Articles | Volume 16, issue 6
https://doi.org/10.5194/cp-16-2203-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-16-2203-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
14 Nov 2020
Research article | Highlight paper |
| 14 Nov 2020
| 14 Nov 2020
Millennial-scale atmospheric CO2 variations during the Marine Isotope Stage 6 period (190–135 ka)
Jinhwa Shin
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
current address: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, T6G 2E3, Canada
Christoph Nehrbass-Ahles
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Department of Earth Sciences, University of Cambridge, Cambridge, UK
Roberto Grilli
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
Jai Chowdhry Beeman
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
Frédéric Parrenin
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
Grégory Teste
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
Amaelle Landais
Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
Loïc Schmidely
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Lucas Silva
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Jochen Schmitt
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Bernhard Bereiter
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Laboratory for Air Pollution/Environmental Technology, Empa,
Dübendorf, Switzerland
current address: Bruker BioSpin AG, Fällanden, Switzerland
Thomas F. Stocker
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Hubertus Fischer
Climate and Environmental Physics, Physics Institute, and Oeschger
Centre for Climate Change Research, University of Bern, Bern, Switzerland
Jérôme Chappellaz
CORRESPONDING AUTHOR
CNRS, Univ. Grenoble-Alpes, Institut des Géosciences de
l'Environnement (IGE), Grenoble, France
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Jakob Schwander, Thomas Franziskus Stocker, Remo Walther, Samuel Marending, Tobias Erhardt, Chantal Zeppenfeld, and Jürg Jost
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Revised manuscript accepted for AMT
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Frédéric Parrenin, Marie Bouchet, Christo Buizert, Emilie Capron, Ellen Corrick, Russell Drysdale, Kenji Kawamura, Amaëlle Landais, Robert Mulvaney, Ikumi Oyabu, and Sune Rasmussen
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Christophe Leroy-Dos Santos, Elise Fourré, Cécile Agosta, Mathieu Casado, Alexandre Cauquoin, Martin Werner, Benedicte Minster, Frédéric Prié, Olivier Jossoud, Leila Petit, and Amaëlle Landais
The Cryosphere, 17, 5241–5254, https://doi.org/10.5194/tc-17-5241-2023, https://doi.org/10.5194/tc-17-5241-2023, 2023
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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
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Marie Bouchet, Amaëlle Landais, Antoine Grisart, Frédéric Parrenin, Frédéric Prié, Roxanne Jacob, Elise Fourré, Emilie Capron, Dominique Raynaud, Vladimir Ya Lipenkov, Marie-France Loutre, Thomas Extier, Anders Svensson, Etienne Legrain, Patricia Martinerie, Markus Leuenberger, Wei Jiang, Florian Ritterbusch, Zheng-Tian Lu, and Guo-Min Yang
Clim. Past, 19, 2257–2286, https://doi.org/10.5194/cp-19-2257-2023, https://doi.org/10.5194/cp-19-2257-2023, 2023
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A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with improved accuracy. Precise ice core timescales are key to studying the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To construct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.
Zhuo Wang, Ailsa Chung, Daniel Steinhage, Frédéric Parrenin, Johannes Freitag, and Olaf Eisen
The Cryosphere, 17, 4297–4314, https://doi.org/10.5194/tc-17-4297-2023, https://doi.org/10.5194/tc-17-4297-2023, 2023
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We combine radar-based observed internal layer stratigraphy of the ice sheet with a 1-D ice flow model in the Dome Fuji region. This results in maps of age and age density of the basal ice, the basal thermal conditions, and reconstructed accumulation rates. Based on modeled age we then identify four potential candidates for ice which is potentially 1.5 Myr old. Our map of basal thermal conditions indicates that melting prevails over the presence of stagnant ice in the study area.
Ailsa Chung, Frédéric Parrenin, Daniel Steinhage, Robert Mulvaney, Carlos Martín, Marie G. P. Cavitte, David A. Lilien, Veit Helm, Drew Taylor, Prasad Gogineni, Catherine Ritz, Massimo Frezzotti, Charles O'Neill, Heinrich Miller, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 17, 3461–3483, https://doi.org/10.5194/tc-17-3461-2023, https://doi.org/10.5194/tc-17-3461-2023, 2023
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We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.
Sune Olander Rasmussen, Dorthe Dahl-Jensen, Hubertus Fischer, Katrin Fuhrer, Steffen Bo Hansen, Margareta Hansson, Christine S. Hvidberg, Ulf Jonsell, Sepp Kipfstuhl, Urs Ruth, Jakob Schwander, Marie-Louise Siggaard-Andersen, Giulia Sinnl, Jørgen Peder Steffensen, Anders M. Svensson, and Bo M. Vinther
Earth Syst. Sci. Data, 15, 3351–3364, https://doi.org/10.5194/essd-15-3351-2023, https://doi.org/10.5194/essd-15-3351-2023, 2023
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Timescales are essential for interpreting palaeoclimate data. The data series presented here were used for annual-layer identification when constructing the timescales named the Greenland Ice-Core Chronology 2005 (GICC05) and the revised version GICC21. Hopefully, these high-resolution data sets will be useful also for other purposes.
Aymeric P. M. Servettaz, Anaïs J. Orsi, Mark A. J. Curran, Andrew D. Moy, Amaelle Landais, Joseph R. McConnell, Trevor J. Popp, Emmanuel Le Meur, Xavier Faïn, and Jérôme Chappellaz
Clim. Past, 19, 1125–1152, https://doi.org/10.5194/cp-19-1125-2023, https://doi.org/10.5194/cp-19-1125-2023, 2023
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The temperature of the past 2000 years is still poorly known in vast parts of the East Antarctic plateau. In this study, we present temperature reconstructions based on water and gas stable isotopes from the Aurora Basin North ice core. Spatial and temporal significance of each proxy differs, and we can identify some cold periods in the snow temperature up to 2°C cooler in the 1000–1400 CE period, which could not be determined with water isotopes only.
Michaela Mühl, Jochen Schmitt, Barbara Seth, James E. Lee, Jon S. Edwards, Edward J. Brook, Thomas Blunier, and Hubertus Fischer
Clim. Past, 19, 999–1025, https://doi.org/10.5194/cp-19-999-2023, https://doi.org/10.5194/cp-19-999-2023, 2023
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Our ice core measurements show that methane, ethane, and propane concentrations are significantly elevated above their past atmospheric background for Greenland ice samples containing mineral dust. The underlying co-production process happens during the classical discrete wet extraction of air from the ice sample and affects previous reconstructions of the inter-polar difference of methane as well as methane stable isotope records derived from dust-rich Greenland ice.
Robert Mulvaney, Eric W. Wolff, Mackenzie M. Grieman, Helene H. Hoffmann, Jack D. Humby, Christoph Nehrbass-Ahles, Rachael H. Rhodes, Isobel F. Rowell, Frédéric Parrenin, Loïc Schmidely, Hubertus Fischer, Thomas F. Stocker, Marcus Christl, Raimund Muscheler, Amaelle Landais, and Frédéric Prié
Clim. Past, 19, 851–864, https://doi.org/10.5194/cp-19-851-2023, https://doi.org/10.5194/cp-19-851-2023, 2023
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We present an age scale for a new ice core drilled at Skytrain Ice Rise, an ice rise facing the Ronne Ice Shelf in Antarctica. Various measurements in the ice and air phases are used to match the ice core to other Antarctic cores that have already been dated, and a new age scale is constructed. The 651 m ice core includes ice that is confidently dated to 117 000–126 000 years ago, in the last interglacial. Older ice is found deeper down, but there are flow disturbances in the deeper ice.
Clémence Paul, Clément Piel, Joana Sauze, Nicolas Pasquier, Frédéric Prié, Sébastien Devidal, Roxanne Jacob, Arnaud Dapoigny, Olivier Jossoud, Alexandru Milcu, and Amaëlle Landais
Biogeosciences, 20, 1047–1062, https://doi.org/10.5194/bg-20-1047-2023, https://doi.org/10.5194/bg-20-1047-2023, 2023
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To improve the interpretation of the δ18Oatm and Δ17O of O2 in air bubbles in ice cores, we need to better quantify the oxygen fractionation coefficients associated with biological processes. We performed a simplified analogue of the terrestrial biosphere in a closed chamber. We found a respiration fractionation in agreement with the previous estimates at the microorganism scale, and a terrestrial photosynthetic fractionation was found. This has an impact on the estimation of the Dole effect.
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.
Jakob Schwander, Thomas F. Stocker, Remo Walther, and Samuel Marending
The Cryosphere, 17, 1151–1164, https://doi.org/10.5194/tc-17-1151-2023, https://doi.org/10.5194/tc-17-1151-2023, 2023
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RADIX (Rapid Access Drilling and Ice eXtraction) is a fast-access ice-drilling system for prospecting future deep-drilling sites on glaciers and polar ice sheets. It consists of a 40 mm rapid firn drill, a 20 mm deep drill and a logger. The maximum depth range of RADIX is 3100 m by design. The nominal drilling speed is on the order of 40 m h-1. The 15 mm diameter logger provides data on the hole inclination and direction and measures temperature and dust in the ice surrounding the borehole.
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.
