Articles | Volume 16, issue 4
https://doi.org/10.5194/cp-16-1159-2020
© 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-16-1159-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Jul 2020
Research article |
| 09 Jul 2020
| 09 Jul 2020
Mysteriously high Δ14C of the glacial atmosphere: influence of 14C production and carbon cycle changes
Ashley Dinauer
CORRESPONDING AUTHOR
Climate and Environmental Physics, Physics Institute and Oeschger
Centre for Climate Change Research, University of Bern, Sidlerstrasse 5,
3012 Bern, Switzerland
Florian Adolphi
Climate and Environmental Physics, Physics Institute and Oeschger
Centre for Climate Change Research, University of Bern, Sidlerstrasse 5,
3012 Bern, Switzerland
Quaternary Sciences, Department of Geology, Lund University,
Sölvegatan 12, 22362 Lund, Sweden
Fortunat Joos
Climate and Environmental Physics, Physics Institute and Oeschger
Centre for Climate Change Research, University of Bern, Sidlerstrasse 5,
3012 Bern, Switzerland
Related authors
No articles found.
Markus Adloff, Aurich Jeltsch-Thömmes, Frerk Pöppelmeier, Thomas F. Stocker, and Fortunat Joos
EGUsphere, https://doi.org/10.5194/egusphere-2024-1754, https://doi.org/10.5194/egusphere-2024-1754, 2024
This preprint is open for discussion and under review for Climate of the Past (CP).
Short summary
Short summary
We used an Earth system model to simulate how different processes changed the amount of carbon in the ocean and atmosphere over the last eight glacial cycles. We found that the effects of interactive marine sediments enlarge the carbon fluxes that result from these processes, especially in the ocean. Comparison with proxy data showed that no single process explains the global carbon cycle changes over glacial cycles, but individual processes can dominate regional and proxy-specific changes.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
Short summary
Short summary
Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Zhen Zhang, Benjamin Poulter, Joe R. Melton, William J. Riley, George H. Allen, David J. Beerling, Philippe Bousquet, Josep G. Canadell, Etienne Fluet-Chouinard, Philippe Ciais, Nicola Gedney, Peter O. Hopcroft, Akihiko Ito, Robert B. Jackson, Atul K. Jain, Katherine Jensen, Fortunat Joos, Thomas Kleinen, Sara Knox, Tingting Li, Xin Li, Xiangyu Liu, Kyle McDonald, Gavin McNicol, Paul A. Miller, Jurek Müller, Prabir K. Patra, Changhui Peng, Shushi Peng, Zhangcai Qin, Ryan M. Riggs, Marielle Saunois, Qing Sun, Hanqin Tian, Xiaoming Xu, Yuanzhi Yao, Xi Yi, Wenxin Zhang, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
EGUsphere, https://doi.org/10.5194/egusphere-2024-1584, https://doi.org/10.5194/egusphere-2024-1584, 2024
Short summary
Short summary
This study assesses global methane emissions from wetlands between 2000 and 2020 using multiple models. We found that wetland emissions increased by 6–7 Tg CH4 per year in the 2010s compared to the 2000s. Rising temperatures primarily drove this increase, while changes in precipitation and CO2 levels also played roles. Our findings highlight the importance of wetlands in the global methane budget and the need for continuous monitoring to understand their impact on climate change.
Markus Adloff, Frerk Pöppelmeier, Aurich Jeltsch-Thömmes, Thomas F. Stocker, and Fortunat Joos
Clim. Past, 20, 1233–1250, https://doi.org/10.5194/cp-20-1233-2024, https://doi.org/10.5194/cp-20-1233-2024, 2024
Short summary
Short summary
The Atlantic Meridional Overturning Circulation (AMOC) is an ocean current that transports heat into the North Atlantic. Over the ice age cycles, AMOC strength and its spatial pattern varied. We tested the role of heat forcing for these AMOC changes by simulating the temperature changes of the last eight glacial cycles. In our model, AMOC shifts between four distinct circulation modes caused by heat and salt redistributions that reproduce reconstructed long-term North Atlantic SST changes.
Emmanuele Russo, Jonathan Buzan, Sebastian Lienert, Guillaume Jouvet, Patricio Velasquez Alvarez, Basil Davis, Patrick Ludwig, Fortunat Joos, and Christoph C. Raible
Clim. Past, 20, 449–465, https://doi.org/10.5194/cp-20-449-2024, https://doi.org/10.5194/cp-20-449-2024, 2024
Short summary
Short summary
We present a series of experiments conducted for the Last Glacial Maximum (~21 ka) over Europe using the regional climate Weather Research and Forecasting model (WRF) at convection-permitting resolutions. The model, with new developments better suited to paleo-studies, agrees well with pollen-based climate reconstructions. This agreement is improved when considering different sources of uncertainty. The effect of convection-permitting resolutions is also assessed.
Yona Silvy, Thomas L. Frölicher, Jens Terhaar, Fortunat Joos, Friedrich A. Burger, Fabrice Lacroix, Myles Allen, Raffaele Bernadello, Laurent Bopp, Victor Brovkin, Jonathan R. Buzan, Patricia Cadule, Martin Dix, John Dunne, Pierre Friedlingstein, Goran Georgievski, Tomohiro Hajima, Stuart Jenkins, Michio Kawamiya, Nancy Y. Kiang, Vladimir Lapin, Donghyun Lee, Paul Lerner, Nadine Mengis, Estela A. Monteiro, David Paynter, Glen P. Peters, Anastasia Romanou, Jörg Schwinger, Sarah Sparrow, Eric Stofferahn, Jerry Tjiputra, Etienne Tourigny, and Tilo Ziehn
EGUsphere, https://doi.org/10.5194/egusphere-2024-488, https://doi.org/10.5194/egusphere-2024-488, 2024
Short summary
Short summary
We apply the Adaptive Emission Reduction Approach with Earth System Models to provide simulations in which all ESMs converge at 1.5 °C and 2 °C warming levels. These simulations provide compatible emission pathways for a given warming level, uncovering uncertainty ranges previously missing in the CMIP scenarios. This new type of target-based emission-driven simulations offers a more coherent assessment across ESMs for studying both the carbon cycle and impacts under climate stabilization.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Peter Landschützer, Corinne Le Quéré, Ingrid T. Luijkx, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Peter Anthoni, Leticia Barbero, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Bertrand Decharme, Laurent Bopp, Ida Bagus Mandhara Brasika, Patricia Cadule, Matthew A. Chamberlain, Naveen Chandra, Thi-Tuyet-Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Xinyu Dou, Kazutaka Enyo, Wiley Evans, Stefanie Falk, Richard A. Feely, Liang Feng, Daniel J. Ford, Thomas Gasser, Josefine Ghattas, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Jens Heinke, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Andrew R. Jacobson, Atul Jain, Tereza Jarníková, Annika Jersild, Fei Jiang, Zhe Jin, Fortunat Joos, Etsushi Kato, Ralph F. Keeling, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Xin Lan, Nathalie Lefèvre, Hongmei Li, Junjie Liu, Zhiqiang Liu, Lei Ma, Greg Marland, Nicolas Mayot, Patrick C. McGuire, Galen A. McKinley, Gesa Meyer, Eric J. Morgan, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin M. O'Brien, Are Olsen, Abdirahman M. Omar, Tsuneo Ono, Melf Paulsen, Denis Pierrot, Katie Pocock, Benjamin Poulter, Carter M. Powis, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Roland Séférian, T. Luke Smallman, Stephen M. Smith, Reinel Sospedra-Alfonso, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Erik van Ooijen, Rik Wanninkhof, Michio Watanabe, Cathy Wimart-Rousseau, Dongxu Yang, Xiaojuan Yang, Wenping Yuan, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng
Earth Syst. Sci. Data, 15, 5301–5369, https://doi.org/10.5194/essd-15-5301-2023, https://doi.org/10.5194/essd-15-5301-2023, 2023
Short summary
Short summary
The Global Carbon Budget 2023 describes the methodology, main results, and data sets used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, land ecosystems, and the ocean over the historical period (1750–2023). These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Minjie Zheng, Hongyu Liu, Florian Adolphi, Raimund Muscheler, Zhengyao Lu, Mousong Wu, and Nønne L. Prisle
Geosci. Model Dev., 16, 7037–7057, https://doi.org/10.5194/gmd-16-7037-2023, https://doi.org/10.5194/gmd-16-7037-2023, 2023
Short summary
Short summary
The radionuclides 7Be and 10Be are useful tracers for atmospheric transport studies. Here we use the GEOS-Chem to simulate 7Be and 10Be with different production rates: the default production rate in GEOS-Chem and two from the state-of-the-art beryllium production model. We demonstrate that reduced uncertainties in the production rates can enhance the utility of 7Be and 10Be as tracers for evaluating transport and scavenging processes in global models.
Chiara I. Paleari, Florian Mekhaldi, Tobias Erhardt, Minjie Zheng, Marcus Christl, Florian Adolphi, Maria Hörhold, and Raimund Muscheler
Clim. Past, 19, 2409–2422, https://doi.org/10.5194/cp-19-2409-2023, https://doi.org/10.5194/cp-19-2409-2023, 2023
Short summary
Short summary
In this study, we test the use of excess meltwater from continuous flow analysis from a firn core from Greenland for the measurement of 10Be for solar activity reconstructions. We show that the quality of results is similar to the measurements on clean firn, which opens the possibility to obtain continuous 10Be records without requiring large amounts of clean ice. Furthermore, we investigate the possibility of identifying solar storm signals in 10Be records from Greenland and Antarctica.
Tobias Erhardt, Camilla Marie Jensen, Florian Adolphi, Helle Astrid Kjær, Remi Dallmayr, Birthe Twarloh, Melanie Behrens, Motohiro Hirabayashi, Kaori Fukuda, Jun Ogata, François Burgay, Federico Scoto, Ilaria Crotti, Azzurra Spagnesi, Niccoló Maffezzoli, Delia Segato, Chiara Paleari, Florian Mekhaldi, Raimund Muscheler, Sophie Darfeuil, and Hubertus Fischer
Earth Syst. Sci. Data, 15, 5079–5091, https://doi.org/10.5194/essd-15-5079-2023, https://doi.org/10.5194/essd-15-5079-2023, 2023
Short summary
Short summary
The presented paper provides a 3.8 kyr long dataset of aerosol concentrations from the East Greenland Ice coring Project (EGRIP) ice core. The data consists of 1 mm depth-resolution profiles of calcium, sodium, ammonium, nitrate, and electrolytic conductivity as well as decadal averages of these profiles. Alongside the data a detailed description of the measurement setup as well as a discussion of the uncertainties are given.
