Io's volcanic enhancement seen in Jupiter's sodium nebula

Abstract:

We present variations in D-line emissions of Jupiter's sodium nebula.
The sodium atoms in the nebula are originated from volcanic gas on Io.
The D-line brightness of the nebula is expected to be reflecting the
volcanism on Io. We have been making ground-based observations of this
nebula at the Haleakala High Altitude Observatory in Maui island in a
conjunction with the Hisaki spacecraft. Until the end of 2014, the
brightness of the nebula had been stably dim and faint. However, the
nebula showed a distinct enhancement from the end of January through the
end of April, 2015. During this event, the brightness is the nebula
jumped by three times. Detailed of this event will be shown in the
presentation.