A Study of Variation of the 11-yr Solar Cycle before the onset of the Spoerer Minimum based on Annually measured 14C Content in tree Rings

Toru Moriya, Hiroko Miyahara, Motonari Ohyama, Masataka Hakozaki, Mirei Takeyama, Hirohisa Sakurai, Fuyuki Tokanai

研究成果: Article査読

6 被引用数 (Scopus)

抄録

Proxy-based observations of solar activity in the past have revealed long-term variations, such as the Gleissberg cycle (∼88 yr), de Vries cycle (∼200 yr), and the Hallstatt cycle (∼2000 yr). Such long-term variations of solar activity sometimes cause the disappearance of sunspots for several decades. Currently, solar activity is becoming weaker, and there is a possibility that another long-term sunspot minimum could occur. However, the detailed mechanism of the weakening in solar activity is unknown, and the prediction of solar activity is ambiguous. In this study, we investigate the transitions of solar cycle length before the onset of the Spoerer Minimum, the longest grand minimum in the past 2000 yr. We measured the 14C content in an asunaro tree (Thujopsis dolabrata) excavated at Shimokita Peninsula from 1368-1420 CE using the compact AMS system at Yamagata University. It is found that the solar cycle lengthened to be 14-16 yr from 2 cycles before the onset of the Spoerer Minimum.

本文言語English
ページ(範囲)1749-1754
ページ数6
ジャーナルRadiocarbon
DOI
出版ステータスAccepted/In press - 2019 1月 1

ASJC Scopus subject areas

  • 考古学
  • 地球惑星科学(全般)

フィンガープリント

「A Study of Variation of the 11-yr Solar Cycle before the onset of the Spoerer Minimum based on Annually measured 14C Content in tree Rings」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル