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

2010 Fiscal Year Final Research Report

• 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
• 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

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 Pages: doi:10.1073/pnas.1000113107
  • 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
  • Peer Reviewed
• [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
  • Year and Date: 20110100
• [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
  • Year and Date: 20100700
• [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
  • Year and Date: 20100700
• [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
  • Year and Date: 20100700
• [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
  • Year and Date: 20100600
• [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
  • Year and Date: 20100400
• [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
  • Year and Date: 20091200
• [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
  • Year and Date: 20090800
• [Remarks] ホームページ等
  • URL: http://www.icrr.u-tokyo.ac.jp/1ry/index.html