella Prokopiou, Patricia Martinerie, Célia J. Sapart, Emmanuel Witrant, Guillaume Monteil, Kentaro Ishijima, Sophie Bernard, Jan Kaiser, Ingeborg Levin, Thomas Blunier, David Etheridge, Ed Dlugokencky, Roderik S. W. van de Wal, and Thomas Röckmann
Atmos. Chem. Phys., 17, 4539–4564, https://doi.org/10.5194/acp-17-4539-2017, https://doi.org/10.5194/acp-17-4539-2017, 2017
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Nitrous oxide is the third most important anthropogenic greenhouse gas with an increasing mole fraction. To understand its natural and anthropogenic sources
we employ isotope measurements. Results show that while the N2O mole fraction increases, its heavy isotope content decreases. The isotopic changes observed underline the dominance of agricultural emissions especially at the early part of the record, whereas in the later decades the contribution from other anthropogenic sources increases.
Tyler R. Jones, James W. C. White, Eric J. Steig, Bruce H. Vaughn, Valerie Morris, Vasileios Gkinis, Bradley R. Markle, and Spruce W. Schoenemann
Atmos. Meas. Tech., 10, 617–632, https://doi.org/10.5194/amt-10-617-2017, https://doi.org/10.5194/amt-10-617-2017, 2017
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New measurement systems have been developed that continuously melt ice core samples, in contrast to other methods that analyze a single sample at a time. These newer systems are capable of reducing analysis time by many years and improving data set resolution. In this study, we introduce improved methodologies that optimize the speed, accuracy, and precision of a water isotope continuous-flow system. The presented system will be used for Antarctic and Greenland ice core projects.
Olivia J. Maselli, Nathan J. Chellman, Mackenzie Grieman, Lawrence Layman, Joseph R. McConnell, Daniel Pasteris, Rachael H. Rhodes, Eric Saltzman, and Michael Sigl
Clim. Past, 13, 39–59, https://doi.org/10.5194/cp-13-39-2017, https://doi.org/10.5194/cp-13-39-2017, 2017
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We analysed two Greenland ice cores for methanesulfonate (MSA) and bromine (Br) and concluded that both species are suitable proxies for local sea ice conditions. Interpretation of the records reveals that there have been sharp declines in sea ice in these areas in the past 250 years. However, at both sites the Br record deviates from MSA during the industrial period, raising questions about the value of Br as a sea ice proxy during recent periods of high, industrial, atmospheric acid pollution.
Michel Legrand, Joseph McConnell, Hubertus Fischer, Eric W. Wolff, Susanne Preunkert, Monica Arienzo, Nathan Chellman, Daiana Leuenberger, Olivia Maselli, Philip Place, Michael Sigl, Simon Schüpbach, and Mike Flannigan
Clim. Past, 12, 2033–2059, https://doi.org/10.5194/cp-12-2033-2016, https://doi.org/10.5194/cp-12-2033-2016, 2016
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Here, we review previous attempts made to reconstruct past forest fire using chemical signals recorded in Greenland ice. We showed that the Greenland ice records of ammonium, found to be a good fire proxy, consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred since the last 15 000 years, including the Little Ice Age and the last large climatic transition.
Christo Buizert and Jeffrey P. Severinghaus
The Cryosphere, 10, 2099–2111, https://doi.org/10.5194/tc-10-2099-2016, https://doi.org/10.5194/tc-10-2099-2016, 2016
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The upper 50–100 m of the world's ice sheets consists of the firn layer, a porous layer of snow that is slowly compacted by overlying snow. Understanding air movement inside the firn is critical for ice core climate reconstructions. Buizert and Severinghaus identify and describe a new mechanism of firn air movement. High- and low-pressure systems force air movement in the firn that drives strong mixing, called dispersion. Dispersion is the main mechanism for air mixing in the deep firn.
Lora S. Koenig, Alvaro Ivanoff, Patrick M. Alexander, Joseph A. MacGregor, Xavier Fettweis, Ben Panzer, John D. Paden, Richard R. Forster, Indrani Das, Joesph R. McConnell, Marco Tedesco, Carl Leuschen, and Prasad Gogineni
The Cryosphere, 10, 1739–1752, https://doi.org/10.5194/tc-10-1739-2016, https://doi.org/10.5194/tc-10-1739-2016, 2016
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Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor surface mass balance in order to improve sea-level rise predictions. Here, we quantify the net annual accumulation over the Greenland Ice Sheet, which comprises the largest component of surface mass balance, at a higher spatial resolution than currently available using high-resolution, airborne-radar data.
