Energy release and transfer processes of rotating magnetospheres uncovered by combinations of space telescope and explorer

2018 Fiscal Year Annual Research Report

• Project/Area Number: 16K17812
• Research Institution: Tohoku University
• Principal Investigator: 木村 智樹 東北大学, 学際科学フロンティア研究所, 助教 (50578804)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 木星 / 磁気圏 / オーロラ / エネルギー輸送

Outline of Annual Research Achievements

本研究では、数10MeVに至る高エネルギー粒子加速を駆動する、木星磁気圏の自励的な電磁エネルギーの解放と輸送過程の解明を最終目的とする。研究代表者は、惑星分光観測衛星「ひさき」とハッブル宇宙望遠鏡による連携観測を初めて実施し、木星の高速自転と衛星イオのプラズマ供給が自励的に駆動する、内部駆動型の突発的オーロラ加速を発見した。

本研究では、２０１６年に観測開始した木星極域探査機Junoを新たに加え、世界初の遠隔－極域その場同時連携観測から、内部駆動型の粒子加速で鍵となる①自励的エネルギー解放と、②木星近傍へのエネルギー輸送過程を解明し、内部駆動形粒子加速の存在を実証する。

実施計画に則り、平成30度は、2017年3月に実施した、ひさき－ハッブル宇宙望遠鏡－Juno探査機の三者連携観測のデータを統合し、オーロラの時空間発展と、木星磁気圏内のその場の磁場・プラズマを網羅的に観測することで、問題の解明に取り組んだ。その結果、内部駆動形エネルギー解放に対応する、突発オーロラ発生時刻前後において、木星中間磁気圏の赤道面付近に磁場のエネルギーが蓄積された後、開放されていることを示唆する磁場変動が発見された。また、開放のタイミングと同時に、地球で見られるような惑星方向の磁化プラズマの流れを示唆する磁場・プラズマの変動が見られた。これらは、突発オーロラ発生時に、磁気再結合が木星磁気圏で起こり、磁場のエネルギーが開放され、木星方向に輸送されている可能性を示している。これにより、本研究の目的である、内部駆動形の突発オーロラ時における木星近傍へのエネルギー輸送の実証過程が大きく進んだ。この結果は、国際誌に投稿され、査読中である。

