Three-dimensional structure of magnetic reconnection in the magnetotail

• Project/Area Number: 25400476
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Nagai Tsugunobu 東京工業大学, 大学院理工学研究科, 教授 (60260527)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2013: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: 磁気リコネクション / サブストーム / 磁気圏尾部 / 磁気圏 / オーロラ / 地球磁気圏 / 宇宙プラズマ

Outline of Final Research Achievements

Magnetic reconnection produces plasma dynamics in the magnetotail through the conversion of the stored magnetic field energy during substorms. Magnetic reconnection usually forms at radial distance of 20-30 Re in the magnetotail. This study has established its three-dimensional structure and size using the observations with the Geotail spacecraft over 20 years. Magnetic reconnection takes place on a line, not as any set of points. The X line (its spatial size is less than one ion inertial length) forms in the center of the magnetic reconnection site, and it is surrounded with the ion-electron decoupling region with a scale size of 10 ion inertial lengths. The X line itself has its dawn-dusk length of > 6 Re in the duskside of the magnetotail.

Research Products

• [Journal Article] The dawn-dusk length of the X line in the near-Earth magnetotail: Geotail survey in 1994-2014 (2015)
  • Author(s): T. Nagai, I. Shinohara, and S. Zenitani
  • Journal Title: Journal of Geophysical Research Volume: 120 Issue: 10 Pages: 87628773-87628773
  • DOI: 10.1002/2015ja021606
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Ion acceleration processes in magnetic reconnection: Geotail observations in the magnetotail (2015)
  • Author(s): T. Nagai, I. Shinohara and S. Zenitani
  • Journal Title: Journal of Geophysical Research. A:Space Physics Volume: 120 Issue: 3 Pages: 1766-1783
  • DOI: 10.1002/2014ja020737
  • Peer Reviewed / Open Access
• [Journal Article] A 2-D empirical plasma sheet pressure model for substorm growth phase using the Support Vector Regression Machine (2015)
  • Author(s): C. Yue, C. Wang, L. Lyons, Y. Wang, T. Hsu, M. Henderson, V. Angelopoulos, A. T. Y. Lui, and T. Nagai
  • Journal Title: Journal of Geophysical Research Volume: 120 Issue: 3 Pages: 19571973-19571973
  • DOI: 10.1002/2014ja020787
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Empirical modeling of 3-D force-balanced plasma and magnetic field structures during substorm growth phase (2015)
  • Author(s): C. Yue, C., C.-P. Wang, Y. Nishimura, K. R. Murphy, X. Xing, L. Lyons, M. Henderson, V. Angelopoulos, A. T. Y. Lui, and T. Nagai
  • Journal Title: Journal of Geophysical Research Volume: 120 Issue: 8 Pages: 64966513-64966513
  • DOI: 10.1002/2015ja021226
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Three-dimensional structure of magnetic reconnection in the magnetotail from Geotail observations (2013)
  • Author(s): T. Nagai, I. Shinohara, S. Zenitani, R. Nakamura, T.K.M. Nakamura, M. Fujimoto, Y. Saito, T. Mukai
  • Journal Title: Journal of Geophysical Research. A:Space Physics Volume: 118 Issue: 4 Pages: 1667-1678
  • DOI: 10.1002/jgra.50247
  • Peer Reviewed
• [Journal Article] Ion and electron dynamics in the ion-electron decoupling region of magnetic reconnection with Geotail observations (2013)
  • Author(s): T. Nagai, S. Zenitani, I. Shinohara, R. Nakamura, M. Fujimoto, Y. Saito, T. Mukai
  • Journal Title: Journal of Geophysical Research. A:Space Physics Volume: 118 Issue: 12 Pages: 7703-7713
  • DOI: 10.1002/2013ja019135
  • Peer Reviewed
• [Journal Article] An empirical model for the location and occurrence rate of near-Earth magnetotail reconnection (2013)
  • Author(s): K. J. Genestreti, S. A. Fuselier, J. Goldstein and T. Nagai
  • Journal Title: Journal of Geophysical Research Volume: 118 Issue: 10 Pages: 6389-6396
  • DOI: 10.1002/2013ja019125
  • Peer Reviewed
• [Presentation] Structure of Magnetic Reconnection in the Near-Earth Magnetotail (2015)
  • Author(s): T. Nagai
  • Organizer: Chapman Conference on Magnetospheric Dynamics
  • Place of Presentation: Fairbanks, USA
  • Year and Date: 2015-09-28
  • Int'l Joint Research
• [Presentation] 人工衛星Geotailによる磁気リコネクションの観測 (2014)
  • Author(s): 長井嗣信
  • Organizer: 日本地球惑星科学連合
  • Place of Presentation: パシフィコ横浜、横浜市
  • Year and Date: 2014-04-28
  • Invited
• [Presentation] Dawn-dusk asymmetry of magnetic reconnection structure in the magnetotail (2013)
  • Author(s): T. nagai
  • Organizer: American Geophysical Union 2013 Fall Meeting
  • Place of Presentation: San Francisco, USA
  • Invited