Articles | Volume 15, issue 23
https://doi.org/10.5194/bg-15-7155-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-15-7155-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
30 Nov 2018
Research article |
| 30 Nov 2018
| 30 Nov 2018
Bipolar carbon and hydrogen isotope constraints on the Holocene methane budget
Climate and Environmental Physics, Physics Institute, University of
Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012
Bern, Switzerland
Michael Bock
Climate and Environmental Physics, Physics Institute, University of
Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012
Bern, Switzerland
Jochen Schmitt
Climate and Environmental Physics, Physics Institute, University of
Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012
Bern, Switzerland
Barbara Seth
Climate and Environmental Physics, Physics Institute, University of
Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012
Bern, Switzerland
Thomas Blunier
Centre for Ice and Climate, Niels Bohr Institute, University of
Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
Hubertus Fischer
Climate and Environmental Physics, Physics Institute, University of
Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012
Bern, Switzerland
Related authors
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
Short summary
Short summary
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.
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
Lison Soussaintjean, Jochen Schmitt, Joël Savarino, J. Andy Menking, Edward J. Brook, Barbara Seth, Vladimir Lipenkov, Thomas Röckmann, and Hubertus Fischer
EGUsphere, https://doi.org/10.5194/egusphere-2025-3108, https://doi.org/10.5194/egusphere-2025-3108, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Nitrous oxide (N2O) produced in dust-rich Antarctic ice complicates the reconstruction of past atmospheric levels from ice core records. Using isotope analysis, we show that N2O forms from two nitrogen precursors, one being nitrate. For the first time, we demonstrate that the site preference (SP) of N2O reflects the isotopic difference between these precursors, not the production pathway, which challenges the common interpretation of SP.
Sindhu Vudayagiri, Bo Vinther, Johannes Freitag, Peter L. Langen, and Thomas Blunier
Clim. Past, 21, 517–528, https://doi.org/10.5194/cp-21-517-2025, https://doi.org/10.5194/cp-21-517-2025, 2025
Short summary
Short summary
Air trapped in polar ice during snowfall reflects atmospheric pressure at the time of occlusion, serving as a proxy for elevation. However, melting, firn structure changes, and air pressure variability complicate this relationship. We measured total air content (TAC) in the RECAP ice core from Renland ice cap, eastern Greenland, spanning 121 000 years. Melt layers and short-term TAC variations, whose origins remain unclear, present challenges in interpreting elevation changes.
Margaret Harlan, Helle Astrid Kjær, Aylin de Campo, Anders Svensson, Thomas Blunier, Vasileios Gkinis, Sarah Jackson, Christopher Plummer, and Tessa Vance
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-335, https://doi.org/10.5194/essd-2024-335, 2024
Preprint under review for ESSD
Short summary
Short summary
This paper provides high-resolution chemistry and impurity measurements from the Mount Brown South ice core in East Antarctica, from 873 to 2009 CE. Measurements include sodium, ammonium, hydrogen peroxide, electrolytic conductivity, and insoluble microparticles. Data are provided on three scales: 1 mm and 3 cm averaged depth resolution and decadally averaged. The paper also describes the continuous flow analysis systems used to collect the data as well as uncertainties and data quality.
Julien Westhoff, Johannes Freitag, Anaïs Orsi, Patricia Martinerie, Ilka Weikusat, Michael Dyonisius, Xavier Faïn, Kevin Fourteau, and Thomas Blunier
The Cryosphere, 18, 4379–4397, https://doi.org/10.5194/tc-18-4379-2024, https://doi.org/10.5194/tc-18-4379-2024, 2024
Short summary
Short summary
We study the EastGRIP area, Greenland, in detail with traditional and novel techniques. Due to the compaction of the ice, at a certain depth, atmospheric gases can no longer exchange, and the atmosphere is trapped in air bubbles in the ice. We find this depth by pumping air from a borehole, modeling, and using a new technique based on the optical appearance of the ice. Our results suggest that the close-off depth lies at around 58–61 m depth and more precisely at 58.3 m depth.
Susanne Preunkert, Pascal Bohleber, Michel Legrand, Adrien Gilbert, Tobias Erhardt, Roland Purtschert, Lars Zipf, Astrid Waldner, Joseph R. McConnell, and Hubertus Fischer
The Cryosphere, 18, 2177–2194, https://doi.org/10.5194/tc-18-2177-2024, https://doi.org/10.5194/tc-18-2177-2024, 2024
Short summary
Short summary
Ice cores from high-elevation Alpine glaciers are an important tool to reconstruct the past atmosphere. However, since crevasses are common at these glacier sites, rigorous investigations of glaciological conditions upstream of drill sites are needed before interpreting such ice cores. On the basis of three ice cores extracted at Col du Dôme (4250 m a.s.l; French Alps), an overall picture of a dynamic crevasse formation is drawn, which disturbs the depth–age relation of two of the three cores.
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.
Xavier Faïn, David M. Etheridge, Kévin Fourteau, Patricia Martinerie, Cathy M. Trudinger, Rachael H. Rhodes, Nathan J. Chellman, Ray L. Langenfelds, Joseph R. McConnell, Mark A. J. Curran, Edward J. Brook, Thomas Blunier, Grégory Teste, Roberto Grilli, Anthony Lemoine, William T. Sturges, Boris Vannière, Johannes Freitag, and Jérôme Chappellaz
Clim. Past, 19, 2287–2311, https://doi.org/10.5194/cp-19-2287-2023, https://doi.org/10.5194/cp-19-2287-2023, 2023
Short summary
Short summary
We report on a 3000-year record of carbon monoxide (CO) levels in the Southern Hemisphere's high latitudes by combining ice core and firn air measurements with modern direct atmospheric samples. Antarctica [CO] remained stable (–835 to 1500 CE), decreased during the Little Ice Age, and peaked around 1985 CE. Such evolution reflects stable biomass burning CO emissions before industrialization, followed by growth from CO anthropogenic sources, which decline after 1985 due to improved combustion.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Merve Polat, Jesper Baldtzer Liisberg, Morten Krogsbøll, Thomas Blunier, and Matthew S. Johnson
Atmos. Meas. Tech., 14, 8041–8067, https://doi.org/10.5194/amt-14-8041-2021, https://doi.org/10.5194/amt-14-8041-2021, 2021
Short summary
Short summary
We have designed a process for removing methane from a gas stream so that nitrous oxide can be measured without interference. These are both key long-lived greenhouse gases frequently studied in relation to ice cores, plants, water treatment and so on. However, many researchers are not aware of the problem of methane interference, and in addition there have not been good methods available for solving the problem. Here we present and evaluate such a method.
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
Short summary
Short summary
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
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.
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
Short summary
Short summary
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.
Andreas Plach, Bo M. Vinther, Kerim H. Nisancioglu, Sindhu Vudayagiri, and Thomas Blunier
Clim. Past, 17, 317–330, https://doi.org/10.5194/cp-17-317-2021, https://doi.org/10.5194/cp-17-317-2021, 2021
Short summary
Short summary
In light of recent large-scale melting of the Greenland ice sheet
(GrIS), e.g., in the summer of 2012 several days with surface melt
on the entire ice sheet (including elevations above 3000 m), we use
computer simulations to estimate the amount of melt during a
warmer-than-present period of the past. Our simulations show more
extensive melt than today. This is important for the interpretation of
ice cores which are used to reconstruct the evolution of the ice sheet
and the climate.
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
Short summary
Short summary
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.
Jinhwa Shin, Christoph Nehrbass-Ahles, Roberto Grilli, Jai Chowdhry Beeman, Frédéric Parrenin, Grégory Teste, Amaelle Landais, Loïc Schmidely, Lucas Silva, Jochen Schmitt, Bernhard Bereiter, Thomas F. Stocker, Hubertus Fischer, and Jérôme Chappellaz
Clim. Past, 16, 2203–2219, https://doi.org/10.5194/cp-16-2203-2020, https://doi.org/10.5194/cp-16-2203-2020, 2020
Short summary
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.
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
Short summary
Short summary
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.
James E. Lee, Edward J. Brook, Nancy A. N. Bertler, Christo Buizert, Troy Baisden, Thomas Blunier, V. Gabriela Ciobanu, Howard Conway, Dorthe Dahl-Jensen, Tyler J. Fudge, Richard Hindmarsh, Elizabeth D. Keller, Frédéric Parrenin, Jeffrey P. Severinghaus, Paul Vallelonga, Edwin D. Waddington, and Mai Winstrup
Clim. Past, 16, 1691–1713, https://doi.org/10.5194/cp-16-1691-2020, https://doi.org/10.5194/cp-16-1691-2020, 2020
Short summary
Short summary
The Roosevelt Island ice core was drilled to investigate climate from the eastern Ross Sea, West Antarctica. We describe the ice age-scale and gas age-scale of the ice core for 0–763 m (83 000 years BP). Old ice near the bottom of the core implies the ice dome existed throughout the last glacial period and that ice streaming was active in the region. Variations in methane, similar to those used as evidence of early human influence on climate, were observed prior to significant human populations.
Anders Svensson, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Thomas Blunier, Sune O. Rasmussen, Bo M. Vinther, Paul Vallelonga, Emilie Capron, Vasileios Gkinis, Eliza Cook, Helle Astrid Kjær, Raimund Muscheler, Sepp Kipfstuhl, Frank Wilhelms, Thomas F. Stocker, Hubertus Fischer, Florian Adolphi, Tobias Erhardt, Michael Sigl, Amaelle Landais, Frédéric Parrenin, Christo Buizert, Joseph R. McConnell, Mirko Severi, Robert Mulvaney, and Matthias Bigler
Clim. Past, 16, 1565–1580, https://doi.org/10.5194/cp-16-1565-2020, https://doi.org/10.5194/cp-16-1565-2020, 2020
Short summary
Short summary
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
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.
Stephen J. Harris, Jesper Liisberg, Longlong Xia, Jing Wei, Kerstin Zeyer, Longfei Yu, Matti Barthel, Benjamin Wolf, Bryce F. J. Kelly, Dioni I. Cendón, Thomas Blunier, Johan Six, and Joachim Mohn
Atmos. Meas. Tech., 13, 2797–2831, https://doi.org/10.5194/amt-13-2797-2020, https://doi.org/10.5194/amt-13-2797-2020, 2020
Short summary
Short summary
The latest commercial laser spectrometers have the potential to revolutionize N2O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data.
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.
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
Short summary
Short summary
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.
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.
Mai Winstrup, Paul Vallelonga, Helle A. Kjær, Tyler J. Fudge, James E. Lee, Marie H. Riis, Ross Edwards, Nancy A. N. Bertler, Thomas Blunier, Ed J. Brook, Christo Buizert, Gabriela Ciobanu, Howard Conway, Dorthe Dahl-Jensen, Aja Ellis, B. Daniel Emanuelsson, Richard C. A. Hindmarsh, Elizabeth D. Keller, Andrei V. Kurbatov, Paul A. Mayewski, Peter D. Neff, Rebecca L. Pyne, Marius F. Simonsen, Anders Svensson, Andrea Tuohy, Edwin D. Waddington, and Sarah Wheatley
Clim. Past, 15, 751–779, https://doi.org/10.5194/cp-15-751-2019, https://doi.org/10.5194/cp-15-751-2019, 2019
Short summary
Short summary
We present a 2700-year timescale and snow accumulation history for an ice core from Roosevelt Island, Ross Ice Shelf, Antarctica. We observe a long-term slightly decreasing trend in accumulation during most of the period but a rapid decline since the mid-1960s. The latter is linked to a recent strengthening of the Amundsen Sea Low and the expansion of regional sea ice. The year 1965 CE may thus mark the onset of significant increases in sea-ice extent in the eastern Ross Sea.
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.
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
Short summary
Short summary
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
Short summary
Short summary
Isotope measurements are useful for separating different methane sources. However, the lack of widely accepted standards and calibration methods for stable carbon and hydrogen isotopic ratios of methane in air has caused significant measurement offsets among laboratories. We conducted worldwide interlaboratory comparisons, surveyed the literature and assessed them systematically. This study may be of help in future attempts to harmonize data sets of isotopic composition of atmospheric methane.
