Research Project
Grant-in-Aid for Scientific Research (C)
A positive relationship between galactic cosmic ray flux and low cloud cover indicates a link between geomagnetic field and climate through an umbrella effect. This was evidenced by the climate cooling, temperature annual range increases, and summer precipitation increases that occurred during geomagnetic reversals when galactic cosmic ray increased by more than 40 %. In this study, we found that the paleoceanic bio-production (a temperature proxy) covaries with the cosmogenic nuclei of 10Be, on time scales of hundreds, from the Chiba Section core TB2. This indicates solar activity controls climate through the umbrella effect of cloud. Using the high-resolution Laschamp Excursion record from the varved sediment core SG14 of Lake Suigetsu, we revealed that the Δ14C of the sediments changes 50 to 400 yr delayed to cosmic ray changes due to the atmosphere-ocean circulation, the phase lags of which depend on periods of changes.
1996年にスベンスマルク効果(銀河宇宙線量と下層雲量の正の相関)が発見されて以降、半世紀以上続く“地磁気と気候のリンク”に関する研究は理論的根拠を得たことでブームが巻き起こった。その結果、地磁気逆転期に寒冷化をはじめ雲の日傘効果で予想される気候変化の証拠が次々と得られ、研究は大きく前進した。本研究は、地磁気同様銀河宇宙線を制御している太陽活動もスベンスマルク効果を介して気候に影響を及ぼすことを明らかにした。これにより、宇宙線が地球の気候に普遍的に影響を及ぼす可能性が一段と高まり、将来の地球の温暖化や寒冷化の予測において考慮すべき重要な気候要素となった。
All 2023 2022 2021 2020 2019 2018 Other
All Int'l Joint Research (7 results) Journal Article (9 results) (of which Int'l Joint Research: 6 results, Peer Reviewed: 9 results, Open Access: 4 results) Presentation (23 results) (of which Int'l Joint Research: 2 results, Invited: 4 results) Remarks (5 results)
Communications Earth & Environment
Volume: 3 Issue: 1 Pages: 1-10
10.1038/s43247-022-00401-0
Annales Societatis Geologorum Poloniae
Volume: 91 Pages: 1-10
10.14241/asgp.2021.02
Progress in Earth and Planetary Science
Volume: 7 Issue: 1 Pages: 1-18
10.1186/s40645-020-00337-z
120006940225
Earth Science Reviews
Volume: 210 Pages: 103385-103385
10.1016/j.earscirev.2020.103385
Journal of Geopysical Research
Volume: 125 Issue: 3 Pages: 1-21
10.1029/2019jb018705
Science
Volume: 367 Pages: 210-214
The Journal of the Geological Society of Japan
Volume: 125 Issue: 1 Pages: 5-22
10.5575/geosoc.2018.0056
130007632544
Scientific Reports
Volume: 9 Issue: 1 Pages: 1-8
10.1038/s41598-019-45466-8
Geoderma
Volume: 330 Pages: 125-135
10.1016/j.geoderma.2018.05.036
https://www.kobe-u.ac.jp/research_at_kobe/NEWS/news/2022_04_08_01.html
https://www.kobe-u.ac.jp/research_at_kobe/NEWS/news/2019_06_28_01.html
https://www.kobe-u.ac.jp/research_at_kobe/NEWS/news/2020_01_16_01.html
https://www.eurekalert.org/pub_releases_ml/2019-07/ku-5070319.php
https://univ-journal.jp/26689/