Long-term variations of solar activity and cosmic rays based on the carbon-14 content in tree rings

• Project/Area Number: 21740162
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: MIYAHARA Hiroko The University of Tokyo, 宇宙線研究所, 特任助教 (00532681)
• Project Period (FY): 2009 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000); Fiscal Year 2010: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2009: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 太陽活動 / 宇宙線 / 気候変動 / 宇宙線生成核種 / 炭素14 / 樹木年輪 / 宇宙線起源核種 / 年輪

Research Abstract

We have measured the carbon-14 content in tree rings with annual time resolution and have detected the lengthening/shortening of the eleven-year solar cycles in the past. Lengths of the eleven-year solar cycles reflect the level of solar magnetic activity. The obtained results have suggested that there is no significant millennial-scale trend in solar activity level.

Research Products

• [Journal Article] Synchronized Northern Hemisphere Climate Change and Solar Magnetic Cycles during the Maunder Minimum (2010)
  • Author(s): Y.T.Yamaguchi, Y.Yokoyama, H.Miyahara, K.Sho, T.Nakatsuka
  • Journal Title: PNAS
  • Peer Reviewed
• [Journal Article] Is the Sun heading for another Maunder Minimum ?-Precursors of the grand solar minima (2010)
  • Author(s): H.Miyahara, K.Kitazawa, K.Nagaya, Y.Yokoyama, H.Matsuzaki, K.Masuda, T.Nakamura, Y.Muraki
  • Journal Title: Journal of Cosmology 8 Pages: 1970-1982
  • Peer Reviewed
• [Journal Article] 過去1200年間における太陽活動および宇宙線変動と気候変動との関わり (2010)
  • Author(s): 宮原ひろ子
  • Journal Title: 地学雑誌,119,3,小特集「グローバル気候変動Part3」 Pages: 510-518
  • NAID: 10030369529
  • Peer Reviewed
• [Journal Article] Synchronized Northern Hemisphere Climate Change and Solar Magnetic Cycles during the Maunder Minimum (2010)
  • Author(s): Y.T.Yamaguchi, Y.Yokoyama, H.Miyahara, K.Sho, T.Nakatsuka
  • Journal Title: Proc.Natl.Acad.Sci. Volume: 107 Pages: 20697-20702
  • Peer Reviewed
• [Journal Article] Is the Sun heading for another Maunder Minimum?-Precursors of the grand solar minima (2010)
  • Author(s): H.Miyahara, K.Kitazawa, K.Nagaya, Y.Yokoyama, H.Matsuzaki, K.Masuda, T.Nakamura, Y.Muraki
  • Journal Title: Journal of Cosmology Volume: 8 Pages: 1970-1982
  • Peer Reviewed
• [Journal Article] Implications for the low latitude cloud formations from solar activity and the Quasi-Biennial Oscillation (2010)
  • Author(s): Pang K.Hong, Hiroko Miyahara, Yusuke Yokoyama, Yukihiro Takahashi, Mitsuteru Sato
  • Journal Title: Journal of Atmospheric and Solar-Terrestrial Physics Volume: 73 Pages: 587-591
  • Peer Reviewed
• [Journal Article] 27-day variation in cloud amount and relationship to the solar cycle (2010)
  • Author(s): Y.Takahashi, Y.Okazaki, M.Sato, H.Miyahara, K.Sakanoi, P.K.Hong
  • Journal Title: Atmospheric Chemistry and Physics 10 Pages: 1577-1584
  • Peer Reviewed
• [Journal Article] 過去1200年間における太陽活動および宇宙線変動と気候変動との関わり (2010)
  • Author(s): 宮原ひろ子
  • Journal Title: 地学雑誌 119(掲載予定)
  • NAID: 10030369529
  • Peer Reviewed
• [Journal Article] Influence of the Schwabe/Hale solar cycles on climate change during the Maunder Minimum (2009)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi
  • Journal Title: Proceedings of the IAU XXVII General Assembly 264 Pages: 427-433
• [Presentation] Variations of solar activity, cosmic rays, and climate during the Maunder Minimum (2011)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, H.Matsuzaki, T.Nakatsuka
  • Organizer: Space Climate Symposium 4 招待講演
  • Place of Presentation: Goa, India
