Study on the acceleration and loss of ring current ions using multiple spacecraft in the inner magnetosphere

• Project/Area Number: 26800257
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Space and upper atmospheric physics
• Research Institution: The University of Tokyo (2016-2017); Nagoya University (2014-2015)
• Principal Investigator: Keika Kunihiro 東京大学, 大学院理学系研究科(理学部), 助教 (10719454)
• Research Collaborator: Lanzerotti Louis J. ニュージャージー工科大学, 特任教授 ; Spence Harlan ニューハンプシャー大学, 教授 ; KASAHARA Satoshi 東京大学, 大学院理学系研究科, 准教授
• Project Period (FY): 2014-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: Inner magnetosphere / geomagnetic storms / ring current / Acceleration and loss / Outflow and transport / 磁気嵐 / 地球内部磁気圏観測 / 酸素イオン加速と供給 / データ解析ソフトウェア開発 / Van Allen Probes衛星 / 国際情報交換 / 酸素イオン供給・加速 / Van Allen Probesミッション / 酸素イオン加速

Outline of Final Research Achievements

This study investigated spatial and temporal variations of plasma pressure in the inner magnetosphere (inside of ~10 Earth radii), the inner part of the region where the Earth’s magnetic field dominates, using data from in-situ observations by several spacecraft. The results show that (1) the energy of plasma that make the dominant contribution to plasma pressure changes in time during a magnetic storm and that (2) oxygen ions of Earth’s atmospheric origin are transported to around the outer edge of the inner magnetosphere to contribute to an increase in plasma pressure. Result (1) indicates the importance of spatial and temporal changes in plasma characteristics in the magnetotail. Result (2) suggests a new picture of the dynamics (transport, acceleration, circulation, etc.) of ionized atmospheric oxygen ions in the magnetosphere.

Research Products

• [Int'l Joint Research] Johns Hopkins Univ. Applied Physics Lab./New Jersey Institute of Technology/University of New Hampshire(米国)
• [Int'l Joint Research] Johns Hopkins Univ. Applied Physics Lab./New Jersey Institute of Technology/University of New Hampshire(米国)
• [Int'l Joint Research] Johns Hopkins Univ. Applied Physics Lab./New Jersey Institute of Technology/University of New Hampshire(米国)
• [Journal Article] Three-step buildup of the 17 March 2015 storm ring current: Implication for the cause of the unexpected storm intensification (2018)
  • Author(s): Keika,K. K. Seki, M. Nos_, Y. Miyoshi, L. Lanzerotti, D. Mitchell, M. Gkioulidou, and J. Manweiler
  • Journal Title: J. Geophys. Res. Volume: 123 Issue: 1 Pages: 1-15
  • DOI: 10.1002/2017ja024462
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Storm time impulsive enhancements of energetic oxygen due to adiabatic acceleration of preexisting warm oxygen in the inner magnetosphere (2016)
  • Author(s): Kunihiro Keika, Kanako Seki, Masahito Nose, Shinobu Machida, Yoshizumi Miyoshi, Louis J. Lanzerotti, Donald G. Mitchell, Matina Gkioulidou, Drew Turner, Harlan Spence, and Brian A. Larsen
  • Journal Title: J. Geophys. Res. Volume: 121 Issue: 8 Pages: 7740-7752
  • DOI: 10.1002/2016ja022384
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] ELF/VLF propagation at subauroral latitudes: Conjugate observation between the ground and Van Allen Probes A (2016)
  • Author(s): Martinez-Calderon, C., K. Shiokawa , Y. Miyoshi , K. Keika , M. Ozaki , I. Schofield , M. Connors , C. Kletzing , M. Hanzelka , O. Santolik , and W. Kurth