Nancy A. N. Bertler, Howard Conway, Dorthe Dahl-Jensen, Daniel B. Emanuelsson, Mai Winstrup, Paul T. Vallelonga, James E. Lee, Ed J. Brook, Jeffrey P. Severinghaus, Taylor J. Fudge, Elizabeth D. Keller, W. Troy Baisden, Richard C. A. Hindmarsh, Peter D. Neff, Thomas Blunier, Ross Edwards, Paul A. Mayewski, Sepp Kipfstuhl, Christo Buizert, Silvia Canessa, Ruzica Dadic, Helle A. Kjær, Andrei Kurbatov, Dongqi Zhang, Edwin D. Waddington, Giovanni Baccolo, Thomas Beers, Hannah J. Brightley, Lionel Carter, David Clemens-Sewall, Viorela G. Ciobanu, Barbara Delmonte, Lukas Eling, Aja Ellis, Shruthi Ganesh, Nicholas R. Golledge, Skylar Haines, Michael Handley, Robert L. Hawley, Chad M. Hogan, Katelyn M. Johnson, Elena Korotkikh, Daniel P. Lowry, Darcy Mandeno, Robert M. McKay, James A. Menking, Timothy R. Naish, Caroline Noerling, Agathe Ollive, Anaïs Orsi, Bernadette C. Proemse, Alexander R. Pyne, Rebecca L. Pyne, James Renwick, Reed P. Scherer, Stefanie Semper, Marius Simonsen, Sharon B. Sneed, Eric J. Steig, Andrea Tuohy, Abhijith Ulayottil Venugopal, Fernando Valero-Delgado, Janani Venkatesh, Feitang Wang, Shimeng Wang, Dominic A. Winski, V. Holly L. Winton, Arran Whiteford, Cunde Xiao, Jiao Yang, and Xin Zhang
Clim. Past, 14, 193–214, https://doi.org/10.5194/cp-14-193-2018, https://doi.org/10.5194/cp-14-193-2018, 2018
Short summary
Short summary
Temperature and snow accumulation records from the annually dated Roosevelt Island Climate Evolution (RICE) ice core show that for the past 2 700 years, the eastern Ross Sea warmed, while the western Ross Sea showed no trend and West Antarctica cooled. From the 17th century onwards, this dipole relationship changed. Now all three regions show concurrent warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea.
Malte Winther, David Balslev-Harder, Søren Christensen, Anders Priemé, Bo Elberling, Eric Crosson, and Thomas Blunier
Biogeosciences, 15, 767–780, https://doi.org/10.5194/bg-15-767-2018, https://doi.org/10.5194/bg-15-767-2018, 2018
Short summary
Short summary
Nitrous oxide (N2O) is an important and strong greenhouse gas in the atmosphere and part of climate. N2O is produced by microbes in terrestrial and aquatic ecosystems. The properties of each specific molecule can be used to determine the source. We implemented continuous measurements of N2O during incubation of denitrifying bacteria and believe that similar experiments will lead to a better understanding of N2O turnover and on the biotic mechanisms behind greenhouse gas exchange of the globe.
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
Short summary
Short summary
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.
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Markella Prokopiou, Patricia Martinerie, Célia J. Sapart, Emmanuel Witrant, Guillaume Monteil, Kentaro Ishijima, Sophie Bernard, Jan Kaiser, Ingeborg Levin, Thomas Blunier, David Etheridge, Ed Dlugokencky, Roderik S. W. van de Wal, and Thomas Röckmann
Atmos. Chem. Phys., 17, 4539–4564, https://doi.org/10.5194/acp-17-4539-2017, https://doi.org/10.5194/acp-17-4539-2017, 2017
Short summary
Short summary
Nitrous oxide is the third most important anthropogenic greenhouse gas with an increasing mole fraction. To understand its natural and anthropogenic sources
we employ isotope measurements. Results show that while the N2O mole fraction increases, its heavy isotope content decreases. The isotopic changes observed underline the dominance of agricultural emissions especially at the early part of the record, whereas in the later decades the contribution from other anthropogenic sources increases.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cathy M. Trudinger, Paul J. Fraser, David M. Etheridge, William T. Sturges, Martin K. Vollmer, Matt Rigby, Patricia Martinerie, Jens Mühle, David R. Worton, Paul B. Krummel, L. Paul Steele, Benjamin R. Miller, Johannes Laube, Francis S. Mani, Peter J. Rayner, Christina M. Harth, Emmanuel Witrant, Thomas Blunier, Jakob Schwander, Simon O'Doherty, and Mark Battle
Atmos. Chem. Phys., 16, 11733–11754, https://doi.org/10.5194/acp-16-11733-2016, https://doi.org/10.5194/acp-16-11733-2016, 2016
Short summary
Short summary
Perfluorocarbons (PFCs) are potent, long-lived and mostly man-made greenhouse gases released to the atmosphere mainly during aluminium production and semiconductor manufacture. Here we present the first continuous histories of three PFCs from 1800 to 2014, derived from measurements of these PFCs in the atmosphere and in air bubbles in polar ice. The records show how human actions have affected these important greenhouse gases over the past century.
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
Short summary
Short summary
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.
Peter Sperlich, Nelly A. M. Uitslag, Jürgen M. Richter, Michael Rothe, Heike Geilmann, Carina van der Veen, Thomas Röckmann, Thomas Blunier, and Willi A. Brand
Atmos. Meas. Tech., 9, 3717–3737, https://doi.org/10.5194/amt-9-3717-2016, https://doi.org/10.5194/amt-9-3717-2016, 2016
Short summary
Short summary
Isotope measurements in atmospheric CH4 are performed since more than 3 decades. However, standard gases to harmonize global measurements are not available to this day. We designed two methods to calibrate a suite of 8 CH4 gases with a wide range in isotopic composition to the VPDB and VSMOW scales with high precision and accuracy. Synthetic air mixtures with ~2 ppm of calibrated CH4 can be provided to the community by the ISOLAB of the Max Planck Institute for Biogeochemistry in Jena, Germany.
Theo Manuel Jenk, Mauro Rubino, David Etheridge, Viorela Gabriela Ciobanu, and Thomas Blunier
Atmos. Meas. Tech., 9, 3687–3706, https://doi.org/10.5194/amt-9-3687-2016, https://doi.org/10.5194/amt-9-3687-2016, 2016
Short summary
Short summary
Atmospheric CO2 and δ13C-CO2 records from polar ice cores provide important constraints on the natural carbon cycle variability. Still, data exist only from a limited number of sampling sites and time periods due to demanding analytical challenges. Additional analytical state-of-the-art resources are desirable. This study describes such a new facility. Its analytical performance and new approaches for dealing with procedural blank contribution and analytical outliers are discussed in detail.
Malte Winther, David Balslev-Harder, Søren Christensen, Anders Priemé, Bo Elberling, Eric Crosson, and Thomas Blunier
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-258, https://doi.org/10.5194/bg-2016-258, 2016
Revised manuscript not accepted
Short summary
Short summary
Nitrous oxide (N2O) is an important and strong greenhouse gas in the atmosphere and part of climate. N2O is produced by microbes in terrestrial and aquatic ecosystems. The properties of each specific molecule can be used to determine the source. We implemented continuous measurements of N2O during incubation of denitrifying bacteria and believe that similar experiments will lead to a better understanding of N2O turnover and on the biotic mechanisms behind greenhouse gas exchange of the Globe.
Rachael H. Rhodes, Xavier Faïn, Edward J. Brook, Joseph R. McConnell, Olivia J. Maselli, Michael Sigl, Jon Edwards, Christo Buizert, Thomas Blunier, Jérôme Chappellaz, and Johannes Freitag
Clim. Past, 12, 1061–1077, https://doi.org/10.5194/cp-12-1061-2016, https://doi.org/10.5194/cp-12-1061-2016, 2016
Short summary
Short summary
Local artifacts in ice core methane data are superimposed on consistent records of past atmospheric variability. These artifacts are not related to past atmospheric history and care should be taken to avoid interpreting them as such. By investigating five polar ice cores from sites with different conditions, we relate isolated methane spikes to melt layers and decimetre-scale variations as "trapping signal" associated with a difference in timing of air bubble closure in adjacent firn layers.
L. M. T. Joelsson, J. A. Schmidt, E. J. K. Nilsson, T. Blunier, D. W. T. Griffith, S. Ono, and M. S. Johnson
Atmos. Chem. Phys., 16, 4439–4449, https://doi.org/10.5194/acp-16-4439-2016, https://doi.org/10.5194/acp-16-4439-2016, 2016
Short summary
Short summary
We present experimental kinetic isotope effects (KIE) for the OH oxidation of CH3D and 13CH3D and their temperature dependence. Our determination of the 13CH3D + OH KIE is novel and we find no "clumped" isotope effect within the experimental uncertainty.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
S. J. Allin, J. C. Laube, E. Witrant, J. Kaiser, E. McKenna, P. Dennis, R. Mulvaney, E. Capron, P. Martinerie, T. Röckmann, T. Blunier, J. Schwander, P. J. Fraser, R. L. Langenfelds, and W. T. Sturges
Atmos. Chem. Phys., 15, 6867–6877, https://doi.org/10.5194/acp-15-6867-2015, https://doi.org/10.5194/acp-15-6867-2015, 2015
Short summary
Short summary
Stratospheric ozone protects life on Earth from harmful UV-B radiation. Chlorofluorocarbons (CFCs) are man-made compounds which act to destroy this barrier.
This paper presents (1) the first measurements of the stratospheric δ(37Cl) of CFCs -11 and -113; (2) the first quantification of long-term trends in the tropospheric δ(37Cl) of CFCs -11, -12 and -113.
This study provides a better understanding of source and sink processes associated with these destructive compounds.