Ikumi Oyabu, Kenji Kawamura, Shuji Fujita, Ryo Inoue, Hideaki Motoyama, Kotaro Fukui, Motohiro Hirabayashi, Yu Hoshina, Naoyuki Kurita, Fumio Nakazawa, Hiroshi Ohno, Konosuke Sugiura, Toshitaka Suzuki, Shun Tsutaki, Ayako Abe-Ouchi, Masashi Niwano, Frédéric Parrenin, Fuyuki Saito, and Masakazu Yoshimori
Clim. Past, 19, 293–321, https://doi.org/10.5194/cp-19-293-2023, https://doi.org/10.5194/cp-19-293-2023, 2023
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We reconstructed accumulation rate around Dome Fuji, Antarctica, over the last 5000 years from 15 shallow ice cores and seven snow pits. We found a long-term decreasing trend in the preindustrial period, which may be associated with secular surface cooling and sea ice expansion. Centennial-scale variations were also found, which may partly be related to combinations of volcanic, solar and greenhouse gas forcings. The most rapid and intense increases of accumulation rate occurred since 1850 CE.
Lars Mächler, Daniel Baggenstos, Florian Krauss, Jochen Schmitt, Bernhard Bereiter, Remo Walther, Christoph Reinhard, Béla Tuzson, Lukas Emmenegger, and Hubertus Fischer
Atmos. Meas. Tech., 16, 355–372, https://doi.org/10.5194/amt-16-355-2023, https://doi.org/10.5194/amt-16-355-2023, 2023
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We present a new method to extract the gases from ice cores and measure their greenhouse gas composition. The ice is sublimated continuously with a near-infrared laser, releasing the gases, which are then analyzed on a laser absorption spectrometer. The main advantage over previous efforts is a low effective resolution of 1–2 cm. This capability is crucial for the analysis of highly thinned ice, as expected from ongoing drilling efforts to extend ice core history further back in time.
Antoine Grisart, Mathieu Casado, Vasileios Gkinis, Bo Vinther, Philippe Naveau, Mathieu Vrac, Thomas Laepple, Bénédicte Minster, Frederic Prié, Barbara Stenni, Elise Fourré, Hans Christian Steen-Larsen, Jean Jouzel, Martin Werner, Katy Pol, Valérie Masson-Delmotte, Maria Hoerhold, Trevor Popp, and Amaelle Landais
Clim. Past, 18, 2289–2301, https://doi.org/10.5194/cp-18-2289-2022, https://doi.org/10.5194/cp-18-2289-2022, 2022
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This paper presents a compilation of high-resolution (11 cm) water isotopic records, including published and new measurements, for the last 800 000 years from the EPICA Dome C ice core, Antarctica. Using this new combined water isotopes (δ18O and δD) dataset, we study the variability and possible influence of diffusion at the multi-decadal to multi-centennial scale. We observe a stronger variability at the onset of the interglacial interval corresponding to a warm period.
Jinhwa Shin, Jinho Ahn, Jai Chowdhry Beeman, Hun-Gyu Lee, Jaemyeong Mango Seo, and Edward J. Brook
Clim. Past, 18, 2063–2075, https://doi.org/10.5194/cp-18-2063-2022, https://doi.org/10.5194/cp-18-2063-2022, 2022
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We present a new and highly resolved atmospheric CO2 record from the Siple Dome ice core, Antarctica, over the early Holocene (11.7–7.4 ka). Atmospheric CO2 decreased by ~10 ppm from 10.9 to 7.3 ka, but the decrease was punctuated by local minima at 11.1, 10.1, 9.1, and 8.3 ka. We found millennial CO2 variability of 2–6 ppm, and the millennial CO2 variations correlate with proxies for solar forcing and local climate in the Southern Ocean, North Atlantic, and eastern equatorial Pacific.
Helene M. Hoffmann, Mackenzie M. Grieman, Amy C. F. King, Jenna A. Epifanio, Kaden Martin, Diana Vladimirova, Helena V. Pryer, Emily Doyle, Axel Schmidt, Jack D. Humby, Isobel F. Rowell, Christoph Nehrbass-Ahles, Elizabeth R. Thomas, Robert Mulvaney, and Eric W. Wolff
Clim. Past, 18, 1831–1847, https://doi.org/10.5194/cp-18-1831-2022, https://doi.org/10.5194/cp-18-1831-2022, 2022
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The WACSWAIN project (WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial) investigates the fate of the West Antarctic Ice Sheet during the last warm period on Earth (115 000–130 000 years before present). Within this framework an ice core was recently drilled at Skytrain Ice Rise. In this study we present a stratigraphic chronology of that ice core based on absolute age markers and annual layer counting for the last 2000 years.
Eric W. Wolff, Hubertus Fischer, Tas van Ommen, and David A. Hodell
Clim. Past, 18, 1563–1577, https://doi.org/10.5194/cp-18-1563-2022, https://doi.org/10.5194/cp-18-1563-2022, 2022
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Projects are underway to drill ice cores in Antarctica reaching 1.5 Myr back in time. Dating such cores will be challenging. One method is to match records from the new core against datasets from existing marine sediment cores. Here we explore the options for doing this and assess how well the ice and marine records match over the existing 800 000-year time period. We are able to recommend a strategy for using marine data to place an age scale on the new ice cores.
Santos J. González-Rojí, Martina Messmer, Christoph C. Raible, and Thomas F. Stocker
Geosci. Model Dev., 15, 2859–2879, https://doi.org/10.5194/gmd-15-2859-2022, https://doi.org/10.5194/gmd-15-2859-2022, 2022
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Different configurations of physics parameterizations of a regional climate model are tested over southern Peru at fine resolution. The most challenging regions compared to observational data are the slopes of the Andes. Model configurations for Europe and East Africa are not perfectly suitable for southern Peru. The experiment with the Stony Brook University microphysics scheme and the Grell–Freitas cumulus parameterization provides the most accurate results over Madre de Dios.
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.
Tobias Erhardt, Matthias Bigler, Urs Federer, Gideon Gfeller, Daiana Leuenberger, Olivia Stowasser, Regine Röthlisberger, Simon Schüpbach, Urs Ruth, Birthe Twarloh, Anna Wegner, Kumiko Goto-Azuma, Takayuki Kuramoto, Helle A. Kjær, Paul T. Vallelonga, Marie-Louise Siggaard-Andersen, Margareta E. Hansson, Ailsa K. Benton, Louise G. Fleet, Rob Mulvaney, Elizabeth R. Thomas, Nerilie Abram, Thomas F. Stocker, and Hubertus Fischer
Earth Syst. Sci. Data, 14, 1215–1231, https://doi.org/10.5194/essd-14-1215-2022, https://doi.org/10.5194/essd-14-1215-2022, 2022
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The datasets presented alongside this manuscript contain high-resolution concentration measurements of chemical impurities in deep ice cores, NGRIP and NEEM, from the Greenland ice sheet. The impurities originate from the deposition of aerosols to the surface of the ice sheet and are influenced by source, transport and deposition processes. Together, these records contain detailed, multi-parameter records of past climate variability over the last glacial period.
Jiamei Lin, Anders Svensson, Christine S. Hvidberg, Johannes Lohmann, Steffen Kristiansen, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Sune Olander Rasmussen, Eliza Cook, Helle Astrid Kjær, Bo M. Vinther, Hubertus Fischer, Thomas Stocker, Michael Sigl, Matthias Bigler, Mirko Severi, Rita Traversi, and Robert Mulvaney
Clim. Past, 18, 485–506, https://doi.org/10.5194/cp-18-485-2022, https://doi.org/10.5194/cp-18-485-2022, 2022
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We employ acidity records from Greenland and Antarctic ice cores to estimate the emission strength, frequency and climatic forcing for large volcanic eruptions from the last half of the last glacial period. A total of 25 volcanic eruptions are found to be larger than any eruption in the last 2500 years, and we identify more eruptions than obtained from geological evidence. Towards the end of the glacial period, there is a notable increase in volcanic activity observed for Greenland.
Frerk Pöppelmeier, David J. Janssen, Samuel L. Jaccard, and Thomas F. Stocker
Biogeosciences, 18, 5447–5463, https://doi.org/10.5194/bg-18-5447-2021, https://doi.org/10.5194/bg-18-5447-2021, 2021
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Chromium (Cr) is a redox-sensitive element that holds promise as a tracer of ocean oxygenation and biological activity. We here implemented the oxidation states Cr(III) and Cr(VI) in the Bern3D model to investigate the processes that shape the global Cr distribution. We find a Cr ocean residence time of 5–8 kyr and that the benthic source dominates the tracer budget. Further, regional model–data mismatches suggest strong Cr removal in oxygen minimum zones and a spatially variable benthic source.
Clément Outrequin, Anne Alexandre, Christine Vallet-Coulomb, Clément Piel, Sébastien Devidal, Amaelle Landais, Martine Couapel, Jean-Charles Mazur, Christophe Peugeot, Monique Pierre, Frédéric Prié, Jacques Roy, Corinne Sonzogni, and Claudia Voigt
Clim. Past, 17, 1881–1902, https://doi.org/10.5194/cp-17-1881-2021, https://doi.org/10.5194/cp-17-1881-2021, 2021
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Continental atmospheric humidity is a key climate parameter poorly captured by global climate models. Model–data comparison approaches that are applicable beyond the instrumental period are essential to progress on this issue but face a lack of quantitative relative humidity proxies. Here, we calibrate the triple oxygen isotope composition of phytoliths as a new quantitative proxy of continental relative humidity suitable for past climate reconstructions.
