Remote sensing of Jupiter's magnetospheric dynamics

This thesis presents and examines evidence of Jupiter’s magnetospheric dynamics, pri- marily using Hubble Space Telescope images of the planet’s ultraviolet aurora. The first two studies discuss the radial transport of hot plasma injections from reconnection return flow. The auroral evidence for a global magnetospheric disturbance is examined and it is found that the aurora showed a significantly super-rotating polar spot poleward of the main emission on the dawnside. The spot transitioned from the polar to main emission region in the presence of a locally broad, bright dawnside main emission feature and two large equatorward emission features. This is taken to be evidence of a prolonged period of reconnection and plasma injection, taking place over several hours. The second chapter examines the effect of hot plasma injection in the middle to inner magnetosphere. The lo- cation of the second oval feature lies between the Ganymede and Europa moon footprint contours between 150 and 240 degrees system III longitude, corresponding to a source in the inner magnetosphere between 9 and 13 RJ . The feature is enhanced in both brightness and longitudinal spread 1-3 days after large hot plasma injections. It was suggested that wave-particle interactions are responsible for the scattering of electrons in this region. A third study investigated the auroral response to co-rotating interaction regions and solar wind compression. It was shown that in there are both high latitude and mid latitude features that arise - large scale flashes appear at high latitudes, sometimes along side significant branching of the main emission region. It is suggested that the arcs in the main emission are a result of strong compression either due to enhanced flow structures at the dusk side or a stepwise co-rotation breakdown in response to increase of azimuthal plasma velocity.

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Lancaster University

Year dc:date.issued

2018

Authors dc:creator

• Gray, Rebecca
• Badman, Sarah