Articles | Volume 12, issue 3
https://doi.org/10.5194/cp-12-769-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/cp-12-769-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
30 Mar 2016
Research article |
| 30 Mar 2016
The WAIS Divide deep ice core WD2014 chronology – Part 2: Annual-layer counting (0–31 ka BP)
Michael Sigl
CORRESPONDING AUTHOR
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Laboratory for Radiochemistry and Environmental Chemistry,
Paul Scherrer Institute, 5232 Villigen, Switzerland
Tyler J. Fudge
Department of Earth and Space Sciences, University of
Washington, Seattle, WA 98195, USA
Mai Winstrup
Department of Earth and Space Sciences, University of
Washington, Seattle, WA 98195, USA
now at: Centre for Ice and Climate, University of Copenhagen, Juliane
Maries Vej 30, 2100 Copenhagen, Denmark
Jihong Cole-Dai
Department of Chemistry and Biochemistry, South Dakota
State University, Brookings, SD 57007, USA
David Ferris
Dartmouth College Department of Earth Sciences, Hanover,
NH 03755, USA
Joseph R. McConnell
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Ken C. Taylor
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Kees C. Welten
Space Science Laboratory, University of California,
Berkeley, Berkeley, CA 94720, USA
Thomas E. Woodruff
Department of Physics and Astronomy, PRIME Laboratory,
Purdue University, West Lafayette, IN 47907, USA
Florian Adolphi
Department of Geology, Lund University, 223 62 Lund,
Sweden
Marion Bisiaux
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Edward J. Brook
College of Earth, Ocean, and Atmospheric Sciences, Oregon
State University, Corvallis, OR 97331, USA
Christo Buizert
College of Earth, Ocean, and Atmospheric Sciences, Oregon
State University, Corvallis, OR 97331, USA
Marc W. Caffee
Department of Physics and Astronomy, PRIME Laboratory,
Purdue University, West Lafayette, IN 47907, USA
Department of Earth, Atmospheric, and Planetary Sciences,
Purdue University, West Lafayette, IN 47907, USA
Nelia W. Dunbar
New Mexico Bureau of Geology & Mineral Resources Earth
and Environmental Science Department, New Mexico Tech, Socorro, NM 87801,
USA
Ross Edwards
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
now at: Department of Physics, Curtin University, Perth, Western
Australia 6845, Australia
Department of Chemistry and Biochemistry, South Dakota
State University, Brookings, SD 57007, USA
Dartmouth College Department of Earth Sciences, Hanover,
NH 03755, USA
Department of Atmospheric Sciences, University of
Washington, Seattle, WA 98195, USA
now at: Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), Université Grenoble Alpes, 3800 Grenoble, France
Nels Iverson
New Mexico Bureau of Geology & Mineral Resources Earth
and Environmental Science Department, New Mexico Tech, Socorro, NM 87801,
USA
Bess Koffman
Lamont-Doherty Earth Observatory, Columbia University,
Palisades, NY 10964, USA
Lawrence Layman
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Olivia J. Maselli
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Kenneth McGwire
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Raimund Muscheler
Department of Geology, Lund University, 223 62 Lund,
Sweden
Kunihiko Nishiizumi
Space Science Laboratory, University of California,
Berkeley, Berkeley, CA 94720, USA
Daniel R. Pasteris
Desert Research Institute, Nevada System of Higher
Education, Reno, NV 89512, USA
Rachael H. Rhodes
College of Earth, Ocean, and Atmospheric Sciences, Oregon
State University, Corvallis, OR 97331, USA
now at: Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, UK
Todd A. Sowers
Department of Geosciences and Earth and Environmental
Systems Institute, Pennsylvania State University, University Park, PA 16802,
USA
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Christopher Halsted, Paul Bierman, Alexandru Codilean, Lee Corbett, and Marc Caffee
Geochronology Discuss., https://doi.org/10.5194/gchron-2024-22, https://doi.org/10.5194/gchron-2024-22, 2024
Preprint under review for GChron
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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.
Peyton M. Cavnar, Paul R. Bierman, Jeremy D. Shakun, Lee B. Corbett, Danielle LeBlanc, Gillian L. Galford, and Marc Caffee
EGUsphere, https://doi.org/10.5194/egusphere-2024-2233, https://doi.org/10.5194/egusphere-2024-2233, 2024
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To investigate the Laurentide Ice Sheet’s erosivity before and during the Last Glacial Maximum, we sampled sand deposited by ice in eastern Canada before final deglaciation. We also sampled modern river sand. The 26Al and 10Be measured in glacial deposited sediments suggests that ice remained during some Pleistocene warm periods and was an inefficient eroder. Similar concentrations of 26Al and 10Be in modern sand suggests that most modern river sediment is sourced from glacial deposits.
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.
Bradley W. Goodfellow, Arjen P. Stroeven, Nathaniel A. Lifton, Jakob Heyman, Alexander Lewerentz, Kristina Hippe, Jens-Ove Näslund, and Marc W. Caffee
Geochronology, 6, 291–302, https://doi.org/10.5194/gchron-6-291-2024, https://doi.org/10.5194/gchron-6-291-2024, 2024
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Carbon-14 produced in quartz (half-life of 5700 ± 30 years) provides a new tool to date exposure of bedrock surfaces. Samples from 10 exposed bedrock surfaces in east-central Sweden give dates consistent with the timing of both landscape emergence above sea level through postglacial rebound and retreat of the last ice sheet shown in previous reconstructions. Carbon-14 in quartz can therefore be used for dating in landscapes where isotopes with longer half-lives give complex exposure results.
Xia Wang, Tao Che, Xueyin Ruan, Shanna Yue, Jing Wang, Chun Zhao, and Lei Geng
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2024-37, https://doi.org/10.5194/gmd-2024-37, 2024
Revised manuscript accepted for GMD
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We employed the WRF-Chem model to parameterize atmospheric nitrate deposition in snow and evaluated its performance in simulating snow cover, snow depth, and concentrations of black carbon (BC), dust, and nitrate using new observations from Northern China. The results generally exhibit reasonable agreement with field observations in northern China, demonstrating the model's capability to simulate snow properties, including concentrations of reservoir species.
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.
Zhuang Jiang, Becky Alexander, Joel Savarino, and Lei Geng
Atmos. Chem. Phys., 24, 4895–4914, https://doi.org/10.5194/acp-24-4895-2024, https://doi.org/10.5194/acp-24-4895-2024, 2024
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Ice-core nitrate could track the past atmospheric NOx and oxidant level, but its interpretation is hampered by the post-depositional processing. In this work, an inverse model was developed and tested against two polar sites and was shown to well reproduce the observed nitrate signals in snow and atmosphere, suggesting that the model can properly correct for the effect of post-depositional processing. This model offers a very useful tool for future studies on ice-core nitrate records.