  • Journal Title: J. Geophys. Res. Volume: 121 Issue: 6 Pages: 1-10
  • DOI: 10.1002/2015ja022264
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Van Allen Probes observations of magnetic field dipolarization and its associated O+ flux variations in the inner magnetosphere at L<6.6 (2016)
  • Author(s): Nose, M., K. Keika, C. A. Kletzing, H. E. Spence, C. W. Smith, R. J. MacDowall, G. D. Reeves, B. A. Larsen, and D. G. Mitchell
  • Journal Title: J. Geophys. Res. Volume: 121 Issue: 8 Pages: 1-18
  • DOI: 10.1002/2016ja022549
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] What caused the rapid recovery of the Carrington storm? (2015)
  • Author(s): K. Keika, R. Kataoka, and Y. Ebihara
  • Journal Title: Earth, Planets and Space Volume: 67 Issue: 1 Pages: 1-12
  • DOI: 10.1186/s40623-015-0234-y
  • NAID: 120005758188
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] An extensive survey of dayside diffuse aurora based on optical observations at Yellow River Station (2015)
  • Author(s): Han, X.-C. Chen , J.-J. Liu, Q. Qiu, K. Keika, Z .-J. Hu, J.-M. Liu, H.-Q. Hu, and H. -G. Yang
  • Journal Title: Journal of Geophysical Research. Space Physics Volume: 120 Issue: 9 Pages: 1-19
  • DOI: 10.1002/2015ja021699
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Pileup accident hypothesis of magnetic storm on 2015 March 17 (2015)
  • Author(s): Kataoka, R.; Shiota, D; Kilpua, E.; Keika, K.
  • Journal Title: Geophysical Research Lettes Volume: 42 Issue: 13 Pages: 5155-5161
  • DOI: 10.1002/2015gl064816
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Formation of the oxygen torus in the inner magnetosphere: Van Allen Probes observations (2015)
  • Author(s): M. Nose, S. Oimatsu, K. Keika, C. A. Kletzing, W. S. Kurth, S. De Pascuale, C. W. Smith, R. J. MacDowall, S. Nakano, G. D. Reeves, H. E. Spence, and B. A. Larsen
  • Journal Title: Journal of Geophysical Research Volume: 120 Issue: 2 Pages: 1182-1196
  • DOI: 10.1002/2014ja020593
  • Peer Reviewed
• [Journal Article] CDF data archive and integrated data analysis platform for ERG-related ground data developed by ERG Science Center (ERG-SC) (2015)
  • Author(s): T. Hori, Y. Miyashita, Y. Miyoshi, K. Seki, T. Segawa, Y.-M. Tanaka, K. Keika, M. Shoji, I. Shinohara, K. Shiokawa, Y. Otsuka, S. Abe, A. Yoshikawa, K. Yumoto, Y. Obana, N. Nishitani, A. S. Yukimatu, T. Nagatsuma, M. Kunitake, K. Hosokawa, Y. Ogawa, K. T. Murata, M. Nose', H. Kawano, and T. Sakanoi
  • Journal Title: J. Sp. Sci. Info. Jpn. Volume: 4 Pages: 75-89
  • NAID: 110009894246
  • Peer Reviewed / Open Access
• [Journal Article] Initial Measurements of O-ion and He-ion Decay Rates Observed from the Van Allen Probes RBSPICE Instrument (2014)
  • Author(s): Gerrard, A., L. J. Lanzerotti, M. Gkioulidou, D. G. Mitchell, J. Manweiler, J. Bortnik, and K. Keika
  • Journal Title: J. Geophys. Res. Volume: 119 Issue: 11 Pages: 8813-8819
  • DOI: 10.1002/2014ja020374
  • Peer Reviewed / Open Access
• [Journal Article] Observational Technique of the Solar System Plasma: Remote Sensing of Planetary Plasma and Atmosphere (2014)
  • Author(s): I. Yoshikawa, K. Yoshioka, K. Keika, and Y. Ezoe
  • Journal Title: Journal of Plasma and Fusion Research Volume: 90 Pages: 786-788
  • Open Access
