Publication Date:
2018-01-10
Description:
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 nonadiabatic magnetospheric energization. ©2017. American Geophysical Union. All Rights Reserved.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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