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.
Andrew G. Jones, Shaun A. Marcott, Andrew L. Gorin, Tori M. Kennedy, Jeremy D. Shakun, Brent M. Goehring, Brian Menounos, Douglas H. Clark, Matias Romero, and Marc W. Caffee
The Cryosphere, 17, 5459–5475, https://doi.org/10.5194/tc-17-5459-2023, https://doi.org/10.5194/tc-17-5459-2023, 2023
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Mountain glaciers today are fractions of their sizes 140 years ago, but how do these sizes compare to the past 11,000 years? We find that four glaciers in the United States and Canada have reversed a long-term trend of growth and retreated to positions last occupied thousands of years ago. Notably, each glacier occupies a unique position relative to its long-term history. We hypothesize that unequal modern retreat has caused the glaciers to be out of sync relative to their Holocene histories.
Minjie Zheng, Hongyu Liu, Florian Adolphi, Raimund Muscheler, Zhengyao Lu, Mousong Wu, and Nønne L. Prisle
Geosci. Model Dev., 16, 7037–7057, https://doi.org/10.5194/gmd-16-7037-2023, https://doi.org/10.5194/gmd-16-7037-2023, 2023
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The radionuclides 7Be and 10Be are useful tracers for atmospheric transport studies. Here we use the GEOS-Chem to simulate 7Be and 10Be with different production rates: the default production rate in GEOS-Chem and two from the state-of-the-art beryllium production model. We demonstrate that reduced uncertainties in the production rates can enhance the utility of 7Be and 10Be as tracers for evaluating transport and scavenging processes in global models.
Eric W. Portenga, David J. Ullman, Lee B. Corbett, Paul R. Bierman, and Marc W. Caffee
Geochronology, 5, 413–431, https://doi.org/10.5194/gchron-5-413-2023, https://doi.org/10.5194/gchron-5-413-2023, 2023
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New exposure ages of glacial erratics on moraines on Isle Royale – the largest island in North America's Lake Superior – show that the Laurentide Ice Sheet did not retreat from the island nor the south shores of Lake Superior until the early Holocene, which is later than previously thought. These new ages unify regional ice retreat histories from the mainland, the Lake Superior lake-bottom stratigraphy, underwater moraines, and meltwater drainage pathways through the Laurentian Great Lakes.
Chiara I. Paleari, Florian Mekhaldi, Tobias Erhardt, Minjie Zheng, Marcus Christl, Florian Adolphi, Maria Hörhold, and Raimund Muscheler
Clim. Past, 19, 2409–2422, https://doi.org/10.5194/cp-19-2409-2023, https://doi.org/10.5194/cp-19-2409-2023, 2023
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In this study, we test the use of excess meltwater from continuous flow analysis from a firn core from Greenland for the measurement of 10Be for solar activity reconstructions. We show that the quality of results is similar to the measurements on clean firn, which opens the possibility to obtain continuous 10Be records without requiring large amounts of clean ice. Furthermore, we investigate the possibility of identifying solar storm signals in 10Be records from Greenland and Antarctica.
Tobias Erhardt, Camilla Marie Jensen, Florian Adolphi, Helle Astrid Kjær, Remi Dallmayr, Birthe Twarloh, Melanie Behrens, Motohiro Hirabayashi, Kaori Fukuda, Jun Ogata, François Burgay, Federico Scoto, Ilaria Crotti, Azzurra Spagnesi, Niccoló Maffezzoli, Delia Segato, Chiara Paleari, Florian Mekhaldi, Raimund Muscheler, Sophie Darfeuil, and Hubertus Fischer
Earth Syst. Sci. Data, 15, 5079–5091, https://doi.org/10.5194/essd-15-5079-2023, https://doi.org/10.5194/essd-15-5079-2023, 2023
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The presented paper provides a 3.8 kyr long dataset of aerosol concentrations from the East Greenland Ice coring Project (EGRIP) ice core. The data consists of 1 mm depth-resolution profiles of calcium, sodium, ammonium, nitrate, and electrolytic conductivity as well as decadal averages of these profiles. Alongside the data a detailed description of the measurement setup as well as a discussion of the uncertainties are given.
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.
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.
Giulia Sinnl, Florian Adolphi, Marcus Christl, Kees C. Welten, Thomas Woodruff, Marc Caffee, Anders Svensson, Raimund Muscheler, and Sune Olander Rasmussen
Clim. Past, 19, 1153–1175, https://doi.org/10.5194/cp-19-1153-2023, https://doi.org/10.5194/cp-19-1153-2023, 2023
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The record of past climate is preserved by several archives from different regions, such as ice cores from Greenland or Antarctica or speleothems from caves such as the Hulu Cave in China. In this study, these archives are aligned by taking advantage of the globally synchronous production of cosmogenic radionuclides. This produces a new perspective on the global climate in the period between 20 000 and 25 000 years ago.
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.
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.
Aaron Chesler, Dominic Winski, Karl Kreutz, Bess Koffman, Erich Osterberg, David Ferris, Zayta Thundercloud, Joseph Mohan, Jihong Cole-Dai, Mark Wells, Michael Handley, Aaron Putnam, Katherine Anderson, and Natalie Harmon
Clim. Past, 19, 477–492, https://doi.org/10.5194/cp-19-477-2023, https://doi.org/10.5194/cp-19-477-2023, 2023
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Ice core microparticle data typically use geometry assumptions to calculate particle mass and flux. We use dynamic particle imaging, a novel technique for ice core dust analyses, combined with traditional laser particle counting and Coulter counter techniques to assess particle shape in the South Pole Ice Core (SPC14) spanning 50–16 ka. Our results suggest that particles are dominantly ellipsoidal in shape and that spherical assumptions overestimate particle mass and flux.
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.
Aaron M. Barth, Elizabeth G. Ceperley, Claire Vavrus, Shaun A. Marcott, Jeremy D. Shakun, and Marc W. Caffee
Geochronology, 4, 731–743, https://doi.org/10.5194/gchron-4-731-2022, https://doi.org/10.5194/gchron-4-731-2022, 2022
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Deposits left behind by past glacial activity provide insight into the previous size and behavior of glaciers and act as another line of evidence for past climate. Here we present new age control for glacial deposits in the mountains of Montana and Wyoming, United States. While some deposits indicate glacial activity within the last 2000 years, others are shown to be older than previously thought, thus redefining the extent of regional Holocene glaciation.