Johannes Sutter, Hubertus Fischer, and Olaf Eisen
The Cryosphere, 15, 3839–3860, https://doi.org/10.5194/tc-15-3839-2021, https://doi.org/10.5194/tc-15-3839-2021, 2021
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Projections of global sea-level changes in a warming world require ice-sheet models. We expand the calibration of these models by making use of the internal architecture of the Antarctic ice sheet, which is formed by its evolution over many millennia. We propose that using our novel approach to constrain ice sheet models, we will be able to both sharpen our understanding of past and future sea-level changes and identify weaknesses in the parameterisation of current continental-scale models.
Loïc Schmidely, Christoph Nehrbass-Ahles, Jochen Schmitt, Juhyeong Han, Lucas Silva, Jinwha Shin, Fortunat Joos, Jérôme Chappellaz, Hubertus Fischer, and Thomas F. Stocker
Clim. Past, 17, 1627–1643, https://doi.org/10.5194/cp-17-1627-2021, https://doi.org/10.5194/cp-17-1627-2021, 2021
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Using ancient gas trapped in polar glaciers, we reconstructed the atmospheric concentrations of methane and nitrous oxide over the penultimate deglaciation to study their response to major climate changes. We show this deglaciation to be characterized by modes of methane and nitrous oxide variability that are also found during the last deglaciation and glacial cycle.
Martina Messmer, Santos J. González-Rojí, Christoph C. Raible, and Thomas F. Stocker
Geosci. Model Dev., 14, 2691–2711, https://doi.org/10.5194/gmd-14-2691-2021, https://doi.org/10.5194/gmd-14-2691-2021, 2021
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Sensitivity experiments with the WRF model are run to find an optimal parameterization setup for precipitation around Mount Kenya at a scale that resolves convection (1 km). Precipitation is compared against many weather stations and gridded observational data sets. Both the temporal correlation of precipitation sums and pattern correlations show that fewer nests lead to a more constrained simulation with higher correlation. The Grell–Freitas cumulus scheme obtains the most accurate results.
David A. Lilien, Daniel Steinhage, Drew Taylor, Frédéric Parrenin, Catherine Ritz, Robert Mulvaney, Carlos Martín, Jie-Bang Yan, Charles O'Neill, Massimo Frezzotti, Heinrich Miller, Prasad Gogineni, Dorthe Dahl-Jensen, and Olaf Eisen
The Cryosphere, 15, 1881–1888, https://doi.org/10.5194/tc-15-1881-2021, https://doi.org/10.5194/tc-15-1881-2021, 2021
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We collected radar data between EDC, an ice core spanning ~800 000 years, and BELDC, the site chosen for a new
oldest icecore at nearby Little Dome C. These data allow us to identify 50 % older internal horizons than previously traced in the area. We fit a model to the ages of those horizons at BELDC to determine the age of deep ice there. We find that there is likely to be 1.5 Myr old ice ~265 m above the bed, with sufficient resolution to preserve desired climatic information.
Christophe Leroy-Dos Santos, Mathieu Casado, Frédéric Prié, Olivier Jossoud, Erik Kerstel, Morgane Farradèche, Samir Kassi, Elise Fourré, and Amaëlle Landais
Atmos. Meas. Tech., 14, 2907–2918, https://doi.org/10.5194/amt-14-2907-2021, https://doi.org/10.5194/amt-14-2907-2021, 2021
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We developed an instrument that can generate water vapor at low humidity at a very stable level. This instrument was conceived to calibrate water vapor isotopic records obtained in very dry places such as central Antarctica. Here, we provide details on the instrument as well as results obtained for correcting water isotopic records for diurnal variability during a long field season at the Concordia station in East Antarctica.
Marcel Haeberli, Daniel Baggenstos, Jochen Schmitt, Markus Grimmer, Adrien Michel, Thomas Kellerhals, and Hubertus Fischer
Clim. Past, 17, 843–867, https://doi.org/10.5194/cp-17-843-2021, https://doi.org/10.5194/cp-17-843-2021, 2021
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Using the temperature-dependent solubility of noble gases in ocean water, we reconstruct global mean ocean temperature (MOT) over the last 700 kyr using noble gas ratios in air enclosed in polar ice cores. Our record shows that glacial MOT was about 3 °C cooler compared to the Holocene. Interglacials before 450 kyr ago were characterized by about 1.5 °C lower MOT than the Holocene. In addition, some interglacials show transient maxima in ocean temperature related to changes in ocean circulation.
Frerk Pöppelmeier, Jeemijn Scheen, Aurich Jeltsch-Thömmes, and Thomas F. Stocker
Clim. Past, 17, 615–632, https://doi.org/10.5194/cp-17-615-2021, https://doi.org/10.5194/cp-17-615-2021, 2021
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The stability of the Atlantic Meridional Overturning Circulation (AMOC) critically depends on its mean state. We simulate the response of the AMOC to North Atlantic freshwater perturbations under different glacial boundary conditions. We find that a closed Bering Strait greatly increases the AMOC's sensitivity to freshwater hosing. Further, the shift from mono- to bistability strongly depends on the chosen boundary conditions, with weaker circulation states exhibiting more abrupt transitions.
Bernhard Bereiter, Béla Tuzson, Philipp Scheidegger, André Kupferschmid, Herbert Looser, Lars Mächler, Daniel Baggenstos, Jochen Schmitt, Hubertus Fischer, and Lukas Emmenegger
Atmos. Meas. Tech., 13, 6391–6406, https://doi.org/10.5194/amt-13-6391-2020, https://doi.org/10.5194/amt-13-6391-2020, 2020
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The record of past greenhouse gas composition from ice cores is crucial for our understanding of global climate change. Deciphering this archive requires highly accurate and spatially resolved analysis of the very small amount of gas that is trapped in the ice. This is achieved with a mid-IR laser absorption spectrometer that provides simultaneous, high-precision measurements of CH4, N2O, CO2, and δ13C(CO2) and which will be coupled to a quantitative sublimation extraction method.
Jeemijn Scheen and Thomas F. Stocker
Earth Syst. Dynam., 11, 925–951, https://doi.org/10.5194/esd-11-925-2020, https://doi.org/10.5194/esd-11-925-2020, 2020
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Variability of sea surface temperatures (SST) in 1200–2000 CE is quite well-known, but the history of deep ocean temperatures is not. Forcing an ocean model with these SSTs, we simulate temperatures in the ocean interior. The circulation changes alter the amplitude and timing of deep ocean temperature fluctuations below 2 km depth, e.g. delaying the atmospheric signal by ~ 200 years in the deep Atlantic. Thus ocean circulation changes are shown to be as important as SST changes at these depths.
Jann Schrod, Dominik Kleinhenz, Maria Hörhold, Tobias Erhardt, Sarah Richter, Frank Wilhelms, Hubertus Fischer, Martin Ebert, Birthe Twarloh, Damiano Della Lunga, Camilla M. Jensen, Joachim Curtius, and Heinz G. Bingemer
Atmos. Chem. Phys., 20, 12459–12482, https://doi.org/10.5194/acp-20-12459-2020, https://doi.org/10.5194/acp-20-12459-2020, 2020
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Ice-nucleating particle (INP) concentrations of the last 6 centuries are presented from an ice core in Greenland. The data are accompanied by physical and chemical aerosol data. INPs are correlated to the dust signal from the ice core and seem to follow the annual input of mineral dust. We find no clear trend in the INP concentration. However, modern-day concentrations are higher and more variable than the concentrations of the past. This might have significant atmospheric implications.
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.
Fortunat Joos, Renato Spahni, Benjamin D. Stocker, Sebastian Lienert, Jurek Müller, Hubertus Fischer, Jochen Schmitt, I. Colin Prentice, Bette Otto-Bliesner, and Zhengyu Liu
Biogeosciences, 17, 3511–3543, https://doi.org/10.5194/bg-17-3511-2020, https://doi.org/10.5194/bg-17-3511-2020, 2020
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Results of the first globally resolved simulations of terrestrial carbon and nitrogen (N) cycling and N2O emissions over the past 21 000 years are compared with reconstructed N2O emissions. Modelled and reconstructed emissions increased strongly during past abrupt warming events. This evidence appears consistent with a dynamic response of biological N fixation to increasing N demand by ecosystems, thereby reducing N limitation of plant productivity and supporting a land sink for atmospheric CO2.
Roberto Grilli, François Darchambeau, Jérôme Chappellaz, Ange Mugisha, Jack Triest, and Augusta Umutoni
Geosci. Instrum. Method. Data Syst., 9, 141–151, https://doi.org/10.5194/gi-9-141-2020, https://doi.org/10.5194/gi-9-141-2020, 2020
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We report the results from the deployment of a newly developed in situ sensor for dissolved gas measurements. Its adaptation to high gas concentrations and dissolved gas pressures was proven. The campaign leads to a first continuous profile of methane on the first 150 m and allowed us to compare the data with previous measurements. The fast response of the instrument makes this technique a good candidate for regular monitoring of those type of lakes, for anticipating disastrous gas eruptions.
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.
Ece Satar, Peter Nyfeler, Bernhard Bereiter, Céline Pascale, Bernhard Niederhauser, and Markus Leuenberger
Atmos. Meas. Tech., 13, 101–117, https://doi.org/10.5194/amt-13-101-2020, https://doi.org/10.5194/amt-13-101-2020, 2020
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Good-quality measurements of atmospheric trace gases are only possible with regular calibrations and stable measurements from the standard cylinders. This study investigates instabilities due to surface effects on newly built aluminum and steel cylinders. We present measurements over a set of temperature and pressure ranges for the amount fractions of CO2, CO, CH4 and H2O using a commercial and a novel laser spectroscopic analyzer.
Anne Alexandre, Elizabeth Webb, Amaelle Landais, Clément Piel, Sébastien Devidal, Corinne Sonzogni, Martine Couapel, Jean-Charles Mazur, Monique Pierre, Frédéric Prié, Christine Vallet-Coulomb, Clément Outrequin, and Jacques Roy
Biogeosciences, 16, 4613–4625, https://doi.org/10.5194/bg-16-4613-2019, https://doi.org/10.5194/bg-16-4613-2019, 2019
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This calibration study shows that despite isotope heterogeneity along grass leaves, the triple oxygen isotope composition of bulk leaf phytoliths can be estimated from the Craig and Gordon model, a mixing equation and a mean leaf water–phytolith fractionation exponent (lambda) of 0.521. The results strengthen the reliability of the 17O–excess of phytoliths to be used as a proxy of atmospheric relative humidity and open tracks for its use as an imprint of leaf water 17O–excess.
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.
Hubertus Fischer, Jochen Schmitt, Michael Bock, Barbara Seth, Fortunat Joos, Renato Spahni, Sebastian Lienert, Gianna Battaglia, Benjamin D. Stocker, Adrian Schilt, and Edward J. Brook
Biogeosciences, 16, 3997–4021, https://doi.org/10.5194/bg-16-3997-2019, https://doi.org/10.5194/bg-16-3997-2019, 2019
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N2O concentrations were subject to strong variations accompanying glacial–interglacial but also rapid climate changes over the last 21 kyr. The sources of these N2O changes can be identified by measuring the isotopic composition of N2O in ice cores and using the distinct isotopic composition of terrestrial and marine N2O. We show that both marine and terrestrial sources increased from the last glacial to the Holocene but that only terrestrial emissions responded quickly to rapid climate changes.
Laurie Menviel, Emilie Capron, Aline Govin, Andrea Dutton, Lev Tarasov, Ayako Abe-Ouchi, Russell N. Drysdale, Philip L. Gibbard, Lauren Gregoire, Feng He, Ruza F. Ivanovic, Masa Kageyama, Kenji Kawamura, Amaelle Landais, Bette L. Otto-Bliesner, Ikumi Oyabu, Polychronis C. Tzedakis, Eric Wolff, and Xu Zhang
Geosci. Model Dev., 12, 3649–3685, https://doi.org/10.5194/gmd-12-3649-2019, https://doi.org/10.5194/gmd-12-3649-2019, 2019
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As part of the Past Global Changes (PAGES) working group on Quaternary Interglacials, we propose a protocol to perform transient simulations of the penultimate deglaciation for the Paleoclimate Modelling Intercomparison Project (PMIP4). This design includes time-varying changes in orbital forcing, greenhouse gas concentrations, continental ice sheets as well as freshwater input from the disintegration of continental ice sheets. Key paleo-records for model-data comparison are also included.
Pär Jansson, Jack Triest, Roberto Grilli, Bénédicte Ferré, Anna Silyakova, Jürgen Mienert, and Jérôme Chappellaz
Ocean Sci., 15, 1055–1069, https://doi.org/10.5194/os-15-1055-2019, https://doi.org/10.5194/os-15-1055-2019, 2019
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Methane seepage from the seafloor west of Svalbard was investigated with a fast-response membrane inlet laser spectrometer. The acquired data were in good agreement with traditional sparse discrete water sampling, subsequent gas chromatography, and with a new 2-D model based on echo-sounder data. However, the acquired high-resolution data revealed unprecedented details of the methane distribution, which highlights the need for high-resolution measurements for future climate studies.
Johannes Sutter, Hubertus Fischer, Klaus Grosfeld, Nanna B. Karlsson, Thomas Kleiner, Brice Van Liefferinge, and Olaf Eisen
The Cryosphere, 13, 2023–2041, https://doi.org/10.5194/tc-13-2023-2019, https://doi.org/10.5194/tc-13-2023-2019, 2019
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The Antarctic Ice Sheet may have played an important role in moderating the transition between warm and cold climate epochs over the last million years. We find that the Antarctic Ice Sheet grew considerably about 0.9 Myr ago, a time when ice-age–warm-age cycles changed from a
40 000 to a 100 000 year periodicity. Our findings also suggest that ice as old as 1.5 Myr still exists at the bottom of the East Antarctic Ice Sheet despite the major climate reorganisations in the past.
Loic Lechevallier, Roberto Grilli, Erik Kerstel, Daniele Romanini, and Jérôme Chappellaz
Atmos. Meas. Tech., 12, 3101–3109, https://doi.org/10.5194/amt-12-3101-2019, https://doi.org/10.5194/amt-12-3101-2019, 2019
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In this work we describe a highly sensitive optical spectrometer for simultaneous measurement of methane, ethane, and the isotopic composition of methane. The coupling of the spectrometer with a dissolved gas extraction system will provide a suitable tool for understanding the origins of the dissolved hydrocarbons and discriminate between the different sources (e.g., biogenic vs. thermogenic).
Andreas Born, Michael A. Imhof, and Thomas F. Stocker
The Cryosphere, 13, 1529–1546, https://doi.org/10.5194/tc-13-1529-2019, https://doi.org/10.5194/tc-13-1529-2019, 2019
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We present a new numerical model to simulate the surface energy and mass balance of snow and ice. While similar models exist and cover a wide range of complexity from empirical models to those that simulate the microscopic structure of individual snow grains, we aim to strike a balance between physical completeness and numerical efficiency. This new model will enable physically accurate simulations over timescales of hundreds of millennia, a key requirement of investigating ice age cycles.
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.
Jonas Beck, Michael Bock, Jochen Schmitt, Barbara Seth, Thomas Blunier, and Hubertus Fischer
Biogeosciences, 15, 7155–7175, https://doi.org/10.5194/bg-15-7155-2018, https://doi.org/10.5194/bg-15-7155-2018, 2018
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Ice core concentration and stable isotope measurements of atmospheric CH4 give valuable insights into the CH4 cycle of the past. New carbon and hydrogen stable isotope CH4 data measured on ice from both Greenland and Antarctica over the Holocene allow us to draw conclusions on the methane emission processes. In particular, our results cast doubt on a hypothesis proposing early human land use to be responsible for the atmospheric methane concentration increase in the second half of the Holocene.
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.
Christoph C. Raible, Martina Messmer, Flavio Lehner, Thomas F. Stocker, and Richard Blender
Clim. Past, 14, 1499–1514, https://doi.org/10.5194/cp-14-1499-2018, https://doi.org/10.5194/cp-14-1499-2018, 2018
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Extratropical cyclones in winter and their characteristics are investigated in depth for the Atlantic European region from 850 to 2100 CE. During the Common Era, cyclone characteristics show pronounced variations mainly caused by internal variability of the coupled climate system. When anthropogenic forcing becomes dominant, a strong increase of extreme cyclone-related precipitation is found due to thermodynamics, though dynamical processes can play an important role during the last millennium.
Andreas Plach, Kerim H. Nisancioglu, Sébastien Le clec'h, Andreas Born, Petra M. Langebroek, Chuncheng Guo, Michael Imhof, and Thomas F. Stocker
Clim. Past, 14, 1463–1485, https://doi.org/10.5194/cp-14-1463-2018, https://doi.org/10.5194/cp-14-1463-2018, 2018
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The Greenland ice sheet is a huge frozen water reservoir which is crucial for predictions of sea level in a warming future climate. Therefore, computer models are needed to reliably simulate the melt of ice sheets. In this study, we use climate model simulations of the last period where it was warmer than today in Greenland. We test different melt models under these climatic conditions and show that the melt models show very different results under these warmer conditions.
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.
Laurie Menviel, Emilie Capron, Aline Govin, Andrea Dutton, Lev Tarasov, Ayako Abe-Ouchi, Russell Drysdale, Philip Gibbard, Lauren Gregoire, Feng He, Ruza Ivanovic, Masa Kageyama, Kenji Kawamura, Amaelle Landais, Bette L. Otto-Bliesner, Ikumi Oyabu, Polychronis Tzedakis, Eric Wolff, and Xu Zhang
Clim. Past Discuss., https://doi.org/10.5194/cp-2018-106, https://doi.org/10.5194/cp-2018-106, 2018
Preprint withdrawn
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The penultimate deglaciation (~ 138–128 ka), which represents the transition into the Last Interglacial period, provides a framework to investigate the climate and environmental response to large changes in boundary conditions. Here, as part of the PAGES-PMIP working group on Quaternary Interglacials, we propose a protocol to perform transient simulations of the penultimate deglaciation as well as a selection of paleo records for upcoming model-data comparisons.