Luke Skinner, Francois Primeau, Aurich Jeltsch-Thömmes, Fortunat Joos, Peter Köhler, and Edouard Bard
Clim. Past, 19, 2177–2202, https://doi.org/10.5194/cp-19-2177-2023, https://doi.org/10.5194/cp-19-2177-2023, 2023
Short summary
Short summary
Radiocarbon is best known as a dating tool, but it also allows us to track CO2 exchange between the ocean and atmosphere. Using decades of data and novel mapping methods, we have charted the ocean’s average radiocarbon ″age” since the last Ice Age. Combined with climate model simulations, these data quantify the ocean’s role in atmospheric CO2 rise since the last Ice Age while also revealing that Earth likely received far more cosmic radiation during the last Ice Age than hitherto believed.
Christoph Heinze, Thorsten Blenckner, Peter Brown, Friederike Fröb, Anne Morée, Adrian L. New, Cara Nissen, Stefanie Rynders, Isabel Seguro, Yevgeny Aksenov, Yuri Artioli, Timothée Bourgeois, Friedrich Burger, Jonathan Buzan, B. B. Cael, Veli Çağlar Yumruktepe, Melissa Chierici, Christopher Danek, Ulf Dieckmann, Agneta Fransson, Thomas Frölicher, Giovanni Galli, Marion Gehlen, Aridane G. González, Melchor Gonzalez-Davila, Nicolas Gruber, Örjan Gustafsson, Judith Hauck, Mikko Heino, Stephanie Henson, Jenny Hieronymus, I. Emma Huertas, Fatma Jebri, Aurich Jeltsch-Thömmes, Fortunat Joos, Jaideep Joshi, Stephen Kelly, Nandini Menon, Precious Mongwe, Laurent Oziel, Sólveig Ólafsdottir, Julien Palmieri, Fiz F. Pérez, Rajamohanan Pillai Ranith, Juliano Ramanantsoa, Tilla Roy, Dagmara Rusiecka, J. Magdalena Santana Casiano, Yeray Santana-Falcón, Jörg Schwinger, Roland Séférian, Miriam Seifert, Anna Shchiptsova, Bablu Sinha, Christopher Somes, Reiner Steinfeldt, Dandan Tao, Jerry Tjiputra, Adam Ulfsbo, Christoph Völker, Tsuyoshi Wakamatsu, and Ying Ye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-182, https://doi.org/10.5194/bg-2023-182, 2023
Revised manuscript under review for BG
Short summary
Short summary
For assessing the consequences of human-induced climate change for the marine realm, it is necessary to not only look at gradual changes but also at abrupt changes of environmental conditions. We summarise abrupt changes in ocean warming, acidification, and oxygen concentration as the key environmental factors for ecosystems. Taking these abrupt changes into account requires greenhouse gas emissions to be reduced to a larger extent than previously thought to limit respective damage.
Sian Kou-Giesbrecht, Vivek K. Arora, Christian Seiler, Almut Arneth, Stefanie Falk, Atul K. Jain, Fortunat Joos, Daniel Kennedy, Jürgen Knauer, Stephen Sitch, Michael O'Sullivan, Naiqing Pan, Qing Sun, Hanqin Tian, Nicolas Vuichard, and Sönke Zaehle
Earth Syst. Dynam., 14, 767–795, https://doi.org/10.5194/esd-14-767-2023, https://doi.org/10.5194/esd-14-767-2023, 2023
Short summary
Short summary
Nitrogen (N) is an essential limiting nutrient to terrestrial carbon (C) sequestration. We evaluate N cycling in an ensemble of terrestrial biosphere models. We find that variability in N processes across models is large. Models tended to overestimate C storage per unit N in vegetation and soil, which could have consequences for projecting the future terrestrial C sink. However, N cycling measurements are highly uncertain, and more are necessary to guide the development of N cycling in models.
Giulia Sinnl, Florian Adolphi, Marcus Christl, Kees C. Welten, Thomas Woodruff, Marc Caffee, Anders Svensson, Raimund Muscheler, and Sune Olander Rasmussen
Clim. Past, 19, 1153–1175, https://doi.org/10.5194/cp-19-1153-2023, https://doi.org/10.5194/cp-19-1153-2023, 2023
Short summary
Short summary
The record of past climate is preserved by several archives from different regions, such as ice cores from Greenland or Antarctica or speleothems from caves such as the Hulu Cave in China. In this study, these archives are aligned by taking advantage of the globally synchronous production of cosmogenic radionuclides. This produces a new perspective on the global climate in the period between 20 000 and 25 000 years ago.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
Short summary
Short summary
Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Elisabeth Tschumi, Sebastian Lienert, Karin van der Wiel, Fortunat Joos, and Jakob Zscheischler
Biogeosciences, 19, 1979–1993, https://doi.org/10.5194/bg-19-1979-2022, https://doi.org/10.5194/bg-19-1979-2022, 2022
Short summary
Short summary
Droughts and heatwaves are expected to occur more often in the future, but their effects on land vegetation and the carbon cycle are poorly understood. We use six climate scenarios with differing extreme occurrences and a vegetation model to analyse these effects. Tree coverage and associated plant productivity increase under a climate with no extremes. Frequent co-occurring droughts and heatwaves decrease plant productivity more than the combined effects of single droughts or heatwaves.
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
Short summary
Short summary
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.
Nathalie Van der Putten, Florian Adolphi, Anette Mellström, Jesper Sjolte, Cyriel Verbruggen, Jan-Berend Stuut, Tobias Erhardt, Yves Frenot, and Raimund Muscheler
Clim. Past Discuss., https://doi.org/10.5194/cp-2021-69, https://doi.org/10.5194/cp-2021-69, 2021
Manuscript not accepted for further review
Short summary
Short summary
In recent decades, Southern Hemisphere westerlies (SHW) moved equator-ward during periods of low solar activity leading to increased winds/precipitation at 46° S, Indian Ocean. We present a terrestrial SHW proxy-record and find stronger SHW influence at Crozet, shortly after 2.8 ka BP, synchronous with a climate shift in the Northern Hemisphere, attributed to a major decline in solar activity. The bipolar response to solar forcing is supported by a climate model forced by solar irradiance only.
Jurek Müller and Fortunat Joos
Biogeosciences, 18, 3657–3687, https://doi.org/10.5194/bg-18-3657-2021, https://doi.org/10.5194/bg-18-3657-2021, 2021
Short summary
Short summary
We present long-term projections of global peatland area and carbon with a continuous transient history since the Last Glacial Maximum. Our novel results show that large parts of today’s northern peatlands are at risk from past and future climate change, with larger emissions clearly connected to larger risks. The study includes comparisons between different emission and land-use scenarios, driver attribution through factorial simulations, and assessments of uncertainty from climate forcing.
Shannon A. Bengtson, Laurie C. Menviel, Katrin J. Meissner, Lise Missiaen, Carlye D. Peterson, Lorraine E. Lisiecki, and Fortunat Joos
Clim. Past, 17, 507–528, https://doi.org/10.5194/cp-17-507-2021, https://doi.org/10.5194/cp-17-507-2021, 2021
Short summary
Short summary
The last interglacial was a warm period that may provide insights into future climates. Here, we compile and analyse stable carbon isotope data from the ocean during the last interglacial and compare it to the Holocene. The data show that Atlantic Ocean circulation was similar during the last interglacial and the Holocene. We also establish a difference in the mean oceanic carbon isotopic ratio between these periods, which was most likely caused by burial and weathering carbon fluxes.
Jurek Müller and Fortunat Joos
Biogeosciences, 17, 5285–5308, https://doi.org/10.5194/bg-17-5285-2020, https://doi.org/10.5194/bg-17-5285-2020, 2020
Short summary
Short summary
We present an in-depth model analysis of transient peatland area and carbon dynamics over the last 22 000 years. Our novel results show that the consideration of both gross positive and negative area changes are necessary to understand the transient evolution of peatlands and their net effect on atmospheric carbon. The study includes the attributions to drivers through factorial simulations, assessments of uncertainty from climate forcing, and determination of the global net carbon balance.
Jesper Sjolte, Florian Adolphi, Bo M. Vinther, Raimund Muscheler, Christophe Sturm, Martin Werner, and Gerrit Lohmann
Clim. Past, 16, 1737–1758, https://doi.org/10.5194/cp-16-1737-2020, https://doi.org/10.5194/cp-16-1737-2020, 2020
Short summary
Short summary
In this study we investigate seasonal climate reconstructions produced by matching climate model output to ice core and tree-ring data, and we evaluate the model–data reconstructions against meteorological observations. The reconstructions capture the main patterns of variability in sea level pressure and temperature in summer and winter. The performance of the reconstructions depends on seasonal climate variability itself, and definitions of seasons can be optimized to capture this variability.