• [Presentation] Energy and mass dependence of the contribution to storm-time plasma pressure observed by Arase/MEP-i (2017)
  • Author(s): K. Keika, S. Kasahara, S. Yokota, M. Hoshino, K. Seki, M. Nose', T. Amano, Y. Miyoshi, I. Shinohara
  • Organizer: AGU 2017 Fall Meeting
  • Int'l Joint Research
• [Presentation] Energy and mass dependence of the contribution to storm-time plasma pressure: Arase/MEP-i observations (2017)
  • Author(s): K. Keika, S. Kasahara, S. Yokota, M. Hoshino, K. Seki, M. Nose', T. Amano, Y. Miyoshi, I. Shinohara
  • Organizer: SGEPSS 2017 Fall Meeting
• [Presentation] Ring current spatio-temporal evolution affected by plasma sheet conditions and magnetosphere- ionosphere coupling (2017)
  • Author(s): K. Keika
  • Organizer: 2017 IAPSO-IAMAS-IAGA Joint Assembly
  • Int'l Joint Research / Invited
• [Presentation] 地球磁気圏尾部での重イオンの振る舞い：最近の研究とERG観測に向けて (2017)
  • Author(s): 桂華邦裕
  • Organizer: 名古屋大学宇宙地球環境研究所研究集会「太陽惑星系宇宙プラズマ中の重イオンに関する研究集会
• [Presentation] Oxygen impulsive energization during the storm main phase and its contribution to the ring current buildup (2017)
  • Author(s): K. Keika, K. Seki, Y. Miyoshi, M. Nose', L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. Gerrard, H. Spence, B. A. Larsen, J. W. Manweiler
  • Organizer: JpGU meeting 2017
  • Int'l Joint Research
• [Presentation] 地球磁気圏尾部での重イオンの振る舞い：最近の研究とERG観測に向けて (2017)
  • Author(s): 桂華邦裕
  • Organizer: 平成28年度名古屋大学宇宙地球環境研究所研究集会「太陽惑星系宇宙プラズマ中の重イオンに関する研究集会」
  • Place of Presentation: 大阪電気通信大学（大阪府 寝屋川市）
• [Presentation] Three-step development of the 17 March 2015 magnetic storm observed by Van Allen Probes (2016)
  • Author(s): K. Keika, Y. Miyoshi, S. Machida, M. Nose', K. Seki, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. Gerrard, and J. W. Manweiler
  • Organizer: 015 ISEE workshop "International GEMSIS and ASINACTR-G2602 Workshop: Future Perspectives of Researches in Space Physics"
  • Place of Presentation: Nagoya University
  • Year and Date: 2016-03-23
  • Int'l Joint Research
• [Presentation] 地球内部磁気圏への酸素イオン供給時期と磁気嵐中の酸素イオン圧突発的増加について (2016)
  • Author(s): 桂華邦裕
  • Organizer: 2015年度名古屋大学太陽地球環境研究所研究集会 「太陽惑星系宇宙プラズマ中の重イオンに関する研究会」
  • Place of Presentation: 名古屋大学
  • Year and Date: 2016-01-27
• [Presentation] Oxygen energization and loss during the main phase of the 17 March 2015 storm: Van Allen Probes observations (2016)
  • Author(s): K. Keika, Y. Miyoshi, S. Machida, M. Nose', K. Seki, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. J. Gerrard, J. W. Manweiler, H. E. Spence, and B. Larsen
  • Organizer: AGU Fall Meeting 2016
  • Place of Presentation: Moscone Center, San Francisco, CA, USA
  • Int'l Joint Research
• [Presentation] Three-step development of the 17 March 2015 magnetic storm: Van Allen Probes/RBSPICE observations (2016)
  • Author(s): K. Keika, Y. Miyoshi, S. Machida, M. Nose', K. Seki, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. J. Gerrard, and J. W. Manweiler
  • Organizer: JpGU Meeting 2016
  • Place of Presentation: 幕張メッセ（千葉県 幕張市）
  • Int'l Joint Research
• [Presentation] 地球電離圏起源イオンの磁気圏ダイナミクスに対する影響について (2016)
  • Author(s): 桂華邦裕
  • Organizer: 平成28年度名古屋大学宇宙地球環境研究所研究集会「宇宙惑星結合系科学の実証的研究の創設に向けて」
  • Place of Presentation: 立教大学（東京都 豊島区）
  • Invited
• [Presentation] Temporal variations of oxygen contribution to the ring current during the 17 March 2015 storm: Van Allen Probes observations (2016)