Olivier Passalacqua, Marie Cavitte, Olivier Gagliardini, Fabien Gillet-Chaulet, Frédéric Parrenin, Catherine Ritz, and Duncan Young
The Cryosphere, 12, 2167–2174, https://doi.org/10.5194/tc-12-2167-2018, https://doi.org/10.5194/tc-12-2167-2018, 2018
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Locating a suitable drill site is a key step in the Antarctic oldest-ice challenge. Here we have conducted a 3-D ice flow simulation in the region of Dome C using a refined bedrock description. Five selection criteria are computed that together provide an objective overview on the local ice flow conditions. We delineate kilometer-scale favorable areas that overlap with the ones recently proposed by another group. We propose a few drill sites that should be surveyed during the next field seasons.
Alexandra Touzeau, Amaëlle Landais, Samuel Morin, Laurent Arnaud, and Ghislain Picard
Geosci. Model Dev., 11, 2393–2418, https://doi.org/10.5194/gmd-11-2393-2018, https://doi.org/10.5194/gmd-11-2393-2018, 2018
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We introduced a new module of water vapor diffusion into the snowpack model Crocus. Vapor transport locally modifies the density of snow layers, possibly influencing compaction. It also affects the original isotopic signature of snow layers. We also introduced water isotopes (𝛿18O) in the model. Over 10 years, the modeled attenuation of isotopic variations due to vapor diffusion is 7–18 % lower than the observations. Thus, other processes are required to explain the total attenuation.
Anne Alexandre, Amarelle Landais, Christine Vallet-Coulomb, Clément Piel, Sébastien Devidal, Sandrine Pauchet, Corinne Sonzogni, Martine Couapel, Marine Pasturel, Pauline Cornuault, Jingming Xin, Jean-Charles Mazur, Frédéric Prié, Ilhem Bentaleb, Elizabeth Webb, Françoise Chalié, and Jacques Roy
Biogeosciences, 15, 3223–3241, https://doi.org/10.5194/bg-15-3223-2018, https://doi.org/10.5194/bg-15-3223-2018, 2018
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There is a lack of proxies suitable for reconstructing, in a quantitative way, past changes in continental atmospheric humidity, which is a key climate parameter. Here, we demonstrate through climate chamber and climate transect calibrations that the triple oxygen isotope composition of phytoliths offers a potential for reconstructing changes in relative humidity.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valerie Masson-Delmotte, and Jean Jouzel
The Cryosphere, 12, 1745–1766, https://doi.org/10.5194/tc-12-1745-2018, https://doi.org/10.5194/tc-12-1745-2018, 2018
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Ice core isotopic records rely on the knowledge of the processes involved in the archival processes of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Marie G. P. Cavitte, Frédéric Parrenin, Catherine Ritz, Duncan A. Young, Brice Van Liefferinge, Donald D. Blankenship, Massimo Frezzotti, and Jason L. Roberts
The Cryosphere, 12, 1401–1414, https://doi.org/10.5194/tc-12-1401-2018, https://doi.org/10.5194/tc-12-1401-2018, 2018
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We reconstruct the pattern of surface accumulation in the region around Dome C, East Antarctica, over the last 73 kyr. We use internal isochrones interpreted from ice-penetrating radar surveys and a 1-D ice flow model to invert for time-averaged and paleo-accumulation rates. We observe that surface accumulation patterns are stable through the last 73 kyr, consistent with current observed regional precipitation gradients and consistent interactions between prevailing winds and surface slope.
Masa Kageyama, Pascale Braconnot, Sandy P. Harrison, Alan M. Haywood, Johann H. Jungclaus, Bette L. Otto-Bliesner, Jean-Yves Peterschmitt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Chris Brierley, Michel Crucifix, Aisling Dolan, Laura Fernandez-Donado, Hubertus Fischer, Peter O. Hopcroft, Ruza F. Ivanovic, Fabrice Lambert, Daniel J. Lunt, Natalie M. Mahowald, W. Richard Peltier, Steven J. Phipps, Didier M. Roche, Gavin A. Schmidt, Lev Tarasov, Paul J. Valdes, Qiong Zhang, and Tianjun Zhou
Geosci. Model Dev., 11, 1033–1057, https://doi.org/10.5194/gmd-11-1033-2018, https://doi.org/10.5194/gmd-11-1033-2018, 2018
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The Paleoclimate Modelling Intercomparison Project (PMIP) takes advantage of the existence of past climate states radically different from the recent past to test climate models used for climate projections and to better understand these climates. This paper describes the PMIP contribution to CMIP6 (Coupled Model Intercomparison Project, 6th phase) and possible analyses based on PMIP results, as well as on other CMIP6 projects.
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.
Thomas Laepple, Thomas Münch, Mathieu Casado, Maria Hoerhold, Amaelle Landais, and Sepp Kipfstuhl
The Cryosphere, 12, 169–187, https://doi.org/10.5194/tc-12-169-2018, https://doi.org/10.5194/tc-12-169-2018, 2018
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We explain why snow pits across different sites in East Antarctica show visually similar isotopic variations. We argue that the similarity and the apparent cycles of around 20 cm in the δD and δ18O variations are the result of a seasonal cycle in isotopes, noise, for example from precipitation intermittency, and diffusion. The near constancy of the diffusion length across many ice-coring sites explains why the structure and cycle length is largely independent of the accumulation conditions.
Pascal Bohleber, Tobias Erhardt, Nicole Spaulding, Helene Hoffmann, Hubertus Fischer, and Paul Mayewski
Clim. Past, 14, 21–37, https://doi.org/10.5194/cp-14-21-2018, https://doi.org/10.5194/cp-14-21-2018, 2018
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The Colle Gnifetti (CG) glacier is the only drilling site in the European Alps offering ice core records back to some 1000 years. We aim to fully exploit these unique long-term records by establishing a reliable long-term age scale and an improved ice core proxy interpretation for reconstructing temperature. Our findings reveal a site-specific temperature-related signal in the trends of the mineral dust proxy Ca2+ that may supplement other proxy evidence over the last millennium.
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.
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.
Bette L. Otto-Bliesner, Pascale Braconnot, Sandy P. Harrison, Daniel J. Lunt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Emilie Capron, Anders E. Carlson, Andrea Dutton, Hubertus Fischer, Heiko Goelzer, Aline Govin, Alan Haywood, Fortunat Joos, Allegra N. LeGrande, William H. Lipscomb, Gerrit Lohmann, Natalie Mahowald, Christoph Nehrbass-Ahles, Francesco S. R. Pausata, Jean-Yves Peterschmitt, Steven J. Phipps, Hans Renssen, and Qiong Zhang
Geosci. Model Dev., 10, 3979–4003, https://doi.org/10.5194/gmd-10-3979-2017, https://doi.org/10.5194/gmd-10-3979-2017, 2017
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The PMIP4 and CMIP6 mid-Holocene and Last Interglacial simulations provide an opportunity to examine the impact of two different changes in insolation forcing on climate at times when other forcings were relatively similar to present. This will allow exploration of the role of feedbacks relevant to future projections. Evaluating these simulations using paleoenvironmental data will provide direct out-of-sample tests of the reliability of state-of-the-art models to simulate climate changes.
Frédéric Parrenin, Marie G. P. Cavitte, Donald D. Blankenship, Jérôme Chappellaz, Hubertus Fischer, Olivier Gagliardini, Valérie Masson-Delmotte, Olivier Passalacqua, Catherine Ritz, Jason Roberts, Martin J. Siegert, and Duncan A. Young
The Cryosphere, 11, 2427–2437, https://doi.org/10.5194/tc-11-2427-2017, https://doi.org/10.5194/tc-11-2427-2017, 2017
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The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC), reaching ~ 800 000 years. Obtaining an older palaeoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we estimate the age of basal ice in the Dome C area. We find that old ice (> 1.5 Myr) likely exists in two regions a few tens of kilometres away from EDC:
Little Dome C Patchand
North Patch.
Olivier Passalacqua, Catherine Ritz, Frédéric Parrenin, Stefano Urbini, and Massimo Frezzotti
The Cryosphere, 11, 2231–2246, https://doi.org/10.5194/tc-11-2231-2017, https://doi.org/10.5194/tc-11-2231-2017, 2017
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As the Dome C region is a key area for oldest-ice research, we need to better constrain the geothermal flux (GF) so that past basal melt rates are well constrained. Our inverse heat model significantly reduces the confidence intervals of the GF regional field around Dome C, which ranges from 48 to 60 mW m−2. Radar echoes need to be interpreted knowing the time lag of the climate signal to reach the bed. Several old-ice targets are confirmed and a new one is suggested, in which the GF is very low.
Jason Roberts, Andrew Moy, Christopher Plummer, Tas van Ommen, Mark Curran, Tessa Vance, Samuel Poynter, Yaping Liu, Joel Pedro, Adam Treverrow, Carly Tozer, Lenneke Jong, Pippa Whitehouse, Laetitia Loulergue, Jerome Chappellaz, Vin Morgan, Renato Spahni, Adrian Schilt, Cecilia MacFarling Meure, David Etheridge, and Thomas Stocker
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-96, https://doi.org/10.5194/cp-2017-96, 2017
Preprint withdrawn
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Here we present a revised Law Dome, Dome Summit South (DSS) ice core age model (denoted LD2017) that significantly improves the chronology over the last 88 thousand years. An ensemble approach was used, allowing for the computation of both a median age and associated uncertainty as a function of depth. We use a non-linear interpolation between age ties and unlike previous studies, we made an independent estimate of the snow accumulation rate, where required, for the use of gas based age ties.