Marielle Saunois, Ann R. Stavert, Ben Poulter, Philippe Bousquet, Josep G. Canadell, Robert B. Jackson, Peter A. Raymond, Edward J. Dlugokencky, Sander Houweling, Prabir K. Patra, Philippe Ciais, Vivek K. Arora, David Bastviken, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Kimberly M. Carlson, Mark Carrol, Simona Castaldi, Naveen Chandra, Cyril Crevoisier, Patrick M. Crill, Kristofer Covey, Charles L. Curry, Giuseppe Etiope, Christian Frankenberg, Nicola Gedney, Michaela I. Hegglin, Lena Höglund-Isaksson, Gustaf Hugelius, Misa Ishizawa, Akihiko Ito, Greet Janssens-Maenhout, Katherine M. Jensen, Fortunat Joos, Thomas Kleinen, Paul B. Krummel, Ray L. Langenfelds, Goulven G. Laruelle, Licheng Liu, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Joe McNorton, Paul A. Miller, Joe R. Melton, Isamu Morino, Jurek Müller, Fabiola Murguia-Flores, Vaishali Naik, Yosuke Niwa, Sergio Noce, Simon O'Doherty, Robert J. Parker, Changhui Peng, Shushi Peng, Glen P. Peters, Catherine Prigent, Ronald Prinn, Michel Ramonet, Pierre Regnier, William J. Riley, Judith A. Rosentreter, Arjo Segers, Isobel J. Simpson, Hao Shi, Steven J. Smith, L. Paul Steele, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Francesco N. Tubiello, Aki Tsuruta, Nicolas Viovy, Apostolos Voulgarakis, Thomas S. Weber, Michiel van Weele, Guido R. van der Werf, Ray F. Weiss, Doug Worthy, Debra Wunch, Yi Yin, Yukio Yoshida, Wenxin Zhang, Zhen Zhang, Yuanhong Zhao, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 12, 1561–1623, https://doi.org/10.5194/essd-12-1561-2020, https://doi.org/10.5194/essd-12-1561-2020, 2020
Short summary
Short summary
Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. We have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. This is the second version of the review dedicated to the decadal methane budget, integrating results of top-down and bottom-up estimates.
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
Short summary
Short summary
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.
Florian Mekhaldi, Markus Czymzik, Florian Adolphi, Jesper Sjolte, Svante Björck, Ala Aldahan, Achim Brauer, Celia Martin-Puertas, Göran Possnert, and Raimund Muscheler
Clim. Past, 16, 1145–1157, https://doi.org/10.5194/cp-16-1145-2020, https://doi.org/10.5194/cp-16-1145-2020, 2020
Short summary
Short summary
Due to chronology uncertainties within paleoclimate archives, it is unclear how climate oscillations from different records relate to one another. By using radionuclides to synchronize Greenland ice cores and a German lake record over 11 000 years, we show that two oscillations observed in these records were not synchronous but terminated and began with the onset of a grand solar minimum. Both this and changes in ocean circulation could have played a role in the two climate oscillations.
Angélique Hameau, Thomas L. Frölicher, Juliette Mignot, and Fortunat Joos
Biogeosciences, 17, 1877–1895, https://doi.org/10.5194/bg-17-1877-2020, https://doi.org/10.5194/bg-17-1877-2020, 2020
Short summary
Short summary
Ocean deoxygenation and warming are observed and projected to intensify under continued greenhouse gas emissions. Whereas temperature is considered the main climate change indicator, we show that in certain regions, thermocline doxygenation may be detectable before warming.
Aurich Jeltsch-Thömmes and Fortunat Joos
Clim. Past, 16, 423–451, https://doi.org/10.5194/cp-16-423-2020, https://doi.org/10.5194/cp-16-423-2020, 2020
Short summary
Short summary
Perturbations in atmospheric CO2 and in its isotopic composition, e.g., in response to carbon release from the land biosphere or from fossil fuel burning, evolve differently in time. We use an Earth system model of intermediate complexity to show that fluxes to and from the solid Earth play an important role in removing these perturbations from the atmosphere over thousands of years.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Olli Peltola, Timo Vesala, Yao Gao, Olle Räty, Pavel Alekseychik, Mika Aurela, Bogdan Chojnicki, Ankur R. Desai, Albertus J. Dolman, Eugenie S. Euskirchen, Thomas Friborg, Mathias Göckede, Manuel Helbig, Elyn Humphreys, Robert B. Jackson, Georg Jocher, Fortunat Joos, Janina Klatt, Sara H. Knox, Natalia Kowalska, Lars Kutzbach, Sebastian Lienert, Annalea Lohila, Ivan Mammarella, Daniel F. Nadeau, Mats B. Nilsson, Walter C. Oechel, Matthias Peichl, Thomas Pypker, William Quinton, Janne Rinne, Torsten Sachs, Mateusz Samson, Hans Peter Schmid, Oliver Sonnentag, Christian Wille, Donatella Zona, and Tuula Aalto
Earth Syst. Sci. Data, 11, 1263–1289, https://doi.org/10.5194/essd-11-1263-2019, https://doi.org/10.5194/essd-11-1263-2019, 2019
Short summary
Short summary
Here we develop a monthly gridded dataset of northern (> 45 N) wetland methane (CH4) emissions. The data product is derived using a random forest machine-learning technique and eddy covariance CH4 fluxes from 25 wetland sites. Annual CH4 emissions from these wetlands calculated from the derived data product are comparable to prior studies focusing on these areas. This product is an independent estimate of northern wetland CH4 emissions and hence could be used, e.g. for process model evaluation.
Aurich Jeltsch-Thömmes, Gianna Battaglia, Olivier Cartapanis, Samuel L. Jaccard, and Fortunat Joos
Clim. Past, 15, 849–879, https://doi.org/10.5194/cp-15-849-2019, https://doi.org/10.5194/cp-15-849-2019, 2019
Short summary
Short summary
A long-standing question in climate science is concerned with what processes contributed to the increase in atmospheric CO2 after the last ice age. From the range of possible processes we try to constrain the change in carbon storage in the land biosphere. By combining ice core and marine sediment data in a modeling framework we show that the carbon storage in the land biosphere increased largely after the last ice age. This will help to further understand processes at work in the Earth system.
Angélique Hameau, Juliette Mignot, and Fortunat Joos
Biogeosciences, 16, 1755–1780, https://doi.org/10.5194/bg-16-1755-2019, https://doi.org/10.5194/bg-16-1755-2019, 2019
Short summary
Short summary
The observed decrease of oxygen and warming in the ocean may adversely affect marine ecosystems and their services. We analyse results from an Earth system model for the last millennium and the 21st century. We find changes in temperature and oxygen due to fossil fuel burning and other human activities to exceed natural variations in many ocean regions already today. Natural variability is biased low in earlier studies neglecting forcing from past volcanic eruptions and solar change.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Jesper Sjolte, Christophe Sturm, Florian Adolphi, Bo M. Vinther, Martin Werner, Gerrit Lohmann, and Raimund Muscheler
Clim. Past, 14, 1179–1194, https://doi.org/10.5194/cp-14-1179-2018, https://doi.org/10.5194/cp-14-1179-2018, 2018
Short summary
Short summary
Tropical volcanic eruptions and variations in solar activity have been suggested to influence the strength of westerly winds across the North Atlantic. We use Greenland ice core records together with a climate model simulation, and find stronger westerly winds for five winters following tropical volcanic eruptions. We see a delayed response to solar activity of 5 years, and the response to solar minima corresponds well to the cooling pattern during the period known as the Little Ice Age.
Minjie Zheng, Jesper Sjolte, Florian Adolphi, Bo Møllesøe Vinther, Hans Christian Steen-Larsen, Trevor James Popp, and Raimund Muscheler
Clim. Past, 14, 1067–1078, https://doi.org/10.5194/cp-14-1067-2018, https://doi.org/10.5194/cp-14-1067-2018, 2018
Short summary
Short summary
We show the seasonal δ18O data from the NEEM site in northwestern Greenland over the last 150 years. We found that the NEEM summer δ18O signal correlates well with summer temperature in western coastal Greenland, while the NEEM winter δ18O signal correlates well with sea ice concentration in Baffin Bay. In contrast with the winter δ18O data from central/southern Greenland, we find no linkage of NEEM winter δ18O to winter NAO.
Gianna Battaglia and Fortunat Joos
Earth Syst. Dynam., 9, 797–816, https://doi.org/10.5194/esd-9-797-2018, https://doi.org/10.5194/esd-9-797-2018, 2018
Short summary
Short summary
Human-caused, climate change hazards in the ocean continue to aggravate over a very long time. For business as usual, we project the ocean oxygen content to decrease by 40 % over the next thousand years. This would likely have severe consequences for marine life. Global warming and oxygen loss are linked, and meeting the warming target of the Paris Climate Agreement effectively limits related marine hazards. Developments over many thousands of years should be considered to assess marine risks.
Fortunat Joos and Brigitte Buchmann
Atmos. Chem. Phys., 18, 7841–7842, https://doi.org/10.5194/acp-18-7841-2018, https://doi.org/10.5194/acp-18-7841-2018, 2018
Markus Czymzik, Raimund Muscheler, Florian Adolphi, Florian Mekhaldi, Nadine Dräger, Florian Ott, Michał Słowinski, Mirosław Błaszkiewicz, Ala Aldahan, Göran Possnert, and Achim Brauer
Clim. Past, 14, 687–696, https://doi.org/10.5194/cp-14-687-2018, https://doi.org/10.5194/cp-14-687-2018, 2018
Short summary
Short summary
Our results provide a proof of concept for facilitating 10Be in varved lake sediments as a novel synchronization tool required for investigating leads and lags of proxy responses to climate variability. They also point to some limitations of 10Be in these archives mainly connected to in-lake sediment resuspension processes.
Kuno M. Strassmann and Fortunat Joos
Geosci. Model Dev., 11, 1887–1908, https://doi.org/10.5194/gmd-11-1887-2018, https://doi.org/10.5194/gmd-11-1887-2018, 2018
Short summary
Short summary
The Bern Simple Climate Model (BernSCM) is a free open-source re-implementation of a reduced-form carbon cycle–climate model widely used in science and IPCC assessments. BernSCM supports up to decadal time steps with high accuracy and is suitable for studies with high computational load, e.g., integrated assessment models (IAMs). Further applications include climate risk assessment in a business, public, or educational context and the estimation of benefits of emission mitigation options.
Sebastian Lienert and Fortunat Joos
Biogeosciences, 15, 2909–2930, https://doi.org/10.5194/bg-15-2909-2018, https://doi.org/10.5194/bg-15-2909-2018, 2018
Short summary
Short summary
Deforestation, shifting cultivation and wood harvesting cause large carbon emissions, altering climate. We apply a dynamic global vegetation model in a probabilistic framework. Diverse observations are assimilated to establish an optimally performing model and a large ensemble of model versions. Land-use carbon emissions are reported for individual countries, regions and the world. We find that parameter-related uncertainties are on the same order of magnitude as process-related effects.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Ray Weiss, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Atmos. Chem. Phys., 17, 11135–11161, https://doi.org/10.5194/acp-17-11135-2017, https://doi.org/10.5194/acp-17-11135-2017, 2017
Short summary
Short summary
Following the Global Methane Budget 2000–2012 published in Saunois et al. (2016), we use the same dataset of bottom-up and top-down approaches to discuss the variations in methane emissions over the period 2000–2012. The changes in emissions are discussed both in terms of trends and quasi-decadal changes. The ensemble gathered here allows us to synthesise the robust changes in terms of regional and sectorial contributions to the increasing methane emissions.