M. Guillevic, L. Bazin, A. Landais, C. Stowasser, V. Masson-Delmotte, T. Blunier, F. Eynaud, S. Falourd, E. Michel, B. Minster, T. Popp, F. Prié, and B. M. Vinther
Clim. Past, 10, 2115–2133, https://doi.org/10.5194/cp-10-2115-2014, https://doi.org/10.5194/cp-10-2115-2014, 2014
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
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
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
J. Chappellaz, C. Stowasser, T. Blunier, D. Baslev-Clausen, E. J. Brook, R. Dallmayr, X. Faïn, J. E. Lee, L. E. Mitchell, O. Pascual, D. Romanini, J. Rosen, and S. Schüpbach
Clim. Past, 9, 2579–2593, https://doi.org/10.5194/cp-9-2579-2013, https://doi.org/10.5194/cp-9-2579-2013, 2013
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
P. Sperlich, C. Buizert, T. M. Jenk, C. J. Sapart, M. Prokopiou, T. Röckmann, and T. Blunier
Atmos. Meas. Tech., 6, 2027–2041, https://doi.org/10.5194/amt-6-2027-2013, https://doi.org/10.5194/amt-6-2027-2013, 2013
V. V. Petrenko, P. Martinerie, P. Novelli, D. M. Etheridge, I. Levin, Z. Wang, T. Blunier, J. Chappellaz, J. Kaiser, P. Lang, L. P. Steele, S. Hammer, J. Mak, R. L. Langenfelds, J. Schwander, J. P. Severinghaus, E. Witrant, G. Petron, M. O. Battle, G. Forster, W. T. Sturges, J.-F. Lamarque, K. Steffen, and J. W. C. White
Atmos. Chem. Phys., 13, 7567–7585, https://doi.org/10.5194/acp-13-7567-2013, https://doi.org/10.5194/acp-13-7567-2013, 2013
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
H. C. Steen-Larsen, S. J. Johnsen, V. Masson-Delmotte, B. Stenni, C. Risi, H. Sodemann, D. Balslev-Clausen, T. Blunier, D. Dahl-Jensen, M. D. Ellehøj, S. Falourd, A. Grindsted, V. Gkinis, J. Jouzel, T. Popp, S. Sheldon, S. B. Simonsen, J. Sjolte, J. P. Steffensen, P. Sperlich, A. E. Sveinbjörnsdóttir, B. M. Vinther, and J. W. C. White
Atmos. Chem. Phys., 13, 4815–4828, https://doi.org/10.5194/acp-13-4815-2013, https://doi.org/10.5194/acp-13-4815-2013, 2013
M. Guillevic, L. Bazin, A. Landais, P. Kindler, A. Orsi, V. Masson-Delmotte, T. Blunier, S. L. Buchardt, E. Capron, M. Leuenberger, P. Martinerie, F. Prié, and B. M. Vinther
Clim. Past, 9, 1029–1051, https://doi.org/10.5194/cp-9-1029-2013, https://doi.org/10.5194/cp-9-1029-2013, 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
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
C. M. Trudinger, I. G. Enting, P. J. Rayner, D. M. Etheridge, C. Buizert, M. Rubino, P. B. Krummel, and T. Blunier
Atmos. Chem. Phys., 13, 1485–1510, https://doi.org/10.5194/acp-13-1485-2013, https://doi.org/10.5194/acp-13-1485-2013, 2013
Related subject area
Biogeochemistry: Greenhouse Gases
Observations of methane net sinks in the upland Arctic tundra
Intercomparison of biogenic CO2 flux models in four urban parks in the city of Zurich
CO2 flux characteristics of the open savanna and its response to environmental factors in the dry–hot valley of Jinsha River, China
Rising Arctic seas and thawing permafrost: uncovering the carbon cycle impact in a thermokarst lagoon system in the outer Mackenzie Delta, Canada
Modelling decadal trends and the impact of extreme events on carbon fluxes in a temperate deciduous forest using a terrestrial biosphere model
Surface CO2 gradients challenge conventional CO2 emission quantification in lentic water bodies under calm conditions
Spatiotemporal variability of CO2, N2O and CH4 fluxes from a semi-deciduous tropical forest soil in the Congo Basin
Organic soil carbon balance in drained and undrained hemiboreal forests
Eddy-covariance fluxes of CO2, CH4 and N2O in a drained peatland forest after clear-cutting
Eddy covariance evaluation of ecosystem fluxes at a temperate saltmarsh in Victoria, Australia, shows large CO2 uptake
Interferences caused by the biogeochemical methane cycle in peats during the assessment of abandoned oil wells
Carbon sequestration in different urban vegetation types in Southern Finland
Groundwater-CO2 Emissions Relationship in Dutch Peatlands Derived by Machine Learning Using Airborne and Ground-Based Eddy Covariance Data
Proglacial methane emissions driven by meltwater and groundwater flushing in a high-Arctic glacial catchment
Technical Note: Pondi – a low-cost logger for long-term monitoring of methane, carbon dioxide, and nitrous oxide in aquatic and terrestrial systems
Seasonal and interannual variability in CO2 fluxes in southern Africa seen by GOSAT
Environmental drivers constraining the seasonal variability of satellite-observed methane at Northern high latitudes
Water chemistry and greenhouse gas concentrations in waterbodies of a thawing permafrost peatland complex in northern Norway
Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in northern Europe
Ensemble estimates of global wetland methane emissions over 2000–2020
Seasonal carbon fluxes from vegetation and soil in a Mediterranean non-tidal salt marsh
Explainable machine learning for modeling of net ecosystem exchange in boreal forests
Dynamics of CO2 and CH4 fluxes in Red Sea mangrove soils
Inferring methane emissions from African livestock by fusing drone, tower, and satellite data
Nitrous oxide (N2O) in Macquarie Harbour, Tasmania
Technical note: A low-cost, automatic soil–plant–atmosphere enclosure system to investigate CO2 and evapotranspiration flux dynamics
Reviews and syntheses: Contribution of sulfate to methane oxidation in upland soils: a mini-review
Tidal influence on carbon dioxide and methane fluxes from tree stems and soils in mangrove forests
Drought conditions disrupt atmospheric carbon uptake in a Mediterranean saline lake
Physicochemical perturbation increases nitrous oxide production from denitrification in soils and sediments
Uncertainties in carbon emissions from land use and land cover change in Indonesia
Carbon degradation and mobilisation potentials of thawing permafrost peatlands in northern Norway inferred from laboratory incubations
Saturating response of photosynthesis to increasing leaf area index allows selective harvest of trees without affecting forest productivity
Seasonal dynamics and regional distribution patterns of CO2 and CH4 in the north-eastern Baltic Sea
Interannual and seasonal variability of the air–sea CO2 exchange at Utö in the coastal region of the Baltic Sea
CO2 emissions of drained coastal peatlands in the Netherlands and potential emission reduction by water infiltration systems
Influence of wind strength and direction on diffusive methane fluxes and atmospheric methane concentrations above the North Sea
Using eddy covariance observations to determine the carbon sequestration characteristics of subalpine forests in the Qinghai–Tibet Plateau
Isotopomer labeling and oxygen dependence of hybrid nitrous oxide production
The emission of CO from tropical rainforest soils
Modelling CO2 and N2O emissions from soils in silvopastoral systems of the West African Sahelian band
A case study on topsoil removal and rewetting for paludiculture: effect on biogeochemistry and greenhouse gas emissions from Typha latifolia, Typha angustifolia, and Azolla filiculoides
Methane, carbon dioxide and nitrous oxide emissions from two clear-water and two turbid-water urban ponds in Brussels (Belgium)
Assessing improvements in global ocean pCO2 machine learning reconstructions with Southern Ocean autonomous sampling
Timescale dependence of airborne fraction and underlying climate–carbon-cycle feedbacks for weak perturbations in CMIP5 models
Technical note: Preventing CO2 overestimation from mercuric or copper(II) chloride preservation of dissolved greenhouse gases in freshwater samples
Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data
Diurnal versus spatial variability of greenhouse gas emissions from an anthropogenically modified lowland river in Germany
Regional assessment and uncertainty analysis of carbon and nitrogen balances at cropland scale using the ecosystem model LandscapeDNDC
Resolving heterogeneous fluxes from tundra halves the growing season carbon budget
Antonio Donateo, Daniela Famulari, Donato Giovannelli, Arturo Mariani, Mauro Mazzola, Stefano Decesari, and Gianluca Pappaccogli
Biogeosciences, 22, 2889–2908, https://doi.org/10.5194/bg-22-2889-2025, https://doi.org/10.5194/bg-22-2889-2025, 2025
Short summary
Short summary
This study focuses on measurements of CO2 and CH4 turbulent fluxes in tundra ecosystems in the Svalbard islands over a 2-year period. Our results reveal dynamic interactions between climatic conditions and ecosystem activities such as photosynthesis and microbial activity. In summer, photosynthesis and microbial activity increase, leading to net carbon uptake and methane consumption. Wind influences soil drying and CH4 emissions. Thermal anomalies can reduce annual carbon uptake.
Stavros Stagakis, Dominik Brunner, Junwei Li, Leif Backman, Anni Karvonen, Lionel Constantin, Leena Järvi, Minttu Havu, Jia Chen, Sophie Emberger, and Liisa Kulmala
Biogeosciences, 22, 2133–2161, https://doi.org/10.5194/bg-22-2133-2025, https://doi.org/10.5194/bg-22-2133-2025, 2025
Short summary
Short summary
The balance between CO2 uptake and emissions from urban green areas is still not well understood. This study evaluated for the first time the urban park CO2 exchange simulations with four different types of biosphere model by comparing them with observations. Even though some advantages and disadvantages of the different model types were identified, there was no strong evidence that more complex models performed better than simple ones.
Chaolei Yang, Yufeng Tian, Jingqi Cui, Guangxiong He, Jingyuan Li, Canfeng Li, Haichuang Duan, Zong Wei, Liu Yan, Xin Xia, Yong Huang, Aihua Jiang, and Yuwen Feng
Biogeosciences, 22, 2097–2114, https://doi.org/10.5194/bg-22-2097-2025, https://doi.org/10.5194/bg-22-2097-2025, 2025
Short summary
Short summary
Due to the influence of extreme-drought events in southwest China, the carbon sequestration capacity of the open savanna in the dry–hot valley of the Jinsha River has been significantly diminished, with soil water content being the key environmental factor governing CO2 flux. Under the climate scenario where the frequency and severity of extreme droughts are expected to continue increasing, the CO2 emissions from the open savanna are also anticipated to rise persistently.
Maren Jenrich, Juliane Wolter, Susanne Liebner, Christian Knoblauch, Guido Grosse, Fiona Giebeler, Dustin Whalen, and Jens Strauss
Biogeosciences, 22, 2069–2086, https://doi.org/10.5194/bg-22-2069-2025, https://doi.org/10.5194/bg-22-2069-2025, 2025
Short summary
Short summary
Climate warming in the Arctic is causing the erosion of permafrost coasts and the transformation of permafrost lakes into lagoons. To understand how this affects greenhouse gas (GHG) emissions, we studied carbon dioxide (CO₂) and methane (CH₄) production in lagoons with varying sea connections. Younger lagoons produce more CH₄, while CO₂ increases under more marine conditions. Flooding of permafrost lowlands due to rising sea levels may lead to higher GHG emissions from Arctic coasts in future.
Tea Thum, Tuuli Miinalainen, Outi Seppälä, Holly Croft, Cheryl Rogers, Ralf Staebler, Silvia Caldararu, and Sönke Zaehle
Biogeosciences, 22, 1781–1807, https://doi.org/10.5194/bg-22-1781-2025, https://doi.org/10.5194/bg-22-1781-2025, 2025
Short summary
Short summary
Climate change has the potential to influence the carbon sequestration potential of terrestrial ecosystems, and here the nitrogen cycle is also important. We used the terrestrial biosphere model QUINCY (QUantifying Interactions between terrestrial Nutrient CYcles and the climate system) in a mixed deciduous forest in Canada. We investigated the usefulness of using the leaf area index and leaf chlorophyll content to improve the parameterization of the model. This work paves the way for using spaceborne observations in model parameterizations, also including information on the nitrogen cycle.
Patrick Aurich, Uwe Spank, and Matthias Koschorreck
Biogeosciences, 22, 1697–1709, https://doi.org/10.5194/bg-22-1697-2025, https://doi.org/10.5194/bg-22-1697-2025, 2025
Short summary
Short summary
Lakes can be sources and sinks of the greenhouse gas carbon dioxide. The gas exchange between the atmosphere and the water can be measured by taking gas samples from them. However, the depth of water samples is not well defined, which may cause errors. We hypothesized that gradients of CO2 concentrations develop under the surface when wind speeds are very low. Our measurements show that such a gradient can occur on calm nights, potentially shifting lakes from a CO2 sink to a source.
Roxanne Daelman, Marijn Bauters, Matti Barthel, Emmanuel Bulonza, Lodewijk Lefevre, José Mbifo, Johan Six, Klaus Butterbach-Bahl, Benjamin Wolf, Ralf Kiese, and Pascal Boeckx
Biogeosciences, 22, 1529–1542, https://doi.org/10.5194/bg-22-1529-2025, https://doi.org/10.5194/bg-22-1529-2025, 2025
Short summary
Short summary
The increase in atmospheric concentrations of several greenhouse gases (GHGs) since 1750 is attributed to human activity. However, natural ecosystems, such as tropical forests, also contribute to GHG budgets. The Congo Basin hosts the second largest tropical forest and is understudied. In this study, measurements of soil GHG exchange were carried out during 16 months in a tropical forest in the Congo Basin. Overall, the soil acted as a major source of CO2 and N2O and a minor sink of CH4.
Aldis Butlers, Raija Laiho, Andis Lazdiņš, Thomas Schindler, Kaido Soosaar, Jyrki Jauhiainen, Arta Bārdule, Muhammad Kamil-Sardar, Ieva Līcīte, Valters Samariks, Andreas Haberl, Hanna Vahter, Dovilė Čiuldienė, Jani Anttila, and Kęstutis Armolaitis
EGUsphere, https://doi.org/10.5194/egusphere-2025-1032, https://doi.org/10.5194/egusphere-2025-1032, 2025
Short summary
Short summary
A two-year study in Estonia, Latvia, and Lithuania evaluated the carbon balance of drained and undrained nutrient-rich forest organic soils, ranging from highly mineralized soils close to the threshold of organic soil definition to deep peat. The soils varied in pH, macronutrient levels, and C:N ratio, which contributed to the observed behavior of the soils demonstrating carbon sink and source dynamics under both drained and undrained conditions.
Olli-Pekka Tikkasalo, Olli Peltola, Pavel Alekseychik, Juha Heikkinen, Samuli Launiainen, Aleksi Lehtonen, Qian Li, Eduardo Martínez-García, Mikko Peltoniemi, Petri Salovaara, Ville Tuominen, and Raisa Mäkipää
Biogeosciences, 22, 1277–1300, https://doi.org/10.5194/bg-22-1277-2025, https://doi.org/10.5194/bg-22-1277-2025, 2025
Short summary
Short summary
The emissions of greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were measured from a clear-cut peatland forest site. The measurements covered the whole year of 2022, which was the second growing season after the clear-cut. The site was a strong GHG source, and the highest emissions came from CO2, followed by N2O and CH4. A statistical model that included information on different surfaces at the site was developed to unravel surface-type-specific GHG fluxes.
Ruth Reef, Edoardo Daly, Tivanka Anandappa, Eboni-Jane Vienna-Hallam, Harriet Robertson, Matthew Peck, and Adrien Guyot
Biogeosciences, 22, 1149–1162, https://doi.org/10.5194/bg-22-1149-2025, https://doi.org/10.5194/bg-22-1149-2025, 2025
Short summary
Short summary
Studies show that saltmarshes excel at capturing carbon from the atmosphere. In this study, we measured CO2 flux in an Australian temperate saltmarsh on French Island. The temperate saltmarsh exhibited strong seasonality. During the warmer growing season, the saltmarsh absorbed 10.5 g CO2 m−2 on average daily from the atmosphere. Even in winter, when plants were dormant, it continued to be a CO2 sink, albeit a smaller one. Cool temperatures and high cloud cover inhibit carbon sequestration.