  • Author(s): K. Keika, Y. Miyoshi, S. Machida, M. Nose', K. Seki, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. J. Gerrard, and J. W. Manweiler
  • Organizer: 地球電磁気・地球惑星圏学会 第140回講演会
  • Place of Presentation: 九州大学（福岡県 福岡市）
• [Presentation] Van Allen Probes衛星で観測された内部磁気圏EMIC波動とイオン速度分布関数 (2016)
  • Author(s): 桂華邦裕
  • Organizer: 平成28年度名古屋大学宇宙地球環境研究所研究集会「ERG衛星観測に向けたEMIC波動および関連現象に関する研究集会」
  • Place of Presentation: 宇宙科学研究所（神奈川県 相模原市）
  • Invited
• [Presentation] Characteristics of ring current protons and oxygen ions during the 7 January 2015 and 17 March 2015 storms: Van Allen Probes/RBSPICE observations (2015)
  • Author(s): Kunihiro Keika, K. Seki, M. Nose', S. Machida, Y. Miyoshi, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, A. J. Gerrard, and J. W. Manweiler
  • Organizer: 2015 AGU Fall Meeting
  • Place of Presentation: Moscone Center, San Francisco
  • Year and Date: 2015-12-17
  • Int'l Joint Research
• [Presentation] Key unresolved issues to be addressed by in-situ ion measurements in the Earth’s inner magnetosphere: ERG and Van Allen Probes collaborations (2015)
  • Author(s): K. Keika
  • Organizer: ISAS Symposium - Magnetospheric Plasmas 2015
  • Place of Presentation: Tokyo Institute of Technology
  • Year and Date: 2015-12-03
  • Int'l Joint Research / Invited
• [Presentation] 2015年3月17日磁気嵐中のリングカレントイオンの振る舞いについて (2015)
  • Author(s): 桂華邦裕
  • Organizer: 第5回極端宇宙天気現象研究会
  • Place of Presentation: 名古屋大学
  • Year and Date: 2015-11-12
• [Presentation] 2015年1月7日および3月18日の磁気嵐におけるリングカレントイオンの特徴 (2015)
  • Author(s): 桂華邦裕, 関華奈子, 能勢正仁, 町田忍, 三好由純, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou
  • Organizer: 地球電磁気・地球惑星圏学会 第138回講演会
  • Place of Presentation: 東京大学
  • Year and Date: 2015-11-01
• [Presentation] Impulsive enhancements of oxygen ions in the inner magnetosphere: Van Allen Probes RBSPICE observations (2015)
  • Author(s): K. Keika, K. Seki, M. Nose', S. Machida, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, and A. Ukhorskiy
  • Organizer: Japan Geoscience Union Meeting 2015
  • Place of Presentation: 幕張メッセ
  • Year and Date: 2015-05-26
  • Int'l Joint Research
• [Presentation] Impulsive enhancements of oxygen ions in the inner magnetosphere during the storm main phase: Van Allen Probes/RBSPICE observations (2015)
  • Author(s): K. Keika, K. Seki, M. Nose', S. Machida, L. J. Lanzerotti, D. G. Mitchell, M. Gkioulidou, and A. Ukhorskiy
  • Organizer: Inner Magnetosphere Coupling III
  • Place of Presentation: University of California Los Angeles, Los Angeles, LA
  • Year and Date: 2015-03-24
• [Presentation] Properties of energetic ion PSD during storm-time substorms observed by Van Allen Probes (2015)
  • Author(s): K. Mitani, K. Seki, K. Keika, L. J. Lanzerrotti, M. Gkioulidou, D. G. Mitchel, and C. A. Kletzing
  • Organizer: Inner Magnetosphere Coupling III
  • Place of Presentation: University of California Los Angeles, Los Angeles, LA
  • Year and Date: 2015-03-24
• [Presentation] Ion composition and energization in the Earth’s inner magnetosphere and the effects on the ring current buildup (2014)
  • Author(s): K. Keika, L. M. Kistler, P. C. Brandt, K. Seki, M. Nose', S. Machida, L. J. Lanzerotti, M. Gkioulidou, A. Ukhorskiy, and D. G. Mitchell
  • Organizer: 2014 AGU Fall Meeting
  • Place of Presentation: Moscone Center, San Francisco, CA.
