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Variation of Jupiter’s Aurora Observed by Hisaki/EXCEED: 4. Quasi-Periodic Variation
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  • Chihiro Tao,
  • Tomoki Kimura,
  • Elena A. Kronberg,
  • Fuminori Tsuchiya,
  • Go Murakami,
  • Atsushi Yamazaki,
  • Marissa F. Vogt,
  • Bertrand Bonfond,
  • Kazuo Yoshioka,
  • Ichiro Yoshikawa,
  • Yasumasa Kasaba,
  • Hajime Kita,
  • Shogo Okamoto
Chihiro Tao
National Institute of Information and Communications Technology (NICT)

Corresponding Author:[email protected]

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Tomoki Kimura
Tohoku University
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Elena A. Kronberg
Ludwig Maximilian University of Munich
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Fuminori Tsuchiya
Tohoku University
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Go Murakami
Japan Aerospace Exploration Agency
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Atsushi Yamazaki
Institute of Space and Astronautical Science
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Marissa F. Vogt
Boston University
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Bertrand Bonfond
Université de Liège
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Kazuo Yoshioka
The University of Tokyo
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Ichiro Yoshikawa
University of Tokyo
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Yasumasa Kasaba
Tohoku University
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Hajime Kita
Tohoku Institute of Technology
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Shogo Okamoto
Nagoya University
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Quasi-periodic variations of a few to several days are observed in the energetic plasma and magnetic dipolarization in Jupiter’s magnetosphere. Variation in the plasma mass flux related to Io’s volcanic activity is proposed as a candidate of the variety of the period. Using a long-term monitoring of Jupiter by the Earth-orbiting space telescope Hisaki, we analyzed the quasi-periodic variation seen in the auroral power integrated over the northern pole for 2014–2016, which included monitoring Io’s volcanically active period in 2015 and the solar wind near Jupiter during Juno’s approach in 2016. Quasi-periodic variation with periods of 0.8–8 days was detected. The difference between the periodicities during volcanically active and quiet periods is not significant. Our dataset suggests that a difference of period between this volcanically active and quiet conditions is below 1.25 days. This is consistent with the expected difference estimated from a proposed relationship based on a theoretical model applied to the plasma variation of this volcanic event. The periodicity does not show a clear correlation with the auroral power, central meridional longitude, or Io phase angle. The periodic variation is continuously observed in addition to the auroral modulation due to solar wind variation. Furthermore, Hisaki auroral data sometimes shows particularly intense auroral bursts of emissions lasting <10h. We find that these bursts coincide with peaks of the periodic variations. Moreover, the occurrence of these bursts increases during the volcanically active period. This auroral observation links parts of previous observations to give a global view of Jupiter’s magnetospheric dynamics.
Feb 2021Published in Journal of Geophysical Research: Space Physics volume 126 issue 2. 10.1029/2020JA028575