Sebastian F. A. Jordan, Stefan Schloemer, Martin Krüger, Tanja Heffner, Marcus A. Horn, and Martin Blumenberg
Biogeosciences, 22, 809–830, https://doi.org/10.5194/bg-22-809-2025, https://doi.org/10.5194/bg-22-809-2025, 2025
Short summary
Short summary
Using a multilayer approach, we studied the methane flux, soil gas composition, and isotopic signatures of soil methane and carbon dioxide at eight cut and buried abandoned oil wells in a peat-rich area of northern Germany. The detected methane emissions were of biogenic, peat origin and were not associated with the abandoned wells. Additional microbial analysis and methane oxidation rate measurements demonstrated a high methane emission mitigation potential in the studied peat soils.
Laura Thölix, Leif Backman, Minttu Havu, Esko Karvinen, Jesse Soininen, Justine Trémeau, Olli Nevalainen, Joyson Ahongshangbam, Leena Järvi, and Liisa Kulmala
Biogeosciences, 22, 725–749, https://doi.org/10.5194/bg-22-725-2025, https://doi.org/10.5194/bg-22-725-2025, 2025
Short summary
Short summary
Cities aim for carbon neutrality and seek to understand urban vegetation's role as a carbon sink. Direct measurements are challenging, so models are used to estimate the urban carbon cycle. We evaluated model performance at estimating carbon sequestration in lawns, park trees, and urban forests in Helsinki, Finland. Models captured seasonal and annual variations well. Trees had higher sequestration rates than lawns, and irrigation often enhanced carbon sinks.
Laura M. van der Poel, Laurent V. Bataille, Bart Kruijt, Wietse Franssen, Wilma Jans, Jan Biermann, Anne Rietman, Alex J. V. Buzacott, Ype van der Velde, Ruben Boelens, and Ronald W. A. Hutjes
EGUsphere, https://doi.org/10.5194/egusphere-2025-431, https://doi.org/10.5194/egusphere-2025-431, 2025
Short summary
Short summary
We combine two types of carbon dioxide (CO2) data from Dutch peatlands in a machine learning model: from fixed measurement towers and from a light research aircraft. We find that emissions increase with deeper water table depths (WTD) by 4.6 tonnes CO2 per hectare per year, per 10 cm deeper WTD on average. The effect is stronger in winter than in summer and varies between locations. This variability should be taken into account when developing mitigation measures.
Gabrielle E. Kleber, Leonard Magerl, Alexandra V. Turchyn, Stefan Schloemer, Mark Trimmer, Yizhu Zhu, and Andrew Hodson
Biogeosciences, 22, 659–674, https://doi.org/10.5194/bg-22-659-2025, https://doi.org/10.5194/bg-22-659-2025, 2025
Short summary
Short summary
Our research on Svalbard shows that glacier melt rivers can transport large amounts of methane, a potent greenhouse gas. By studying a glacier over one summer, we found that its river was highly concentrated in methane, suggesting that rivers could provide a significant source of methane emissions as the Arctic warms and glaciers melt. This is the first time such emissions have been measured on Svalbard, indicating a wider environmental concern as such processes are occurring across the Arctic.
Martino E. Malerba, Blake Edwards, Lukas Schuster, Omosalewa Odebiri, Josh Glen, Rachel Kelly, Paul Phan, Alistair Grinham, and Peter I. Macreadie
EGUsphere, https://doi.org/10.31219/osf.io/54rd2, https://doi.org/10.31219/osf.io/54rd2, 2025
Short summary
Short summary
The Pondi is a cost-effective, lightweight logger designed for long-term monitoring of carbon dioxide, methane, and nitrous oxide emissions in both terrestrial and aquatic ecosystems. It addresses key challenges in greenhouse gas monitoring by providing an automated, low-cost, solar-powered solution with cloud connectivity and real-time analytics. Its robust design enables deployment in diverse environmental conditions, supporting large-scale, high-resolution emission assessments.
Eva-Marie Metz, Sanam Noreen Vardag, Sourish Basu, Martin Jung, and André Butz
Biogeosciences, 22, 555–584, https://doi.org/10.5194/bg-22-555-2025, https://doi.org/10.5194/bg-22-555-2025, 2025
Short summary
Short summary
We estimate CO2 fluxes in semiarid southern Africa from 2009 to 2018 based on satellite CO2 measurements and atmospheric inverse modeling. By selecting process-based vegetation models, which agree with the satellite CO2 fluxes, we find that soil respiration mainly drives the seasonality, whereas photosynthesis substantially influences the interannual variability. Our study emphasizes the need for better representation of the response of semiarid ecosystems to soil rewetting in vegetation models.
Ella Kivimäki, Tuula Aalto, Michael Buchwitz, Kari Luojus, Jouni Pulliainen, Kimmo Rautiainen, Oliver Schneising, Anu-Maija Sundström, Johanna Tamminen, Aki Tsuruta, and Hannakaisa Lindqvist
EGUsphere, https://doi.org/10.5194/egusphere-2025-249, https://doi.org/10.5194/egusphere-2025-249, 2025
Short summary
Short summary
We investigate how environmental variables influencing natural methane fluxes explain the large-scale seasonal variability of satellite-observed methane at Northern high latitudes. Our findings show that soil moisture, snow cover, and soil temperature have the strongest influence, with snowmelt playing a surprisingly significant role, likely through soil isolation and wetting. This study highlights the value of multi-satellite observations for understanding large-scale wetland emissions.
Jacqueline Kay Knutson, François Clayer, Peter Dörsch, Sebastian Westermann, and Heleen A. de Wit
EGUsphere, https://doi.org/10.5194/egusphere-2025-184, https://doi.org/10.5194/egusphere-2025-184, 2025
Short summary
Short summary
Thawing permafrost at Iškoras in northern Norway is transforming peat plateaus into thermokarst ponds and wetlands. These small ponds show striking oversaturation of dissolved greenhouse gases like carbon dioxide (CO2) and methane (CH4), partly due to organic matter processing. Streams nearby emit CO2 driven by turbulence. As permafrost disappears, carbon dynamics will change, potentially increasing emissions of CH4. This study highlights the need to integrate these changes into climate models.
Tuula Aalto, Aki Tsuruta, Jarmo Mäkelä, Jurek Müller, Maria Tenkanen, Eleanor Burke, Sarah Chadburn, Yao Gao, Vilma Mannisenaho, Thomas Kleinen, Hanna Lee, Antti Leppänen, Tiina Markkanen, Stefano Materia, Paul A. Miller, Daniele Peano, Olli Peltola, Benjamin Poulter, Maarit Raivonen, Marielle Saunois, David Wårlind, and Sönke Zaehle
Biogeosciences, 22, 323–340, https://doi.org/10.5194/bg-22-323-2025, https://doi.org/10.5194/bg-22-323-2025, 2025
Short summary
Short summary
Wetland methane responses to temperature and precipitation were studied in a boreal wetland-rich region in northern Europe using ecosystem models, atmospheric inversions, and upscaled flux observations. The ecosystem models differed in their responses to temperature and precipitation and in their seasonality. However, multi-model means, inversions, and upscaled fluxes had similar seasonality, and they suggested co-limitation by temperature and precipitation.
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 H. 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, Yi Xi, Wenxin Zhang, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Biogeosciences, 22, 305–321, https://doi.org/10.5194/bg-22-305-2025, https://doi.org/10.5194/bg-22-305-2025, 2025
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 yr-1 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.
Lorena Carrasco-Barea, Dolors Verdaguer, Maria Gispert, Xavier D. Quintana, Hélène Bourhis, and Laura Llorens
Biogeosciences, 22, 289–304, https://doi.org/10.5194/bg-22-289-2025, https://doi.org/10.5194/bg-22-289-2025, 2025
Short summary
Short summary
Carbon dioxide fluxes have been measured seasonally in four plant species in a Mediterranean non-tidal salt marsh, highlighting the high carbon removal potential that these species have. Carbon dioxide and methane emissions from soil showed high variability among the habitats studied, and they were generally higher than those observed in tidal salt marshes. Our results are important for making more accurate predictions regarding carbon emissions from these ecosystems.
Ekaterina Ezhova, Topi Laanti, Anna Lintunen, Pasi Kolari, Tuomo Nieminen, Ivan Mammarella, Keijo Heljanko, and Markku Kulmala
Biogeosciences, 22, 257–288, https://doi.org/10.5194/bg-22-257-2025, https://doi.org/10.5194/bg-22-257-2025, 2025
Short summary
Short summary
Machine learning (ML) models are gaining popularity in biogeosciences. They are applied as gap-filling methods and used to upscale carbon fluxes to larger areas. Here we use explainable artificial intelligence (XAI) methods to elucidate the performance of machine learning models for carbon dioxide fluxes in boreal forests. We show that statistically equal models treat input variables differently. XAI methods can help scientists make informed decisions when applying ML models in their research.
Jessica Breavington, Alexandra Steckbauer, Chuancheng Fu, Mongi Ennasri, and Carlos M. Duarte
Biogeosciences, 22, 117–134, https://doi.org/10.5194/bg-22-117-2025, https://doi.org/10.5194/bg-22-117-2025, 2025
Short summary
Short summary
Mangrove carbon storage in the Red Sea is lower than average due to challenging growth conditions. We collected mangrove soil cores over multiple seasons to measure greenhouse gas (GHG) flux of carbon dioxide and methane. GHG emissions are a small offset to mangrove carbon storage overall but punctuated by periods of high emission. This variation is linked to environmental and soil properties, which were also measured. The findings aid understanding of GHG dynamics in arid mangrove ecosystems.
Alouette van Hove, Kristoffer Aalstad, Vibeke Lind, Claudia Arndt, Vincent Odongo, Rodolfo Ceriani, Francesco Fava, John Hulth, and Norbert Pirk
EGUsphere, https://doi.org/10.5194/egusphere-2024-3994, https://doi.org/10.5194/egusphere-2024-3994, 2025
Short summary
Short summary
Research on methane emissions from African livestock is limited. We used a probabilistic method fusing drone and flux tower observations with an atmospheric model to estimate emissions from various herds. This approach proved robust under non-stationary wind conditions and effective in estimating emissions as low as 100 g h-1. We also detected herd locations using spectral anomalies in satellite data. Our approach can be used to estimate diverse sources, thereby improving emission inventories.
Johnathan Daniel Maxey, Neil D. Hartstein, Hermann W. Bange, and Moritz Müller
Biogeosciences, 21, 5613–5637, https://doi.org/10.5194/bg-21-5613-2024, https://doi.org/10.5194/bg-21-5613-2024, 2024
Short summary
Short summary
The distribution of N2O in fjord-like estuaries is poorly described in the Southern Hemisphere. Our study describes N2O distribution and its drivers in one such system in Macquarie Harbour, Tasmania. Water samples were collected seasonally in 2022 and 2023. Results show the system removes atmospheric N2O when river flow is high, whereas the system emits N2O when the river flow is low. N2O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.
Wael Al Hamwi, Maren Dubbert, Jörg Schaller, Matthias Lück, Marten Schmidt, and Mathias Hoffmann
Biogeosciences, 21, 5639–5651, https://doi.org/10.5194/bg-21-5639-2024, https://doi.org/10.5194/bg-21-5639-2024, 2024
Short summary
Short summary
We present a fully automatic, low-cost soil–plant enclosure system to monitor CO2 and evapotranspiration fluxes within greenhouse experiments. It operates in two modes: independent, using low-cost sensors, and dependent, where multiple chambers connect to a single gas analyzer via a low-cost multiplexer. This system provides precise, accurate measurements and high temporal resolution, enabling comprehensive monitoring of plant–soil responses to various treatments and conditions.
Rui Su, Kexin Li, Nannan Wang, Fenghui Yuan, Ying Zhao, Yunjiang Zuo, Ying Sun, Liyuan He, Xiaofeng Xu, and Lihua Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3347, https://doi.org/10.5194/egusphere-2024-3347, 2024
Short summary
Short summary
This research examines the effect of sulfate on methane oxidation in soil, finding that sulfate may facilitate methane oxidation. Considering methane's role as a greenhouse gas and rising sulfate deposition, the study aims to predict changes in methane oxidation due to acid deposition. Future experiments will explore microbial mechanisms, as sulfate reduces methane emissions while enhancing its consumption, providing insights for mitigation strategies.
Zhao-Jun Yong, Wei-Jen Lin, Chiao-Wen Lin, and Hsing-Juh Lin
Biogeosciences, 21, 5247–5260, https://doi.org/10.5194/bg-21-5247-2024, https://doi.org/10.5194/bg-21-5247-2024, 2024
Short summary
Short summary
We measured CO2 and CH4 fluxes from mangrove stems and soils of Avicennia marina and Kandelia obovata during tidal cycles. Both stem types served as CO2 and CH4 sources, emitting less CH4 than soils, with no difference in CO2 flux. While A. marina stems showed increased CO2 fluxes from low to high tides, they acted as a CH4 sink before flooding and as a source after ebbing. However, K. obovata stems showed no flux pattern. This study highlights the need to consider tidal influence and species.
Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz
Biogeosciences, 21, 5117–5129, https://doi.org/10.5194/bg-21-5117-2024, https://doi.org/10.5194/bg-21-5117-2024, 2024
Short summary
Short summary
Inland saline lakes are crucial in the global carbon cycle, but increased droughts may alter their carbon exchange capacity. We measured CO2 and CH4 fluxes in a Mediterranean saline lake using the eddy covariance method under dry and wet conditions. We found the lake acts as a carbon sink during wet periods but not during droughts. These results highlight the importance of saline lakes in carbon sequestration and their vulnerability to climate-change-induced droughts.
Nathaniel B. Weston, Cynthia Troy, Patrick J. Kearns, Jennifer L. Bowen, William Porubsky, Christelle Hyacinthe, Christof Meile, Philippe Van Cappellen, and Samantha B. Joye
Biogeosciences, 21, 4837–4851, https://doi.org/10.5194/bg-21-4837-2024, https://doi.org/10.5194/bg-21-4837-2024, 2024
Short summary
Short summary
Nitrous oxide (N2O) is a potent greenhouse and ozone-depleting gas produced largely from microbial nitrogen cycling processes, and human activities have resulted in increases in atmospheric N2O. We investigate the role of physical and chemical disturbances to soils and sediments in N2O production. We demonstrate that physicochemical perturbation increases N2O production, microbial community adapts over time, and initial perturbation appears to confer resilience to subsequent disturbance.
Ida Bagus Mandhara Brasika, Pierre Friedlingstein, Stephen Sitch, Michael O'Sullivan, Maria Carolina Duran-Rojas, Thais Michele Rosan, Kees Klein Goldewijk, Julia Pongratz, Clemens Schwingshackl, Louise P. Chini, and George C. Hurtt
EGUsphere, https://doi.org/10.5194/egusphere-2024-3165, https://doi.org/10.5194/egusphere-2024-3165, 2024
Short summary
Short summary
Indonesia is 3 world's highest carbon emitter from land use change. However, there are uncertainties of the carbon emission of Indonesia that can be reduced with satellite-based datasets. But later, we found that the uncertainties are also caused by the difference of carbon pool in various models. Our best estimation of carbon emissions from land use change in Indonesia is 0.12 ± 0.02 PgC/yr with steady trend. This double when include peat fire and peat drainage emissions.
Sigrid Trier Kjær, Sebastian Westermann, Nora Nedkvitne, and Peter Dörsch
Biogeosciences, 21, 4723–4737, https://doi.org/10.5194/bg-21-4723-2024, https://doi.org/10.5194/bg-21-4723-2024, 2024
Short summary
Short summary
Permafrost peatlands are thawing due to climate change, releasing large quantities of carbon that degrades upon thawing and is released as CO2, CH4 or dissolved organic carbon (DOC). We incubated thawed Norwegian permafrost peat plateaus and thermokarst pond sediment found next to permafrost for up to 350 d to measure carbon loss. CO2 production was initially the highest, whereas CH4 production increased over time. The largest carbon loss was measured at the top of the peat plateau core as DOC.
Olivier Bouriaud, Ernst-Detlef Schulze, Konstantin Gregor, Issam Bourkhris, Peter Högberg, Roland Irslinger, Phillip Papastefanou, Julia Pongratz, Anja Rammig, Riccardo Valentini, and Christian Körner
EGUsphere, https://doi.org/10.5194/egusphere-2024-3092, https://doi.org/10.5194/egusphere-2024-3092, 2024
Short summary
Short summary
The impact of harvesting on forests' carbon sink capacities is debated. One view is that their sink strength is resilient to harvesting, the other that it disrupts these capacities. Our work shows that leaf area index (LAI) has been overlooked in this discussion. We found that temperate forests' carbon uptake is largely insensitive to variations in LAI beyond about 4 m² m-², but that forests operate at higher levels.
Silvie Lainela, Erik Jacobs, Stella-Theresa Luik, Gregor Rehder, and Urmas Lips
Biogeosciences, 21, 4495–4519, https://doi.org/10.5194/bg-21-4495-2024, https://doi.org/10.5194/bg-21-4495-2024, 2024
Short summary
Short summary
We evaluate the variability of carbon dioxide and methane in the surface layer of the north-eastern basins of the Baltic Sea in 2018. We show that the shallower coastal areas have considerably higher spatial variability and seasonal amplitude of surface layer pCO2 and cCH4 than measured in the offshore areas of the Baltic Sea. Despite this high variability, caused mostly by coastal physical processes, the average annual air–sea CO2 fluxes differed only marginally between the sub-basins.
Martti Honkanen, Mika Aurela, Juha Hatakka, Lumi Haraguchi, Sami Kielosto, Timo Mäkelä, Jukka Seppälä, Simo-Matti Siiriä, Ken Stenbäck, Juha-Pekka Tuovinen, Pasi Ylöstalo, and Lauri Laakso
Biogeosciences, 21, 4341–4359, https://doi.org/10.5194/bg-21-4341-2024, https://doi.org/10.5194/bg-21-4341-2024, 2024
Short summary
Short summary
The exchange of CO2 between the sea and the atmosphere was studied in the Archipelago Sea, Baltic Sea, in 2017–2021, using an eddy covariance technique. The sea acted as a net source of CO2 with an average yearly emission of 27.1 gC m-2 yr-1, indicating that the marine ecosystem respired carbon that originated elsewhere. The yearly CO2 emission varied between 18.2–39.2 gC m-2 yr-1, mostly due to the yearly variation of ecosystem carbon uptake.
Ralf C. H. Aben, Daniël van de Craats, Jim Boonman, Stijn H. Peeters, Bart Vriend, Coline C. F. Boonman, Ype van der Velde, Gilles Erkens, and Merit van den Berg
Biogeosciences, 21, 4099–4118, https://doi.org/10.5194/bg-21-4099-2024, https://doi.org/10.5194/bg-21-4099-2024, 2024
Short summary
Short summary
Drained peatlands cause high CO2 emissions. We assessed the effectiveness of subsurface water infiltration systems (WISs) in reducing CO2 emissions related to increases in water table depth (WTD) on 12 sites for up to 4 years. Results show WISs markedly reduced emissions by 2.1 t CO2-C ha-1 yr-1. The relationship between the amount of carbon above the WTD and CO2 emission was stronger than the relationship between WTD and emission. Long-term monitoring is crucial for accurate emission estimates.
Ingeborg Bussmann, Eric P. Achterberg, Holger Brix, Nicolas Brüggemann, Götz Flöser, Claudia Schütze, and Philipp Fischer
Biogeosciences, 21, 3819–3838, https://doi.org/10.5194/bg-21-3819-2024, https://doi.org/10.5194/bg-21-3819-2024, 2024
Short summary
Short summary
Methane (CH4) is an important greenhouse gas and contributes to climate warming. However, the input of CH4 from coastal areas to the atmosphere is not well defined. Dissolved and atmospheric CH4 was determined at high spatial resolution in or above the North Sea. The atmospheric CH4 concentration was mainly influenced by wind direction. With our detailed study on the spatial distribution of CH4 fluxes we were able to provide a detailed and more realistic estimation of coastal CH4 fluxes.
Niu Zhu, Jinniu Wang, Dongliang Luo, Xufeng Wang, Cheng Shen, and Ning Wu
Biogeosciences, 21, 3509–3522, https://doi.org/10.5194/bg-21-3509-2024, https://doi.org/10.5194/bg-21-3509-2024, 2024
Short summary
Short summary
Our study delves into the vital role of subalpine forests in the Qinghai–Tibet Plateau as carbon sinks in the context of climate change. Utilizing advanced eddy covariance systems, we uncover their significant carbon sequestration potential, observing distinct seasonal patterns influenced by temperature, humidity, and radiation. Notably, these forests exhibit robust carbon absorption, with potential implications for global carbon balance.
Colette L. Kelly, Nicole M. Travis, Pascale Anabelle Baya, Claudia Frey, Xin Sun, Bess B. Ward, and Karen L. Casciotti
Biogeosciences, 21, 3215–3238, https://doi.org/10.5194/bg-21-3215-2024, https://doi.org/10.5194/bg-21-3215-2024, 2024
Short summary
Short summary
Nitrous oxide, a potent greenhouse gas, accumulates in regions of the ocean that are low in dissolved oxygen. We used a novel combination of chemical tracers to determine how nitrous oxide is produced in one of these regions, the eastern tropical North Pacific Ocean. Our experiments showed that the two most important sources of nitrous oxide under low-oxygen conditions are denitrification, an anaerobic process, and a novel “hybrid” process performed by ammonia-oxidizing archaea.
Hella van Asperen, Thorsten Warneke, Alessandro Carioca de Araújo, Bruce Forsberg, Sávio José Filgueiras Ferreira, Thomas Röckmann, Carina van der Veen, Sipko Bulthuis, Leonardo Ramos de Oliveira, Thiago de Lima Xavier, Jailson da Mata, Marta de Oliveira Sá, Paulo Ricardo Teixeira, Julie Andrews de França e Silva, Susan Trumbore, and Justus Notholt
Biogeosciences, 21, 3183–3199, https://doi.org/10.5194/bg-21-3183-2024, https://doi.org/10.5194/bg-21-3183-2024, 2024
Short summary
Short summary
Carbon monoxide (CO) is regarded as an important indirect greenhouse gas. Soils can emit and take up CO, but, until now, uncertainty remains as to which process dominates in tropical rainforests. We present the first soil CO flux measurements from a tropical rainforest. Based on our observations, we report that tropical rainforest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.
Yélognissè Agbohessou, Claire Delon, Manuela Grippa, Eric Mougin, Daouda Ngom, Espoir Koudjo Gaglo, Ousmane Ndiaye, Paulo Salgado, and Olivier Roupsard
Biogeosciences, 21, 2811–2837, https://doi.org/10.5194/bg-21-2811-2024, https://doi.org/10.5194/bg-21-2811-2024, 2024
Short summary
Short summary
Emissions of greenhouse gases in the Sahel are not well represented because they are considered weak compared to the rest of the world. However, natural areas in the Sahel emit carbon dioxide and nitrous oxides, which need to be assessed because of extended surfaces. We propose an assessment of such emissions in Sahelian silvopastoral systems and of how they are influenced by environmental characteristics. These results are essential to inform climate change strategies in the region.
Merit van den Berg, Thomas M. Gremmen, Renske J. E. Vroom, Jacobus van Huissteden, Jim Boonman, Corine J. A. van Huissteden, Ype van der Velde, Alfons J. P. Smolders, and Bas P. van de Riet
Biogeosciences, 21, 2669–2690, https://doi.org/10.5194/bg-21-2669-2024, https://doi.org/10.5194/bg-21-2669-2024, 2024
Short summary
Short summary
Drained peatlands emit 3 % of the global greenhouse gas emissions. Paludiculture is a way to reduce CO2 emissions while at the same time generating an income for landowners. The side effect is the potentially high methane emissions. We found very high methane emissions for broadleaf cattail compared with narrowleaf cattail and water fern. The rewetting was, however, effective to stop CO2 emissions for all species. The highest potential to reduce greenhouse gas emissions had narrowleaf cattail.
Thomas Bauduin, Nathalie Gypens, and Alberto V. Borges
EGUsphere, https://doi.org/10.5194/egusphere-2024-1315, https://doi.org/10.5194/egusphere-2024-1315, 2024
Short summary
Short summary
Greenhouse gases (GHG) emissions from ponds can vary depending on the state of ponds (clear-water with macrophytes or turbid-water with phytoplankton). We studied CO2, CH4, and N2O emissions in clear and turbid urban ponds (June 2021 to December 2023) in Brussels. We observed seasonal differences in methanogenesis pathways, in CH4 emissions between clear and turbid ponds, and annual differences in total emissions of GHG, likely from intense El Niño event in 2023.
Thea H. Heimdal, Galen A. McKinley, Adrienne J. Sutton, Amanda R. Fay, and Lucas Gloege
Biogeosciences, 21, 2159–2176, https://doi.org/10.5194/bg-21-2159-2024, https://doi.org/10.5194/bg-21-2159-2024, 2024
Short summary
Short summary
Measurements of ocean carbon are limited in time and space. Machine learning algorithms are therefore used to reconstruct ocean carbon where observations do not exist. Improving these reconstructions is important in order to accurately estimate how much carbon the ocean absorbs from the atmosphere. In this study, we find that a small addition of observations from the Southern Ocean, obtained by autonomous sampling platforms, could significantly improve the reconstructions.