Nathan J. Chellman, Meredith G. Hastings, and Joseph R. McConnell
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-163, https://doi.org/10.5194/tc-2016-163, 2016
Revised manuscript not accepted
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This manuscript analyzes the changing sources of nitrate deposition to Greenland since 1760 CE using a dataset consisting of sub-seasonally resolved nitrogen isotopes of nitrate and source tracers. Correlations amongst ion concentration, source tracers, and the δ15N–NO3− provide evidence of the impact of biomass burning and fossil fuel combustion emissions of nitrogen oxides and suggest that oil combustion is the likely driver of increased nitrate concentration in Greenland ice since 1940 CE.
Stef Vansteenberge, Sophie Verheyden, Hai Cheng, R. Lawrence Edwards, Eddy Keppens, and Philippe Claeys
Clim. Past, 12, 1445–1458, https://doi.org/10.5194/cp-12-1445-2016, https://doi.org/10.5194/cp-12-1445-2016, 2016
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The use of stalagmites for last interglacial continental climate reconstructions in Europe has been successful in the past; however to expand the geographical coverage, additional data from Belgium is presented. It has been shown that stalagmite growth, morphology and stable isotope content reflect regional and local climate conditions, with Eemian optimum climate occurring between 125.3 and 117.3 ka. The start the Weichselian is expressed by a stop of growth caused by a drying climate.
Rachael H. Rhodes, Xavier Faïn, Edward J. Brook, Joseph R. McConnell, Olivia J. Maselli, Michael Sigl, Jon Edwards, Christo Buizert, Thomas Blunier, Jérôme Chappellaz, and Johannes Freitag
Clim. Past, 12, 1061–1077, https://doi.org/10.5194/cp-12-1061-2016, https://doi.org/10.5194/cp-12-1061-2016, 2016
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Local artifacts in ice core methane data are superimposed on consistent records of past atmospheric variability. These artifacts are not related to past atmospheric history and care should be taken to avoid interpreting them as such. By investigating five polar ice cores from sites with different conditions, we relate isolated methane spikes to melt layers and decimetre-scale variations as "trapping signal" associated with a difference in timing of air bubble closure in adjacent firn layers.
Michael Sigl, Tyler J. Fudge, Mai Winstrup, Jihong Cole-Dai, David Ferris, Joseph R. McConnell, Ken C. Taylor, Kees C. Welten, Thomas E. Woodruff, Florian Adolphi, Marion Bisiaux, Edward J. Brook, Christo Buizert, Marc W. Caffee, Nelia W. Dunbar, Ross Edwards, Lei Geng, Nels Iverson, Bess Koffman, Lawrence Layman, Olivia J. Maselli, Kenneth McGwire, Raimund Muscheler, Kunihiko Nishiizumi, Daniel R. Pasteris, Rachael H. Rhodes, and Todd A. Sowers
Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, https://doi.org/10.5194/cp-12-769-2016, 2016
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Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide ice core, which is based on layer counting of distinctive annual cycles preserved in the elemental, chemical and electrical conductivity records. We validated the chronology by comparing it to independent high-accuracy, absolutely dated chronologies. Given its demonstrated high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere.
A. Spolaor, T. Opel, J. R. McConnell, O. J. Maselli, G. Spreen, C. Varin, T. Kirchgeorg, D. Fritzsche, A. Saiz-Lopez, and P. Vallelonga
The Cryosphere, 10, 245–256, https://doi.org/10.5194/tc-10-245-2016, https://doi.org/10.5194/tc-10-245-2016, 2016
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The role of sea ice in the Earth climate system is still under debate, although it is known to influence albedo, ocean circulation, and atmosphere-ocean heat and gas exchange. Here we present a reconstruction of 1950 to 1998 AD sea ice in the Laptev Sea based on the Akademii Nauk ice core (Severnaya Zemlya, Russian Arctic) and halogen measurements. The results suggest a connection between bromine and sea ice, as well as a connection between iodine concentration in snow and summer sea ice.