Research Products

• [Int'l Joint Research] リエージュ大学(ベルギー)
  • Country Name: BELGIUM
  • Counterpart Institution: リエージュ大学
• [Int'l Joint Research] コロラド大学/ジョンズ・ホプキンス大学応用物理研究所/サウスウェスト研究所(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: コロラド大学/ジョンズ・ホプキンス大学応用物理研究所/サウスウェスト研究所
• [Int'l Joint Research] ユニバーシティーカレッジロンドン(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: ユニバーシティーカレッジロンドン
• [Journal Article] Azimuthal variation in the Io plasma torus observed by the Hisaki satellite from 2013 to 2016 (2019)
  • Author(s): F. Tsuchiya, R. Arakawa, H. Misawa, M. Kagitani, R. Koga, F. Suzuki, R. Hikida, K. Yoshioka, A. Steffl, F. Bagenal, P. Delamere, T. Kimura, Y. Kasaba, G. Murakami, I. Yoshikawa, A. Yamazaki
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: in press Pages: 印刷中
  • DOI: 10.1029/2018JA026038
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Short-term Variation in the Dawn-dusk Asymmetry of the Jovian Radiation Belt Obtained from GMRT and Hisaki EXCEED Observations (2019)
  • Author(s): Kita, H., H. Misawa, A. Bhardwaj, F. Tsuchiya, G. Murakami, C. Tao, T. Kimura, K. Yoshioka, A. Yamazaki, Y. Kasaba, I. Yoshikawa, and M. Fujimoto
  • Journal Title: Astrophys. J. Lett. Volume: 872 Pages: L24
  • DOI: 10.3847/2041-8213/ab0427
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Development of ground pipeline system for high-level scientific data products of the Hisaki satellite mission and its application to planetary space weather (2019)
  • Author(s): Tomoki Kimura, Atsushi Yamazaki, Kazuo Yoshioka, Go Murakami, Fuminori Tsuchiya, Hajime Kita, Chihiro Tao, Ichiro Yoshikawa, and Chisato Yamauchi
  • Journal Title: Topical Issue "Planetary Space Weather" of Journal of Space Weather and Space Climate Volume: 9 Pages: A8
  • DOI: 10.1051/swsc/2019005
  • Peer Reviewed
• [Journal Article] Corotation of bright features in the Io plasma torus (2018)
  • Author(s): Suzuki, F., Yoshioka, K., Hikida, R., Murakami, G., Tsuchiya, F., Kimura, T., & Yoshikawa, I.
  • Journal Title: Journal of Geophysical Research Volume: 123 Pages: 9420-9429
  • DOI: 10.1029/2018JA025363
  • Peer Reviewed
• [Journal Article] Small satellites with MEMS x-ray telescopes for x-ray astronomy and solar system exploration (2018)
  • Author(s): Yuichiro Ezoe, Yoshizumi Miyoshi, Satoshi Kasahara, Tomoki Kimura, Kumi Ishikawa, Masaki Fujimoto, Kazuhisa Mitsuda, Hironori Sahara, Naoki Isobe, Hiroshi Nakajima, Takaya Ohashi, Haruki Nagata, Ryu Funase, Munetaka Ueno, Graziella Branduardi-Raymont
  • Journal Title: Proc. SPIE 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray Volume: 106990V Pages: 106990V
  • DOI: 10.1117/12.2311422
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The influence of Io's 2015 volcanic activity on Jupiter's magnetospheric dynamics (2018)
  • Author(s): Yoshioka, K., F. Tsuchiya M. Kagitani T. Kimura G. Murakami D. Fukuyama A. Yamazaki I. Yoshikawa M. Fujimoto
  • Journal Title: Geophysical Research Letters Volume: 45 Pages: 10193-10,199
  • DOI: 10.1029/2018GL079264
  • Peer Reviewed
• [Journal Article] Precipitating electron energy flux and characteristic energies in Jupiter's main auroral region as measured by Juno/JEDI (2018)
  • Author(s): Clark, G., C. Tao, B. Mauk, J. Nichols, J. Saur, E. Bunce, F. Allegrini ,R. Gladstone, F. Bagenal, S. Bolton, B. Bonfond, J. Connerney, R. Ebert, D. Gershman, D. Haggerty, T. Kimura, P. Kollmann, S. Kotsiaros, W. Kurs, S. Levin, D. McComas, G. Murakami, C. Paranicas, A. Rymer, P. Valek
  • Journal Title: Journal of Geophysical Research Volume: 123 Pages: 7554-7567
  • DOI: 10.1029/2018JA025639
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Enhancement of the Jovian Magnetospheric Plasma Circulation Caused by the Change in Plasma Supply from the Satellite Io (2018)
