Study on Jupiter's auroral radiation and lightning as viewed from Juno and Earth-based telescopes

2021 Fiscal Year Annual Research Report

• Project/Area Number: 20K22371
• Research Institution: Niihama National College of Technology
• Principal Investigator: 今井 雅文 新居浜工業高等専門学校, 電気情報工学科, 助教 (10877260)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 木星オーロラ電波 / 雷 / Juno / 地上電波望遠鏡 / ハッブル宇宙望遠鏡

Outline of Annual Research Achievements

2016年7月に米国・NASAのJuno探査機が初めて木星極周回軌道に投入され、極軌道でしか見ることができない木星オーロラや雷の新しい様相が明らかとなってきた。しかしながら、オーロラや雷のような突発的な現象は空間的にも時間的にも変動するため、従来の1地点衛星観測からでは全貌を明らかにすることは難しく、新しい視点での研究のアプローチが必要である。本研究の目的は、Juno探査機と地上望遠鏡の連携観測を駆使し、木星オーロラ電波の多地点観測からその電波源の位置や紫外オーロラの発光領域との関係を理解すること、Juno探査機で得られる木星の雷や電離層の情報とハッブル宇宙望遠鏡で観測可能な異なる高度の木星の雲との関連を解き明かすことである。
令和3年度は、申請者が観測責任者として採択された大型低周波電波望遠鏡LWAの2020年観測データを閲覧・解析できるようなシステムにアップデートし、Juno探査機で観測された木星オーロラ電波と木星雷データの解析を行った。また、最新の木星内部磁場モデルJRM33と外部磁場モデルを組み合わせたモデルを使用して、Juno探査機やガリレオ衛星のフットプリントを計算することも行った。これらの計算結果は、多地点観測で得られたデータを総合的に理解するために使用しているだけでなく、Junoミッションの科学観測計画を支援している。本年度に得られた研究成果は国内学会・国際研究会と査読付き論文にまとめて発表した。