J. Ruan, F. Kherbouche, D. Genty, D. Blamart, H. Cheng, F. Dewilde, S. Hachi, R. L. Edwards, E. Régnier, and J.-L. Michelot
Clim. Past, 12, 1–14, https://doi.org/10.5194/cp-12-1-2016, https://doi.org/10.5194/cp-12-1-2016, 2016
P. Kuipers Munneke, S. R. M. Ligtenberg, B. P. Y. Noël, I. M. Howat, J. E. Box, E. Mosley-Thompson, J. R. McConnell, K. Steffen, J. T. Harper, S. B. Das, and M. R. van den Broeke
The Cryosphere, 9, 2009–2025, https://doi.org/10.5194/tc-9-2009-2015, https://doi.org/10.5194/tc-9-2009-2015, 2015
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The snow layer on top of the Greenland Ice Sheet is changing: it is thickening in the high and cold interior due to increased snowfall, while it is thinning around the margins. The marginal thinning is caused by compaction, and by more melt.
This knowledge is important: there are satellites that measure volume change of the ice sheet. It can be caused by increased ice discharge, or by compaction of the snow layer. Here, we quantify the latter, so that we can translate volume to mass change.
S. J. Burns, L. C. Kanner, H. Cheng, and R. Lawrence Edwards
Clim. Past, 11, 931–938, https://doi.org/10.5194/cp-11-931-2015, https://doi.org/10.5194/cp-11-931-2015, 2015
M. Van Rampelbergh, S. Verheyden, M. Allan, Y. Quinif, H. Cheng, L. R. Edwards, E. Keppens, and P. Claeys
Clim. Past, 11, 789–802, https://doi.org/10.5194/cp-11-789-2015, https://doi.org/10.5194/cp-11-789-2015, 2015
L. Geng, J. Cole-Dai, B. Alexander, J. Erbland, J. Savarino, A. J. Schauer, E. J. Steig, P. Lin, Q. Fu, and M. C. Zatko
Atmos. Chem. Phys., 14, 13361–13376, https://doi.org/10.5194/acp-14-13361-2014, https://doi.org/10.5194/acp-14-13361-2014, 2014
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Examinations on snowpit and firn core results from Summit, Greenland suggest that there are two mechanisms leading to the observed double nitrate peaks in some years in the industrial era: 1) long-rang transport of nitrate and 2) enhanced local photochemical production of nitrate. Both of these mechanisms are related to pollution transport, as the additional nitrate from either direct transport or enhanced local photochemistry requires enhanced nitrogen sources from anthropogenic emissions.
P. X. Wang, B. Wang, H. Cheng, J. Fasullo, Z. T. Guo, T. Kiefer, and Z. Y. Liu
Clim. Past, 10, 2007–2052, https://doi.org/10.5194/cp-10-2007-2014, https://doi.org/10.5194/cp-10-2007-2014, 2014
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All regional monsoons belong to a cohesive global monsoon circulation system, albeit thateach regional subsystem has its own indigenous features. A comprehensive review of global monsoon variability reveals that regional monsoons can vary coherently across a range of timescales, from interannual up to orbital and tectonic. Study of monsoon variability from both global and regional perspectives is imperative and advantageous for integrated understanding of the modern and paleo-monsoon dynamics.
J. Apaéstegui, F. W. Cruz, A. Sifeddine, M. Vuille, J. C. Espinoza, J. L. Guyot, M. Khodri, N. Strikis, R. V. Santos, H. Cheng, L. Edwards, E. Carvalho, and W. Santini
Clim. Past, 10, 1967–1981, https://doi.org/10.5194/cp-10-1967-2014, https://doi.org/10.5194/cp-10-1967-2014, 2014
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In this paper we explore a speleothem δ18O record from Palestina cave, northwestern Peru, on the eastern side of the Andes cordillera, in the upper Amazon Basin. The δ18O record is interpreted as a proxy for South American Summer Monsoon (SASM) intensity and allows the reconstruction of its variability during the last 1600 years. Replicating regional climate signals from different sites and using different proxies is essential for a comprehensive understanding of past changes in SASM activity.