  • Author(s): F. Tsuchiya, K. Yoshioka, T. Kimura, R. Koga, G. Murakami, A. Yamazaki, M. Kagitani, C. Tao, F. Suzuki, R. Hikida, I. Yoshikawa, Y. Kasaba, H. Kita, H. Misawa, and T. Sakanoi
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 123 Pages: 6514-6532
  • DOI: 10.1029/2018JA025316
  • Peer Reviewed
• [Journal Article] Identification of Extreme Ultraviolet Emission Lines of the Io Plasma Torus Observed by Hisaki/EXCEED (2018)
  • Author(s): Hikida, Reina, Kazuo Yoshioka, Go Murakami, Tomoki Kimura, Fuminori Tsuchiya, Atsushi Yamazaki, Ichiro Yoshikawa, Naomoto Iwagami
  • Journal Title: Journal of Geophysical Research: Planet Volume: 123 Pages: 1723-1731
  • DOI: 10.1029/2018JE005629
  • Peer Reviewed
• [Journal Article] Spatial distribution of Io’s neutral oxygen cloud observed by Hisaki (2018)
  • Author(s): R. Koga, F. Tsuchiya, M. Kagitani, T. Sakanoi, M. Yoneda, K. Yoshioka, I. Yoshikawa, T. Kimura, G. Murakami, A. Yamazaki, H. T. Smith and F. Bagenal
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 123 Pages: 3764-3776
  • DOI: 10.1029/2018JA025328
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Response of Jupiter's Aurora to Plasma Mass Loading Rate Monitored by the Hisaki Satellite During Volcanic Eruptions at Io (2018)
  • Author(s): Tomoki Kimura, Y. Hiraki, C. Tao, F. Tsuchiya, P. Delamere, K. Yoshioka, G. Murakami, A. Yamazaki, H. Kita, S. V. Badman, K. Fukazawa, I. Yoshikawa, M. Fujimoto
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 123 Pages: 1885-1899
  • DOI: 10.1002/2017JA025029
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Jupiter's aurora observed with HST during Juno orbits 3 to 7 (2018)
  • Author(s): Denis, G., Bonfond, B., Yao, Z., G_rard, J.-C., Radioti, A., Dumont, M. B. Palmaerts, A. Adriani, S. V. Badman, E. J. Bunce, J. T. Clarke, J. E. P. Connerney, G. R. Gladstone, T. Greathouse, T. Kimura, W. S. Kurth, B. H. Mauk, D. J. McComas, J. D. Nichols, G. S. Orton, L. Roth, J. Saur, P. Valek
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 123 Pages: 3299-3319
  • DOI: 10.1002/2017JA025046
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Variation of Jupiter's Aurora Observed by Hisaki/EXCEED: 3. Volcanic Control of Jupiter's Aurora, Geophysical Research Letters (2018)
  • Author(s): Chihiro Tao, Tomoki Kimura, Fuminori Tsuchiya, Go Muirakami, Kazuo Yoshioka, Atsushi Yamazaki, Sarah V. Badman, Hiroaki Misawa, Hajime Kita, Yasumasa Kasaba, Ichiro Yoshikawa, Masaki Fujimoto
  • Journal Title: Geophysical Research Letters Volume: 45 Pages: 71-79
  • DOI: 10.1002/2017GL075814
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Response of Jupiter's Aurora to Plasma Mass Loading Rate Monitored by the Hisaki Satellite During Volcanic Eruptions at Io (2018)
  • Author(s): Tomoki Kimura, J. D. Nichols, R. L. Gray, C. Tao, G. Murakami, A. Yamazaki, S. V. Badman, F. Tsuchiya, K. Yoshioka, H. Kita, et al.
  • Organizer: Japan Geoscience Union 2018
  • Int'l Joint Research
• [Presentation] Icy Moon’s Interior Uncovered by Modeling of Space Weather with Laboratory Experiment (2018)
  • Author(s): 木村智樹
  • Organizer: 日本地球惑星科学連合2018年大会
• [Presentation] ひさき衛星による木星磁気圏観測とグローバルMHDシミュレーションの連携解析の概要 (2018)
  • Author(s): 木村智樹
  • Organizer: 地球電磁気・地球惑星圏学会 第 142 回総会・講演会
• [Presentation] Response of Jupiter's Aurora to Plasma Mass Loading Rate Monitored by the Hisaki Satellite During Volcanic Eruptions at Io (2018)
  • Author(s): Tomoki Kimura, J. D. Nichols, R. L. Gray, C. Tao, G. Murakami, A. Yamazaki, S. V. Badman, F. Tsuchiya, K. Yoshioka, H. Kita, et al.
  • Organizer: Magnetospheres of Outer Planets 2018
  • Int'l Joint Research
• [Presentation] Evolution of Icy Moon’s Interior and Surface Uncovered by Laboratory Experiment: Modeling of Plasma Space Weathering by Ion Irradiation (2018)
  • Author(s): 木村智樹
  • Organizer: 地球電磁気・地球惑星圏学会 第 142 回総会・講演会