Guilherme L. Torres Mendonça, Julia Pongratz, and Christian H. Reick
Biogeosciences, 21, 1923–1960, https://doi.org/10.5194/bg-21-1923-2024, https://doi.org/10.5194/bg-21-1923-2024, 2024
Short summary
Short summary
We study the timescale dependence of airborne fraction and underlying feedbacks by a theory of the climate–carbon system. Using simulations we show the predictive power of this theory and find that (1) this fraction generally decreases for increasing timescales and (2) at all timescales the total feedback is negative and the model spread in a single feedback causes the spread in the airborne fraction. Our study indicates that those are properties of the system, independently of the scenario.
François Clayer, Jan Erik Thrane, Kuria Ndungu, Andrew King, Peter Dörsch, and Thomas Rohrlack
Biogeosciences, 21, 1903–1921, https://doi.org/10.5194/bg-21-1903-2024, https://doi.org/10.5194/bg-21-1903-2024, 2024
Short summary
Short summary
Determination of dissolved greenhouse gas (GHG) in freshwater allows us to estimate GHG fluxes. Mercuric chloride (HgCl2) is used to preserve water samples prior to GHG analysis despite its environmental and health impacts and interferences with water chemistry in freshwater. Here, we tested the effects of HgCl2, two substitutes and storage time on GHG in water from two boreal lakes. Preservation with HgCl2 caused overestimation of CO2 concentration with consequences for GHG flux estimation.
Helena Rautakoski, Mika Korkiakoski, Jarmo Mäkelä, Markku Koskinen, Kari Minkkinen, Mika Aurela, Paavo Ojanen, and Annalea Lohila
Biogeosciences, 21, 1867–1886, https://doi.org/10.5194/bg-21-1867-2024, https://doi.org/10.5194/bg-21-1867-2024, 2024
Short summary
Short summary
Current and future nitrous oxide (N2O) emissions are difficult to estimate due to their high variability in space and time. Several years of N2O fluxes from drained boreal peatland forest indicate high importance of summer precipitation, winter temperature, and snow conditions in controlling annual N2O emissions. The results indicate increasing year-to-year variation in N2O emissions in changing climate with more extreme seasonal weather conditions.
Matthias Koschorreck, Norbert Kamjunke, Uta Koedel, Michael Rode, Claudia Schuetze, and Ingeborg Bussmann
Biogeosciences, 21, 1613–1628, https://doi.org/10.5194/bg-21-1613-2024, https://doi.org/10.5194/bg-21-1613-2024, 2024
Short summary
Short summary
We measured the emission of carbon dioxide (CO2) and methane (CH4) from different sites at the river Elbe in Germany over 3 days to find out what is more important for quantification: small-scale spatial variability or diurnal temporal variability. We found that CO2 emissions were very different between day and night, while CH4 emissions were more different between sites. Dried out river sediments contributed to CO2 emissions, while the side areas of the river were important CH4 sources.
Odysseas Sifounakis, Edwin Haas, Klaus Butterbach-Bahl, and Maria P. Papadopoulou
Biogeosciences, 21, 1563–1581, https://doi.org/10.5194/bg-21-1563-2024, https://doi.org/10.5194/bg-21-1563-2024, 2024
Short summary
Short summary
We performed a full assessment of the carbon and nitrogen cycles of a cropland ecosystem. An uncertainty analysis and quantification of all carbon and nitrogen fluxes were deployed. The inventory simulations include greenhouse gas emissions of N2O, NH3 volatilization and NO3 leaching from arable land cultivation in Greece. The inventory also reports changes in soil organic carbon and nitrogen stocks in arable soils.
Sarah M. Ludwig, Luke Schiferl, Jacqueline Hung, Susan M. Natali, and Roisin Commane
Biogeosciences, 21, 1301–1321, https://doi.org/10.5194/bg-21-1301-2024, https://doi.org/10.5194/bg-21-1301-2024, 2024
Short summary
Short summary
Landscapes are often assumed to be homogeneous when using eddy covariance fluxes, which can lead to biases when calculating carbon budgets. In this study we report eddy covariance carbon fluxes from heterogeneous tundra. We used the footprints of each flux observation to unmix the fluxes coming from components of the landscape. We identified and quantified hot spots of carbon emissions in the landscape. Accurately scaling with landscape heterogeneity yielded half as much regional carbon uptake.
Cited articles
Baumgartner, M., Schilt, A., Eicher, O., Schmitt, J., Schwander, J., Spahni,
R., Fischer, H., and Stocker, T. F.: High-resolution interpolar difference of
atmospheric methane around the Last Glacial Maximum, Biogeosciences, 9,
3961–3977, https://doi.org/10.5194/bg-9-3961-2012, 2012.
Baumgartner, M., Kindler, P., Eicher, O., Floch, G., Schilt, A., Schwander,
J., Spahni, R., Capron, E., Chappellaz, J., Leuenberger, M., Fischer, H., and
Stocker, T. F.: NGRIP CH4 concentration from 120 to 10 kyr before present and
its relation to a δ15N temperature reconstruction from the same ice core,
Clim. Past, 10, 903–920, https://doi.org/10.5194/cp-10-903-2014, 2014.
Bazin, L., Landais, A., Lemieux-Dudon, B., Toyé Mahamadou Kele, H., Veres,
D., Parrenin, F., Martinerie, P., Ritz, C., Capron, E., Lipenkov, V., Loutre,
M.-F., Raynaud, D., Vinther, B., Svensson, A., Rasmussen, S. O., Severi, M.,
Blunier, T., Leuenberger, M., Fischer, H., Masson-Delmotte, V., Chappellaz,
J., and Wolff, E.: An optimized multi-proxy, multi-site Antarctic ice and gas
orbital chronology (AICC2012): 120–800 ka, Clim. Past, 9, 1715–1731,
https://doi.org/10.5194/cp-9-1715-2013, 2013.
Berger, A. and Loutre, M.-F.: Insolation values for the climate of the last
10 million years, Quaternary Sci. Rev., 10, 297–317, 1991.
Blunier, T., Chappellaz, J., Schwander, J., Stauffer, B., and Raynaud, D.:
Variations in atmospheric methane concentration during the Holocene epoch,
Nature, 374, 46–49, https://doi.org/10.1038/374046a0, 1995.
Bock, M., Schmitt, J., Behrens, M., Möller, L., Schneider, R., Sapart,
C., and Fischer, H.: A gas chromatography/pyrolysis/isotope ratio mass
spectrometry system for high-precision δD measurements of
atmospheric methane extracted from ice cores, Rapid Commun. Mass Sp.,
24, 621–633, https://doi.org/10.1002/rcm.4429, 2010.
Bock, M., Schmitt, J., Beck, J., Schneider, R., and Fischer, H.: Improving
accuracy and precision of ice core δD(CH4) analyses using methane
pre-pyrolysis and hydrogen post-pyrolysis trapping and subsequent
chromatographic separation, Atmos. Meas. Tech., 7, 1999–2012,
https://doi.org/10.5194/amt-7-1999-2014, 2014.
Bock, M., Schmitt, J., Beck, J., Seth, B., Chappellaz, J., and Fischer, H.:
Glacial/interglacial wetland, biomass burning, and geologic methane
emissions constrained by dual stable isotopic CH4 ice core records,
P. Natl. Acad. Sci. USA, 114, E5778–E5786, https://doi.org/10.1073/pnas.1613883114,
2017.
Brenninkmeijer, C. A. M., Lowe, D. C., Manning, M. R., Sparks, R. J., and
vanVelthoven, P. F. J.: The 13C, 14C, and 18O isotopic
composition of CO, CH4, and CO2 in the higher southern latitudes
lower stratosphere, J. Geophys. Res., 100, 26163–26172,
https://doi.org/10.1029/95JD02528, 1995.
Brook, E. J.: Methane measurements from the GISP2 and Siple Dome ice cores,
available at: http://nsidc.org/data/nsidc-0440 (last access: 13 October 2018), 2009.
Brook, E. J., Sowers, T., and Orchardo, J.: Rapid variations in atmospheric
methane concentration during the past 110,000 years, Science, 273,
1087–1091, https://doi.org/10.1126/science.273.5278.1087, 1996.
Brook, E. J., Harder, S., Severinghaus, J., Steig, E. J., and Sucher, C. M.:
On the origin and timing of rapid changes in atmospheric methane during the
last glacial period, Global. Biogeochem. Cy., 14, 559–572,
https://doi.org/10.1029/1999GB001182, 2000.
Buizert, C., Martinerie, P., Petrenko, V. V., Severinghaus, J. P., Trudinger,
C. M., Witrant, E., Rosen, J. L., Orsi, A. J., Rubino, M., Etheridge, D. M.,
Steele, L. P., Hogan, C., Laube, J. C., Sturges, W. T., Levchenko, V. A.,
Smith, A. M., Levin, I., Conway, T. J., Dlugokencky, E. J., Lang, P. M.,
Kawamura, K., Jenk, T. M., White, J. W. C., Sowers, T., Schwander, J., and
Blunier, T.: Gas transport in firn: multiple-tracer characterisation and
model intercomparison for NEEM, Northern Greenland, Atmos. Chem. Phys., 12,
4259–4277, https://doi.org/10.5194/acp-12-4259-2012, 2012.
Buizert, C., Sowers, T., and Blunier, T.: Assessment of diffusive isotopic
fractionation in polar firn, and application to ice core trace gas records,
Earth Planet. Sc. Lett., 361, 110–119, https://doi.org/10.1016/j.epsl.2012.11.039,
2013.
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.
Cantrell, C. A., Shetter, R. E., McDaniel, A. H., Calvert, J. G., Davidson,
J, A., Lowe, D. C., Tyler, S. C., Cicerone, R. J., and Greenberg, J. P.:
Carbon kinetic isotope effect in the oxidation of methane by the hydroxyl
radical, J. Geophys. Res., 95, 22455–22462,
https://doi.org/10.1029/JD095iD13p22455, 1990.
Capron, E., Landais, A., Buiron, D., Cauquoin, A., Chappellaz, J., Debret,
M., Jouzel, J., Leuenberger, M., Martinerie, P., Masson-Delmotte, V.,
Mulvaney, R., Parrenin, F., and Prié, F.: Glacial–interglacial dynamics of
Antarctic firn columns: comparison between simulations and ice core air-δ15N
measurements, Clim. Past, 9, 983–999, https://doi.org/10.5194/cp-9-983-2013,
2013.
Channan, S., Collins, K., and Emanuel, W. R.: Global mosaics of the standard
MODIS land cover type data, University of Maryland and the Pacific Northwest National
Laboratory, College Park, MD, available at: http://glcf.umd.edu/data/lc/ (last access: 14 November 2018), 2014.
Chappellaz, J., Blunier, T., Raynaud, D., Barnola, J. M., Schwander, J. and
Stauffer, B.: Synchronous changes in atmospheric CH4 and Greenland
climate between 40 and 8 kyr BP, Nature, 366, 443–445,
https://doi.org/10.1038/366443a0, 1993.
Chappellaz, J., Blunier, T., Kints, S., Dällenbach, A., Barnola, J.-M.,
Schwander, J., Raynaud, D., and Stauffer, B.: Changes in the atmospheric
CH4 gradient between Greenland and Antarctica during the Holocene, J.
Geophys. Res.-Atmos., 102, 15987–15997, https://doi.org/10.1029/97JD01017,
1997.
Crill, P. M. and Thornton, B. F.: Whither methane in the IPCC process?, Nat.
Clim. Change, 7, 678–680, https://doi.org/10.1038/nclimate3403, 2017.
CSIRO: Latest Cape Grim greenhouse gas data, available at:
https://www.csiro.au/en/Research/OandA/Areas/Assessing-our-climate/Latest-greenhouse-gas-data, last access: 27 November 2017.
Dalsøren, S. B., Myhre, C. L., Myhre, G., Gomez-Pelaez, A. J., Søvde, O. A.,
Isaksen, I. S. A., Weiss, R. F., and Harth, C. M.: Atmospheric methane
evolution the last 40 years, Atmos. Chem. Phys., 16, 3099–3126,
https://doi.org/10.5194/acp-16-3099-2016, 2016.
Daniau, A.-L., Bartlein, P. J., Harrison, S.
P., Prentice, I. C., Brewer, S., Friedlingstein, P., Harrison-Prentice, T.
I., Inoue, J., Izumi, K., Marlon, J. R., Mooney, S., Power, M. J.,
Stevenson, J., Tinner, W., and Andrič, M.: Predictability of biomass
burning in response to climate changes, Global. Biogeochem. Cy.,
26, GB4007, https://doi.org/10.1029/2011GB004249, 2012.