James C. Orr, Raymond G. Najjar, Olivier Aumont, Laurent Bopp, John L. Bullister, Gokhan Danabasoglu, Scott C. Doney, John P. Dunne, Jean-Claude Dutay, Heather Graven, Stephen M. Griffies, Jasmin G. John, Fortunat Joos, Ingeborg Levin, Keith Lindsay, Richard J. Matear, Galen A. McKinley, Anne Mouchet, Andreas Oschlies, Anastasia Romanou, Reiner Schlitzer, Alessandro Tagliabue, Toste Tanhua, and Andrew Yool
Geosci. Model Dev., 10, 2169–2199, https://doi.org/10.5194/gmd-10-2169-2017, https://doi.org/10.5194/gmd-10-2169-2017, 2017
Short summary
Short summary
The Ocean Model Intercomparison Project (OMIP) is a model comparison effort under Phase 6 of the Coupled Model Intercomparison Project (CMIP6). Its physical component is described elsewhere in this special issue. Here we describe its ocean biogeochemical component (OMIP-BGC), detailing simulation protocols and analysis diagnostics. Simulations focus on ocean carbon, other biogeochemical tracers, air-sea exchange of CO2 and related gases, and chemical tracers used to evaluate modeled circulation.
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
Sifan Gu, Zhengyu Liu, Alexandra Jahn, Johannes Rempfer, Jiaxu Zhang, and Fortunat Joos
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2017-40, https://doi.org/10.5194/gmd-2017-40, 2017
Revised manuscript not accepted
Short summary
Short summary
This paper is the documentation of the implementation of neodymium (Nd) isotopes in the ocean model of CESM. Our model can simulate both Nd concentration and Nd isotope ratio in good agreement with observations. Our Nd-enabled ocean model makes it possible for direct model-data comparison in paleoceanographic studies, which can help to resolve some uncertainties and controversies in our understanding of past ocean evolution. Therefore, our model provides a useful tool for paleoclimate studies.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Victor Brovkin, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Charles Curry, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Julia Marshall, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Catherine Prigent, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Paul Steele, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Michiel van Weele, Guido R. van der Werf, Ray Weiss, Christine Wiedinmyer, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Earth Syst. Sci. Data, 8, 697–751, https://doi.org/10.5194/essd-8-697-2016, https://doi.org/10.5194/essd-8-697-2016, 2016
Short summary
Short summary
An accurate assessment of the methane budget is important to understand the atmospheric methane concentrations and trends and to provide realistic pathways for climate change mitigation. The various and diffuse sources of methane as well and its oxidation by a very short lifetime radical challenge this assessment. We quantify the methane sources and sinks as well as their uncertainties based on both bottom-up and top-down approaches provided by a broad international scientific community.
Chantal Camenisch, Kathrin M. Keller, Melanie Salvisberg, Benjamin Amann, Martin Bauch, Sandro Blumer, Rudolf Brázdil, Stefan Brönnimann, Ulf Büntgen, Bruce M. S. Campbell, Laura Fernández-Donado, Dominik Fleitmann, Rüdiger Glaser, Fidel González-Rouco, Martin Grosjean, Richard C. Hoffmann, Heli Huhtamaa, Fortunat Joos, Andrea Kiss, Oldřich Kotyza, Flavio Lehner, Jürg Luterbacher, Nicolas Maughan, Raphael Neukom, Theresa Novy, Kathleen Pribyl, Christoph C. Raible, Dirk Riemann, Maximilian Schuh, Philip Slavin, Johannes P. Werner, and Oliver Wetter
Clim. Past, 12, 2107–2126, https://doi.org/10.5194/cp-12-2107-2016, https://doi.org/10.5194/cp-12-2107-2016, 2016
Short summary
Short summary
Throughout the last millennium, several cold periods occurred which affected humanity. Here, we investigate an exceptionally cold decade during the 15th century. The cold conditions challenged the food production and led to increasing food prices and a famine in parts of Europe. In contrast to periods such as the “Year Without Summer” after the eruption of Tambora, these extreme climatic conditions seem to have occurred by chance and in relation to the internal variability of the climate system.
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
Sonja G. Keel, Fortunat Joos, Renato Spahni, Matthias Saurer, Rosemarie B. Weigt, and Stefan Klesse
Biogeosciences, 13, 3869–3886, https://doi.org/10.5194/bg-13-3869-2016, https://doi.org/10.5194/bg-13-3869-2016, 2016
Short summary
Short summary
Records of stable oxygen isotope ratios in tree rings are valuable tools for reconstructing past climatic conditions. So far, they have not been used in global dynamic vegetation models. Here we present a model that simulates oxygen isotope ratios in tree rings. Our results compare well with measurements performed in European forests. The model is useful for studying oxygen isotope patterns of tree ring cellulose at large spatial and temporal scales.
Gianna Battaglia, Marco Steinacher, and Fortunat Joos
Biogeosciences, 13, 2823–2848, https://doi.org/10.5194/bg-13-2823-2016, https://doi.org/10.5194/bg-13-2823-2016, 2016
Short summary
Short summary
The marine cycle of calcium carbonate (CaCO3) influences the distribution of CO2 between atmosphere and ocean, and thereby climate. We constrain export of biogenic CaCO3 (globally: 0.72–1.05 Gt C yr−1) and dissolution within the water column (~ 80 %) in a novel Monte Carlo set-up with the Bern3D model based on alkalinity data. Whether CaCO3 dissolves in the upper ocean remains unresolved. We recommend using constant (saturation-independent) dissolution rates in Earth system models.
Michael Sigl, Tyler J. Fudge, Mai Winstrup, Jihong Cole-Dai, David Ferris, Joseph R. McConnell, Ken C. Taylor, Kees C. Welten, Thomas E. Woodruff, Florian Adolphi, Marion Bisiaux, Edward J. Brook, Christo Buizert, Marc W. Caffee, Nelia W. Dunbar, Ross Edwards, Lei Geng, Nels Iverson, Bess Koffman, Lawrence Layman, Olivia J. Maselli, Kenneth McGwire, Raimund Muscheler, Kunihiko Nishiizumi, Daniel R. Pasteris, Rachael H. Rhodes, and Todd A. Sowers
Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, https://doi.org/10.5194/cp-12-769-2016, 2016
Short summary
Short summary
Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide ice core, which is based on layer counting of distinctive annual cycles preserved in the elemental, chemical and electrical conductivity records. We validated the chronology by comparing it to independent high-accuracy, absolutely dated chronologies. Given its demonstrated high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere.
M. Steinacher and F. Joos
Biogeosciences, 13, 1071–1103, https://doi.org/10.5194/bg-13-1071-2016, https://doi.org/10.5194/bg-13-1071-2016, 2016
F. Adolphi and R. Muscheler
Clim. Past, 12, 15–30, https://doi.org/10.5194/cp-12-15-2016, https://doi.org/10.5194/cp-12-15-2016, 2016
Short summary
Short summary
Here we employ common variations in tree-ring 14C and Greenland ice core 10Be records to synchronize the Greenland ice core (GICC05) and the radiocarbon (IntCal13) timescale over the Holocene. We propose a transfer function between both timescales that allows continuous comparisons between radiocarbon dated and ice core climate records at unprecedented chronological precision.
B. D. Stocker and F. Joos
Earth Syst. Dynam., 6, 731–744, https://doi.org/10.5194/esd-6-731-2015, https://doi.org/10.5194/esd-6-731-2015, 2015
Short summary
Short summary
Estimates for land use change CO2 emissions (eLUC) rely on different approaches, implying conceptual differences of what eLUC represents. We use an Earth System Model and quantify differences between two commonly applied methods to be ~20% for historical eLUC but increasing under a future scenario. We decompose eLUC into component fluxes, quantify them, and discuss best practices for global carbon budget accountings and model-data intercomparisons relying on different methods to estimate eLUC.
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
Short summary
Short summary
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. D. Stocker, R. Spahni, and F. Joos
Geosci. Model Dev., 7, 3089–3110, https://doi.org/10.5194/gmd-7-3089-2014, https://doi.org/10.5194/gmd-7-3089-2014, 2014
Short summary
Short summary
Simulating the spatio-temporal dynamics of inundation is key to understanding the role of wetlands under past and future climate change. Here, we describe and assess the DYPTOP model that predicts the extent of inundation and the global spatial distribution of peatlands. DYPTOP makes use of high-resolution topography information and uses ecosystem water balance and peatland soil C balance criteria to simulate peatland spatial dynamics and carbon accumulation.
M. Gehlen, R. Séférian, D. O. B. Jones, T. Roy, R. Roth, J. Barry, L. Bopp, S. C. Doney, J. P. Dunne, C. Heinze, F. Joos, J. C. Orr, L. Resplandy, J. Segschneider, and J. Tjiputra
Biogeosciences, 11, 6955–6967, https://doi.org/10.5194/bg-11-6955-2014, https://doi.org/10.5194/bg-11-6955-2014, 2014
Short summary
Short summary
This study evaluates potential impacts of pH reductions on North Atlantic deep-sea ecosystems in response to latest IPCC scenarios.Multi-model projections of pH changes over the seafloor are analysed with reference to a critical threshold based on palaeo-oceanographic studies, contemporary observations and model results. By 2100 under the most severe IPCC CO2 scenario, pH reductions occur over ~23% of deep-sea canyons and ~8% of seamounts – including seamounts proposed as marine protected areas.
