Prolonged production of 14C during the ~660 BCE solar proton event from Japanese tree rings
Year: 2020
Type: article
Abstract: Annual rings record the intensity of cosmic rays (CRs) that had entered into the Earth’s atmosphere. Several rapid 14C increases in the past, such as the 775 CE and 994CE 14C spikes, have been reported to originate from extreme solar proton events (SPEs). Another rapid 14C increase, also known as the ca. 660 BCE event in German oak tree rings as well as increases of 10Be and 36Cl in ice cores, was presumed similar to the 775 CE event; however, as the 14C increase of approximately 10‰ in 660 BCE had taken a rather longer rise time of 3–4 years as compared to that of the 775 CE event, the occurrence could not be simply associated to an extreme SPE. In this study, to elucidate the rapid increase in 14C concentrations in tree rings around 660 BCE, we have precisely measured the 14C concentrations of earlywoods and latewoods inside the annual rings of Japanese cedar for the period 669–633 BCE. Based on the feature of 14C production rate calculated from the fine measured profile of the 14C concentrations, we found that the 14C rapid increase occurred within 665–663.5 BCE, and that duration of 14C production describing the event is distributed from one month to 41 months. The possibility of occurrence of consecutive SPEs over up to three years is offered.
Source: Scientific Reports
Institutions: Yamagata University, Institute for Space-Earth Environmental Research, Nagoya University, Nagoya University, Hirosaki University, Tohoku University, Tohoku University Botanical Gardens, National Museum of Japanese History, The Graduate University for Advanced Studies, SOKENDAI, Nara National Research Institute for Cultural Properties, National Institutes for Cultural Heritage
Language: English
Topic: Tree-ring climate responses
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,870
Awards: Development of ring-width and stable isotope tree-ring chronology network for dendroprovenancing, Search for secular variations of in cosmic rays over the past 10 million years using muon-induced cosmogenic nuclides in deep underground granite rocks, G2894712977, Dendrochronology of the wooden tablets: re-interpretation based on dendrochronological same wood estimation and development of regional reference chronologies using shipping label wooden tablets, A Study of Cosmic Ray Spectrum due to Measurements of yearly time variations for Cosmic Ray Intensity in the Past 2500 year, Occurrence rate of extreme SPEs for the last 5000 years, Elucidating the history of solar/geomagnetic variations and cosmic ray events through high-resolution multi-archive analyses
OpenAlex ID: W2999329410