A challenge to construct a new substorm image by coordinating ground auroral observations and in-situ spacecraft observations

2017 Fiscal Year Final Research Report

• Project/Area Number: 26247082
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: Nagoya University
• Principal Investigator: Machida Shinobu 名古屋大学, 宇宙地球環境研究所, 教授 (70209469)
• Co-Investigator(Kenkyū-buntansha): 長井 嗣信 東京工業大学, 理学院, 教授 (60260527) ; 門倉 昭 国立極地研究所, 研究教育系, 教授 (70185883) ; 齋藤 義文 国立研究開発法人宇宙航空研究開発機構, 宇宙科学研究所, 准教授 (30260011) ; 篠原 育 国立研究開発法人宇宙航空研究開発機構, 宇宙科学研究所, 准教授 (20301723) ; 家田 章正 名古屋大学, 宇宙地球環境研究所, 助教 (70362209) ; 堀 智昭 名古屋大学, 宇宙地球環境研究所, 特任准教授 (30467344) ; 寺田 直樹 東北大学, 理学研究科, 准教授 (70470060) ; 宮下 幸長 名古屋大学, 宇宙地球環境研究所, 特任助教 (20435811)
• Co-Investigator(Renkei-kenkyūsha): ZENITANI Seiji 京都大学, 生存圏研究所, 特任講師 (10623952)
• Research Collaborator: NISHIMURA Yukitoshi 米国UCLA, 海洋大気科学科, 研究員
• Project Period (FY): 2014-06-27 – 2017-03-31
• Keywords: サブストーム / 地球惑星磁気圏 / オーロラ / 磁気リコネクション / カタパルト電流層 / GEOTAIL衛星 / THEMIS計画 / MMS衛星

Outline of Final Research Achievements

We have conducted integrated study by analyzing the ground-based auroral imager data and the in-situ observational data from GEOTAIL, THEMIS and MMS spacecraft, and further performing numerical plasma simulations. As a result, it was found that the electron tearing mode instability takes place in the catapult current sheet, resulting in the magnetic reconnection at the near-Earth neutral line. Moreover, the resultant high-speed plasma flows toward the Earth excites instability caused by non-uniformity of the pressure, such as the ballooning instability, and generates large-scale auroral disturbances. We could obtain a new substorm model revising previous models. Furthermore, related studies have largely advanced our understanding on the magnetic reconnection.

Free Research Field

磁気圏物理学