Camille Bréant, Patricia Martinerie, Anaïs Orsi, Laurent Arnaud, and Amaëlle Landais
Clim. Past, 13, 833–853, https://doi.org/10.5194/cp-13-833-2017, https://doi.org/10.5194/cp-13-833-2017, 2017
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All firn densification models applied to deglaciations show a large disagreement with δ15N measurements at sites in East Antarctica, predicting larger firn thickness during the Last Glacial Maximum, whereas δ15N suggests a reduced firn thickness compared to the Holocene. Here we present modifications, which significantly reduce the model–data mismatch for the gas trapping depth evolution over the last deglaciation at the coldest sites in East Antarctica, to the LGGE firn densification model.
Peter Köhler, Christoph Nehrbass-Ahles, Jochen Schmitt, Thomas F. Stocker, and Hubertus Fischer
Earth Syst. Sci. Data, 9, 363–387, https://doi.org/10.5194/essd-9-363-2017, https://doi.org/10.5194/essd-9-363-2017, 2017
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We document our best available data compilation of published ice core records of the greenhouse gases CO2, CH4, and N2O and recent measurements on firn air and atmospheric samples covering the time window from 156 000 years BP to the beginning of the year 2016 CE. A smoothing spline method is applied to translate the discrete and irregularly spaced data points into continuous time series. The radiative forcing for each greenhouse gas is computed using well-established, simple formulations.
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).
Kathrin M. Keller, Sebastian Lienert, Anil Bozbiyik, Thomas F. Stocker, Olga V. Churakova (Sidorova), David C. Frank, Stefan Klesse, Charles D. Koven, Markus Leuenberger, William J. Riley, Matthias Saurer, Rolf Siegwolf, Rosemarie B. Weigt, and Fortunat Joos
Biogeosciences, 14, 2641–2673, https://doi.org/10.5194/bg-14-2641-2017, https://doi.org/10.5194/bg-14-2641-2017, 2017
Grant M. Raisbeck, Alexandre Cauquoin, Jean Jouzel, Amaelle Landais, Jean-Robert Petit, Vladimir Y. Lipenkov, Juerg Beer, Hans-Arno Synal, Hans Oerter, Sigfus J. Johnsen, Jorgen P. Steffensen, Anders Svensson, and Françoise Yiou
Clim. Past, 13, 217–229, https://doi.org/10.5194/cp-13-217-2017, https://doi.org/10.5194/cp-13-217-2017, 2017
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Using records of a long-lived radioactive nuclide (10Be) that is formed globally in the atmosphere and deposited within a few years to the earth’s surface, we have synchronized three Antarctic ice cores to one from Greenland. This permits the climate and other environmental parameters registered in these ice cores to be put on a common timescale with a precision of a few decades, thus allowing different models and mechanisms associated with these parameters to be tested with the same precision.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, and Jean Jouzel
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-263, https://doi.org/10.5194/tc-2016-263, 2016
Revised manuscript not accepted
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Ice core isotopic records rely on the knowledge of the processes involved in the archival of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Stefan Muthers, Christoph C. Raible, Eugene Rozanov, and Thomas F. Stocker
Earth Syst. Dynam., 7, 877–892, https://doi.org/10.5194/esd-7-877-2016, https://doi.org/10.5194/esd-7-877-2016, 2016
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The Atlantic Meridional Overturning Circulation (AMOC) is an important oceanic circulation system which transports large amounts of heat from the tropics to the north. This circulation is strengthened when less solar irradiance reaches the Earth, e.g. due to reduced solar activity or geoengineering techniques. In climate models, however, this response is overestimated when chemistry–climate interactions and the following shift in the atmospheric circulation systems are not considered.
Niklaus Merz, Andreas Born, Christoph C. Raible, and Thomas F. Stocker
Clim. Past, 12, 2011–2031, https://doi.org/10.5194/cp-12-2011-2016, https://doi.org/10.5194/cp-12-2011-2016, 2016
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The last (Eemian) interglacial is studied with a global climate model focusing on Greenland and the adjacent high latitudes. A set of model experiments demonstrates the crucial role of changes in sea ice and sea surface temperatures for the magnitude of Eemian atmospheric warming. Greenland temperatures are found highly sensitive to sea ice changes in the Nordic Seas but rather insensitive to changes in the Labrador Sea. This behavior has important implications for Greenland ice core signals.
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.
Bette L. Otto-Bliesner, Pascale Braconnot, Sandy P. Harrison, Daniel J. Lunt, Ayako Abe-Ouchi, Samuel Albani, Patrick J. Bartlein, Emilie Capron, Anders E. Carlson, Andrea Dutton, Hubertus Fischer, Heiko Goelzer, Aline Govin, Alan Haywood, Fortunat Joos, Allegra N. Legrande, William H. Lipscomb, Gerrit Lohmann, Natalie Mahowald, Christoph Nehrbass-Ahles, Jean-Yves Peterschmidt, Francesco S.-R. Pausata, Steven Phipps, and Hans Renssen
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-106, https://doi.org/10.5194/cp-2016-106, 2016
Preprint retracted
Olivier Eicher, Matthias Baumgartner, Adrian Schilt, Jochen Schmitt, Jakob Schwander, Thomas F. Stocker, and Hubertus Fischer
Clim. Past, 12, 1979–1993, https://doi.org/10.5194/cp-12-1979-2016, https://doi.org/10.5194/cp-12-1979-2016, 2016
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A new high-resolution total air content record over the NGRIP ice core, spanning 0.3–120 kyr is presented. In agreement with Antarctic ice cores, we find a strong local insolation signature but also 3–5 % decreases in total air content as a local response to Dansgaard–Oeschger events, which can only partly be explained by changes in surface pressure and temperature. Accordingly, a dynamic response of firnification to rapid climate changes on the Greenland ice sheet must have occurred.
Amaelle Landais, Valérie Masson-Delmotte, Emilie Capron, Petra M. Langebroek, Pepijn Bakker, Emma J. Stone, Niklaus Merz, Christoph C. Raible, Hubertus Fischer, Anaïs Orsi, Frédéric Prié, Bo Vinther, and Dorthe Dahl-Jensen
Clim. Past, 12, 1933–1948, https://doi.org/10.5194/cp-12-1933-2016, https://doi.org/10.5194/cp-12-1933-2016, 2016
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The last lnterglacial (LIG; 116 000 to 129 000 years before present) surface temperature at the upstream Greenland NEEM deposition site is estimated to be warmer by +7 to +11 °C compared to the preindustrial period. We show that under such warm temperatures, melting of snow probably led to a significant surface melting. There is a paradox between the extent of the Greenland ice sheet during the LIG and the strong warming during this period that models cannot solve.
Timothé Bolliet, Patrick Brockmann, Valérie Masson-Delmotte, Franck Bassinot, Valérie Daux, Dominique Genty, Amaelle Landais, Marlène Lavrieux, Elisabeth Michel, Pablo Ortega, Camille Risi, Didier M. Roche, Françoise Vimeux, and Claire Waelbroeck
Clim. Past, 12, 1693–1719, https://doi.org/10.5194/cp-12-1693-2016, https://doi.org/10.5194/cp-12-1693-2016, 2016
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This paper presents a new database of past climate proxies which aims to facilitate the distribution of data by using a user-friendly interface. Available data from the last 40 years are often fragmented, with lots of different formats, and online libraries are sometimes nonintuitive. We thus built a new dynamic web portal for data browsing, visualizing, and batch downloading of hundreds of datasets presenting a homogeneous format.
Thomas Röckmann, Simon Eyer, Carina van der Veen, Maria E. Popa, Béla Tuzson, Guillaume Monteil, Sander Houweling, Eliza Harris, Dominik Brunner, Hubertus Fischer, Giulia Zazzeri, David Lowry, Euan G. Nisbet, Willi A. Brand, Jaroslav M. Necki, Lukas Emmenegger, and Joachim Mohn
Atmos. Chem. Phys., 16, 10469–10487, https://doi.org/10.5194/acp-16-10469-2016, https://doi.org/10.5194/acp-16-10469-2016, 2016
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A dual isotope ratio mass spectrometric system (IRMS) and a quantum cascade laser absorption spectroscopy (QCLAS)-based technique were deployed at the Cabauw experimental site for atmospheric research (CESAR) in the Netherlands and performed in situ, high-frequency (approx. hourly) measurements for a period of more than 5 months, yielding a combined dataset with more than 2500 measurements of both δ13C and δD.
Mathieu Casado, Amaelle Landais, Valérie Masson-Delmotte, Christophe Genthon, Erik Kerstel, Samir Kassi, Laurent Arnaud, Ghislain Picard, Frederic Prie, Olivier Cattani, Hans-Christian Steen-Larsen, Etienne Vignon, and Peter Cermak
Atmos. Chem. Phys., 16, 8521–8538, https://doi.org/10.5194/acp-16-8521-2016, https://doi.org/10.5194/acp-16-8521-2016, 2016
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Climatic conditions in Concordia are very cold (−55 °C in average) and very dry, imposing difficult conditions to measure the water vapour isotopic composition. New developments in infrared spectroscopy enable now the measurement of isotopic composition in water vapour traces (down to 20 ppmv). Here we present the results results of a first campaign of measurement of isotopic composition of water vapour in Concordia, the site where the 800 000 years long ice core was drilled.
