Japan Geoscience Union Meeting 2016

Presentation information

International Session (Poster)

Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM06] Magnetospheric Multi-Scale (MMS) mission -- A new age of magnetospheric physics

Tue. May 24, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Seiji Zenitani(National Astronomical Observatory of Japan), Naritoshi Kitamura(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Yoshifumi Saito(Solar System Science Division, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Paul Cassak(West Virginia University), Li-Jen Chen(NASA Goddard Space Flight Center), Craig Pollock(NASA Goddard Space Flight Center)

5:15 PM - 6:30 PM

[PEM06-P06] Active and non-active flow reversals observed in the magnetotail

*Iku Shinohara1, Tsugunobu Nagai2, Masaki Fujimoto1, Hirotsugu Kojima3, Seiji Zenitani4 (1.Japan Aerospace Exploration Agency/Institute of Space and Astronautical Science, 2.Tokyo Institute of Technology, 3.Kyoto University/Research Institute for Sustainable Humanosphere, 4.National Astronomical Observatory of Japan)

Keywords:magnetotail, flow reversal, magnetic reconnection

We have statistically examined low-frequency plasma wave activity observed in the near Earth magnetotail flow reversals. 2/3 of the flow reversals have enhanced cross-tail electron current layer and ion-electron decoupling region detected in association with the simultaneous plasma flow and magnetic field reversals (“active” X-line), while the rest events do not show visible ion-electron decoupling features (“non-active” flow reversal). The most important conclusion of the present study on the electric wave activity in the lower hybrid frequency range is that only the active X-line events are accompanied by strong wave activities. Since the region where the strong wave activities are observed overlaps well with the ion-electron decoupling region, the ion-electron decoupling process would be related to excitation mechanisms of the intense electric wave activity. It means that the electric wave power around the flow reversals is a possible indicator for the ion-electron decoupling region (possibly, the liveliness of reconnection). This new finding would be one of the clues leading to our understanding of large-scale evolution of the magnetotail reconnection site. It is hard to address the physical meaning of the differences between active and non-active flow reversals only with single spacecraft measurements. This would be a good topic to be explored using MMS.