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Zhang Q, Sharma U, Dennis JA, Scifo A, Kuitems M, Büntgen U, Owens MJ, Dee MW, Pope BJS. Modelling cosmic radiation events in the tree-ring radiocarbon record. Proc Math Phys Eng Sci 2022. [DOI: 10.1098/rspa.2022.0497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Annually resolved measurements of the radiocarbon content in tree-rings have revealed rare sharp rises in carbon-14 production. These ‘Miyake events’ are likely produced by rare increases in cosmic radiation from the Sun or other energetic astrophysical sources. The radiocarbon produced is not only circulated through the Earth’s atmosphere and oceans, but also absorbed by the biosphere and locked in the annual growth rings of trees. To interpret high-resolution tree-ring radiocarbon measurements therefore necessitates modelling the entire global carbon cycle. Here, we introduce ‘
ticktack
’ (
https://github.com/SharmaLlama/ticktack/
), the first open-source Python package that connects box models of the carbon cycle with modern Bayesian inference tools. We use this to analyse all public annual
14
C
tree data, and infer posterior parameters for all six known Miyake events. They do not show a consistent relationship to the solar cycle, and several display extended durations that challenge either astrophysical or geophysical models.
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Affiliation(s)
- Qingyuan Zhang
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Utkarsh Sharma
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Jordan A. Dennis
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Andrea Scifo
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Margot Kuitems
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Ulf Büntgen
- Department of Geography, University of Cambridge, Cambridge CB2 3EN, UK
- Global Change Research Institute (CzechGlobe), Czech Academy of Sciences, 60300 Brno, Czech Republic
- Department of Geography, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
- Swiss Federal Research Institute (WSL), 8903 Birmensdorf, Switzerland
| | - Mathew J. Owens
- Department of Meteorology, University of Reading, Earley Gate,PO Box 243, Reading RG6 6BB, UK
| | - Michael W. Dee
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Benjamin J. S. Pope
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
- Centre for Astrophysics, University of Southern Queensland,West Street, Toowoomba, Queensland 4350, Australia
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Scifo A, Kuitems M, Neocleous A, Pope BJS, Miles D, Jansma E, Doeve P, Smith AM, Miyake F, Dee MW. Radiocarbon Production Events and their Potential Relationship with the Schwabe Cycle. Sci Rep 2019; 9:17056. [PMID: 31745128 PMCID: PMC6863917 DOI: 10.1038/s41598-019-53296-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
Extreme cosmic radiation events occurred in the years 774/5 and 993/4 CE, as revealed by anomalies in the concentration of radiocarbon in known-age tree-rings. Most hypotheses point towards intense solar storms as the cause for these events, although little direct experimental support for this claim has thus far come to light. In this study, we perform very high-precision accelerator mass spectrometry (AMS) measurements on dendrochronological tree-rings spanning the years of the events of interest, as well as the Carrington Event of 1859 CE, which is recognized as an extreme solar storm even though it did not generate an anomalous radiocarbon signature. Our data, comprising 169 new and previously published measurements, appear to delineate the modulation of radiocarbon production due to the Schwabe (11-year) solar cycle. Moreover, they suggest that all three events occurred around the maximum of the solar cycle, adding experimental support for a common solar origin.
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Affiliation(s)
- A Scifo
- University of Groningen, Centre for Isotope Research, Nijenborgh 6, 9747AG, Groningen, The Netherlands.
| | - M Kuitems
- University of Groningen, Centre for Isotope Research, Nijenborgh 6, 9747AG, Groningen, The Netherlands
| | - A Neocleous
- University of Cyprus, Department of Computer Science, 1 University Avenue, 2109, Aglantzia, Cyprus
| | - B J S Pope
- NASA Sagan Fellow, Center for Cosmology and Particle Physics and Center for Data Science, New York, NY, USA
| | - D Miles
- Oxford University, Oxford Dendrochronology Laboratory, Mill Farm, Mapledurham, Oxfordshire, RG4 7TX, United Kingdom
| | - E Jansma
- Cultural Heritage Agency of The Netherlands, Smallepad 5, 3811 MG, Amersfoort, The Netherlands
| | - P Doeve
- Cultural Heritage Agency of The Netherlands, Smallepad 5, 3811 MG, Amersfoort, The Netherlands
| | - A M Smith
- Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Rd, Lucas Heights, NSW, 2234, Australia
| | - F Miyake
- Nagoya University, Institute for Space-Earth Environmental Research, Chikusa-ku, Nagoya, 464-8601, Japan
| | - M W Dee
- University of Groningen, Centre for Isotope Research, Nijenborgh 6, 9747AG, Groningen, The Netherlands
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Abstract
The discovery of past spikes in atmospheric radiocarbon activity, caused by major solar energetic particle events, has opened up new possibilities for high-precision chronometry. The two spikes, or Miyake Events, have now been widely identified in tree-rings that grew in the years 775 and 994 CE. Furthermore, all other plant material that grew in these years would also have incorporated the anomalously high concentrations of radiocarbon. Crucially, some plant-based artefacts, such as papyrus documents, timber beams and linen garments, can also be allocated to specific positions within long, currently unfixed, historical sequences. Thus, Miyake Events represent a new source of tie-points that could provide the means for anchoring early chronologies to the absolute timescale. Here, we explore this possibility, outlining the most expeditious approaches, the current challenges and obstacles, and how they might best be overcome.
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Affiliation(s)
- Michael W Dee
- RLAHA, Dyson Perrins Building , University of Oxford , Oxford OX1 3QY , UK
| | - Benjamin J S Pope
- Oxford Astrophysics, Denys Wilkinson Building , University of Oxford , Oxford OX1 3RH , UK
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