Adrian M. Bender, Richard O. Lease, Lee B. Corbett, Paul R. Bierman, Marc W. Caffee, James V. Jones, and Doug Kreiner
Earth Surf. Dynam., 10, 1041–1053, https://doi.org/10.5194/esurf-10-1041-2022, https://doi.org/10.5194/esurf-10-1041-2022, 2022
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To understand landscape evolution in the mineral resource-rich Yukon River basin (Alaska and Canada), we mapped and cosmogenic isotope-dated river terraces along the Charley River. Results imply widespread Yukon River incision that drove increased Bering Sea sedimentation and carbon sequestration during global climate changes 2.6 and 1 million years ago. Such erosion may have fed back to late Cenozoic climate change by reducing atmospheric carbon as observed in many records worldwide.
Yanzhi Cao, Zhuang Jiang, Becky Alexander, Jihong Cole-Dai, Joel Savarino, Joseph Erbland, and Lei Geng
Atmos. Chem. Phys., 22, 13407–13422, https://doi.org/10.5194/acp-22-13407-2022, https://doi.org/10.5194/acp-22-13407-2022, 2022
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We investigate the potential of ice-core preserved nitrate isotopes as proxies of stratospheric ozone variability by measuring nitrate isotopes in a shallow ice core from the South Pole. The large variability in the snow accumulation rate and its slight increase after the 1970s masked any signals caused by the ozone hole. Moreover, the nitrate oxygen isotope decrease may reflect changes in the atmospheric oxidation environment in the Southern Ocean.
Xueyin Ruan, Chun Zhao, Rahul A. Zaveri, Pengzhen He, Xinming Wang, Jingyuan Shao, and Lei Geng
Geosci. Model Dev., 15, 6143–6164, https://doi.org/10.5194/gmd-15-6143-2022, https://doi.org/10.5194/gmd-15-6143-2022, 2022
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Accurate prediction of aerosol pH in chemical transport models is essential to aerosol modeling. This study examines the performance of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) on aerosol pH predictions and the sensitivities to emissions of nonvolatile cations and NH3, aerosol-phase state assumption, and heterogeneous sulfate production. Temporal evolution of aerosol pH during haze cycles in Beijing and the driving factors are also presented and discussed.
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.
Zhuang Jiang, Joel Savarino, Becky Alexander, Joseph Erbland, Jean-Luc Jaffrezo, and Lei Geng
The Cryosphere, 16, 2709–2724, https://doi.org/10.5194/tc-16-2709-2022, https://doi.org/10.5194/tc-16-2709-2022, 2022
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A record of year-round atmospheric nitrate isotopic composition along with snow nitrate isotopic data from Summit, Greenland, revealed apparent enrichments in nitrogen isotopes in snow nitrate compared to atmospheric nitrate, in addition to a relatively smaller degree of changes in oxygen isotopes. The results suggest that at this site post-depositional processing takes effect, which should be taken into account when interpreting ice-core nitrate isotope records.
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.
Mae Kate Campbell, Paul R. Bierman, Amanda H. Schmidt, Rita Sibello Hernández, Alejandro García-Moya, Lee B. Corbett, Alan J. Hidy, Héctor Cartas Águila, Aniel Guillén Arruebarrena, Greg Balco, David Dethier, and Marc Caffee
Geochronology, 4, 435–453, https://doi.org/10.5194/gchron-4-435-2022, https://doi.org/10.5194/gchron-4-435-2022, 2022
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We used cosmogenic radionuclides in detrital river sediment to measure erosion rates of watersheds in central Cuba; erosion rates are lower than rock dissolution rates in lowland watersheds. Data from two different cosmogenic nuclides suggest that some basins may have a mixed layer deeper than is typically modeled and could have experienced significant burial after or during exposure. We conclude that significant mass loss may occur at depth through chemical weathering processes.
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.
Brendon J. Quirk, Elizabeth Huss, Benjamin J. C. Laabs, Eric Leonard, Joseph Licciardi, Mitchell A. Plummer, and Marc W. Caffee
Clim. Past, 18, 293–312, https://doi.org/10.5194/cp-18-293-2022, https://doi.org/10.5194/cp-18-293-2022, 2022
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Glaciers in the northern Rocky Mountains began retreating 17 000 to 18 000 years ago, after the end of the most recent global ice volume maxima. Climate in the region during this time was likely 10 to 8.5° colder than modern with less than or equal to present amounts of precipitation. Glaciers across the Rockies began retreating at different times but eventually exhibited similar patterns of retreat, suggesting a common mechanism influencing deglaciation.
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.
Jamey Stutz, Andrew Mackintosh, Kevin Norton, Ross Whitmore, Carlo Baroni, Stewart S. R. Jamieson, Richard S. Jones, Greg Balco, Maria Cristina Salvatore, Stefano Casale, Jae Il Lee, Yeong Bae Seong, Robert McKay, Lauren J. Vargo, Daniel Lowry, Perry Spector, Marcus Christl, Susan Ivy Ochs, Luigia Di Nicola, Maria Iarossi, Finlay Stuart, and Tom Woodruff
The Cryosphere, 15, 5447–5471, https://doi.org/10.5194/tc-15-5447-2021, https://doi.org/10.5194/tc-15-5447-2021, 2021
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Understanding the long-term behaviour of ice sheets is essential to projecting future changes due to climate change. In this study, we use rocks deposited along the margin of the David Glacier, one of the largest glacier systems in the world, to reveal a rapid thinning event initiated over 7000 years ago and endured for ~ 2000 years. Using physical models, we show that subglacial topography and ocean heat are important drivers for change along this sector of the Antarctic Ice Sheet.
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.
Zhuang Jiang, Becky Alexander, Joel Savarino, Joseph Erbland, and Lei Geng
The Cryosphere, 15, 4207–4220, https://doi.org/10.5194/tc-15-4207-2021, https://doi.org/10.5194/tc-15-4207-2021, 2021
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We used a snow photochemistry model (TRANSITS) to simulate the seasonal nitrate snow profile at Summit, Greenland. Comparisons between model outputs and observations suggest that at Summit post-depositional processing is active and probably dominates the snowpack δ15N seasonality. We also used the model to assess the degree of snow nitrate loss and the consequences in its isotopes at present and in the past, which helps for quantitative interpretations of ice-core nitrate records.
Nathalie Van der Putten, Florian Adolphi, Anette Mellström, Jesper Sjolte, Cyriel Verbruggen, Jan-Berend Stuut, Tobias Erhardt, Yves Frenot, and Raimund Muscheler
Clim. Past Discuss., https://doi.org/10.5194/cp-2021-69, https://doi.org/10.5194/cp-2021-69, 2021
Manuscript not accepted for further review
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In recent decades, Southern Hemisphere westerlies (SHW) moved equator-ward during periods of low solar activity leading to increased winds/precipitation at 46° S, Indian Ocean. We present a terrestrial SHW proxy-record and find stronger SHW influence at Crozet, shortly after 2.8 ka BP, synchronous with a climate shift in the Northern Hemisphere, attributed to a major decline in solar activity. The bipolar response to solar forcing is supported by a climate model forced by solar irradiance only.