T. K. Bauska, E. J. Brook, A. C. Mix, and A. Ross
Atmos. Meas. Tech., 7, 3825–3837, https://doi.org/10.5194/amt-7-3825-2014, https://doi.org/10.5194/amt-7-3825-2014, 2014
P. Zennaro, N. Kehrwald, J. R. McConnell, S. Schüpbach, O. J. Maselli, J. Marlon, P. Vallelonga, D. Leuenberger, R. Zangrando, A. Spolaor, M. Borrotti, E. Barbaro, A. Gambaro, and C. Barbante
Clim. Past, 10, 1905–1924, https://doi.org/10.5194/cp-10-1905-2014, https://doi.org/10.5194/cp-10-1905-2014, 2014
J.-J. Yin, D.-X. Yuan, H.-C. Li, H. Cheng, T.-Y. Li, R. L. Edwards, Y.-S. Lin, J.-M. Qin, W. Tang, Z.-Y. Zhao, and H.-S. Mii
Clim. Past, 10, 1803–1816, https://doi.org/10.5194/cp-10-1803-2014, https://doi.org/10.5194/cp-10-1803-2014, 2014
E. J. Steig, V. Gkinis, A. J. Schauer, S. W. Schoenemann, K. Samek, J. Hoffnagle, K. J. Dennis, and S. M. Tan
Atmos. Meas. Tech., 7, 2421–2435, https://doi.org/10.5194/amt-7-2421-2014, https://doi.org/10.5194/amt-7-2421-2014, 2014
B. Medley, I. Joughin, B. E. Smith, S. B. Das, E. J. Steig, H. Conway, S. Gogineni, C. Lewis, A. S. Criscitiello, J. R. McConnell, M. R. van den Broeke, J. T. M. Lenaerts, D. H. Bromwich, J. P. Nicolas, and C. Leuschen
The Cryosphere, 8, 1375–1392, https://doi.org/10.5194/tc-8-1375-2014, https://doi.org/10.5194/tc-8-1375-2014, 2014
P. Vallelonga, K. Christianson, R. B. Alley, S. Anandakrishnan, J. E. M. Christian, D. Dahl-Jensen, V. Gkinis, C. Holme, R. W. Jacobel, N. B. Karlsson, B. A. Keisling, S. Kipfstuhl, H. A. Kjær, M. E. L. Kristensen, A. Muto, L. E. Peters, T. Popp, K. L. Riverman, A. M. Svensson, C. Tibuleac, B. M. Vinther, Y. Weng, and M. Winstrup
The Cryosphere, 8, 1275–1287, https://doi.org/10.5194/tc-8-1275-2014, https://doi.org/10.5194/tc-8-1275-2014, 2014
C. Spötl and H. Cheng
Clim. Past, 10, 1349–1362, https://doi.org/10.5194/cp-10-1349-2014, https://doi.org/10.5194/cp-10-1349-2014, 2014
T. J. Fudge, E. D. Waddington, H. Conway, J. M. D. Lundin, and K. Taylor
Clim. Past, 10, 1195–1209, https://doi.org/10.5194/cp-10-1195-2014, https://doi.org/10.5194/cp-10-1195-2014, 2014
E. D. Sofen, B. Alexander, E. J. Steig, M. H. Thiemens, S. A. Kunasek, H. M. Amos, A. J. Schauer, M. G. Hastings, J. Bautista, T. L. Jackson, L. E. Vogel, J. R. McConnell, D. R. Pasteris, and E. S. Saltzman
Atmos. Chem. Phys., 14, 5749–5769, https://doi.org/10.5194/acp-14-5749-2014, https://doi.org/10.5194/acp-14-5749-2014, 2014
Y. Peng, C. Shen, H. Cheng, and Y. Xu
Clim. Past, 10, 1079–1091, https://doi.org/10.5194/cp-10-1079-2014, https://doi.org/10.5194/cp-10-1079-2014, 2014
G. D. Clow
Earth Syst. Sci. Data, 6, 201–218, https://doi.org/10.5194/essd-6-201-2014, https://doi.org/10.5194/essd-6-201-2014, 2014
X. Faïn, J. Chappellaz, R. H. Rhodes, C. Stowasser, T. Blunier, J. R. McConnell, E. J. Brook, S. Preunkert, M. Legrand, T. Debois, and D. Romanini
Clim. Past, 10, 987–1000, https://doi.org/10.5194/cp-10-987-2014, https://doi.org/10.5194/cp-10-987-2014, 2014
