Recurrent Large‐Scale Solar Proton Events Before the Onset of the Wolf Grand Solar Minimum
Year: 2022
Type: article
Abstract: Carbon‐14 in tree rings have suggested there had been multiple extreme solar proton events (SPEs) in the past. While the largest events such as in 774–775 CE can be significantly detected by the typical precision of accelerator mass spectrometry, smaller but possibly more frequent events have been difficult to be detected. Thus, the frequency or any characteristics of such relatively smaller events are still largely unknown. In this paper, we report that large SPEs had occurred in 1261–1262, 1268–1269, and 1279–1280 CE before the onset of the Wolf minimum based on high‐precision carbon‐14 analyses. It is suggested that they had occurred at the maximum and the declining phase of solar cycles, and that they had occurred during the transition time of solar activity into a deep minimum. We propose that this episode may provide a unique opportunity to elucidate a potential interaction between the solar dynamo and extreme solar flares.
Source: Geophysical Research Letters
DOI: 10.1029/2021gl097201
Authors: Hiroko Miyahara, Fuyuki Tokanai, Toru Moriya, Mirei Takeyama, Hirohisa Sakurai, Motonari Ohyama, Kazuho Horiuchi, Hideyuki Hotta
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
Awards: 古代における年輪年代学的木材産地推定を可能にする標準年輪曲線ネットワークの整備, Advancing Solar Dynamo Research through Ultra-High-Precision Analyses of Carbon-14, Research on cosmic ray anomalies by developing high-precision carbon-14 measurement method, Development of a new long-term tree-ring chronology network for cypress species in central Japan, Challenge for convective conundrum with large-scale numerical simulations, Solar activity over the past 10,000 years, Study of single-year 14C spike dating using a new compact AMS system with high precision, Reconstruction of the tree-line elevation and forest development process since the Last Glacial Maximum in the central highlands of Japan, Theoretical studies on evolution of stellar coronae, Understanding and realization of advanced prediction for solar explosions with the integrated model including from stellar convection zone to interplanetary space, Elucidating the history of solar/geomagnetic variations and cosmic ray events through high-resolution multi-archive analyses
OpenAlex ID: W4212854331