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.
Nicolás E. Young, Alia J. Lesnek, Josh K. Cuzzone, Jason P. Briner, Jessica A. Badgeley, Alexandra Balter-Kennedy, Brandon L. Graham, Allison Cluett, Jennifer L. Lamp, Roseanne Schwartz, Thibaut Tuna, Edouard Bard, Marc W. Caffee, Susan R. H. Zimmerman, and Joerg M. Schaefer
Clim. Past, 17, 419–450, https://doi.org/10.5194/cp-17-419-2021, https://doi.org/10.5194/cp-17-419-2021, 2021
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Retreat of the Greenland Ice Sheet (GrIS) margin is exposing a bedrock landscape that holds clues regarding the timing and extent of past ice-sheet minima. We present cosmogenic nuclide measurements from recently deglaciated bedrock surfaces (the last few decades), combined with a refined chronology of southwestern Greenland deglaciation and model simulations of GrIS change. Results suggest that inland retreat of the southwestern GrIS margin was likely minimal in the middle to late Holocene.
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.
Helle Astrid Kjær, Patrick Zens, Ross Edwards, Martin Olesen, Ruth Mottram, Gabriel Lewis, Christian Terkelsen Holme, Samuel Black, Kasper Holst Lund, Mikkel Schmidt, Dorthe Dahl-Jensen, Bo Vinther, Anders Svensson, Nanna Karlsson, Jason E. Box, Sepp Kipfstuhl, and Paul Vallelonga
The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-337, https://doi.org/10.5194/tc-2020-337, 2021
Manuscript not accepted for further review
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We have reconstructed accumulation in 6 firn cores and 8 snow cores in Northern Greenland and compared with a regional Climate model over Greenland. We find the model underestimate precipitation especially in north-eastern part of the ice cap- an important finding if aiming to reconstruct surface mass balance.
Temperatures at 10 meters depth at 6 sites in Greenland were also determined and show a significant warming since the 1990's of 0.9 to 2.5 °C.
Michael Sarnthein, Kevin Küssner, Pieter M. Grootes, Blanca Ausin, Timothy Eglinton, Juan Muglia, Raimund Muscheler, and Gordon Schlolaut
Clim. Past, 16, 2547–2571, https://doi.org/10.5194/cp-16-2547-2020, https://doi.org/10.5194/cp-16-2547-2020, 2020
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The dating technique of 14C plateau tuning uses U/Th-based model ages, refinements of the Lake Suigetsu age scale, and the link of surface ocean carbon to the globally mixed atmosphere as basis of age correlation. Our synthesis employs data of 20 sediment cores from the global ocean and offers a coherent picture of global ocean circulation evolving over glacial-to-deglacial times on semi-millennial scales to be compared with climate records stored in marine sediments, ice cores, and speleothems.
Leonie Peti, Kathryn E. Fitzsimmons, Jenni L. Hopkins, Andreas Nilsson, Toshiyuki Fujioka, David Fink, Charles Mifsud, Marcus Christl, Raimund Muscheler, and Paul C. Augustinus
Geochronology, 2, 367–410, https://doi.org/10.5194/gchron-2-367-2020, https://doi.org/10.5194/gchron-2-367-2020, 2020
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Orakei Basin – a former maar lake in Auckland, New Zealand – provides an outstanding sediment record over the last ca. 130 000 years, but an age model is required to allow the reconstruction of climate change and volcanic eruptions contained in the sequence. To construct a relationship between depth in the sediment core and age of deposition, we combined tephrochronology, radiocarbon dating, luminescence dating, and the relative intensity of the paleomagnetic field in a Bayesian age–depth model.
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.
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.
Jesper Sjolte, Florian Adolphi, Bo M. Vinther, Raimund Muscheler, Christophe Sturm, Martin Werner, and Gerrit Lohmann
Clim. Past, 16, 1737–1758, https://doi.org/10.5194/cp-16-1737-2020, https://doi.org/10.5194/cp-16-1737-2020, 2020
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In this study we investigate seasonal climate reconstructions produced by matching climate model output to ice core and tree-ring data, and we evaluate the model–data reconstructions against meteorological observations. The reconstructions capture the main patterns of variability in sea level pressure and temperature in summer and winter. The performance of the reconstructions depends on seasonal climate variability itself, and definitions of seasons can be optimized to capture this variability.
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.
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
Ashley Dinauer, Florian Adolphi, and Fortunat Joos
Clim. Past, 16, 1159–1185, https://doi.org/10.5194/cp-16-1159-2020, https://doi.org/10.5194/cp-16-1159-2020, 2020
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Despite intense focus on the ~ 190 ‰ drop in Δ14C across the deglacial
mystery interval, the specific mechanisms responsible for the apparent Δ14C excess in the glacial atmosphere have received considerably less attention. Sensitivity experiments with the computationally efficient Bern3D Earth system model suggest that our inability to reproduce the elevated Δ14C levels during the last glacial may reflect an underestimation of 14C production and/or a biased-high reconstruction of Δ14C.
Florian Mekhaldi, Markus Czymzik, Florian Adolphi, Jesper Sjolte, Svante Björck, Ala Aldahan, Achim Brauer, Celia Martin-Puertas, Göran Possnert, and Raimund Muscheler
Clim. Past, 16, 1145–1157, https://doi.org/10.5194/cp-16-1145-2020, https://doi.org/10.5194/cp-16-1145-2020, 2020
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Due to chronology uncertainties within paleoclimate archives, it is unclear how climate oscillations from different records relate to one another. By using radionuclides to synchronize Greenland ice cores and a German lake record over 11 000 years, we show that two oscillations observed in these records were not synchronous but terminated and began with the onset of a grand solar minimum. Both this and changes in ocean circulation could have played a role in the two climate oscillations.
Kévin Fourteau, Laurent Arnaud, Xavier Faïn, Patricia Martinerie, David M. Etheridge, Vladimir Lipenkov, and Jean-Marc Barnola
Earth Syst. Sci. Data, 12, 1171–1177, https://doi.org/10.5194/essd-12-1171-2020, https://doi.org/10.5194/essd-12-1171-2020, 2020
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Measurements of the porosity of three polar firns were conducted in the 1990s by Jean-Marc Barnola using the method of gas pycnometry. From these data, a parametrization of firn pore closure was produced and used in different published articles. However, the data have not been published in their own right yet. We have made the data publicly accessible on the PANGAEA database and here propose describing how they were obtained and used to produce the pore closure parametrization.
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.
