A Single‐Year Cosmic Ray Event at 5410 BCE Registered in 14C of Tree Rings

作者：Fusa Miyake, Irina P. Panyushkina, A. J. T. Jull, Florian Adolphi, Nicolás Brehm, Samuli Helama, K. Kanzawa, Tôru Moriya, Raimund Muscheler, Kurt Nicolussi, M. Oinonen, Matthew W. Salzer, Mirei Takeyama, Fuyuki Tokanai, Lukas Wacker · 发表于：Geophysical Research Letters · 年份：2021 · DOI：10.1029/2021gl093419 · 被引用次数：53 · 研究领域：Solar and Space Plasma Dynamics、Astro and Planetary Science、Geomagnetism and Paleomagnetism Studies

Abstract The annual 14 C data in tree rings is an outstanding proxy for uncovering extreme solar energetic particle (SEP) events in the past. Signatures of extreme SEP events have been reported in 774/775 CE, 992/993 CE, and ∼660 BCE. Here, we report another rapid increase of 14 C concentration in tree rings from California, Switzerland, and Finland around 5410 BCE. These 14 C data series show a significant increase of ∼6‰ in 5411–5410 BCE. The signature of 14 C variation is very similar to the confirmed three SEP events and points to an extreme short‐term flux of cosmic ray radiation into the atmosphere. The rapid 14 C increase in 5411/5410 BCE rings occurred during a period of high solar activity and 60 years after a grand 14 C excursion during 5481–5471 BCE. The similarity of our 14 C data to previous events suggests that the origin of the 5410 BCE event is an extreme SEP event.