M. Berkelhammer, A. Sinha, M. Mudelsee, H. Cheng, K. Yoshimura, and J. Biswas
Clim. Past, 10, 733–744, https://doi.org/10.5194/cp-10-733-2014, https://doi.org/10.5194/cp-10-733-2014, 2014
H. C. Steen-Larsen, V. Masson-Delmotte, M. Hirabayashi, R. Winkler, K. Satow, F. Prié, N. Bayou, E. Brun, K. M. Cuffey, D. Dahl-Jensen, M. Dumont, M. Guillevic, S. Kipfstuhl, A. Landais, T. Popp, C. Risi, K. Steffen, B. Stenni, and A. E. Sveinbjörnsdottír
Clim. Past, 10, 377–392, https://doi.org/10.5194/cp-10-377-2014, https://doi.org/10.5194/cp-10-377-2014, 2014
S. O. Rasmussen, P. M. Abbott, T. Blunier, A. J. Bourne, E. Brook, S. L. Buchardt, C. Buizert, J. Chappellaz, H. B. Clausen, E. Cook, D. Dahl-Jensen, S. M. Davies, M. Guillevic, S. Kipfstuhl, T. Laepple, I. K. Seierstad, J. P. Severinghaus, J. P. Steffensen, C. Stowasser, A. Svensson, P. Vallelonga, B. M. Vinther, F. Wilhelms, and M. Winstrup
Clim. Past, 9, 2713–2730, https://doi.org/10.5194/cp-9-2713-2013, https://doi.org/10.5194/cp-9-2713-2013, 2013
K. Kawamura, J. P. Severinghaus, M. R. Albert, Z. R. Courville, M. A. Fahnestock, T. Scambos, E. Shields, and C. A. Shuman
Atmos. Chem. Phys., 13, 11141–11155, https://doi.org/10.5194/acp-13-11141-2013, https://doi.org/10.5194/acp-13-11141-2013, 2013
J. Chappellaz, C. Stowasser, T. Blunier, D. Baslev-Clausen, E. J. Brook, R. Dallmayr, X. Faïn, J. E. Lee, L. E. Mitchell, O. Pascual, D. Romanini, J. Rosen, and S. Schüpbach
Clim. Past, 9, 2579–2593, https://doi.org/10.5194/cp-9-2579-2013, https://doi.org/10.5194/cp-9-2579-2013, 2013
H. Fischer, J. Severinghaus, E. Brook, E. Wolff, M. Albert, O. Alemany, R. Arthern, C. Bentley, D. Blankenship, J. Chappellaz, T. Creyts, D. Dahl-Jensen, M. Dinn, M. Frezzotti, S. Fujita, H. Gallee, R. Hindmarsh, D. Hudspeth, G. Jugie, K. Kawamura, V. Lipenkov, H. Miller, R. Mulvaney, F. Parrenin, F. Pattyn, C. Ritz, J. Schwander, D. Steinhage, T. van Ommen, and F. Wilhelms
Clim. Past, 9, 2489–2505, https://doi.org/10.5194/cp-9-2489-2013, https://doi.org/10.5194/cp-9-2489-2013, 2013
J.-F. Lamarque, F. Dentener, J. McConnell, C.-U. Ro, M. Shaw, R. Vet, D. Bergmann, P. Cameron-Smith, S. Dalsoren, R. Doherty, G. Faluvegi, S. J. Ghan, B. Josse, Y. H. Lee, I. A. MacKenzie, D. Plummer, D. T. Shindell, R. B. Skeie, D. S. Stevenson, S. Strode, G. Zeng, M. Curran, D. Dahl-Jensen, S. Das, D. Fritzsche, and M. Nolan
Atmos. Chem. Phys., 13, 7997–8018, https://doi.org/10.5194/acp-13-7997-2013, https://doi.org/10.5194/acp-13-7997-2013, 2013
V. V. Petrenko, P. Martinerie, P. Novelli, D. M. Etheridge, I. Levin, Z. Wang, T. Blunier, J. Chappellaz, J. Kaiser, P. Lang, L. P. Steele, S. Hammer, J. Mak, R. L. Langenfelds, J. Schwander, J. P. Severinghaus, E. Witrant, G. Petron, M. O. Battle, G. Forster, W. T. Sturges, J.-F. Lamarque, K. Steffen, and J. W. C. White
