@article{865ad137e1af43ddbf1f04167e5448d7,
title = "Energetic Electron Precipitation Associated With Pulsating Aurora Observed by VLF Radio Propagation During the Recovery Phase of a Substorm on 27 March 2017",
abstract = "Recent studies suggest that electrons with energies up to several hundred keV precipitate into the atmosphere associated with pulsating aurora (PsA). It is debated the highest energy of precipitating electrons associated with PsA. Here we report for the first time that the energy extends to relativistic energies. PsA was observed by THEMIS all-sky imagers during a substorm that occurred on 27 March 2017. Energetic electron precipitation was detected by very low frequency subionospheric propagation. We found similar time variations between the auroral intensity and perturbation of the received radio signal intensity when the PsA occurred on the radio path. The perturbation showed a short recovery time of ~2 s. The recovery time indicates relaxation from ionospheric modification due to energetic electron precipitation and depends on the stopping altitude of the electrons. The recovery time required a stopping altitude of 50–60 km and indicates that the PsA is accompanied by relativistic electron precipitation.",
keywords = "pulsating aurora, radiation belt, relativistic electron precipitation",
author = "F. Tsuchiya and A. Hirai and T. Obara and H. Misawa and S. Kurita and Y. Miyoshi and K. Shiokawa and M. Connors and M. Ozaki and Y. Kasahara and A. Kumamoto and Y. Kasaba and A. Matsuoka and M. Shoji and I. Shinohara",
note = "Funding Information: This work was supported by JSPS Grants-in-Aid for Scientific Research (20740281, 15H05815, 15H05747, and 16H06286). This work was carried out by the joint research program of the Institute for Space-Earth Environmental Research (ISEE), Nagoya University, and the Interuniversity Upper atmosphere Global Observation NETwork (IUGONET) project funded by the Ministry of Education, Culture, Sports, Science and Technology of Japan. The VLF data (subionospheric propagation) used in this paper are opened through Planetary Plasma and Atmospheric Research Center (PPARC), Tohoku University (http://c.gp.tohoku.ac.jp/lf/). The induction search coil magnetometer and the VLF/ELF loop antenna data at Athabasca are operated through ISEE, Nagoya University, in facilities of Athabasca University funded by the Canada Foundation for Innovation. Digital data are available through the ERG Science Center operated by the Institute of Space and Astronautical Science of the Japan Aerospace eXploration Agency (ISAS/JAXA) and ISEE, Nagoya University (https://ergsc. isee.nagoya-u.ac.jp/index.shtml.en). We thank NASA for contract NAS5-02099 and S. Mende and E. Donovan for use of the ASI data. The SYM-H and AE indices are available from the NASA/NSSDC. The ERG (Arase) satellite science data were provided from the ERG Science Centre. PWE/HFA L3 ver00.02 was used for the electron density data. The Arase satellite data will be publicly available via ERG Science Center on a project-agreed schedule. Funding Information: This work was supported by JSPS Grants-in-Aid for Scientific Research (20740281, 15H05815, 15H05747, and 16H06286). This work was carried out by the joint research program of the Institute for Space-Earth Environmental Research (ISEE), Nagoya University, and the Interuniversity Upper atmosphere Global Observation NETwork (IUGONET) project funded by the Ministry of Education, Culture, Sports, Science and Technology of Japan. The VLF data (subionospheric propagation) used in this paper are opened through Planetary Plasma and Atmospheric Research Center (PPARC), Tohoku University (http://c.gp.tohoku.ac.jp/lf/). The induction search coil magnetometer and the VLF/ELF loop antenna data at Athabasca are operated through ISEE, Nagoya University, in facilities of Athabasca University funded by the Canada Foundation for Innovation. Digital data are available through the ERG Science Center operated by the Institute of Space and Astronautical Science of the Japan Aerospace eXploration Agency (ISAS/JAXA) and ISEE, Nagoya University (https://ergsc.isee.nagoya-u.ac.jp/index.shtml.en). We thank NASA for contract NAS5-02099 and S. Mende and E. Donovan for use of the ASI data. The SYM-H and AE indices are available from the NASA/NSSDC. The ERG (Arase) satellite science data were provided from the ERG Science Centre. PWE/HFA L3 ver00.02 was used for the electron density data. The Arase satellite data will be publicly available via ERG Science Center on a project-agreed schedule. Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = dec,
day = "16",
doi = "10.1029/2018GL080222",
language = "English",
volume = "45",
pages = "12,651--12,660",
number = "23",
}