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Alexey A. Ekaykin, Jérôme Chappellaz, and Vladimir Lipenkov
Clim. Past, 16, 503–522, https://doi.org/10.5194/cp-16-503-2020, https://doi.org/10.5194/cp-16-503-2020, 2020
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We quantify how the greenhouse gas records of East Antarctic ice cores (which are the oldest ice cores) might differ from the actual atmosphere history. It is required to properly interpret ice core data. For this, we measured the methane of five new East Antarctic ice core sections using a high-resolution technique. We found that in these very old ice cores, one can retrieve concentration variations occurring in only a few centuries, allowing climatologists to study climate's fast dynamics.
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
Niccolò Maffezzoli, Paul Vallelonga, Ross Edwards, Alfonso Saiz-Lopez, Clara Turetta, Helle Astrid Kjær, Carlo Barbante, Bo Vinther, and Andrea Spolaor
Clim. Past, 15, 2031–2051, https://doi.org/10.5194/cp-15-2031-2019, https://doi.org/10.5194/cp-15-2031-2019, 2019
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This study provides the first ice-core-based history of sea ice in the North Atlantic Ocean, reaching 120 000 years back in time. This record was obtained from bromine and sodium measurements in the RECAP ice core, drilled in east Greenland. We found that, during the last deglaciation, sea ice started to melt ~ 17 500 years ago. Over the 120 000 years of the last glacial cycle, sea ice extent was maximal during MIS2, while minimum sea ice extent exists for the Holocene.
Juan Pablo Corella, Niccolo Maffezzoli, Carlos Alberto Cuevas, Paul Vallelonga, Andrea Spolaor, Giulio Cozzi, Juliane Müller, Bo Vinther, Carlo Barbante, Helle Astrid Kjær, Ross Edwards, and Alfonso Saiz-Lopez
Clim. Past, 15, 2019–2030, https://doi.org/10.5194/cp-15-2019-2019, https://doi.org/10.5194/cp-15-2019-2019, 2019
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This study provides the first reconstruction of atmospheric iodine levels in the Arctic during the last 11 700 years from an ice core record in coastal Greenland. Dramatic shifts in iodine level variability coincide with abrupt climatic transitions in the North Atlantic. Since atmospheric iodine levels have significant environmental and climatic implications, this study may serve as a past analog to predict future changes in Arctic climate in response to global warming.
Kévin Fourteau, Patricia Martinerie, Xavier Faïn, Christoph F. Schaller, Rebecca J. Tuckwell, Henning Löwe, Laurent Arnaud, Olivier Magand, Elizabeth R. Thomas, Johannes Freitag, Robert Mulvaney, Martin Schneebeli, and Vladimir Ya. Lipenkov
The Cryosphere, 13, 3383–3403, https://doi.org/10.5194/tc-13-3383-2019, https://doi.org/10.5194/tc-13-3383-2019, 2019
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Understanding gas trapping in polar ice is essential to study the relationship between greenhouse gases and past climates. New data of bubble closure, used in a simple gas-trapping model, show inconsistency with the final air content in ice. This suggests gas trapping is not fully understood. We also use a combination of high-resolution measurements to investigate the effect of polar snow stratification on gas trapping and find that all strata have similar pores, but that some close in advance.
Svante Björck, Jesper Sjolte, Karl Ljung, Florian Adolphi, Roger Flower, Rienk H. Smittenberg, Malin E. Kylander, Thomas F. Stocker, Sofia Holmgren, Hui Jiang, Raimund Muscheler, Yamoah K. K. Afrifa, Jayne E. Rattray, and Nathalie Van der Putten
Clim. Past, 15, 1939–1958, https://doi.org/10.5194/cp-15-1939-2019, https://doi.org/10.5194/cp-15-1939-2019, 2019
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Southern Hemisphere westerlies play a key role in regulating global climate. A lake sediment record on a mid-South Atlantic island shows changes in the westerlies and hydroclimate 36.4–18.6 ka. Before 31 ka the westerlies shifted in concert with the bipolar seesaw mechanism in a fairly warm climate, followed by southerly westerlies and falling temperatures. After 27.5 ka temperatures dropped 3 °C with drier conditions and with shifting westerlies possibly triggering the variable LGM CO2 levels.
Gabriel Lewis, Erich Osterberg, Robert Hawley, Hans Peter Marshall, Tate Meehan, Karina Graeter, Forrest McCarthy, Thomas Overly, Zayta Thundercloud, and David Ferris
The Cryosphere, 13, 2797–2815, https://doi.org/10.5194/tc-13-2797-2019, https://doi.org/10.5194/tc-13-2797-2019, 2019
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We present accumulation records from sixteen 22–32 m long firn cores and 4436 km of ground-penetrating radar, covering the past 20–60 years of accumulation, collected across the western Greenland Ice Sheet percolation zone. Trends from both radar and firn cores, as well as commonly used regional climate models, show decreasing accumulation over the 1996–2016 period.
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.
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.
Tobias Erhardt, Emilie Capron, Sune Olander Rasmussen, Simon Schüpbach, Matthias Bigler, Florian Adolphi, and Hubertus Fischer
Clim. Past, 15, 811–825, https://doi.org/10.5194/cp-15-811-2019, https://doi.org/10.5194/cp-15-811-2019, 2019
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The cause of the rapid warming events documented in proxy records across the Northern Hemisphere during the last glacial has been a long-standing puzzle in paleo-climate research. Here, we use high-resolution ice-core data from to cores in Greenland to investigate the progression during the onset of these events on multi-annual timescales to test their plausible triggers. We show that atmospheric circulation changes preceded the warming in Greenland and the collapse of the sea ice by a decade.
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.
Dimitri Osmont, Michael Sigl, Anja Eichler, Theo M. Jenk, and Margit Schwikowski
Clim. Past, 15, 579–592, https://doi.org/10.5194/cp-15-579-2019, https://doi.org/10.5194/cp-15-579-2019, 2019
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We present the first black carbon (BC) ice-core record from the Andes (Illimani, Bolivia). It spans the entire Holocene and reflects biomass burning emissions from the Amazon Basin, with high (low) concentrations during warm–dry (wet–cold) periods. The highest fire activity occurred during the Holocene Climatic Optimum (7000–3000 BCE). Recent BC levels, increasing since 1730 CE, do not exceed those of the Medieval Warm Period. The contribution from industrial and traffic emissions remains minor.
Florian Adolphi, Christopher Bronk Ramsey, Tobias Erhardt, R. Lawrence Edwards, Hai Cheng, Chris S. M. Turney, Alan Cooper, Anders Svensson, Sune O. Rasmussen, Hubertus Fischer, and Raimund Muscheler
Clim. Past, 14, 1755–1781, https://doi.org/10.5194/cp-14-1755-2018, https://doi.org/10.5194/cp-14-1755-2018, 2018
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The last glacial period was characterized by a number of rapid climate changes seen, for example, as abrupt warmings in Greenland and changes in monsoon rainfall intensity. However, due to chronological uncertainties it is challenging to know how tightly coupled these changes were. Here we exploit cosmogenic signals caused by changes in the Sun and Earth magnetic fields to link different climate archives and improve our understanding of the dynamics of abrupt climate change.
