Articles | Volume 18, issue 12
https://doi.org/10.5194/bg-18-3539-2021
© Author(s) 2021. 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-18-3539-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Jun 2021
Research article |
| 17 Jun 2021
| 17 Jun 2021
High-resolution 14C bomb peak dating and climate response analyses of subseasonal stable isotope signals in wood of the African baobab – a case study from Oman
Franziska Slotta
Institute of Geological Sciences, Freie Universität Berlin,
Berlin, Germany
Section 4.3 Climate
Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany
Laboratory of Ion Beam Physics, ETH Zürich, Zurich,
Switzerland
Frank Riedel
Institute of Geological Sciences, Freie Universität Berlin,
Berlin, Germany
Karl-Uwe Heußner
Scientific Department of
the Head Office, Deutsches Archäologisches Institut, Berlin, Germany
Kai Hartmann
Institute of Geological Sciences, Freie Universität Berlin,
Berlin, Germany
Institute of Geological Sciences, Freie Universität Berlin,
Berlin, Germany
Section 4.3 Climate
Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany
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We developed a framework using rates and 14C-derived ages of soil-respired CO2 and its sources (autotrophic, heterotrophic) to identify carbon cycling pathways in different land-use types. Rates, ages and sources of respired CO2 varied across forests, grasslands, croplands, and managed peatlands. Our results suggest that the relationship between rates and ages of respired CO2 serves as a robust indicator of carbon retention or destabilization from natural to disturbed systems.
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Radiocarbon (14C) is an optimal tracer of methane (CH4) emissions, as 14C measurements enable distinguishing between fossil methane and biogenic methane. However, these measurements are particularly challenging, mainly due to technical difficulties in the sampling procedure. We made the sample extraction much simpler and time efficient, providing a new technology that can be used by any research group, with the goal of expanding 14C measurements for an improved understanding of methane sources.
Viorica Nagavciuc, Gerhard Helle, Maria Rădoane, Cătălin-Constantin Roibu, Mihai-Gabriel Cotos, and Monica Ionita
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We reconstructed drought conditions for the past 200 years for central and eastern parts of Europe (Romania) using δ18O in oak tree ring cellulose from Romania, revealing periods of both extreme wetness (e.g., 1905–1915) and dryness (e.g., 1818–1835). The most severe droughts occurred in the 19th and 21st centuries, likely linked to large-scale atmospheric circulation. This research highlights the potential of tree rings to improve our understanding of long-term climate variability in Europe.
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The main aim of this paper is to present the summer vapor pressure deficit (VPD) reconstruction dataset for the last 400 years over Europe based on δ18O records by using a random forest approach. We provide both a spatial and a temporal long-term perspective on the past summer VPD and new insights into the relationship between summer VPD and large-scale atmospheric circulation. This is the first gridded reconstruction of the European summer VPD over the past 400 years.
Achim Brauer, Ingo Heinrich, Markus J. Schwab, Birgit Plessen, Brian Brademann, Matthias Köppl, Sylvia Pinkerneil, Daniel Balanzategui, Gerhard Helle, and Theresa Blume
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Daniel Balting, Simon Michel, Viorica Nagavciuc, Gerhard Helle, Mandy Freund, Gerhard H. Schleser, David Steger, Gerrit Lohmann, and Monica Ionita
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-47, https://doi.org/10.5194/essd-2022-47, 2022
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Vapor pressure deficit is a key component of vegetation dynamics, soil science, meteorology, and soil science. In this study, we reconstruct the variability of the vapor pressure deficit in the past and examine the changes in future scenarios using climate models. In this way, past, present and future changes of the vapor pressure deficit can be detected locally, regionally, and continentally with higher statistical significance.
Caroline Welte, Jens Fohlmeister, Melina Wertnik, Lukas Wacker, Bodo Hattendorf, Timothy I. Eglinton, and Christoph Spötl
Clim. Past, 17, 2165–2177, https://doi.org/10.5194/cp-17-2165-2021, https://doi.org/10.5194/cp-17-2165-2021, 2021
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Stalagmites are valuable climate archives, but unlike other proxies the use of stable carbon isotopes (δ13C) is still difficult. A stalagmite from the Austrian Alps was analyzed using a new laser ablation method for fast radiocarbon (14C) analysis. This allowed 14C and δ13C to be combined, showing that besides soil and bedrock a third source is contributing during periods of warm, wet climate: old organic matter.
Daniel F. Balting, Monica Ionita, Martin Wegmann, Gerhard Helle, Gerhard H. Schleser, Norel Rimbu, Mandy B. Freund, Ingo Heinrich, Diana Caldarescu, and Gerrit Lohmann
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To extend climate information back in time, we investigate the climate sensitivity of a δ18O network from tree rings, consisting of 26 European sites and covering the last 400 years. Our results suggest that the δ18O variability is associated with large-scale anomaly patterns that resemble those observed for the El Niño–Southern Oscillation. We conclude that the investigation of large-scale climate signals far beyond instrumental records can be done with a δ18O network derived from tree rings.
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Short summary
The African baobab is a challenging climate and environmental archive for its semi-arid habitat due to dating uncertainties and parenchyma-rich wood anatomy. Annually resolved F14C data of tree-ring cellulose (1941–2005) from a tree in Oman show the annual character of the baobab’s growth rings but were up to 8.8 % lower than expected for 1964–1967. Subseasonal δ13C and δ18O patterns reveal years with low average monsoon rain as well as heavy rainfall events from pre-monsoonal cyclones.
The African baobab is a challenging climate and environmental archive for its semi-arid habitat...
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