Ding, W., Cai, Z., and Tsuruta, H.: Plant species effects on methane
emissions from freshwater marshes, Atmos. Environ., 39, 3199–3207,
https://doi.org/10.1016/j.atmosenv.2005.02.022, 2005.
Dlugokencky, E. J., Myers, R. C., Lang, P. M., Masarie, K. A., Crotwell, A.
M., Thoning, K. W., Hall, B. D., Elkins, J. W., and Steele, L. P.: Conversion
of NOAA atmospheric dry air CH4 mole fractions to a gravimetrically
prepared standard scale, J. Geophys. Res.-Atmos., 110, D18306,
https://doi.org/10.1029/2005JD006035, 2005.
Dlugokencky, E. J., Lang, P. M., Crotwell, A. M., Mund, J. W., Crotwell, M.
J., and Thoning, K. W.: Atmospheric methane dry air mole fractions from the
NOAA ESRL Carbon Cycle Cooperative Global Air Sampling Network, 1983–2016,
available at:
ftp://aftp.cmdl.noaa.gov/data/trace_gases/ch4/flask/surface/README_surface_flask_ch4.html, last access: 20 October 2017.
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,
https://doi.org/10.1002/2015PA002874, 2016.
Enting, I. G.: On the use of smoothing splines to filter CO2 data, J.
Geophys. Res.-Atmos., 92, 10977–10984, 1987.
Etheridge, D. M., Steele, L. P., Francey, R. J., and Langenfelds, R. L.:
Atmospheric methane between 1000 A.D. and present: Evidence of anthropogenic
emissions and climatic variability, J. Geophys. Res.-Atmos., 103,
15979–15993, https://doi.org/10.1029/98JD00923, 1998.
Etiope, G., Milkov, A. V., and Derbyshire, E.: Did geologic emissions of
methane play any role in Quaternary climate change?, Global. Planet. Change,
61, 79–88, https://doi.org/10.1016/j.gloplacha.2007.08.008, 2008.
Farquhar, G. D., Ehleringer, J. R., and Hubick, K. T.: Carbon isotope
discrimination and photosynthesis, Annu. Rev. Plant Biol., 40, 503–537,
1989.
Feilberg, K. L., Griffith, D. W., Johnson, M. S., and Nielsen, C. J.: The 13C
and D kinetic isotope effects in the reaction of CH4 with Cl, Int. J.
Chem. Kinet., 37, 110–118, https://doi.org/10.1002/kin.20058, 2005.
Fischer, H., Behrens, M., Bock, M., Richter, U., Schmitt, J., Loulergue, L.,
Chappellaz, J., Spahni, R., Blunier, T., Leuenberger, M. and Stocker, T. F.:
Changing boreal methane sources and constant biomass burning during the last
termination, Nature, 452(7189), 864–867, https://doi.org/10.1038/nature06825, 2008.
Flückiger, J., Monnin, E., Stauffer, B., Schwander, J., Stocker, T. F.,
Chappellaz, J., Raynaud, D., and Barnola, J.-M.: High-resolution Holocene
N2O ice core record and its relationship with CH4 and CO2,
Global. Biogeochem. Cy., 16, 10-1–10-8, https://doi.org/10.1029/2001GB001417, 2002.
Geller, L. S., Elkins, J. W., Lobert, J. M., Clarke, A. D., Hurst, D. F.,
Butler, J. H., and Myers, R. C.: Tropospheric SF6: Observed latitudinal
distribution and trends, derived emissions and interhemispheric exchange
time, Geophys. Res. Lett., 24, 675–678, https://doi.org/10.1029/97GL00523, 1997.
Gierczak, T., Alukdar, R. K., Herndon, S. C., Vaghjiani, G. L., and
Ravishankara, A. R.: Rate Coefficients for the Reactions of Hydroxyl
Radicals with Methane and Deuterated Methanes, J. Phys. Chem. A, 101,
3125–3134, https://doi.org/10.1021/jp963892r, 1997.
Gow, A. J., Meese, D. A., Alley, R. B., Fitzpatrick, J. J., Anandakrishnan,
S., Woods, G. A., and Elder, B. C.: Physical and structural properties of the
Greenland Ice Sheet Project 2 ice core: A review, J. Geophys. Res.-Oceans,
102, 26559–26575, https://doi.org/10.1029/97JC00165, 1997.
Haug, G. H., Hughen, K. A., Sigman, D. M., Peterson, L. C., and Röhl, U.:
Southward migration of the intertropical convergence zone through the
Holocene, Science, 293, 1304–1308, https://doi.org/10.1126/science.1059725, 2001.
Hornibrook, E. R. C.: The stable carbon isotope composition of methane
produced and emitted from northern peatlands, in: Carbon Cycling in Northern
Peatlands, edited by: Baird, A. J., Belyea, L. R., Comas, X., Reeve, A. S., and
Slater, L. D., American Geophysical Union, Washington D.C., USA, 187–203, 2013.
Houweling, S., Dentener, F., and Lelieveld, J.: Simulation of preindustrial
atmospheric methane to constrain the global source strength of natural
wetlands, J. Geophys. Res.-Atmos., 105, 17243–17255,
https://doi.org/10.1029/2000JD900193, 2000.
Irion, F. W., Moyer, E. J., Gunson, M. R., Rinsland, C. P., Yung, Y. L.,
Michelsen, H. A., Salawitch, R. J., Chang, A. Y., Newchurch, M. J., Abbas,
M. M., Abrams, M. C., and Zander, R.: Stratospheric observations of CH3D
and HDO from ATMOS infrared solar spectra: Enrichments of deuterium in
methane and implications for HD, Geophys. Res. Lett., 23, 2381–2384,
https://doi.org/10.1029/96GL01402, 1996.
Kaplan, J. O., Folberth, G., and Hauglustaine, D. A.: Role of methane and
biogenic volatile organic compound sources in late glacial and Holocene
fluctuations of atmospheric methane concentrations, Global. Biogeochem.
Cy., 20, GB2016, https://doi.org/10.1029/2005GB002590, 2006.
Kaplan, J. O., Krumhardt, K. M., Ellis, E. C., Ruddiman, W. F., Lemmen, C.,
and Goldewijk, K. K.: Holocene carbon emissions as a result of anthropogenic
land cover change, The Holocene, 21, 775–791,
https://doi.org/10.1177/0959683610386983, 2011.
Kirschke, S., Bousquet, P., Ciais, P., Saunois, M., Canadell, J. G.,
Dlugokencky, E. J., Bergamaschi, P., Bergmann, D., Blake, D. R., Bruhwiler,
L.,Cameron-Smith, P., Castaldi, S., Chevallier, F., Feng, L., Fraser, A.,
Heimann, M., Hodson, E. L., Houweling, S., Josse, B., Fraser, P. J.,
Krummel, P. B., Lamarque, J. F., Langenfelds, R. L., Le Quéré, C.,
Naik, V., O'doherty, S., Palmer, P. I., Pison, I., Plummer, D., Poulter, B.,
Prinn, R. G., Rigby, M., Ringeval, B., Santini, M., Schmidt, M., Shindell,
D. T., Simpson, I. J., Spahni, R., Steele, L. P., Strode, S. A., Sudo, K.,
Szopa, S., Van Der Werf, G. R., Voulgarakis, A., Van Weele, M., Weiss, R.
F., Williams, J. E., and Zeng, G.: Three decades of global methane sources
and sinks, Nat. Geosci., 6, 813–823, https://doi.org/10.1038/ngeo1955, 2013.
Kovács, T., Feng, W., Totterdill, A., Plane, J. M. C., Dhomse, S.,
Gómez-Martín, J. C., Stiller, G. P., Haenel, F. J., Smith, C., Forster, P.
M., García, R. R., Marsh, D. R., and Chipperfield, M. P.: Determination of
the atmospheric lifetime and global warming potential of sulfur hexafluoride
using a three-dimensional model, Atmos. Chem. Phys., 17, 883–898,
https://doi.org/10.5194/acp-17-883-2017, 2017.
Landais, A., Barnola, J. M., Kawamura, K., Caillon, N., Delmotte, M., Van
Ommen, T., Dreyfus, G., Jouzel, J., Masson-Delmotte, V., Minster, B.,
Freitag, J., Leuenberger, M., Schwander, J., Huber, C., Etheridge, D., and
Morgan, V.: Firn-air δ15N in modern polar sites and
glacial–interglacial ice: a model-data mismatch during glacial periods in
Antarctica?, Quaternary Sci. Rev., 25, 49–62,
https://doi.org/10.1016/j.quascirev.2005.06.007, 2006.
Levin, I., Naegler, T., Heinz, R., Osusko, D., Cuevas, E., Engel, A.,
Ilmberger, J., Langenfelds, R. L., Neininger, B., Rohden, C. v., Steele, L.
P., Weller, R., Worthy, D. E., and Zimov, S. A.: The global SF6 source
inferred from long-term high precision atmospheric measurements and its
comparison with emission inventories, Atmos. Chem. Phys., 10, 2655–2662,
https://doi.org/10.5194/acp-10-2655-2010, 2010.
Levine, J. G., Wolff, E. W., Jones, A. E., Sime, L. C., Valdes, P. J.,
Archibald, A. T., Carver, G. D., Warwick, N. J., and Pyle, J. A.: Reconciling
the changes in atmospheric methane sources and sinks between the Last
Glacial Maximum and the pre-industrial era, Geophys. Res. Lett., 38,
1–6, https://doi.org/10.1029/2011GL049545, 2011a.
Levine, J. G., Wolff, E. W., Jones, A. E., and Sime, L. C.: The role of
atomic chlorine in glacial-interglacial changes in the carbon-13 content of
atmospheric methane, Geophys. Res. Lett., 38, 1–6,
https://doi.org/10.1029/2010GL046122, 2011b.
Loulergue, L., Schilt, A., Spahni, R., Masson-Delmotte, V., Blunier, T.,
Lemieux, B., Barnola, J.-M., Raynaud, D., Stocker, T. F., and Chappellaz, J.:
Orbital and millennial-scale features of atmospheric CH4 over the past
800 000 years, Nature, 453, 383–386, https://doi.org/10.1038/nature06950, 2008.
MacFarling Meure, C., Etheridge, D., Trudinger, C., Steele, P., 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.
Marshall, J., Donohoe, A., Ferreira, D., and McGee, D.: The ocean's role in
setting the mean position of the Inter-Tropical Convergence Zone, Clim.
Dynam., 42, 1967–1979, https://doi.org/10.1007/s00382-013-1767-z, 2014.
McGee, D., Donohoe, A., Marshall, J., and Ferreira, D.: Changes in ITCZ
location and cross-equatorial heat transport at the Last Glacial Maximum,
Heinrich Stadial 1, and the mid-Holocene, Earth Planet. Sc. Lett., 390,
69–79, https://doi.org/10.1016/j.epsl.2013.12.043, 2014.
Meese, D. A., Gow, A. J., Grootes, P., Stuiver, M., Mayewski, P. A.,
Zielinski, G. A., Ram, M., Taylor, K. C., and Waddington, E. D.: The
accumulation record from the GISP2 Core as an indicator of climate change
throughout the Holocene, Science, 266, 1680–1682,
https://doi.org/10.1126/science.266.5191.1680, 1994.
Mitchell, L., Brook, E., Lee, J. E., Buizert, C., and Sowers, T.: Constraints
on the late Holocene anthropogenic contribution to the atmospheric methane
budget, Science, 342, 964–966, https://doi.org/10.1126/science.1238920, 2013.
Möller, L., Sowers, T., Bock, M., Spahni, R., Behrens, M., Schmitt, J.,
Miller, H., and Fischer, H.: Independent variations of CH4 emissions and
isotopic composition over the past 160,000 years, Nat. Geosci., 6,
885–890, https://doi.org/10.1038/NGEO1922, 2013.
Naik, V., Voulgarakis, A., Fiore, A. M., Horowitz, L. W., Lamarque, J.-F.,
Lin, M., Prather, M. J., Young, P. J., Bergmann, D., Cameron-Smith, P. J.,
Cionni, I., Collins, W. J., Dalsøren, S. B., Doherty, R., Eyring, V.,
Faluvegi, G., Folberth, G. A., Josse, B., Lee, Y. H., MacKenzie, I. A.,
Nagashima, T., van Noije, T. P. C., Plummer, D. A., Righi, M., Rumbold, S.
T., Skeie, R., Shindell, D. T., Stevenson, D. S., Strode, S., Sudo, K.,
Szopa, S., and Zeng, G.: Preindustrial to present-day changes in tropospheric
hydroxyl radical and methane lifetime from the Atmospheric Chemistry and
Climate Model Intercomparison Project (ACCMIP), Atmos. Chem. Phys., 13,
5277–5298, https://doi.org/10.5194/acp-13-5277-2013, 2013.