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.
Michael Sigl, Nerilie J. Abram, Jacopo Gabrieli, Theo M. Jenk, Dimitri Osmont, and Margit Schwikowski
The Cryosphere, 12, 3311–3331, https://doi.org/10.5194/tc-12-3311-2018, https://doi.org/10.5194/tc-12-3311-2018, 2018
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The fast retreat of Alpine glaciers since the mid-19th century documented in photographs is used as a symbol for the human impact on global climate, yet the key driving forces remain elusive. Here we argue that not industrial soot but volcanic eruptions were responsible for an apparently accelerated deglaciation starting in the 1850s. Our findings support a negligible role of human activity in forcing glacier recession at the end of the Little Ice Age, highlighting the role of natural drivers.
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.
Dimitri Osmont, Isabel A. Wendl, Loïc Schmidely, Michael Sigl, Carmen P. Vega, Elisabeth Isaksson, and Margit Schwikowski
Atmos. Chem. Phys., 18, 12777–12795, https://doi.org/10.5194/acp-18-12777-2018, https://doi.org/10.5194/acp-18-12777-2018, 2018
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This study presents the first long-term and high-resolution refractory black carbon (rBC) ice core record from Svalbard, spanning the last 800 years. Our results show that rBC has had a predominant anthropogenic origin since the beginning of the Industrial Revolution in Europe and that rBC concentrations have been declining in the last 40 years. We discuss the impact of 20th century snowmelt on our record. We reconstruct biomass burning trends prior to 1800 by using a multi-proxy approach.
Christian M. Zdanowicz, Bernadette C. Proemse, Ross Edwards, Wang Feiteng, Chad M. Hogan, Christophe Kinnard, and David Fisher
Atmos. Chem. Phys., 18, 12345–12361, https://doi.org/10.5194/acp-18-12345-2018, https://doi.org/10.5194/acp-18-12345-2018, 2018
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Black carbon (BC) particles emitted by natural and anthropogenic sources (e.g., wildfires, coal burning) can amplify climate warming by increasing sunlight energy absorption on snow-covered surfaces. This paper presents a new ice-core record of historical (1810–1990) BC deposition in the Canadian Arctic. The Devon ice cap record differs from Greenland ice cores, implying large variations in BC deposition across the Arctic that must be accounted for to better quantity their future climate impact.
Jesper Sjolte, Christophe Sturm, Florian Adolphi, Bo M. Vinther, Martin Werner, Gerrit Lohmann, and Raimund Muscheler
Clim. Past, 14, 1179–1194, https://doi.org/10.5194/cp-14-1179-2018, https://doi.org/10.5194/cp-14-1179-2018, 2018
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Tropical volcanic eruptions and variations in solar activity have been suggested to influence the strength of westerly winds across the North Atlantic. We use Greenland ice core records together with a climate model simulation, and find stronger westerly winds for five winters following tropical volcanic eruptions. We see a delayed response to solar activity of 5 years, and the response to solar minima corresponds well to the cooling pattern during the period known as the Little Ice Age.
Minjie Zheng, Jesper Sjolte, Florian Adolphi, Bo Møllesøe Vinther, Hans Christian Steen-Larsen, Trevor James Popp, and Raimund Muscheler
Clim. Past, 14, 1067–1078, https://doi.org/10.5194/cp-14-1067-2018, https://doi.org/10.5194/cp-14-1067-2018, 2018
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We show the seasonal δ18O data from the NEEM site in northwestern Greenland over the last 150 years. We found that the NEEM summer δ18O signal correlates well with summer temperature in western coastal Greenland, while the NEEM winter δ18O signal correlates well with sea ice concentration in Baffin Bay. In contrast with the winter δ18O data from central/southern Greenland, we find no linkage of NEEM winter δ18O to winter NAO.
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.
Markus Czymzik, Raimund Muscheler, Florian Adolphi, Florian Mekhaldi, Nadine Dräger, Florian Ott, Michał Słowinski, Mirosław Błaszkiewicz, Ala Aldahan, Göran Possnert, and Achim Brauer
Clim. Past, 14, 687–696, https://doi.org/10.5194/cp-14-687-2018, https://doi.org/10.5194/cp-14-687-2018, 2018
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Our results provide a proof of concept for facilitating 10Be in varved lake sediments as a novel synchronization tool required for investigating leads and lags of proxy responses to climate variability. They also point to some limitations of 10Be in these archives mainly connected to in-lake sediment resuspension processes.
Pengzhen He, Becky Alexander, Lei Geng, Xiyuan Chi, Shidong Fan, Haicong Zhan, Hui Kang, Guangjie Zheng, Yafang Cheng, Hang Su, Cheng Liu, and Zhouqing Xie
Atmos. Chem. Phys., 18, 5515–5528, https://doi.org/10.5194/acp-18-5515-2018, https://doi.org/10.5194/acp-18-5515-2018, 2018
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We use observations of the oxygen isotopic composition of sulfate aerosol as a fingerprint to quantify various sulfate formation mechanisms during pollution events in Beijing, China. We found that heterogeneous reactions on aerosols dominated sulfate production in general; however, in-cloud reactions would dominate haze sulfate production when cloud liquid water content was high. The findings also suggest the heterogeneity of aerosol acidity should be parameterized in models.
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.
Taku Umezawa, Carl A. M. Brenninkmeijer, Thomas Röckmann, Carina van der Veen, Stanley C. Tyler, Ryo Fujita, Shinji Morimoto, Shuji Aoki, Todd Sowers, Jochen Schmitt, Michael Bock, Jonas Beck, Hubertus Fischer, Sylvia E. Michel, Bruce H. Vaughn, John B. Miller, James W. C. White, Gordon Brailsford, Hinrich Schaefer, Peter Sperlich, Willi A. Brand, Michael Rothe, Thomas Blunier, David Lowry, Rebecca E. Fisher, Euan G. Nisbet, Andrew L. Rice, Peter Bergamaschi, Cordelia Veidt, and Ingeborg Levin
Atmos. Meas. Tech., 11, 1207–1231, https://doi.org/10.5194/amt-11-1207-2018, https://doi.org/10.5194/amt-11-1207-2018, 2018
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Isotope measurements are useful for separating different methane sources. However, the lack of widely accepted standards and calibration methods for stable carbon and hydrogen isotopic ratios of methane in air has caused significant measurement offsets among laboratories. We conducted worldwide interlaboratory comparisons, surveyed the literature and assessed them systematically. This study may be of help in future attempts to harmonize data sets of isotopic composition of atmospheric methane.
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.
