Tree-rings reveal two strong solar proton events in 7176 and 5259 BCE
Brehm, Nicolas; Christl, Marcus; Knowles, Timothy D. J.; Casanova, Emmanuelle; Evershed, Richard P.; Adolphi, Florian; Muscheler, Raimund; Synal, Hans-Arno; Mekhaldi, Florian; Paleari, Chiara I.; Leuschner, Hanns-Hubert; Bayliss, Alex; Nicolussi, Kurt; Pichler, Thomas; Schlüchter, Christian; Pearson, Charlotte L.; Salzer, Matthew W.; Fonti, Patrick; Nievergelt, Daniel; Hantemirov, Rashit; Brown, David M.; Usoskin, Ilya; Wacker, Lukas (2022-03-07)
Brehm, N., Christl, M., Knowles, T.D.J. et al. Tree-rings reveal two strong solar proton events in 7176 and 5259 BCE. Nat Commun 13, 1196 (2022). https://doi.org/10.1038/s41467-022-28804-9
© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
https://creativecommons.org/licenses/by/4.0/
https://urn.fi/URN:NBN:fi-fe2022051736124
Tiivistelmä
Abstract
The Sun sporadically produces eruptive events leading to intense fluxes of solar energetic particles (SEPs) that dramatically disrupt the near-Earth radiation environment. Such events have been directly studied for the last decades but little is known about the occurrence and magnitude of rare, extreme SEP events. Presently, a few events that produced measurable signals in cosmogenic radionuclides such as ¹⁴C, ¹⁰Be and ³⁶Cl have been found. Analyzing annual ¹⁴C concentrations in tree-rings from Switzerland, Germany, Ireland, Russia, and the USA we discovered two spikes in atmospheric ¹⁴C occurring in 7176 and 5259 BCE. The ~2% increases of atmospheric ¹⁴C recorded for both events exceed all previously known ¹⁴C peaks but after correction for the geomagnetic field, they are comparable to the largest event of this type discovered so far at 775 CE. These strong events serve as accurate time markers for the synchronization with floating tree-ring and ice core records and provide critical information on the previous occurrence of extreme solar events which may threaten modern infrastructure.
Kokoelmat
- Avoin saatavuus [34311]