Olivier Passalacqua, Olivier Gagliardini, Frédéric Parrenin, Joe Todd, Fabien Gillet-Chaulet, and Catherine Ritz
Geosci. Model Dev., 9, 2301–2313, https://doi.org/10.5194/gmd-9-2301-2016, https://doi.org/10.5194/gmd-9-2301-2016, 2016
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In ice-flow modelling, computing in 3-D requires a lot of resources, but 2-D models lack physical likelihood when the flow is diverging. That is why 2-D models accounting for the divergence, so-called 2.5-D models, are an interesting trade-off. However, the applicability of these 2.5-D models has never been systematically examined. We show that these models are ineffective in the case of highly diverging flows, but also for varying temperature, which was not suspected.
Basil Neff, Andreas Born, and Thomas F. Stocker
Earth Syst. Dynam., 7, 397–418, https://doi.org/10.5194/esd-7-397-2016, https://doi.org/10.5194/esd-7-397-2016, 2016
Alexandra Touzeau, Amaëlle Landais, Barbara Stenni, Ryu Uemura, Kotaro Fukui, Shuji Fujita, Sarah Guilbaud, Alexey Ekaykin, Mathieu Casado, Eugeni Barkan, Boaz Luz, Olivier Magand, Grégory Teste, Emmanuel Le Meur, Mélanie Baroni, Joël Savarino, Ilann Bourgeois, and Camille Risi
The Cryosphere, 10, 837–852, https://doi.org/10.5194/tc-10-837-2016, https://doi.org/10.5194/tc-10-837-2016, 2016
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The relationship between water isotope ratios and temperature is investigated in precipitation snow at Vostok and Dome C, as well as in surface snow along traverses. The temporal slope of the linear regression for the precipitation is smaller than the geographical slope. Thus, using the latter could lead to an underestimation of past temperature changes. The processes active at remote sites (best glacial analogs) are explored through a combination of water isotopes in short snow pits.
Lucie Bazin, Amaelle Landais, Emilie Capron, Valérie Masson-Delmotte, Catherine Ritz, Ghislain Picard, Jean Jouzel, Marie Dumont, Markus Leuenberger, and Frédéric Prié
Clim. Past, 12, 729–748, https://doi.org/10.5194/cp-12-729-2016, https://doi.org/10.5194/cp-12-729-2016, 2016
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We present new measurements of δO2⁄N2 and δ18Oatm performed on well-conserved ice from EDC covering MIS5 and between 380 and 800 ka. The combination of the observation of a 100 ka periodicity in the new δO2⁄N2 record with a MIS5 multi-site multi-proxy study has revealed a potential influence of local climatic parameters on δO2⁄N2. Moreover, we propose that the varying delay between d18Oatm and precession for the last 800 ka is affected by the occurrence of ice sheet discharge events.
Shin'ya Nakano, Kazue Suzuki, Kenji Kawamura, Frédéric Parrenin, and Tomoyuki Higuchi
Nonlin. Processes Geophys., 23, 31–44, https://doi.org/10.5194/npg-23-31-2016, https://doi.org/10.5194/npg-23-31-2016, 2016
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This paper proposes a technique for dating an ice core. The proposed technique employs a hybrid method combining the sequential Monte Carlo method and the Markov chain Monte Carlo method, which is referred to as the particle Markov chain Monte Carlo method. The sequential Monte Carlo method, which is also known as the particle filter, is widely used for nonlinear time-series analysis. This paper demonstrates the usefulness of the approach in time-series analysis for dating an ice core.
S. Eyer, B. Tuzson, M. E. Popa, C. van der Veen, T. Röckmann, M. Rothe, W. A. Brand, R. Fisher, D. Lowry, E. G. Nisbet, M. S. Brennwald, E. Harris, C. Zellweger, L. Emmenegger, H. Fischer, and J. Mohn
Atmos. Meas. Tech., 9, 263–280, https://doi.org/10.5194/amt-9-263-2016, https://doi.org/10.5194/amt-9-263-2016, 2016
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We present a newly developed field-deployable, autonomous platform simultaneously measuring the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy.
The instrument consists of a compact quantum cascade laser absorption spectrometer (QCLAS) coupled to a preconcentration unit, called TRace gas EXtractor (TREX).
The performance of this new in situ technique was investigated during a 2-week measurement campaign and compared to other techniques.
C. Reutenauer, A. Landais, T. Blunier, C. Bréant, M. Kageyama, M.-N. Woillez, C. Risi, V. Mariotti, and P. Braconnot
Clim. Past, 11, 1527–1551, https://doi.org/10.5194/cp-11-1527-2015, https://doi.org/10.5194/cp-11-1527-2015, 2015
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Isotopes of atmospheric O2 undergo millennial-scale variations during the last glacial period, and systematically increase during Heinrich stadials.
Such variations are mostly due to vegetation and water cycle processes.
Our modeling approach reproduces the main observed features of Heinrich stadials in terms of climate, vegetation and rainfall.
It highlights the strong role of hydrology on O2 isotopes, which can be seen as a global integrator of precipitation changes over vegetated areas.
S. Fujita, F. Parrenin, M. Severi, H. Motoyama, and E. W. Wolff
Clim. Past, 11, 1395–1416, https://doi.org/10.5194/cp-11-1395-2015, https://doi.org/10.5194/cp-11-1395-2015, 2015
G. van der Wel, H. Fischer, H. Oerter, H. Meyer, and H. A. J. Meijer
The Cryosphere, 9, 1601–1616, https://doi.org/10.5194/tc-9-1601-2015, https://doi.org/10.5194/tc-9-1601-2015, 2015
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The diffusion of the stable water isotope signal during firnification of snow is a temperature-dependent process. Therefore, past local temperatures can be derived from the differential diffusion length. In this paper we develop a new method for determining this quantity and compare it with the existing method. Both methods are applied to a large number of synthetic data sets to assess the precision and accuracy of the reconstruction and to a section of the Antarctic EDML ice core record.
J.-L. Tison, M. de Angelis, G. Littot, E. Wolff, H. Fischer, M. Hansson, M. Bigler, R. Udisti, A. Wegner, J. Jouzel, B. Stenni, S. Johnsen, V. Masson-Delmotte, A. Landais, V. Lipenkov, L. Loulergue, J.-M. Barnola, J.-R. Petit, B. Delmonte, G. Dreyfus, D. Dahl-Jensen, G. Durand, B. Bereiter, A. Schilt, R. Spahni, K. Pol, R. Lorrain, R. Souchez, and D. Samyn
The Cryosphere, 9, 1633–1648, https://doi.org/10.5194/tc-9-1633-2015, https://doi.org/10.5194/tc-9-1633-2015, 2015
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The oldest paleoclimatic information is buried within the lowermost layers of deep ice cores. It is therefore essential to judge how deep these records remain unaltered. We study the bottom 60 meters of the EPICA Dome C ice core from central Antarctica to show that the paleoclimatic signal is only affected at the small scale (decimeters) in terms of some of the global ice properties. However our data suggest that the time scale has been considerably distorted by mechanical stretching.
V. Masson-Delmotte, H. C. Steen-Larsen, P. Ortega, D. Swingedouw, T. Popp, B. M. Vinther, H. Oerter, A. E. Sveinbjornsdottir, H. Gudlaugsdottir, J. E. Box, S. Falourd, X. Fettweis, H. Gallée, E. Garnier, V. Gkinis, J. Jouzel, A. Landais, B. Minster, N. Paradis, A. Orsi, C. Risi, M. Werner, and J. W. C. White
The Cryosphere, 9, 1481–1504, https://doi.org/10.5194/tc-9-1481-2015, https://doi.org/10.5194/tc-9-1481-2015, 2015
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The deep NEEM ice core provides the oldest Greenland ice core record, enabling improved understanding of the response of ice core records to local climate. Here, we focus on shallow ice cores providing a stack record of accumulation and water-stable isotopes spanning the past centuries. For the first time, we document the ongoing warming in a Greenland ice core. By combining our data with other Greenland ice cores and model results, we characterise the spatio-temporal patterns of variability.
F. Lehner, F. Joos, C. C. Raible, J. Mignot, A. Born, K. M. Keller, and T. F. Stocker
Earth Syst. Dynam., 6, 411–434, https://doi.org/10.5194/esd-6-411-2015, https://doi.org/10.5194/esd-6-411-2015, 2015
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We present the first last-millennium simulation with the Community Earth System Model (CESM) including an interactive carbon cycle in both ocean and land component. Volcanic eruptions emerge as the strongest forcing factor for the preindustrial climate and carbon cycle. We estimate the climate-carbon-cycle feedback in CESM to be at the lower bounds of empirical estimates (1.3ppm/°C). The time of emergence for interannual global land and ocean carbon uptake rates are 1947 and 1877, respectively.