Atmos. Chem. Phys., 13, 7567–7585, https://doi.org/10.5194/acp-13-7567-2013, https://doi.org/10.5194/acp-13-7567-2013, 2013
M. Luetscher, M. Borreguero, G. E. Moseley, C. Spötl, and R. L. Edwards
The Cryosphere, 7, 1073–1081, https://doi.org/10.5194/tc-7-1073-2013, https://doi.org/10.5194/tc-7-1073-2013, 2013
A. Svensson, M. Bigler, T. Blunier, H. B. Clausen, D. Dahl-Jensen, H. Fischer, S. Fujita, K. Goto-Azuma, S. J. Johnsen, K. Kawamura, S. Kipfstuhl, M. Kohno, F. Parrenin, T. Popp, S. O. Rasmussen, J. Schwander, I. Seierstad, M. Severi, J. P. Steffensen, R. Udisti, R. Uemura, P. Vallelonga, B. M. Vinther, A. Wegner, F. Wilhelms, and M. Winstrup
Clim. Past, 9, 749–766, https://doi.org/10.5194/cp-9-749-2013, https://doi.org/10.5194/cp-9-749-2013, 2013
Y. H. Lee, J.-F. Lamarque, M. G. Flanner, C. Jiao, D. T. Shindell, T. Berntsen, M. M. Bisiaux, J. Cao, W. J. Collins, M. Curran, R. Edwards, G. Faluvegi, S. Ghan, L. W. Horowitz, J. R. McConnell, J. Ming, G. Myhre, T. Nagashima, V. Naik, S. T. Rumbold, R. B. Skeie, K. Sudo, T. Takemura, F. Thevenon, B. Xu, and J.-H. Yoon
Atmos. Chem. Phys., 13, 2607–2634, https://doi.org/10.5194/acp-13-2607-2013, https://doi.org/10.5194/acp-13-2607-2013, 2013
K. M. Sterle, J. R. McConnell, J. Dozier, R. Edwards, and M. G. Flanner
The Cryosphere, 7, 365–374, https://doi.org/10.5194/tc-7-365-2013, https://doi.org/10.5194/tc-7-365-2013, 2013
Related subject area
Subject: Proxy Use-Development-Validation | Archive: Ice Cores | Timescale: Pleistocene
New estimates of sulfate diffusion rates in the EPICA Dome C ice core
Evaluating marine dust records as templates for optical dating of Oldest Ice
Total Air Content measurements from the RECAP ice core
Effective diffusivity of sulfuric acid in Antarctic ice cores
The WAIS Divide deep ice core WD2014 chronology – Part 2: Annual-layer counting (0–31 ka BP)
Comparing past accumulation rate reconstructions in East Antarctic ice cores using 10Be, water isotopes and CMIP5-PMIP3 models
On the gas-ice depth difference (Δdepth) along the EPICA Dome C ice core
Centennial mineral dust variability in high-resolution ice core data from Dome C, Antarctica
Rachael H. Rhodes, Yvan Bollet-Quivogne, Piers Barnes, Mirko Severi, and Eric W. Wolff
Clim. Past, 20, 2031–2043, https://doi.org/10.5194/cp-20-2031-2024, https://doi.org/10.5194/cp-20-2031-2024, 2024
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Some ionic components slowly move through glacier ice by diffusion, but the rate of this diffusion, its exact mechanism(s), and the factors that might influence it are poorly understood. In this study, we model how peaks in sulfate, deposited at Dome C on the Antarctic ice sheet after volcanic eruptions, change with depth and time. We find that the sulfate diffusion rate in ice is relatively fast in young ice near the surface, but the rate is markedly reduced over time.