Lauren Marshall, Anja Schmidt, Matthew Toohey, Ken S. Carslaw, Graham W. Mann, Michael Sigl, Myriam Khodri, Claudia Timmreck, Davide Zanchettin, William T. Ball, Slimane Bekki, James S. A. Brooke, Sandip Dhomse, Colin Johnson, Jean-Francois Lamarque, Allegra N. LeGrande, Michael J. Mills, Ulrike Niemeier, James O. Pope, Virginie Poulain, Alan Robock, Eugene Rozanov, Andrea Stenke, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, and Fiona Tummon
Atmos. Chem. Phys., 18, 2307–2328, https://doi.org/10.5194/acp-18-2307-2018, https://doi.org/10.5194/acp-18-2307-2018, 2018
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We use four global aerosol models to compare the simulated sulfate deposition from the 1815 Mt. Tambora eruption to ice core records. Inter-model volcanic sulfate deposition differs considerably. Volcanic sulfate deposited on polar ice sheets is used to estimate the atmospheric sulfate burden and subsequently radiative forcing of historic eruptions. Our results suggest that deriving such relationships from model simulations may be associated with greater uncertainties than previously thought.
Kévin Fourteau, Xavier Faïn, Patricia Martinerie, Amaëlle Landais, Alexey A. Ekaykin, Vladimir Ya. Lipenkov, and Jérôme Chappellaz
Clim. Past, 13, 1815–1830, https://doi.org/10.5194/cp-13-1815-2017, https://doi.org/10.5194/cp-13-1815-2017, 2017
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We measured methane concentrations from a polar ice core to quantify the differences between the ice record and the past true atmospheric conditions. Two effects were investigated by combining data analysis and modeling: the stratification of polar snow before gas enclosure driving chronological hiatuses in the record and the gradual formation of bubbles in the ice attenuating fast atmospheric variations. This study will contribute to improving future climatic interpretations from ice archives.
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.
Johann H. Jungclaus, Edouard Bard, Mélanie Baroni, Pascale Braconnot, Jian Cao, Louise P. Chini, Tania Egorova, Michael Evans, J. Fidel González-Rouco, Hugues Goosse, George C. Hurtt, Fortunat Joos, Jed O. Kaplan, Myriam Khodri, Kees Klein Goldewijk, Natalie Krivova, Allegra N. LeGrande, Stephan J. Lorenz, Jürg Luterbacher, Wenmin Man, Amanda C. Maycock, Malte Meinshausen, Anders Moberg, Raimund Muscheler, Christoph Nehrbass-Ahles, Bette I. Otto-Bliesner, Steven J. Phipps, Julia Pongratz, Eugene Rozanov, Gavin A. Schmidt, Hauke Schmidt, Werner Schmutz, Andrew Schurer, Alexander I. Shapiro, Michael Sigl, Jason E. Smerdon, Sami K. Solanki, Claudia Timmreck, Matthew Toohey, Ilya G. Usoskin, Sebastian Wagner, Chi-Ju Wu, Kok Leng Yeo, Davide Zanchettin, Qiong Zhang, and Eduardo Zorita
Geosci. Model Dev., 10, 4005–4033, https://doi.org/10.5194/gmd-10-4005-2017, https://doi.org/10.5194/gmd-10-4005-2017, 2017
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Climate model simulations covering the last millennium provide context for the evolution of the modern climate and for the expected changes during the coming centuries. They can help identify plausible mechanisms underlying palaeoclimatic reconstructions. Here, we describe the forcing boundary conditions and the experimental protocol for simulations covering the pre-industrial millennium. We describe the PMIP4 past1000 simulations as contributions to CMIP6 and additional sensitivity experiments.
Matthew Toohey and Michael Sigl
Earth Syst. Sci. Data, 9, 809–831, https://doi.org/10.5194/essd-9-809-2017, https://doi.org/10.5194/essd-9-809-2017, 2017
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Based on ice core sulfate records from Greenland and Antarctica, the eVolv2k database provides volcanic stratospheric sulfur injection estimates from 500 BCE to 1900 CE along with reconstructed aerosol optical properties needed for climate model simulations. The eVolv2k database constitutes a significant update to prior ice-core-based volcanic forcing reconstructions for climate models, improving the accuracy of volcanic forcing, especially before 1250 CE, and extending the record by 1000 years.
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.
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.
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.
Irène Ventrillard, Irène Xueref-Remy, Martina Schmidt, Camille Yver Kwok, Xavier Faïn, and Daniele Romanini
Atmos. Meas. Tech., 10, 1803–1812, https://doi.org/10.5194/amt-10-1803-2017, https://doi.org/10.5194/amt-10-1803-2017, 2017
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We present a comparison of CO measurements performed with a portable OF-CEAS laser spectrometer against a high-performance gas chromatograph. For both surface and airborne measurements, the instruments show an excellent agreement very close to the 2 ppb World Meteorological Organization recommendation for CO inter-laboratory comparison. This work establishes that this laser technique allows for the development of sensitive, compact, robust and reliable instruments for in situ trace-gas analysis.
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.
Saehee Lim, Xavier Faïn, Patrick Ginot, Vladimir Mikhalenko, Stanislav Kutuzov, Jean-Daniel Paris, Anna Kozachek, and Paolo Laj
Atmos. Chem. Phys., 17, 3489–3505, https://doi.org/10.5194/acp-17-3489-2017, https://doi.org/10.5194/acp-17-3489-2017, 2017
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A record of light-absorbing refractory black carbon (rBC), emitted by fossil fuel combustion and biomass burning, was reconstructed from the ice cores drilled at a high-altitude eastern European site in Mt. Elbrus. This record reports for the first time the high-resolution rBC mass concentrations in the European outflows over the past 189 years. Our study suggests that the past changes in BC emissions of eastern Europe need to be considered in assessing ongoing air quality regulations.
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.
Chiara Uglietti, Alexander Zapf, Theo Manuel Jenk, Michael Sigl, Sönke Szidat, Gary Salazar, and Margit Schwikowski
The Cryosphere, 10, 3091–3105, https://doi.org/10.5194/tc-10-3091-2016, https://doi.org/10.5194/tc-10-3091-2016, 2016
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A meaningful interpretation of the climatic history contained in ice cores requires a precise chronology. For dating the older and deeper part of the glaciers, radiocarbon analysis can be used when organic matter such as plant or insect fragments are found in the ice. Since this happens rarely, a complementary dating tool, based on radiocarbon dating of the insoluble fraction of carbonaceous aerosols entrapped in the ice, allows for ice dating between 200 and more than 10 000 years.
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.
V. Holly L. Winton, Ross Edwards, Andrew R. Bowie, Melita Keywood, Alistair G. Williams, Scott D. Chambers, Paul W. Selleck, Maximilien Desservettaz, Marc D. Mallet, and Clare Paton-Walsh
Atmos. Chem. Phys., 16, 12829–12848, https://doi.org/10.5194/acp-16-12829-2016, https://doi.org/10.5194/acp-16-12829-2016, 2016
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The deposition of soluble aerosol iron (Fe) can initiate nitrogen fixation and trigger toxic algal blooms in nitrate-poor tropical waters. We present dry season soluble Fe data from northern Australia that reflect coincident dust and biomass burning sources of soluble Fe. Our results show that while biomass burning species are not a direct source of soluble Fe, biomass burning may substantially enhance the solubility of mineral dust with fractional Fe solubility up to 12 % in mixed aerosols.
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.
Qianjie Chen, Lei Geng, Johan A. Schmidt, Zhouqing Xie, Hui Kang, Jordi Dachs, Jihong Cole-Dai, Andrew J. Schauer, Madeline G. Camp, and Becky Alexander
Atmos. Chem. Phys., 16, 11433–11450, https://doi.org/10.5194/acp-16-11433-2016, https://doi.org/10.5194/acp-16-11433-2016, 2016
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The formation mechanisms of sulfate in the marine boundary layer are not well understood, which could result in large uncertainties in aerosol radiative forcing. We measure the oxygen isotopic composition (Δ17O) of sulfate collected in the MBL and analyze with a global transport model. Our results suggest that 33–50 % of MBL sulfate is formed via oxidation of S(IV) by hypohalous acids HOBr / HOCl in the aqueous phase, and the daily-mean HOBr/HOCl concentrations are on the order of 0.01–0.1 ppt.
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.
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.
Holly Winton, Andrew Bowie, Melita Keywood, Pier van der Merwe, and Ross Edwards
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2016-12, https://doi.org/10.5194/amt-2016-12, 2016
Revised manuscript not accepted
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Aerosols containing iron have been investigated over the remote Southern Ocean to constrain iron budgets in surface waters and related biological production. Protocols for the sampling of ambient air were used to assess the suitability of high-volume aerosol samplers for aerosol iron studies in pristine air masses. Significant evidence of airborne insect and local soil contamination was detected in exposure blank filters. Suggestions for future aerosol iron sampling in clean air are provided.
Markus Czymzik, Raimund Muscheler, and Achim Brauer
Clim. Past, 12, 799–805, https://doi.org/10.5194/cp-12-799-2016, https://doi.org/10.5194/cp-12-799-2016, 2016
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Integrating discharge data of the River Ammer back to 1926 and a 5500-year flood layer record from an annually laminated sediment core of the downstream Ammersee allowed investigating changes in the frequency of major floods in Central Europe on interannual to multi-centennial timescales. Significant correlations between flood frequency variations in both archives and changes in the activity of the Sun suggest a solar influence on the frequency of these hydrometeorological extremes.
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.
F. Adolphi and R. Muscheler
Clim. Past, 12, 15–30, https://doi.org/10.5194/cp-12-15-2016, https://doi.org/10.5194/cp-12-15-2016, 2016
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Here we employ common variations in tree-ring 14C and Greenland ice core 10Be records to synchronize the Greenland ice core (GICC05) and the radiocarbon (IntCal13) timescale over the Holocene. We propose a transfer function between both timescales that allows continuous comparisons between radiocarbon dated and ice core climate records at unprecedented chronological precision.
V. Mikhalenko, S. Sokratov, S. Kutuzov, P. Ginot, M. Legrand, S. Preunkert, I. Lavrentiev, A. Kozachek, A. Ekaykin, X. Faïn, S. Lim, U. Schotterer, V. Lipenkov, and P. Toropov
The Cryosphere, 9, 2253–2270, https://doi.org/10.5194/tc-9-2253-2015, https://doi.org/10.5194/tc-9-2253-2015, 2015
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For the first time an ice core unaffected by melting was recovered from the western Elbrus plateau in the Caucasus. The preserved chemical and isotopic data are considered a source of paleo-climate information for southern/eastern Europe. Considerable snow accumulation (about 1500mm w.e.) and high sampling resolution allowed seasonal variability to be obtained in climate signals, covering a time period of about 200 years. Ice flow models suggest that the basal ice age can be more than 600 years.
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.
A. Ellis, R. Edwards, M. Saunders, R. K. Chakrabarty, R. Subramanian, A. van Riessen, A. M. Smith, D. Lambrinidis, L. J. Nunes, P. Vallelonga, I. D. Goodwin, A. D. Moy, M. A. J. Curran, and T. D. van Ommen
Atmos. Meas. Tech., 8, 3959–3969, https://doi.org/10.5194/amt-8-3959-2015, https://doi.org/10.5194/amt-8-3959-2015, 2015
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Black carbon is an important environmental pollutant, and the structure and composition of these particles are important to measuring their affect on the climate. Historical records of black carbon emissions are stored in polar ice. This paper details a new method to study black carbon preserved in Antarctic ice cores. By combining filtration to concentrate the particles and electron microscopy to characterize them, this method opens up a new avenue to study the history of our atmosphere.
C. Buizert, K. M. Cuffey, J. P. Severinghaus, D. Baggenstos, T. J. Fudge, E. J. Steig, B. R. Markle, M. Winstrup, R. H. Rhodes, E. J. Brook, T. A. Sowers, G. D. Clow, H. Cheng, R. L. Edwards, M. Sigl, J. R. McConnell, and K. C. Taylor
Clim. Past, 11, 153–173, https://doi.org/10.5194/cp-11-153-2015, https://doi.org/10.5194/cp-11-153-2015, 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. 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
S. Lim, X. Faïn, M. Zanatta, J. Cozic, J.-L. Jaffrezo, P. Ginot, and P. Laj
Atmos. Meas. Tech., 7, 3307–3324, https://doi.org/10.5194/amt-7-3307-2014, https://doi.org/10.5194/amt-7-3307-2014, 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
B. W. Goodfellow, A. P. Stroeven, D. Fabel, O. Fredin, M.-H. Derron, R. Bintanja, and M. W. Caffee
Earth Surf. Dynam., 2, 383–401, https://doi.org/10.5194/esurf-2-383-2014, https://doi.org/10.5194/esurf-2-383-2014, 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
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
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
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
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
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
Comparing past accumulation rate reconstructions in East Antarctic ice cores using 10Be, water isotopes and CMIP5-PMIP3 models
The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference
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.
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
Short summary
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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.
C. Buizert, K. M. Cuffey, J. P. Severinghaus, D. Baggenstos, T. J. Fudge, E. J. Steig, B. R. Markle, M. Winstrup, R. H. Rhodes, E. J. Brook, T. A. Sowers, G. D. Clow, H. Cheng, R. L. Edwards, M. Sigl, J. R. McConnell, and K. C. Taylor
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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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Short summary
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.
Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West...