B. Lemieux-Dudon, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, M. Guillevic, P. Kindler, F. Parrenin, and P. Martinerie
Clim. Past, 11, 959–978, https://doi.org/10.5194/cp-11-959-2015, https://doi.org/10.5194/cp-11-959-2015, 2015
F. Parrenin, L. Bazin, E. Capron, A. Landais, B. Lemieux-Dudon, and V. Masson-Delmotte
Geosci. Model Dev., 8, 1473–1492, https://doi.org/10.5194/gmd-8-1473-2015, https://doi.org/10.5194/gmd-8-1473-2015, 2015
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This manuscript describes a probabilistic model which aims at optimizing the chronology of ice cores by combining different sources of information.
A. Cauquoin, A. Landais, G. M. Raisbeck, J. Jouzel, L. Bazin, M. Kageyama, J.-Y. Peterschmitt, M. Werner, E. Bard, and ASTER Team
Clim. Past, 11, 355–367, https://doi.org/10.5194/cp-11-355-2015, https://doi.org/10.5194/cp-11-355-2015, 2015
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We present a new 10Be record at EDC between 269 and 355ka. Our 10Be-based accumulation rate is in good agreement with the one associated with the EDC3 timescale except for the warm MIS 9.3 optimum. This suggests that temperature reconstruction from water isotopes may be underestimated by 2.4K for the difference between the MIS 9.3 and present day. The CMIP5-PMIP3 models do not quantitatively reproduce changes in precipitation vs. temperature increase during glacial–interglacial transitions.
F. Parrenin, S. Fujita, A. Abe-Ouchi, K. Kawamura, V. Masson-Delmotte, H. Motoyama, F. Saito, M. Severi, B. Stenni, R. Uemura, and E. Wolff
Clim. Past Discuss., https://doi.org/10.5194/cpd-11-377-2015, https://doi.org/10.5194/cpd-11-377-2015, 2015
Revised manuscript has not been submitted
J. Schmitt, B. Seth, M. Bock, and H. Fischer
Atmos. Meas. Tech., 7, 2645–2665, https://doi.org/10.5194/amt-7-2645-2014, https://doi.org/10.5194/amt-7-2645-2014, 2014
M. Bock, J. Schmitt, J. Beck, R. Schneider, and H. Fischer
Atmos. Meas. Tech., 7, 1999–2012, https://doi.org/10.5194/amt-7-1999-2014, https://doi.org/10.5194/amt-7-1999-2014, 2014
N. Merz, A. Born, C. C. Raible, H. Fischer, and T. F. Stocker
Clim. Past, 10, 1221–1238, https://doi.org/10.5194/cp-10-1221-2014, https://doi.org/10.5194/cp-10-1221-2014, 2014
M. Baumgartner, P. Kindler, O. Eicher, G. Floch, A. Schilt, J. Schwander, R. Spahni, E. Capron, J. Chappellaz, M. Leuenberger, H. Fischer, and T. F. Stocker
Clim. Past, 10, 903–920, https://doi.org/10.5194/cp-10-903-2014, https://doi.org/10.5194/cp-10-903-2014, 2014
H. C. Steen-Larsen, V. Masson-Delmotte, M. Hirabayashi, R. Winkler, K. Satow, F. Prié, N. Bayou, E. Brun, K. M. Cuffey, D. Dahl-Jensen, M. Dumont, M. Guillevic, S. Kipfstuhl, A. Landais, T. Popp, C. Risi, K. Steffen, B. Stenni, and A. E. Sveinbjörnsdottír
Clim. Past, 10, 377–392, https://doi.org/10.5194/cp-10-377-2014, https://doi.org/10.5194/cp-10-377-2014, 2014
B. Bereiter, H. Fischer, J. Schwander, and T. F. Stocker
The Cryosphere, 8, 245–256, https://doi.org/10.5194/tc-8-245-2014, https://doi.org/10.5194/tc-8-245-2014, 2014
S. Schüpbach, U. Federer, P. R. Kaufmann, S. Albani, C. Barbante, T. F. Stocker, and H. Fischer
Clim. Past, 9, 2789–2807, https://doi.org/10.5194/cp-9-2789-2013, https://doi.org/10.5194/cp-9-2789-2013, 2013
R. Schneider, J. Schmitt, P. Köhler, F. Joos, and H. Fischer
Clim. Past, 9, 2507–2523, https://doi.org/10.5194/cp-9-2507-2013, https://doi.org/10.5194/cp-9-2507-2013, 2013
H. Fischer, J. Severinghaus, E. Brook, E. Wolff, M. Albert, O. Alemany, R. Arthern, C. Bentley, D. Blankenship, J. Chappellaz, T. Creyts, D. Dahl-Jensen, M. Dinn, M. Frezzotti, S. Fujita, H. Gallee, R. Hindmarsh, D. Hudspeth, G. Jugie, K. Kawamura, V. Lipenkov, H. Miller, R. Mulvaney, F. Parrenin, F. Pattyn, C. Ritz, J. Schwander, D. Steinhage, T. van Ommen, and F. Wilhelms
Clim. Past, 9, 2489–2505, https://doi.org/10.5194/cp-9-2489-2013, https://doi.org/10.5194/cp-9-2489-2013, 2013
N. Merz, C. C. Raible, H. Fischer, V. Varma, M. Prange, and T. F. Stocker
Clim. Past, 9, 2433–2450, https://doi.org/10.5194/cp-9-2433-2013, https://doi.org/10.5194/cp-9-2433-2013, 2013
L. Bazin, A. Landais, B. Lemieux-Dudon, H. Toyé Mahamadou Kele, D. Veres, F. Parrenin, P. Martinerie, C. Ritz, E. Capron, V. Lipenkov, M.-F. Loutre, D. Raynaud, B. Vinther, A. Svensson, S. O. Rasmussen, M. Severi, T. Blunier, M. Leuenberger, H. Fischer, V. Masson-Delmotte, J. Chappellaz, and E. Wolff
Clim. Past, 9, 1715–1731, https://doi.org/10.5194/cp-9-1715-2013, https://doi.org/10.5194/cp-9-1715-2013, 2013
D. Veres, L. Bazin, A. Landais, H. Toyé Mahamadou Kele, B. Lemieux-Dudon, F. Parrenin, P. Martinerie, E. Blayo, T. Blunier, E. Capron, J. Chappellaz, S. O. Rasmussen, M. Severi, A. Svensson, B. Vinther, and E. W. Wolff
Clim. Past, 9, 1733–1748, https://doi.org/10.5194/cp-9-1733-2013, https://doi.org/10.5194/cp-9-1733-2013, 2013
J. Schmitt, B. Seth, M. Bock, C. van der Veen, L. Möller, C. J. Sapart, M. Prokopiou, T. Sowers, T. Röckmann, and H. Fischer
Atmos. Meas. Tech., 6, 1425–1445, https://doi.org/10.5194/amt-6-1425-2013, https://doi.org/10.5194/amt-6-1425-2013, 2013
E. Capron, A. Landais, D. Buiron, A. Cauquoin, J. Chappellaz, M. Debret, J. Jouzel, M. Leuenberger, P. Martinerie, V. Masson-Delmotte, R. Mulvaney, F. Parrenin, and F. Prié
Clim. Past, 9, 983–999, https://doi.org/10.5194/cp-9-983-2013, https://doi.org/10.5194/cp-9-983-2013, 2013
S. Zürcher, R. Spahni, F. Joos, M. Steinacher, and H. Fischer
Biogeosciences, 10, 1963–1981, https://doi.org/10.5194/bg-10-1963-2013, https://doi.org/10.5194/bg-10-1963-2013, 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
A. Born, T. F. Stocker, and A. B. Sandø
Ocean Sci. Discuss., https://doi.org/10.5194/osd-10-555-2013, https://doi.org/10.5194/osd-10-555-2013, 2013
Revised manuscript not accepted
B. Bereiter, T. F. Stocker, and H. Fischer
Atmos. Meas. Tech., 6, 251–262, https://doi.org/10.5194/amt-6-251-2013, https://doi.org/10.5194/amt-6-251-2013, 2013
F. Parrenin and D. Paillard
Clim. Past, 8, 2031–2037, https://doi.org/10.5194/cp-8-2031-2012, https://doi.org/10.5194/cp-8-2031-2012, 2012
Related subject area
Subject: Carbon Cycle | Archive: Ice Cores | Timescale: Millenial/D-O
Estimation of gas record alteration in very low-accumulation ice cores
A 21 000-year record of fluorescent organic matter markers in the WAIS Divide ice core
Abrupt rise in atmospheric CO2 at the onset of the Bølling/Allerød: in-situ ice core data versus true atmospheric signals
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.
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.
P. Köhler, G. Knorr, D. Buiron, A. Lourantou, and J. Chappellaz
Clim. Past, 7, 473–486, https://doi.org/10.5194/cp-7-473-2011, https://doi.org/10.5194/cp-7-473-2011, 2011
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Short summary
We reconstruct atmospheric CO2 from the EPICA Dome C ice core during Marine Isotope Stage 6 (185–135 ka) to understand carbon mechanisms under the different boundary conditions of the climate system. The amplitude of CO2 is highly determined by the Northern Hemisphere stadial duration. Carbon dioxide maxima show different lags with respect to the corresponding abrupt CH4 jumps, the latter reflecting rapid warming in the Northern Hemisphere.
We reconstruct atmospheric CO2 from the EPICA Dome C ice core during Marine Isotope Stage 6...