• [Presentation] Variations of solar activity, cosmic rays, and climate during the Maunder Minimum (2011)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, H.Matsuzaki, T.Nakatsuka
  • Organizer: Space Climate Symposium 4
  • Place of Presentation: Goa, India
• [Presentation] Historical changes in solar activity and its impact on regional-global climate (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, H.Matsuzaki, T.Nakatsuka, K.Horiuchi, S.Fallon
  • Organizer: 2010 PAGES (PAst Global changES) Regional Workshop
  • Place of Presentation: 名古屋大学
  • Year and Date: 2010-06-05
• [Presentation] Variability of cosmic rays and its influence on climate change at the multi-decadal time scale (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, H.Matsuzaki, T.Nakatsuka
  • Organizer: COSPAR meeting
  • Place of Presentation: Bremen, Germany
• [Presentation] Long-term Variation of Solar Activity Level during the Past 7000 Years (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, K.Horiuchi, S.Fallon, H.Matsuzaki
  • Organizer: Asia Oceania Geosciences Society meeting 招待講演
  • Place of Presentation: Hyderabad, India
• [Presentation] Variability of solar activity and cosmic rays, and their influences on climate change (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, T.Nakatsuka, K.Horiuchi, S.Fallon, H.Matsuzaki
  • Organizer: SCOSTEP STP-12 Symposium
  • Place of Presentation: Berlin, Germany
• [Presentation] Historical changes in solar activity and its impact on regional-global climate (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, Y.T.Yamaguchi, H.Matsuzaki, T.Nakatsuka, K.Horiuchi, S.Fallon
  • Organizer: 2010 PAGES (PAst Global changES) Regional Workshop in Japan 招待講演
  • Place of Presentation: Nagoya, Japan
• [Presentation] Long-term variation of solar activity during the last 7000 years (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, H.Matsuzaki, K.Horiuchi, S.Fallon
  • Organizer: WCU International Workshop 2010
  • Place of Presentation: Seoul, Korea
• [Presentation] Long-term Variation of Solar Activity Level during the Past 7000 Years (2010)
  • Author(s): H.Miyahara, Y.Yokoyama, K.Horiuchi, S.Fallon, H.Matsuzaki
  • Organizer: Asia Oceania Geosciences Society meeting
  • Place of Presentation: Hyderabad, India
• [Presentation] 樹木年輪中の放射性炭素濃度分析による太陽活動および地磁気変動の復元について (2009)
  • Author(s): 宮原ひろ子, 横山祐典, 松崎浩之, 永冶健太朗, 増田公明, 中村俊夫, 村木綏
  • Organizer: 地球電磁気・地球惑星圏学会
  • Place of Presentation: 金沢大学
  • Year and Date: 2009-09-28
• [Presentation] Influence of the Schwabe/Hale solar cycles on climate change (2009)
  • Author(s): 宮原ひろ子, et al.
  • Organizer: XXVII General Assembly of International Astronomical Union
  • Place of Presentation: ブラジル・リオデジャネイロ
  • Year and Date: 2009-08-07
• [Presentation] Long-term variation of solar activity deduced from carbon-14 content in tree rings (2009)
  • Author(s): H.Miyahara, Y.Yokoyama, H.Matsuzaki, K.Masuda, K.Nagaya, T.Nakamura, Y.Muraki
  • Organizer: American Geophysical Union, Fall Meeting (poster)
  • Place of Presentation: San Francisco, USA
• [Presentation] Influence of the Schwabe/Hale solar cycles on climate change (2009)
  • Author(s): H.Miyahara, et al.
  • Organizer: XXVII General Assembly of International Astronomical Union 招待講演
  • Place of Presentation: Rio de Janeiro
• [Remarks] ホームページ等
  • URL: http://www.icrr.u-tokyo.ac.jp/1ry/index.html
• [Remarks]
  • URL: http://www.icrr.u-tokyo.ac.jp/~hmiya/
• [Remarks]
  • URL: http://www.icrr.u-tokyo.ac.jp/lry/index.html