R. Roth, S. P. Ritz, and F. Joos
Earth Syst. Dynam., 5, 321–343, https://doi.org/10.5194/esd-5-321-2014, https://doi.org/10.5194/esd-5-321-2014, 2014
K. M. Keller, F. Joos, and C. C. Raible
Biogeosciences, 11, 3647–3659, https://doi.org/10.5194/bg-11-3647-2014, https://doi.org/10.5194/bg-11-3647-2014, 2014
B. Ringeval, S. Houweling, P. M. van Bodegom, R. Spahni, R. van Beek, F. Joos, and T. Röckmann
Biogeosciences, 11, 1519–1558, https://doi.org/10.5194/bg-11-1519-2014, https://doi.org/10.5194/bg-11-1519-2014, 2014
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
R. Roth and F. Joos
Clim. Past, 9, 1879–1909, https://doi.org/10.5194/cp-9-1879-2013, https://doi.org/10.5194/cp-9-1879-2013, 2013
R. Spahni, F. Joos, B. D. Stocker, M. Steinacher, and Z. C. Yu
Clim. Past, 9, 1287–1308, https://doi.org/10.5194/cp-9-1287-2013, https://doi.org/10.5194/cp-9-1287-2013, 2013
M. Eby, A. J. Weaver, K. Alexander, K. Zickfeld, A. Abe-Ouchi, A. A. Cimatoribus, E. Crespin, S. S. Drijfhout, N. R. Edwards, A. V. Eliseev, G. Feulner, T. Fichefet, C. E. Forest, H. Goosse, P. B. Holden, F. Joos, M. Kawamiya, D. Kicklighter, H. Kienert, K. Matsumoto, I. I. Mokhov, E. Monier, S. M. Olsen, J. O. P. Pedersen, M. Perrette, G. Philippon-Berthier, A. Ridgwell, A. Schlosser, T. Schneider von Deimling, G. Shaffer, R. S. Smith, R. Spahni, A. P. Sokolov, M. Steinacher, K. Tachiiri, K. Tokos, M. Yoshimori, N. Zeng, and F. Zhao
Clim. Past, 9, 1111–1140, https://doi.org/10.5194/cp-9-1111-2013, https://doi.org/10.5194/cp-9-1111-2013, 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
V. Cocco, F. Joos, M. Steinacher, T. L. Frölicher, L. Bopp, J. Dunne, M. Gehlen, C. Heinze, J. Orr, A. Oschlies, B. Schneider, J. Segschneider, and J. Tjiputra
Biogeosciences, 10, 1849–1868, https://doi.org/10.5194/bg-10-1849-2013, https://doi.org/10.5194/bg-10-1849-2013, 2013
F. Joos, R. Roth, J. S. Fuglestvedt, G. P. Peters, I. G. Enting, W. von Bloh, V. Brovkin, E. J. Burke, M. Eby, N. R. Edwards, T. Friedrich, T. L. Frölicher, P. R. Halloran, P. B. Holden, C. Jones, T. Kleinen, F. T. Mackenzie, K. Matsumoto, M. Meinshausen, G.-K. Plattner, A. Reisinger, J. Segschneider, G. Shaffer, M. Steinacher, K. Strassmann, K. Tanaka, A. Timmermann, and A. J. Weaver
Atmos. Chem. Phys., 13, 2793–2825, https://doi.org/10.5194/acp-13-2793-2013, https://doi.org/10.5194/acp-13-2793-2013, 2013
Related subject area
Subject: Carbon Cycle | Archive: Modelling only | Timescale: Millenial/D-O
Impact of iron fertilisation on atmospheric CO2 during the last glaciation
The atmospheric bridge communicated the δ13C decline during the last deglaciation to the global upper ocean
Ocean carbon inventory under warmer climate conditions – the case of the Last Interglacial
The influence of carbonate platform interactions with subduction zone volcanism on palaeo-atmospheric CO2 since the Devonian
Scaling laws for perturbations in the ocean–atmosphere system following large CO2 emissions
Systematic study of the impact of fresh water fluxes on the glacial carbon cycle
Fingerprints of changes in the terrestrial carbon cycle in response to large reorganizations in ocean circulation
Himadri Saini, Katrin J. Meissner, Laurie Menviel, and Karin Kvale
Clim. Past, 19, 1559–1584, https://doi.org/10.5194/cp-19-1559-2023, https://doi.org/10.5194/cp-19-1559-2023, 2023
Short summary
Short summary
Understanding the changes in atmospheric CO2 during the last glacial cycle is crucial to comprehend the impact of climate change in the future. Previous research has hypothesised a key role of greater aeolian iron input into the Southern Ocean in influencing the global atmospheric CO2 levels by impacting the changes in the marine phytoplankton response. In our study, we test this iron hypothesis using climate modelling and constrain the impact of ocean iron supply on global CO2 decrease.
Jun Shao, Lowell D. Stott, Laurie Menviel, Andy Ridgwell, Malin Ödalen, and Mayhar Mohtadi
Clim. Past, 17, 1507–1521, https://doi.org/10.5194/cp-17-1507-2021, https://doi.org/10.5194/cp-17-1507-2021, 2021
Short summary
Short summary
Planktic and shallow benthic foraminiferal stable carbon isotope
(δ13C) data show a rapid decline during the last deglaciation. This widespread signal was linked to respired carbon released from the deep ocean and its transport through the upper-ocean circulation. Using numerical simulations in which a stronger flux of respired carbon upwells and outcrops in the Southern Ocean, we find that the depleted δ13C signal is transmitted to the rest of the upper ocean through air–sea gas exchange.
Augustin Kessler, Eirik Vinje Galaasen, Ulysses Silas Ninnemann, and Jerry Tjiputra
Clim. Past, 14, 1961–1976, https://doi.org/10.5194/cp-14-1961-2018, https://doi.org/10.5194/cp-14-1961-2018, 2018
Short summary
Short summary
We analyze the changes in oceanic carbon dynamics, using a state-of-the-art Earth system model, by comparing two quasi-equilibrium states: the early, warm Eemian (125 ka) versus the cooler, late Eemian (115 ka). Our results suggest a considerably weaker ocean dissolved inorganic carbon storage at 125 ka, an alteration of the deep-water geometry and ventilation in the South Atlantic, and heterogeneous changes in phosphate availability and carbon export between the Pacific and Atlantic basins.
Jodie Pall, Sabin Zahirovic, Sebastiano Doss, Rakib Hassan, Kara J. Matthews, John Cannon, Michael Gurnis, Louis Moresi, Adrian Lenardic, and R. Dietmar Müller
Clim. Past, 14, 857–870, https://doi.org/10.5194/cp-14-857-2018, https://doi.org/10.5194/cp-14-857-2018, 2018
Short summary
Short summary
Subduction zones intersecting buried carbonate platforms liberate significant atmospheric CO2 and have the potential to influence global climate. We model the spatio-temporal distribution of carbonate platform accumulation within a plate tectonic framework and use wavelet analysis to analyse linked behaviour between atmospheric CO2 and carbonate-intersecting subduction zone (CISZ) lengths since the Devonian. We find that increasing CISZ lengths likely contributed to a warmer Palaeogene climate.
N. Towles, P. Olson, and A. Gnanadesikan
Clim. Past, 11, 991–1007, https://doi.org/10.5194/cp-11-991-2015, https://doi.org/10.5194/cp-11-991-2015, 2015
Short summary
Short summary
In this paper we find scaling relationships for perturbations to atmosphere and ocean variables from large transient CO2 emissions. We use a carbon cycle box model to calculate peak perturbations to a variety of ocean and atmosphere variables resulting from idealized emission events. As these scaling relationships depend on the physical setup, they represent a compact way of characterizing how different climates respond to large transient perturbations.
N. Bouttes, D. M. Roche, and D. Paillard
Clim. Past, 8, 589–607, https://doi.org/10.5194/cp-8-589-2012, https://doi.org/10.5194/cp-8-589-2012, 2012
A. Bozbiyik, M. Steinacher, F. Joos, T. F. Stocker, and L. Menviel
Clim. Past, 7, 319–338, https://doi.org/10.5194/cp-7-319-2011, https://doi.org/10.5194/cp-7-319-2011, 2011
Cited articles
Adolphi, F. and Muscheler, R.: Synchronizing the Greenland ice core and radiocarbon timescales over the Holocene Bayesian wiggle-matching of cosmogenic radionuclide records, Clim. Past, 12, 15–30, https://doi.org/10.5194/cp-12-15-2016, 2016.
Adolphi, F., Muscheler, R., Svensson, A., Aldahan, A., Possnert, G., Beer, J., Sjolte, J., Björck, S., Matthes, K., and Thiéblemont, R.: Persistent link between solar activity and Greenland climate during the Last Glacial Maximum, Nat. Geosci., 7,
662–666, 2014.
Adolphi, F., Bronk Ramsey, C., Erhardt, T., Edwards, R. L., Cheng, H., Turney, C. S. M., Cooper, A., Svensson, A., Rasmussen, S. O., Fischer, H., and Muscheler, R.: Connecting the Greenland ice-core and U/Th timescales via cosmogenic radionuclides: testing the synchroneity of DansgaardOeschger events, Clim. Past, 14, 1755–1781, https://doi.org/10.5194/cp-14-1755-2018, 2018.
Ahn, J. and Brook, E. J.: Siple Dome ice reveals two modes of millennial
CO2 change during the last ice age, Nat. Commun., 5, 3723,
https://doi.org/10.1038/ncomms4723, 2014.
Ahn, J., Brook, E. J., Mitchell, L., Rosen, J., McConnell, J. R., Taylor, K., Etheridge, D., and Rubino, M.: Atmospheric CO2 over the last 1000
years: A high-resolution record from the West Antarctic Ice Sheet (WAIS)
Divide ice core, Global Biogeochem. Cy., 26, GB2027,
https://doi.org/10.1029/2011GB004247, 2012.
Allen, C. S., Pike, J., and Pudsey, C. J.: Last glacial–interglacial
sea-ice cover in the SW Atlantic and its potential role in global
deglaciation, Quaternary Sci. Rev., 30, 2446–2458, 2011.
Archer, D. and Maier-Reimer, E.: Effect of deep-sea sedimentary calcite
preservation on atmospheric CO2 concentration, Nature, 367, 260–263,
1994.
Archer, D., Lyle, M., Rodgers, K., and Froelich, P.: What controls opal
preservation in tropical deep-sea sediments?, Paleoceanography, 8, 7–21,
1993.