Neff, P. D.: A review of the brittle ice zone in polar ice cores, Ann.
Glaciol., 55, 72–82, https://doi.org/10.3189/2014AoG68A023, 2014.
NOAA: Paleo Data Search, available at:
https://www.ncdc.noaa.gov/paleo/study/25350, last access: 13 October
2018.
NOAA/ESRL: Combined Sulfur hexaflouride data from the NOAA/ESRL Global
Monitoring Division, available at:
https://www.esrl.noaa.gov/gmd/hats/combined/SF6.html, last access: 10 October
2017.
Poss, C.: Untersuchung der Variabilität des atmosphärischen
Methanhaushalts hochpolarer Breiten anhand eines regionalen
Trajektorienmodells und der Messung stabiler Isotope, Universität
Heidelberg, available at: http://www.ub.uni-heidelberg.de/archiv/3966 (last access: 15 September 2017),
2003.
Prather, M. J. Holmes, C. D., and Hsu, J.: Reactive greenhouse gas
scenarios: Systematic exploration of uncertainties and the role of
atmospheric chemistry, Geophys. Res. Lett., 39, L09803,
https://doi.org/10.1029/2012GL051440, 2012.
Quay, P., Stutsman, J., Wilbur, D., Snover,
A., Dlugokencky, E., and Brown, T.: The isotopic composition of atmospheric
methane, Global. Biogeochem. Cy., 13, 445–461,
https://doi.org/10.1029/1998GB900006, 1999.
Rasmussen, S. O., Andersen, K. K., Svensson, A. M., Steffensen, J. P.,
Vinther, B. M., Clausen, H. B., Andersen, M. L., Johnsen, S. J., Larsen, L.
B., Bigler, M., Röthlisberger, R., Fischer, H., Goto-Azuma, K., Hansson,
M. E., and Ruth, U.: A new Greenland ice core chronology for the last glacial
termination, J. Geophys. Res.-Atmos., 111, D06102, https://doi.org/10.1029/2005JD006079, 2006.
Rasmussen, S. O., Bigler, M., Blockley, S. P., Blunier, T., Buchardt, S. L.,
Clausen, H. B., Cvijanovic, I., Dahl-Jensen, D., Johnsen, S. J., Fischer,
H., Gkinis, V., Guillevic, M., Hoek, W. Z., Lowe, J. J., Pedro, J. B., Popp,
T., Seierstad, I. K., Steffensen, J. P., Svensson, A. M., Vallelonga, P.,
Vinther, B. M., Walker, M. J. C., Wheatley, J. J., and Winstrup, M.: A
stratigraphic framework for abrupt climatic changes during the Last Glacial
period based on three synchronized Greenland ice-core records: refining and
extending the INTIMATE event stratigraphy, Quaternary Sci. Rev., 106, 14–28, https://doi.org/10.1016/j.quascirev.2014.09.007, 2014.
Ruddiman, W. F.: The anthropogenic greenhouse era began thousands of years
ago, Clim. Change, 61, 261–293, 2003.
Ruddiman, W. F. and Thomson, J. S.: The case for human causes of increased
atmospheric CH4 over the last 5000 years, Quaternary Sci. Rev., 20,
1769–1777, https://doi.org/10.1016/S0277-3791(01)00067-1, 2001.
Ruddiman, W. F., Guo, Z., Zhou, X., Wu, H., and Yu, Y.: Early rice farming
and anomalous methane trends, Quaternary Sci. Rev., 27, 1291–1295,
https://doi.org/10.1016/j.quascirev.2008.03.007, 2008.
Saueressig, G., Crowley, J. N., Bergamaschi, P., Brühl, C.,
Brenninkmeijer, C. A. M., and Fischer, H.: Carbon 13 and D kinetic isotope
effects in the reactions of CH4 with O(1D) and OH: New laboratory
measurements and their implications for the isotopic composition of
stratospheric methane, J. Geophys. Res., 106, 23127–23138,
https://doi.org/10.1029/2000JD000120, 2001.
Schaefer, H., Mikaloff Fletcher, S. E., Veidt, C., Lassey, K. R.,
Brailsford, G. W., Bromley, T. M., Dlugokencky, E. J., Michel, S. E.,
Miller, J. B., Levin, I., Lowe, D. C., Martin, R. J., Vaughn, B. H., and
White, J. W. C.: A 21st-century shift from fossil-fuel to biogenic methane
emissions indicated by 13CH4, Science, 352, 80–84, https://doi.org/10.1126/science.aad2705, 2016.
Schilt, A., Baumgartner, M., Schwander, J., Buiron, D., Capron, E.,
Chappellaz, J., Loulergue, L., Schüpbach, S., Spahni, R., and Fischer,
H.: Atmospheric nitrous oxide during the last 140 000 years, Earth Planet.
Sc. Lett., 300, 33–43, https://doi.org/10.1016/j.epsl.2010.09.027, 2010.
Schmitt, J., Seth, B., Bock, M., van der Veen, C., Möller, L., Sapart, C. J.,
Prokopiou, M., Sowers, T., Röckmann, T., and Fischer, H.: On the interference
of Kr during carbon isotope analysis of methane using continuous-flow
combustio–isotope ratio mass spectrometry, Atmos. Meas. Tech., 6, 1425–1445,
https://doi.org/10.5194/amt-6-1425-2013, 2013.
Schmitt, J., Seth, B., Bock, M., and Fischer, H.: Online technique for
isotope and mixing ratios of CH4, N2O, Xe and mixing ratios of organic trace
gases on a single ice core sample, Atmos. Meas. Tech., 7, 2645–2665,
https://doi.org/10.5194/amt-7-2645-2014, 2014.
Schwander, J.: Gas Diffusion in Firn, in: Chemical Exchange Between the
Atmosphere and Polar Snow, edited by: Wolff, E. W. and Bales, R. C., Springer, Berlin, Heidelberg, Germany, 527–540, 1996.
Seierstad, I. K., Abbott, P. M., Bigler, M., Blunier, T., Bourne, A. J.,
Brook, E., Buchardt, S. L., Buizert, C., Clausen, H. B., Cook, E.,
Dahl-Jensen, D., Davies, S. M., Guillevic, M., Johnsen, S. J., Pedersen, D.
S., Popp, T. J., Rasmussen, S. O., Severinghaus, J. P., Svensson, A., and
Vinther, B. M.: Consistently dated records from the Greenland GRIP, GISP2
and NGRIP ice cores for the past 104 ka reveal regional millennial-scale
δ18O gradients with possible Heinrich event imprint, Quaternary Sci.
Rev., 106, 29–46, https://doi.org/10.1016/j.quascirev.2014.10.032, 2014.
Severinghaus, J. P., Sowers, T., Brook, E. J., Alley, R. B., and Bender, M.
L.: Timing of abrupt climate change at the end of the Younger Dryas interval
from thermally fractionated gases in polar ice, Nature, 391, 141–146,
https://doi.org/10.1038/34346, 1998.
Singarayer, J. S., Valdes, P. J., Friedlingstein, P., Nelson, S., and
Beerling, D. J.: Late Holocene methane rise caused by orbitally controlled
increase in tropical sources, Nature, 470, 82–85,
https://doi.org/10.1038/nature09739, 2011.
Snover, A. K. and Quay, P. D.: Hydrogen and carbon kinetic isotope effects
during soil uptake of atmospheric methane, Global. Biogeochem. Cy., 14,
25–39, https://doi.org/10.1029/1999GB900089, 2000.
Sowers, T.: Atmospheric methane isotope records covering the Holocene
period, Quaternary Sci. Rev., 29, 213–221,
https://doi.org/10.1016/j.quascirev.2009.05.023, 2010.
Steele, L. P., Dlugokencky, E. J., Lang, P. M., Tans, P. P., Martin, R. C.,
and Masarie, K. A.: Slowing down of the global accumulation of atmospheric
methane during the 1980s, Nature, 358, 313–316, https://doi.org/10.1038/358313a0,
1992.
Tyler, S. C., Crill, P. M., and Brailsford, G. W.: 13C/12C Fractionation of
methane during oxidation in a temperate forested soil, Geochim. Cosmochim.
Ac., 58, 1625–1633, https://doi.org/10.1016/0016-7037(94)90564-9, 1994.
Umezawa, T., Brenninkmeijer, C. A. M., Röckmann, T., van der Veen, C., Tyler,
S. C., Fujita, R., Morimoto, S., Aoki, S., Sowers, T., Schmitt, J., Bock, M.,
Beck, J., Fischer, H., Michel, S. E., Vaughn, B. H., Miller, J. B., White, J.
W. C., Brailsford, G., Schaefer, H., Sperlich, P., Brand, W. A., Rothe, M.,
Blunier, T., Lowry, D., Fisher, R. E., Nisbet, E. G., Rice, A. L.,
Bergamaschi, P., Veidt, C., and Levin, I.: Interlaboratory comparison of δ13C
and δD measurements of atmospheric CH4 for combined use of data sets from
different laboratories, Atmos. Meas. Tech., 11, 1207–1231,
https://doi.org/10.5194/amt-11-1207-2018, 2018.
Veres, D., Bazin, L., Landais, A., Toyé Mahamadou Kele, H., Lemieux-Dudon,
B., Parrenin, F., Martinerie, P., Blayo, E., Blunier, T., Capron, E.,
Chappellaz, J., Rasmussen, S. O., Severi, M., Svensson, A., Vinther, B., and
Wolff, E. W.: The Antarctic ice core chronology (AICC2012): an optimized
multi-parameter and multi-site dating approach for the last 120 thousand
years, Clim. Past, 9, 1733–1748, https://doi.org/10.5194/cp-9-1733-2013,
2013.
Vinther, B. M., Clausen, H. B., Johnsen, S. J., Rasmussen, S. O., Andersen,
K. K., Buchardt, S. L., Dahl-Jensen, D., Seierstad, I. K.,
Siggaard-Andersen, M.-L., Steffensen, J. P., Svensson, A., Olsen, J., and
Heinemeier, J.: A synchronized dating of three Greenland ice cores
throughout the Holocene, J. Geophys. Res.-Atmos., 111, D13102, https://doi.org/10.1029/2005JD006921, 2006.
Walter, K. M., Edwards, M. E., Grosse, G., Zimov, S. A., and Chapin, F. S.:
Thermokarst lakes as a source of atmospheric CH4 during the last
deglaciation, Science, 318, 633–636, https://doi.org/10.1126/science.1142924,
2007.
Walter, K. M., Chanton, J. P., Chapin, F. S., Schuur, E. A. G. and Zimov, S.
A.: Methane production and bubble emissions from arctic lakes: Isotopic
implications for source pathways and ages, J. Geophys. Res.-Biogeo.,
113, G00A08, https://doi.org/10.1029/2007JG000569, 2008.
Wang, P. X., Wang, B., Cheng, H., Fasullo, J., Guo, Z. T., Kiefer, T., and
Liu, Z. Y.: The global monsoon across timescales: coherent variability of
regional monsoons, Clim. Past, 10, 2007–2052,
https://doi.org/10.5194/cp-10-2007-2014, 2014.
Whiticar, M. and Schaefer, H.: Constraining past global tropospheric methane
budgets with carbon and hydrogen isotope ratios in ice, Philos. T. Roy. Soc. A,
365, 1793–1828, https://doi.org/10.1098/rsta.2007.2048, 2007.
Whiticar, M. J.: Stable isotopes and global budgets, in Atmospheric methane:
sources, sinks, and role in global change, Springer, Berlin, Germany, 138–167, 1993.
Yang, J.-W., Ahn, J., Brook, E. J., and Ryu, Y.: Atmospheric methane control
mechanisms during the early Holocene, Clim. Past, 13, 1227–1242,
https://doi.org/10.5194/cp-13-1227-2017, 2017.
Yu, Z., Loisel, J., Turetsky, M. R., Cai, S., Zhao, Y., Frolking, S.,
MacDonald, G. M., and Bubier, J. L.: Evidence for elevated emissions from
high-latitude wetlands contributing to high atmospheric CH4
concentration in the early Holocene, Global. Biogeochem. Cy., 27,
131–140, https://doi.org/10.1002/gbc.20025, 2013.
Zhao, Y. and Harrison, S. P.: Mid-Holocene monsoons: a multi-model analysis
of the inter-hemispheric differences in the responses to orbital forcing and
ocean feedbacks, Clim. Dynam., 39, 1457–1487, 2012.
Short summary
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.
Ice core concentration and stable isotope measurements of atmospheric CH4 give valuable insights...
Altmetrics
Final-revised paper
Preprint