  • Year and Date: 2014-12-16
  • Invited
• [Presentation] Energetic protons and oxygen ions observed by Van Allen Probes/RBSPICE during storm-time substorms (2014)
  • Author(s): K. Keika, K. Seki, M. Nose', S. Machida, L. J. Lanzerotti, M. Gkioulidou, A. Ukhorskiy, and D. G. Mitchell
  • Organizer: The 12th International Conference on Substorms
  • Place of Presentation: Ise-shima Royal Hotel, Ise, Japan
  • Year and Date: 2014-11-13
• [Presentation] Properties of energetic ion PSD during storm-time substorms observed by Van Allen Probes (2014)
  • Author(s): K. Mitani, K. Seki, K. Keika, L. J. Lanzerrotti, M. Gkioulidou, D. G. Mitchel, and C. A. Kletzing
  • Organizer: The 12th International Conference on Substorms
  • Place of Presentation: Ise-shima Royal Hotel, Ise, Japan
  • Year and Date: 2014-11-12
• [Presentation] Properties of energetic ion PSD during storm-time substorms observed by Van Allen Probes (2014)
  • Author(s): K. Mitani, K. Seki, K. Keika, L. J. Lanzerrotti, M. Gkioulidou, D. G. Mitchel, and C. A. Kletzing
  • Organizer: 地球電磁気・地球惑星圏学会 第136回講演会
  • Place of Presentation: キッセイ文化ホール
  • Year and Date: 2014-11-03
• [Presentation] Van Allen Probes衛星搭載RBSPICE粒子検出器による磁気嵐中高エネルギー水素および酸素イオンの複数点観測 (2014)
  • Author(s): 桂華邦裕, 関華奈子, 能勢正仁, 町田忍, L. J. Lanzerotti, M. Gkioulidou, A. Ukhorskiy, D. G. Mitchell
  • Organizer: 地球電磁気・地球惑星圏学会 第136回講演会
  • Place of Presentation: キッセイ文化ホール
  • Year and Date: 2014-11-01
• [Remarks] 東京大学大学院理学系研究科地球惑星科学専攻
  • URL: http://www.eps.s.u-tokyo.ac.jp
• [Remarks] 名古屋大学宇宙地球環境研究所統合解析研究部
  • URL: http://www.isee.nagoya-u.ac.jp/study06.html
• [Remarks] ERGサイエンスセンター
  • URL: http://ergsc.stelab.nagoya-u.ac.jp
• [Remarks] 実証型ジオスペース環境モデリングシステム
  • URL: http://st4a.stelab.nagoya-u.ac.jp/gemsis/
• [Remarks] 名古屋大学太陽地球環境研究所総合解析部門メンバー
  • URL: http://st4a.stelab.nagoya-u.ac.jp/jp/
• [Remarks] 名古屋大学太陽地球環境研究所 実証型ジオスペース環境モデリングシステム
  • URL: http://st4a.stelab.nagoya-u.ac.jp/gemsis/
• [Remarks] ERG Science Center
  • URL: http://ergsc.stelab.nagoya-u.ac.jp