Archer, D., Winguth, A., Lea, D., and Mahowald, N.: What caused the
glacial/interglacial atmospheric pCO2 cycles?, Rev. Geophys.,
38, 159–189, 2000.
Audi, G., Bersillon, O., Blachot, J., and Wapstra, A. H.: The Nubase
evaluation of nuclear and decay properties, Nucl. Phys. A, 729, 3–128,
2003.
Bard, E., Raisbeck, G. M., Yiou, F., and Jouzel, J.: Solar modulation of
cosmogenic nuclide production over the last millennium: comparison between
14C and 10Be records, Earth Planet Sc. Lett., 150,
453–462, 1997.
Baumgartner, S., Beer, J., Wagner, G., Kubik, P., Suter, M., Raisbeck, G. M., and Yiou, F.: 10Be and dust, Nucl. Instrum. Meth. B, 123,
296–301, 1997.
Baumgartner, S., Beer, J., Masarik, J., Wagner, G., Meynadier, L., and
Synal, H.-A.: Geomagnetic Modulation of the 36Cl Flux in the GRIP Ice
Core, Greenland, Science, 279, 1330–1332, 1998.
Bauska, T. K., Joos, F., Mix, A. C., Roth, R., Ahn, J., and Brook, E. J.:
Links between atmospheric carbon dioxide, the land carbon reservoir and
climate over the past millennium, Nat. Geosci., 8, 383–387, 2015.
Bé, M.-M., Chisté, V., Dulieu, C., Mougeot, X., Chechev, V., Kondev, F., Nichols, A., Huang, X., and Wang, B.: Table of Radionuclides (Comments on evaluations), Monographie BIPM-5, vol. 7, 2013.
Bereiter, B., Lüthi, D., Siegrist, M., Schüpbach, S., Stocker, T. F., and Fischer, H.: Mode change of millennial CO2 variability during
the last glacial cycle associated with a bipolar marine carbon seesaw, P. Natl. Acad. Sci. USA, 109, 9755–9760, 2012.
Berger, A. L.: Long-term variations of daily insolation and Quaternary
climatic changes, J. Atmos. Sci., 35, 2362–2367, 1978.
Broecker, W. and Barker, S.: A 190 ‰ drop in
atmosphere's Δ14C during the “Mystery Interval” (17.5 to 14.5 kyr), Earth Planet. Sc. Lett., 256, 90–99, 2007.
Broecker, W. S. and Peng, T.-H.: Gas exchange rates between air and sea,
Tellus, 26, 21–35, 1974.
Bronk Ramsey, C., Staff, R. A., Bryant, C. L., Brock, F., Kitagawa, H., van
der Plicht, J., Schlolaut, G., Marshall, M. H., Brauer, A., Lamb, H. F.,
Payne, R. L., Tarasov, P. E., Haraguchi, T., Gotanda, K., Yonenobu, H.,
Yokoyama, Y., Tada, R., and Nakagawa, T.: A complete terrestrial radiocarbon
record for 11.2 to 52.8 kyr B. P., Science, 338, 370–374, 2012.
Brovkin, V., Ganopolski, A., Archer, D., and Munhoven, G.: Glacial CO2 cycle as a succession of key physical and biogeochemical processes, Clim. Past, 8, 251–264, https://doi.org/10.5194/cp-8-251-2012, 2012.
Butzin, M., Köhler, P., and Lohmann, G.: Marine radiocarbon reservoir
age simulations for the past 50 000 years, Geophys. Res. Lett., 44,
8473–8480, 2017.
Buizert, C., Cuffey, K. M., Severinghaus, J. P., Baggenstos, D., Fudge, T. J., Steig, E. J., Markle, B. R., Winstrup, M., Rhodes, R. H., Brook, E. J.,
Sowers, T. A., Clow, G. D., Cheng, H., Edwards, R. L., Sigl, M., McConnell, J. R., and Taylor, K. C.: The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference, Clim. Past, 11, 153–173, https://doi.org/10.5194/cp-11-153-2015, 2015.
Channell, J. E., Hodell, D. A., Crowhurst, S. J., Skinner, L. C., and
Muscheler, R.: Relative paleointensity (RPI) in the latest Pleistocene
(10–45 ka) and implications for deglacial atmospheric radiocarbon,
Quaternary Sci. Rev., 191, 57–72, 2018.
Cheng, H., Edwards, R. L., Southon, J., Matsumoto, K., Feinberg, J. M.,
Sinha, A., Zhou, W., Li, H., Li, X., Xu, Y., Chen, S., Tan, M., Wang, Q., Wang, Y., and Ning, Y.: Atmospheric 14C∕12C changes during the
last glacial period from Hulu Cave, Science, 362, 1293–1297, 2018.
Delaygue, G., Stocker, T. F., Joos, F., and Plattner, G.-K.: Simulation of
atmospheric radiocarbon during abrupt oceanic circulation changes: trying to
reconcile models and reconstructions, Quaternary Sci. Rev., 22,
1647–1658, 2003.
Dlugokencky, E., Lang, P., Mund, J., Crotwell, A., Crotwell, M., and
Thoning, K.: Atmospheric Carbon Dioxide Dry Air Mole Fractions from the NOAA
ESRL Carbon Cycle Cooperative Global Air Sampling Network, 1968–2015,
Version: 2016-08-30, available at:
ftp://aftp.cmdl.noaa.gov/data/trace_gases/co2/flask/surface/, last access: 17 August 2016.
Edwards, N. R. and Marsh, R.: Uncertainties due to transport-parameter
sensitivity in an efficient 3-D ocean-climate model, Clim. Dynam., 24,
415–433, 2005.
Edwards, N. R., Willmott, A. J., and Killworth, P. D.: On the Role of
Topography and Wind Stress on the Stability of the Thermohaline Circulation, J. Phys. Oceanogr., 28, 756–778, 1998.
Eggleston, S., Schmitt, J., Bereiter, B., Schneider, R., and Fischer, H.:
Evolution of the stable carbon isotope composition of atmospheric CO2
over the last glacial cycle, Paleoceanography, 31, 434–452, 2016.
Elsässer, C., Wagenbach, D., Levin, I., Stanzick, A., Christl, M., Wallner, A., Kipfstuhl, S., Seierstad, I. K., Wershofen, H., and Dibb, J.: Simulating ice core 10Be on the glacial–interglacial timescale, Clim. Past, 11, 115–133, https://doi.org/10.5194/cp-11-115-2015, 2015.
Field, C. V., Schmidt, G. A., Koch, D., and Salyk, C.: Modeling production
and climate-related impacts on 10Be concentration in ice cores, J. Geophys. Res., 111, D15107, https://doi.org/10.1029/2005JD006410, 2006.
Finkel, R. C. and Nishiizumi, K.: Beryllium 10 concentrations in the
Greenland Ice Sheet Project 2 ice core from 3–40 ka, J. Geophys.
Res.-Oceans, 102, 26699–26706, 1997.
Fischer, H., Schmitt, J., Lüthi, D., Stocker, T. F., Tschumi, T.,
Parekh, P., Joos, F., Köhler, P., Völker, C., Gersonde, R., Barbante, C., Le Floch, M., Raynaud, D., and Wolff, E.: The role of Southern Ocean processes in orbital
and millennial CO2 variations – A synthesis, Quaternary Sci. Rev., 29, 193–205, 2010.
Galbraith, E. D. and Skinner, L. C.: The Biological Pump During the Last
Glacial Maximum, Annu. Rev. Mar. Sci., 12, 559–586, 2020.
Ganopolski, A. and Brovkin, V.: Simulation of climate, ice sheets and CO2 evolution during the last four glacial cycles with an Earth system model of intermediate complexity, Clim. Past, 13, 1695–1716, https://doi.org/10.5194/cp-13-1695-2017, 2017.
Gehlen, M., Bopp, L., Emprin, N., Aumont, O., Heinze, C., and Ragueneau, O.: Reconciling surface ocean productivity, export fluxes and sediment composition in a global biogeochemical ocean model, Biogeosciences, 3, 521–537, https://doi.org/10.5194/bg-3-521-2006, 2006.
Gersonde, R., Crosta, X., Abelmann, A., and Armand, L.: Sea-surface
temperature and sea ice distribution of the Southern Ocean at the EPILOG
Last Glacial Maximum – a circum-Antarctic view based on siliceous
microfossil records, Quaternary Sci. Rev., 24, 869–896, 2005.
Gkinis, V., Simonsen, S. B., Buchardt, S. L., White, J. W., and Vinther, B. M.: Water isotope diffusion rates from the NorthGRIP ice core for the last
16 000 years – Glaciological and paleoclimatic implications, Earth Planet. Sc. Lett., 405, 132–141, 2014.
Griffies, S. M.: The Gent-McWilliams Skew Flux, J. Phys. Oceanogr., 28, 831–841, 1998.
Hain, M. P., Sigman, D. M., and Haug, G. H.: Distinct roles of the Southern
Ocean and North Atlantic in the deglacial atmospheric radiocarbon decline,
Earth Planet. Sc. Lett., 394, 198–208, 2014.
Heikkilä, U., Beer, J., and Feichter, J.: Meridional transport and deposition of atmospheric 10Be, Atmos. Chem. Phys., 9, 515–527, https://doi.org/10.5194/acp-9-515-2009, 2009.
Heikkilä, U., Phipps, S. J., and Smith, A. M.: 10Be in late deglacial
climate simulated by ECHAM5-HAM – Part 1: Climatological influences on 10Be deposition, Clim. Past, 9, 2641–2649, https://doi.org/10.5194/cp-9-2641-2013, 2013.
Heinze, C., Maier-Reimer, E., Winguth, A. M., and Archer, D.: A global
oceanic sediment model for long-term climate studies, Global Biogeochem.
Cy., 13, 221–250, 1999.
Herbst, K., Muscheler, R., and Heber, B.: The new local interstellar spectra
and their influence on the production rates of the cosmogenic radionuclides
10Be and 14C, J. Geophys. Res.-Space, 122,
23–34, 2017.
Hoff, U., Rasmussen, T. L., Stein, R., Ezat, M. M., and Fahl, K.: Sea ice
and millennial-scale climate variability in the Nordic seas 90 kyr ago to
present, Nat. Commun., 7, https://doi.org/10.1038/ncomms12247, 2016.
