Three-dimensional structure of magnetic reconnection in the magnetotail

2015 Fiscal Year Final Research Report

• 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
• 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

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.

Free Research Field

宇宙空間物理学