Jessica Ng, Jeffrey Severinghaus, Ryan Bay, and Delia Tosi
Clim. Past, 20, 1437–1449, https://doi.org/10.5194/cp-20-1437-2024, https://doi.org/10.5194/cp-20-1437-2024, 2024
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The pattern of Earth’s ice age cycles shifted around a million years ago, becoming more extreme and longer in duration. Multiple projects are underway to obtain an Antarctic ice core that covers this time period, as ice cores contain important clues to why the transition happened. To make sure the ice is old enough at the bottom, we demonstrate how to use new technology to quickly measure dust patterns in the ice and compare them to dust in deep-ocean sediments whose ages are known.
Sindhu Vudayagiri, Bo Vinther, Johannes Freitag, Peter L. Langen, and Thomas Blunier
EGUsphere, https://doi.org/10.5194/egusphere-2024-237, https://doi.org/10.5194/egusphere-2024-237, 2024
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During the formation of ice from natural snowfall air is occluded in polar ice. The amount of air occluded (total air content) mainly reflects air pressure when the air is occluded and is therefore a proxy for elevation. However, there are several complications, such as melt, changes in firn structure and air pressure variability. We measured total air content in the RECAP ice core on the Renland Icecap in East Greenland. The core covers the period back to 121 thousand years before present.
Tyler J. Fudge, Raphael Sauvage, Linh Vu, Benjamin H. Hills, Mirko Severi, and Edwin D. Waddington
Clim. Past, 20, 297–312, https://doi.org/10.5194/cp-20-297-2024, https://doi.org/10.5194/cp-20-297-2024, 2024
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We use the oldest Antarctic ice core to estimate the rate of diffusion of sulfuric acid. Sulfuric acid is a marker of past volcanic activity and is critical in developing ice core timescales. The rate of diffusion is uncertain and is important to know, both for selecting future ice core locations and interpreting ice core records. We find the effective diffusivity of sulfate is 10 times smaller than previously estimated, indicating that the sulfuric acid signals will persist for longer.
Michael Sigl, Tyler J. Fudge, Mai Winstrup, Jihong Cole-Dai, David Ferris, Joseph R. McConnell, Ken C. Taylor, Kees C. Welten, Thomas E. Woodruff, Florian Adolphi, Marion Bisiaux, Edward J. Brook, Christo Buizert, Marc W. Caffee, Nelia W. Dunbar, Ross Edwards, Lei Geng, Nels Iverson, Bess Koffman, Lawrence Layman, Olivia J. Maselli, Kenneth McGwire, Raimund Muscheler, Kunihiko Nishiizumi, Daniel R. Pasteris, Rachael H. Rhodes, and Todd A. Sowers
Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, https://doi.org/10.5194/cp-12-769-2016, 2016
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Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide ice core, which is based on layer counting of distinctive annual cycles preserved in the elemental, chemical and electrical conductivity records. We validated the chronology by comparing it to independent high-accuracy, absolutely dated chronologies. Given its demonstrated high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere.
A. Cauquoin, A. Landais, G. M. Raisbeck, J. Jouzel, L. Bazin, M. Kageyama, J.-Y. Peterschmitt, M. Werner, E. Bard, and ASTER Team
Clim. Past, 11, 355–367, https://doi.org/10.5194/cp-11-355-2015, https://doi.org/10.5194/cp-11-355-2015, 2015
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We present a new 10Be record at EDC between 269 and 355ka. Our 10Be-based accumulation rate is in good agreement with the one associated with the EDC3 timescale except for the warm MIS 9.3 optimum. This suggests that temperature reconstruction from water isotopes may be underestimated by 2.4K for the difference between the MIS 9.3 and present day. The CMIP5-PMIP3 models do not quantitatively reproduce changes in precipitation vs. temperature increase during glacial–interglacial transitions.
F. Parrenin, S. Barker, T. Blunier, J. Chappellaz, J. Jouzel, A. Landais, V. Masson-Delmotte, J. Schwander, and D. Veres
Clim. Past, 8, 1239–1255, https://doi.org/10.5194/cp-8-1239-2012, https://doi.org/10.5194/cp-8-1239-2012, 2012
F. Lambert, M. Bigler, J. P. Steffensen, M. Hutterli, and H. Fischer
Clim. Past, 8, 609–623, https://doi.org/10.5194/cp-8-609-2012, https://doi.org/10.5194/cp-8-609-2012, 2012
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