論文

2022年8月

An event of extreme relativistic and ultra-relativistic electron enhancements following the arrival of consecutive corotating interaction regions: Coordinated observations by Van Allen Probes, Arase, THEMIS and Galileo satellites

FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
  • Afroditi Nasi
  • Christos Katsavrias
  • Ioannis A. Daglis
  • Ingmar Sandberg
  • Sigiava Aminalragia-Giamini
  • Wen Li
  • Yoshizumi Miyoshi
  • Hugh Evans
  • Takefumi Mitani
  • Ayako Matsuoka
  • Iku Shinohara
  • Takeshi Takashima
  • Tomoaki Hori
  • Georgios Balasis
  • 全て表示

9
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3389/fspas.2022.949788
出版者・発行元
FRONTIERS MEDIA SA

During July to October of 2019, a sequence of isolated Corotating Interaction Regions (CIRs) impacted the magnetosphere, for four consecutive solar rotations, without any interposed Interplanetary Coronal Mass Ejections. Even though the series of CIRs resulted in relatively weak geomagnetic storms, the net effect of the outer radiation belt during each disturbance was different, depending on the electron energy. During the August-September CIR group, significant multi-MeV electron enhancements occurred, up to ultra-relativistic energies of 9.9 MeV in the heart of the outer Van Allen radiation belt. These characteristics deemed this time period a fine case for studying the different electron acceleration mechanisms. In order to do this, we exploited coordinated data from the Van Allen Probes, the Time History of Events and Macroscale Interactions during Substorms Mission (THEMIS), Arase and Galileo satellites, covering seed, relativistic and ultra-relativistic electron populations, investigating their Phase Space Density (PSD) profile dependence on the values of the second adiabatic invariant K, ranging from near-equatorial to off equatorial mirroring populations. Our results indicate that different acceleration mechanisms took place for different electron energies. The PSD profiles were dependent not only on the mu value, but also on the K value, with higher K values corresponding to more pronounced local acceleration by chorus waves. The 9.9 MeV electrons were enhanced prior to the 7.7 MeV, indicating that different mechanisms took effect on different populations. Finally, all ultra-relativistic enhancements took place below geosynchronous orbit, emphasizing the need for more Medium Earth Orbit (MEO) missions.

リンク情報
DOI
https://doi.org/10.3389/fspas.2022.949788
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000869793400001&DestApp=WOS_CPL
ID情報
  • DOI : 10.3389/fspas.2022.949788
  • ISSN : 2296-987X
  • Web of Science ID : WOS:000869793400001

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