Hughen, K., Lehman, S., Southon, J., Overpeck, J., Marchal, O., Herring, C.,
and Turnbull, J.: 14C Activity and Global Carbon Cycle Changes over the
Past 50 000 Years, Science, 303, 202–207, 2004.
Huiskamp, W. N. and Meissner, K. J.: Oceanic carbon and water masses during
the Mystery Interval: A model-data comparison study, Paleoceanogr.
Paleoclimatol., 27, PA4206, https://doi.org/10.1029/2012PA002368, 2012.
Jeltsch-Thömmes, A., Battaglia, G., Cartapanis, O., Jaccard, S. L., and Joos, F.: Low terrestrial carbon storage at the Last Glacial Maximum: constraints from multi-proxy data, Clim. Past, 15, 849–879, https://doi.org/10.5194/cp-15-849-2019, 2019.
Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L.,
Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D.: The NCEP/NCAR
40-Year Reanalysis Project, B. Am. Meteorol. Soc., 77, 437–471, 1996.
Key, R. M., Kozyr, A., Sabine, C. L., Lee, K., Wanninkhof, R., Bullister, J. L., Feely, R. A., Millero, F. J., Mordy, C., and Peng, T.-H.: A global ocean carbon climatology: Results from
Global Data Analysis Project (GLODAP), Global Biogeochem. Cy., 18, GB4031,
https://doi.org/10.1029/2004GB002247, 2004.
Köhler, P., Muscheler, R., and Fischer, H.: A model-based interpretation
of low-frequency changes in the carbon cycle during the last 120 000 years
and its implications for the reconstruction of atmospheric Δ14C, Geochem. Geophys. Geosy., 7, 1–22, 2006.
Köhler, P., Nehrbass-Ahles, C., Schmitt, J., Stocker, T. F., and Fischer, H.: A 156 kyr smoothed history of the atmospheric greenhouse gases CO2, CH4, and N2O and their radiative forcing, Earth Syst. Sci. Data, 9, 363–387, https://doi.org/10.5194/essd-9-363-2017, 2017.
Krakauer, N. Y., Randerson, J. T., Primeau, F. W., Gruber, N., and
Menemenlis, D.: Carbon isotope evidence for the latitudinal distribution and
wind speed dependence of the air-sea gas transfer velocity, Tellus B, 58, 390–417, 2006.
Kukla, G. and Robinson, D.: Annual Cycle of Surface Albedo, Mon. Weather
Rev., 108, 56–68, 1980.
Laj, C., Kissel, C., Mazaud, A., Channell, J. E., and Beer, J.: North
Atlantic palaeointensity stack since 75 ka (NAPIS-75) and the duration of the
Laschamp event, Philos. T. Roy. Soc. A, 358, 1009–1025,
2000.
Laj, C., Kissel, C., Mazaud, A., Michel, E., Muscheler, R., and Beer, J.:
Geomagnetic field intensity, North Atlantic Deep Water circulation and
atmospheric Δ14C during the last 50 kyr, Earth Planet.
Sc. Lett., 200, 177–190, 2002.
Laj, C., Kissel, C., and Beer, J.: High resolution global paleointensity
stack since 75 kyr (GLOPIS-75) calibrated to absolute values,
Geoph. Monog. Series, 145, 255–265, 2004.
Laj, C., Guillou, H., and Kissel, C.: Dynamics of the earth magnetic field
in the 10–75 kyr period comprising the Laschamp and Mono Lake excursions:
New results from the French Chaîne des Puys in a global perspective,
Earth Planet. Sc. Lett., 387, 184–197, 2014.
Lisiecki, L. E. and Stern, J. V.: Regional and global benthic δ18O
stacks for the last glacial cycle, Paleoceanography, 31, 1368–1394, 2016.
Lourantou, A., Chappellaz, J., Barnola, J.-M., Masson-Delmotte, V., and
Raynaud, D.: Changes in atmospheric CO2 and its carbon isotopic ratio
during the penultimate deglaciation, Quaternary Sci. Rev., 29,
1983–1992, 2010.
Lüthi, D., Bereiter, B., Stauffer, B., Winkler, R., Schwander, J.,
Kindler, P., Leuenberger, M., Kipfstuhl, S., Capron, E., Landais, A.,
Fischer, H., and Stocker, T. F.: CO2 and O2∕N2 variations in
and just below the bubble-clathrate transformation zone of Antarctic ice
cores, Earth Planet. Sc. Lett., 297, 226–233, 2010.
MacFarling-Meure, C., Etheridge, D., Trudinger, C., Langenfelds, R., van
Ommen, T., Smith, A., and Elkins, J.: Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP, Geophys. Res.
Lett., 33, L14810, https://doi.org/10.1029/2006GL026152, 2006.
Marcott, S. A., Bauska, T. K., Buizert, C., Steig, E. J., Rosen, J. L.,
Cuffey, K. M., Fudge, T. J., Severinghaus, J. P., Ahn, J., Kalk, M. L.,
McConnell, J. R., Sowers, T., Taylor, K. C., White, J. W., and Brook, E. J.:
Centennial Scale Changes in the Global Carbon Cycle During the Last
Deglaciation, Nature, 514, 616–619, 2014.
Marchal, O., Stocker, T. F., and Muscheler, R.: Atmospheric radiocarbon
during the Younger Dryas: production, ventilation, or both?, Earth
Planet. Sc. Lett., 185, 383–395, 2001.
Mariotti, V., Paillard, D., Bopp, L., Roche, D. M., and Bouttes, N.:
A coupled model for carbon and radiocarbon evolution during the last
deglaciation, Geophys. Res. Lett., 43, 1306–1313, 2016.
Masarik, J. and Beer, J.: Simulation of particle fluxes and cosmogenic
nuclide production in the Earth's atmosphere, J. Geophys.
Res.-Atmos., 104, 12099–12111, 1999.
Masarik, J. and Beer, J.: An updated simulation of particle fluxes and
cosmogenic nuclide production in the Earth's atmosphere, J. Geophys. Res., 114, D11103, https://doi.org/10.1029/2008JD010557, 2009.
Menviel, L., Joos, F., and Ritz, S. P.: Simulating atmospheric CO2,
13C and the marine carbon cycle during the Last Glacial–Interglacial
cycle: possible role for a deepening of the mean remineralization depth and
an increase in the oceanic nutrient inventory, Quaternary Sci. Rev.,
56, 46–68, 2012.
Monnin, E., Indermühle, A., Dällenbach, A., Flückiger, J.,
Stauffer, B., Stocker, T. F., Raynaud, D., and Barnola, J.-M.: Atmospheric
CO2 concentrations over the last glacial termination, Science, 291,
112–114, 2001.
Monnin, E., Steig, E. J., Siegenthaler, U., Kawamura, K., Schwander, J.,
Stauffer, B., Stocker, T. F., Morse, D. L., Barnola, J.-M., Bellier, B.,
Raynaud, D., and Fischer, H.: Evidence for substantial accumulation rate
variability in Antarctica during the Holocene, through synchronization of
CO2 in the Taylor Dome, Dome C and DML ice cores, Earth Planet.
Sc. Lett., 224, 45–54, 2004.
Müller, J. and Stein, R.: High-resolution record of late glacial and
deglacial sea ice changes in Fram Strait corroborates ice–ocean
interactions during abrupt climate shifts, Earth Planet. Sc.
Lett., 403, 446–455, 2014.
Müller, S. A., Joos, F., Edwards, N. R., and Stocker, T. F.: Water Mass
Distribution and Ventilation Time Scales in a Cost-Efficient,
Three-Dimensional Ocean Model, J. Climate, 19, 5479–5499, 2006.
Müller, S. A., Joos, F., Plattner, G.-K., Edwards, N. R., and Stocker, T. F.: Modeled natural and excess radiocarbon: Sensitivities to the gas
exchange formulation and ocean transport strength, Global Biogeochem.
Cy., 22, GB3011, https://doi.org/10.1029/2007GB003065, 2008.
Muscheler, R., and Heikkilä, U.: Constraints on long-term changes in
solar activity from the range of variability of cosmogenic radionuclide
records, Astrophys. Space Sci. T., 7, 355–364, 2011.
Muscheler, R., Beer, J., Wagner, G., Laj, C., Kissel, C., Raisbeck, G. M., Yiou, F., and Kubike, P. W.: Changes in the carbon cycle during the last deglaciation
as indicated by the comparison of 10Be and 14C records, Earth Planet. Sc. Lett., 219, 325–340, 2004.
Muscheler, R., Adolphi, F., Herbst, K., and Nilsson, A.: The Revised Sunspot
Record in Comparison to Cosmogenic Radionuclide-Based Solar Activity
Reconstructions, Sol. Phys., 291, 3025–3043, 2016.
Nowaczyk, N. R., Arz, H. W., Frank, U., Kind, J., and Plessen, B.: Dynamics
of the Laschamp geomagnetic excursion from Black Sea sediments, Earth Planet. Sc. Lett., 351–352, 54–69, 2012.
Nowaczyk, N. R., Frank, U., Kind, J., and Arz, H. W.: A high-resolution
paleointensity stack of the past 14 to 68 ka from Black Sea sediments, Earth
Planet. Sc. Lett., 384, 1–16, 2013.
Orr, J. C., Najjar, R. G., Aumont, O., Bopp, L., Bullister, J. L., Danabasoglu, G., Doney, S. C., Dunne, J. P., Dutay, J.-C., Graven, H., Griffies, S. M., John, J. G., Joos, F., Levin, I., Lindsay, K., Matear, R. J., McKinley, G. A., Mouchet, A., Oschlies, A., Romanou, A., Schlitzer, R., Tagliabue, A., Tanhua, T., and Yool, A.: Biogeochemical protocols and diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP), Geosci. Model Dev., 10, 2169–2199, https://doi.org/10.5194/gmd-10-2169-2017, 2017.
Parekh, P., Joos, F., and Müller, S. A.: A modeling assessment of the
interplay between aeolian iron fluxes and iron-binding ligands in
controlling carbon dioxide fluctuations during Antarctic warm events,
Paleoceanogr. Paleoclimatol., 23, PA4202,
https://doi.org/10.1029/2007PA001531, 2008.
