Japan Geoscience Union Meeting 2018

Presentation information

[EE] Poster

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

[P-EM16] Dynamics of Earth's Inner Magnetosphere and Initial Results from Arase

Tue. May 22, 2018 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Danny Summers(Memorial University of Newfoundland), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Keisuke Hosokawa(電気通信大学大学院情報理工学研究科, 共同), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University)

[PEM16-P06] Sub-relativistic electron precipitation associated with pulsating aurora observed by sub-ionospheric radio propagation during recovery phase of substorm on 27 March 2017

*Fuminori Tsuchiya1, Hirai Asuka1, Takahiro Obara1, Hiroaki Misawa1, Satoshi Kurita2, Yoshizumi Miyoshi2, Kazuo Shiokawa2, Martin G Connors3 (1.Planetary Plasma and Atmospheric Research Center, Graduate School of Science, Tohoku University, 2.ISEE, Nagoya University, 3.Athabasca University)

Keywords:pulsating auroras, Sub-relativistic electron precipitation

Recent studies on pulsating auroras (PsA) suggest that energetic electrons (up to several hundred keV) simultaneously precipitate into the atmosphere and they are caused by pitch angle scattering through wave-particle interaction with whistler mode chorus waves. However, the pulsating signature of the sub-relativistic electron precipitation with time scale of the main pulsation period of PsA (several seconds) has not been reported yet. Here, we report correlations between PsA and sub-relativistic electron precipitation with time scale of several second during recovery phase of substorm occurred on 27 March 2017. Energetic electron precipitation was detected by using sub-ionospheric propagation of VLF radio waves. The sub-ionospheric propagation is sensitive to the electron precipitation with energy higher than 100 keV. The VLF/LF radio waves from several transmitters has been observed at Athabasca with 0.1-sec time resolution. In this study, the transmitter at North Dakota (NDK, 25.2kHz) was used. PsA was observed by the THEMIS GBO all sky imagers at Athabasca (ATHA), The Pas (TPAS), and Pinawa (PINA) with 3-sec cadence. The radio propagation path from NDK to Athabasca is included in a convened field-of-view of the three imagers. We searched for correlations between aurora light curves at each pixel and amplitude variations in the received radio signal. The better correlations were found in the south-west part of the TPAS field-of-view than the other area. This is around the central point of the radio propagation path. The result shows that the sub-relativistic electron precipitation into the atmosphere has the pulsation signature and occurs associated with PsA.