Research Products

• [Int'l Joint Research] University of Iowa/University of California, Berkeley/Southwest Research Institute(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: University of Iowa/University of California, Berkeley/Southwest Research Institute
  • # of Other Institutions: 1
• [Int'l Joint Research] Institute of Atmospheric Physics/Charles University(チェコ)
  • Country Name: CZECH
  • Counterpart Institution: Institute of Atmospheric Physics/Charles University
• [Journal Article] A Comprehensive Set of Juno In Situ and Remote Sensing Observations of the Ganymede Auroral Footprint (2022)
  • Author(s): Hue, V.、Szalay, J. R.、 Greathouse T. K.、 [and 24 others, including M. Imai]
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: e2021GL096994
  • DOI: 10.1029/2021GL096994
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Loss of energetic ions comprising the ring current populations of Jupiter's middle and inner magnetosphere (2022)
  • Author(s): Mauk B. H.、Allegrini F.、Bagenal F.、Bolton S. J.、Clark G.、Connerney J. E. P.、Gershman D. J.、Haggerty D. K.、Hue V.、Imai M.、Kollmann P.、Kurth W. S.、Nenon Q.、Paranicas C. P.、Rymer A. M.、Smith H. T.、Sulaiman A. H.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: e2022JA030293
  • DOI: 10.1029/2022JA030293
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Simultaneous UV Images and High‐Latitude Particle and Field Measurements During an Auroral Dawn Storm at Jupiter (2021)
  • Author(s): Ebert R. W.、Greathouse T. K.、Clark G.、Hue V.、Allegrini F.、Bagenal F.、Bolton S. J.、Bonfond B.、Connerney J. E. P.、Gladstone G. R.、Imai M.、Kotsiaros S.、Kurth W. S.、Levin S.、Louarn P.、Mauk B. H.、McComas D. J.、Paranicas C.、Sulaiman A. H.、Szalay J. R.、Thomsen M. F.、Wilson R. J.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 126 Pages: e2021JA029679
  • DOI: 10.1029/2021JA029679
  • Peer Reviewed / Int'l Joint Research
• [Presentation] New understanding on Jupiter's lightning in the atmosphere as revealed by Juno (2021)
  • Author(s): M. Imai, W. S. Kurth, I. Kolmasova, O. Santolik, M. H. Wong, S. T. Brown, G. B. Hospodarsky, T. Guillot, H. N. Becker, S. J. Bolton, S. M. Levin
  • Organizer: Japan Geoscience Union Meeting 2021
  • Int'l Joint Research / Invited
• [Presentation] Simultaneous UV Images and High-Latitude Particle and Field Measurements During an Auroral Dawn Storm at Jupiter (2021)
  • Author(s): R. W. Ebert, T. K. Greathouse, G. Clark, V. Hue, F. Allegrini, F. Bagenal, S. J. Bolton, B. Bonfond, J. E. P. Connerney, G. R. Gladstone, M. Imai, Stavros Kotsiaros, W. S. Kurth, S. Levin, P. Louarn, B. H. Mauk, D. J. McComas, C. Paranicas, A. H. Sulaiman, J. R. Szalay, M. F. Thomsen, R. J. Wilson
  • Organizer: Magnetospheres of the Outer Planets 2021
  • Int'l Joint Research
• [Presentation] Loss Processes of Energetic Ring Current Ions in Jupiter's Inner and Middle Magnetosphere (2021)
  • Author(s): B. H. Mauk, F. Allegrini, F. Bagenal, S. J. Bolton, G. Clark, J. E. P. Connerney, D. J. Gershman, D. K. Haggerty, V. Hue, M. Imai, P. Kollmann, W. S. Kurth, C. P. Paranicas, A. M. Rymer, H. T. Smith, A. Sulaiman
  • Organizer: Magnetospheres of the Outer Planets 2021
  • Int'l Joint Research
• [Presentation] Planetary Radio Observation CubeSat: Current Step on Earth to Next Step on Moon (2021)
  • Author(s): M. Imai, K. Imai, N. Hirakoso, M. Nishio, T. Takada, K. Kitamura, J. Nakaya, Y. Murakami, M. Tokumitsu, M. Wakabayashi
  • Organizer: ISAS Planetary Exploration Workshop 2021
  • Int'l Joint Research
• [Presentation] Juno Waves Observations of Long Dispersion Lightning Whistlers Associated with the Io Torus (2021)
  • Author(s): G.B. Hospodarsky, W.S. Kurth, M. Imai, I. Kolmasova, O. Santolik, J.E.P. Connerney, S.J. Bolton
  • Organizer: American Geophysical Union (hybrid) meeting
  • Int'l Joint Research
• [Presentation] A Comprehensive Set of Juno In Situ and Remote Sensing Observations of the Ganymede Auroral Footprint (2021)
  • Author(s): V. Hue, J.R Szalay, T. Greathouse, [and 24 others, including M. Imai]
  • Organizer: American Geophysical Union (hybrid) meeting
  • Int'l Joint Research
• [Presentation] Electromagnetic Evidence of Stepwise Extension of the Jovian Lightning Channels (2021)
  • Author(s): I. Kolmasova, O. Santolik, M. Imai, W.S. Kurth, G.B. Hospodarsky, S.J. Bolton, J.E.P. Connerney
  • Organizer: American Geophysical Union (hybrid) meeting
  • Int'l Joint Research
• [Presentation] Jupiter’s magnetic field and the generation and control of decameter radiation observed by the Juno spacecraft (2021)
  • Author(s): Y.M. Martos, J.E.P. Connerney, M. Imai, W.M. Farrell, W.S. Kurth
  • Organizer: American Geophysical Union (hybrid) meeting
  • Int'l Joint Research
• [Presentation] KOSEN-1 Jupiter radio observation campaign with ground-based radio telescopes (2021)
  • Author(s): M. Imai, K. Imai, N. Hirakoso, Y. Ito, T. Sugawara, S. Suzuki, M. Nishio, T. Takada, K. Kitamura, J. Nakaya, Y. Murakami, M. Tokumitsu, T. E. Clarke, C. A. Higgins, J. F. Helmboldt, KOSEN-1 team
  • Organizer: SGEPSS Fall Meeting 2021