Japan Geoscience Union Meeting 2018

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS01] Outer Solar System Exploration Today, and Tomorrow

Mon. May 21, 2018 1:45 PM - 3:15 PM 302 (3F International Conference Hall, Makuhari Messe)

convener:Jun Kimura(Osaka University), Yasumasa Kasaba(Dep. Geophysics Graduate School of Science Tohoku University), Steven Vance(Jet Propulsion Laboratory, Caltech, 共同), Kunio M. Sayanagi (Hampton University), Chairperson:Kimura Tomoki(Tohoku University), Sayanagi Kunio(Hampton University)

2:00 PM - 2:15 PM

[PPS01-13] Volcanic Control of Jupiter's Aurora and Middle Magnetosphere Dynamics Observed by Hisaki/EXCEED

*Chihiro Tao1, Tomoki Kimura2, Fuminori Tsuchiya3, Go Murakami4, Kazuo Yoshioka5, Atsushi Yamazaki4, Sarah V Badman6, Hiroaki Misawa3, Hajime Kita3, Yasumasa Kasaba3, Ichiro Yoshikawa5, Masaki Fujimoto4 (1.National Institute of Information and Communications Technology, 2.Riken, 3.Tohoku University, 4.ISAS/JAXA, 5.University of Tokyo, 6.Lancaster University)

Keywords:Hisaki, Jupiter, Aurora

Temporal variation of Jupiter's northern aurora during enhanced Io volcanic activity was detected using the EXCEED spectrometer on board the Hisaki Earth-orbiting planetary space telescope. It was found that in association with reported Io volcanic events in early 2015, auroral power and estimated field-aligned currents were enhanced during day of year 40–120. Furthermore, the far ultraviolet color ratio decreased during the event, indicating a decrease of auroral electron mean energy and total acceleration by <30%. During the episode of enhanced Io volcanic activity, Jupiter's magnetosphere contains more source current via increased suprathermal plasma density by up to 42%; therefore, it would have required correspondingly less electron acceleration to maintain the enhanced field-aligned current and corotation enforcement current. Sporadic large enhancements in auroral emission detected more frequently during the active period could have been contributed by non-adiabatic magnetospheric energization.