Peltier, W. R.: Ice Age Paleotopography, Science, 265, 195–201, 1994.
Poluianov, S. V., Kovaltsov, G. A., Mishev, A. L., and Usoskin, I. G.:
Production of cosmogenic isotopes 7Be, 10Be, 14C, 22Na,
and 36Cl in the atmosphere: Altitudinal profiles of yield functions, J. Geophys. Res.-Atmos., 121, 8125–8136, 2016.
Potgieter, M. S., Vos, E. E., Boezio, M., De Simone, N., Di Felice, V., and
Formato, V.: Modulation of Galactic Protons in the Heliosphere During the
Unusual Solar Minimum of 2006 to 2009, Sol. Phys., 289, 391–406, 2014.
Primeau, F.: Characterizing Transport between the Surface Mixed Layer and
the Ocean Interior with a Forward and Adjoint Global Ocean Transport Model, J. Phys. Oceanogr., 35, 545–564, 2005.
Raisbeck, G. M., Cauquoin, A., Jouzel, J., Landais, A., Petit, J.-R., Lipenkov, V. Y., Beer, J., Synal, H.-A., Oerter, H., Johnsen, S. J., Steffensen, J. P., Svensson, A., and Yiou, F.: An improved northsouth synchronization of ice core records around the 41 kyr 10Be peak, Clim. Past, 13, 217–229, https://doi.org/10.5194/cp-13-217-2017, 2017.
Rasmussen, S. O., Abbott, P. M., Blunier, T., Bourne, A. J., Brook, E., Buchardt, S. L., Buizert, C., Chappellaz, J., Clausen, H. B., Cook, E., Dahl-Jensen, D., Davies, S. M., Guillevic, M., Kipfstuhl, S., Laepple, T., Seierstad, I. K., Severinghaus, J. P., Steffensen, J. P., Stowasser, C., Svensson, A., Vallelonga, P., Vinther, B. M., Wilhelms, F., and Winstrup, M.: A first chronology for the North Greenland Eemian Ice Drilling (NEEM) ice core, Clim. Past, 9, 2713–2730, https://doi.org/10.5194/cp-9-2713-2013, 2013.
Reimer, P., Bard, E., Bayliss, A., Beck, J., Blackwell, P., Bronk Ramsey, C., Buck, C. E., Cheng, H., Edwards, R. L., Friedrich, M., Grootes, P. M., Guilderson, T. P., Haflidason, H., Hajdas, I., Hatté, C., Heaton, T. J., Hoffmann, D. L., Hogg, A. G., Hughen, K. A., Kaiser, K. F., Kromer, B., Manning, S. W., Niu, M., Reimer, R. W., Richards, D. A., Scott, E. M., Southon, J. R., Staff, R. A., Turney, C. S. M., and Van der Plicht, J.: IntCal13 and Marine13 Radiocarbon Age Calibration
Curves 0–50 000 Years cal BP, Radiocarbon, 55, 1869–1887, 2013.
Reimer, P., Austin, W. E. N., Bard, E., Bayliss, A., Blackwell, P. G., Ramsey, C. B.,Bronk Ramsey, C., Butzin, M., Cheng, H., Edwards, R. L., Friedrich, M., Grootes, P. M., Guilderson, T. P., Hajdas, I., Heaton, T. J., and Hogg A. G.: The IntCal20 Northern Hemisphere radiocarbon age
calibration curve (0–55 kcal BP), Radiocarbon, in
press, 2020.
Ritz, S. P., Stocker, T. F., and Joos, F.: A Coupled Dynamical Ocean–Energy
Balance Atmosphere Model for Paleoclimate Studies, J. Climate, 24,
349–375, 2011.
Roth, R. and Joos, F.: A reconstruction of radiocarbon production and total solar irradiance from the Holocene 14C and CO2 records: implications of data and model uncertainties, Clim. Past, 9, 1879–1909, https://doi.org/10.5194/cp-9-1879-2013, 2013.
Roth, R., Ritz, S. P., and Joos, F.: Burial-nutrient feedbacks amplify the sensitivity of atmospheric carbon dioxide to changes in organic matter remineralisation, Earth Syst. Dynam., 5, 321–343, https://doi.org/10.5194/esd-5-321-2014, 2014.
Rubino, M., Etheridge, D. M., Trudinger, C. M., Allison, C. E., Battle, M. O., Langenfelds, R. L., Steele, L. P., Curran, M., Bender, M., White, J. W. C., Jenk, T. M., Blunier, T., and Francey, R. J.: A revised 1000-year
atmospheric δ13C-CO2 record from Law Dome and South Pole,
Antarctica, J. Geophys. Res.-Atmos., 118, 8482–8499,
2013.
Sarnthein, M., Schneider, B., and Grootes, P. M.: Peak glacial 14C ventilation ages suggest major draw-down of carbon into the abyssal ocean, Clim. Past, 9, 2595–2614, https://doi.org/10.5194/cp-9-2595-2013, 2013.
Schneider, R., Schmitt, J., Köhler, P., Joos, F., and Fischer, H.: A reconstruction of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the last glacial inception, Clim. Past, 9, 2507–2523, https://doi.org/10.5194/cp-9-2507-2013, 2013.
Siegenthaler, U. and Oeschger, H.: Biospheric CO2 emissions during the
past 200 years reconstructed by deconvolution of ice core data, Tellus B, 39,
140–154, 1987.
Siegenthaler, U., Heimann, M., and Oeschger, H.: 14C Variations Caused
by Changes in the Global Carbon Cycle, Radiocarbon, 22, 177–191, 1980.
Sigl, M., Fudge, T. J., Winstrup, M., Cole-Dai, J., Ferris, D., McConnell, J. R., Taylor, K. C., Welten, K. C., Woodruff, T. E., Adolphi, F., Bisiaux, M., Brook, E. J., Buizert, C., Caffee, M. W., Dunbar, N. W., Edwards, R.,
Geng, L., Iverson, N., Koffman, B., Layman, L., Maselli, O. J., McGwire, K.,
Muscheler, R., Nishiizumi, K., Pasteris, D. R., Rhodes, R. H., and Sowers, T. A.: The WAIS Divide deep ice core WD2014 chronology – Part 2: Annual-layer counting (0–31 ka BP), Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, 2016.
Skinner, L. C., Fallon, S., Waelbroeck, C., Michel, E., and Barker, S.:
Ventilation of the Deep Southern Ocean and Deglacial CO2 Rise, Science,
328, 1147–1151, 2010.
Skinner, L. C., Primeau, F., Freeman, E., de la Fuente, M., Goodwin, P. A.,
Gottschalk, J., Huang, E., McCave, I. N., Noble, T. L., and Scrivner, A. E.: Radiocarbon constraints on the
glacial ocean circulation and its impact on atmospheric CO2, Nat.
Commun., 8, 16010, https://doi.org/10.1038/ncomms16010, 2017.
Skinner, L. C., Muschitiello, F., and Scrivner, A. E.: Marine Reservoir Age
Variability Over the Last Deglaciation: Implications for Marine Carbon
Cycling and Prospects for Regional Radiocarbon Calibrations,
Paleoceanogr. Paleoclimatol., 34, 1807–1815, 2019.
Soulet, G., Skinner, L. C., Beaupré, S. R., and Galy, V.: A Note on
Reporting of Reservoir 14C Disequilibria and Age Offsets, Radiocarbon,
58, 205–211, 2016.
Southon, J., Noronha, A. L., Cheng, H., Edwards, R. L., and Wang, Y.:
A high-resolution record of atmospheric 14C based on Hulu Cave speleothem
H82, Quaternary Sci. Rev., 33, 32–41, 2012.
Stuiver, M. and Polach, H. A.: Discussion: Reporting of 14C Data,
Radiocarbon, 19, 355–363, 1977.
Tschumi, T., Joos, F., and Parekh, P.: How important are Southern Hemisphere
wind changes for low glacial carbon dioxide? A model study, Paleoceanogr.
Paleoclimatol., 23, PA4208, https://doi.org/10.1029/2008PA001592, 2008.
Tschumi, T., Joos, F., Gehlen, M., and Heinze, C.: Deep ocean ventilation, carbon isotopes, marine sedimentation and the deglacial CO2 rise, Clim. Past, 7, 771–800, https://doi.org/10.5194/cp-7-771-2011, 2011.
Usoskin, I. G., Hulot, G., Gallet, Y., Roth, R., Licht, A., Joos, F., Kovaltsov, G. A., Thébault, E., and Khokhlov, A.: Evidence for distinct modes of solar activity, Astron. Astrophys., 562, 1–4, 2014.
Wagner, G., Beer, J., Masarik, J., Muscheler, R., Kubik, P. W., Mende, W., Laj, C., Raisbeck, G. M., and Yiou, F.: Presence of the solar de Vries cycle (∼205
years) during the last ice age, Geophys. Res. Lett., 28, 303–306,
2001.
Wallmann, K., Schneider, B., and Sarnthein, M.: Effects of eustatic sea-level change, ocean dynamics, and nutrient utilization on atmospheric pCO2 and seawater composition over the last 130 000 years: a model study, Clim. Past, 12, 339–375, https://doi.org/10.5194/cp-12-339-2016, 2016.
Yiou, F., Raisbeck, G. M., Baumgartner, S., Beer, J., Hammer, C., Johnsen, S., Jouzel, J., Kubik, P. W., Lestringuez, J., Stiévenard, M., Suter, M., and Yiou, P.: Beryllium 10 in the Greenland Ice Core Project ice core
at Summit, Greenland, J. Geophys. Res.-Oceans, 102,
26783–26794, 1997.
Short summary
Despite intense focus on the ~ 190 ‰ drop in Δ14C across the deglacial
mystery interval, the specific mechanisms responsible for the apparent Δ14C excess in the glacial atmosphere have received considerably less attention. Sensitivity experiments with the computationally efficient Bern3D Earth system model suggest that our inability to reproduce the elevated Δ14C levels during the last glacial may reflect an underestimation of 14C production and/or a biased-high reconstruction of Δ14C.
Despite intense focus on the ~ 190 ‰ drop in Δ14C across the deglacial
mystery interval, the...
