Characterization of Jupiter's secondary auroral oval and its response to hot plasma injections

Gray, R.L.; Badman, S.V.; Woodfield, E.E. ORCID: https://orcid.org/0000-0002-0531-8814; Tao, C.. 2017 Characterization of Jupiter's secondary auroral oval and its response to hot plasma injections. Journal of Geophysical Research: Space Physics, 122 (6). 6415-6429. 10.1002/2017JA024214

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Official URL: https://doi.org/10.1002/2017JA024214

Abstract/Summary

We present Jovian auroral observations from the 2014 January Hubble Space Telescope (HST) campaign and characterize the auroral second oval feature with particular attention to the response to hot plasma injections. The location of the second oval feature lies between the Ganymede and Europa moon footprint contours between 150 and 240° system III longitude, corresponding to a source in the inner magnetosphere between 9 and 13 RJ. At the examined longitudes, this is in the same region of 11–16 RJ known as the pitch angle distribution boundary, beyond which electrons are thought to be scattered into a field-aligned configuration and cause auroral precipitation. The feature is enhanced in both brightness and longitudinal spread 1–3 days after large hot plasma injections. The precipitating electrons have a higher-energy and lower flux than the electrons generating large injection signatures. We suggest that wave-particle interactions are responsible for the scattering of electrons in this region. We also suggest that the plasma injections can act as a temperature anisotropy and particle source to enhance electron scattering into the aurora and the brightness of the second oval feature. Changes to the magnetic field topology around an injection may also generate shear Alfvén waves and therefore accelerate electrons parallel to the magnetic field resulting in precipitation.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1002/2017JA024214
Programmes:	BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere
ISSN:	21699380
Additional Keywords:	Jupiter, aurora, plasma injections, HST, wave-particle interactions
Date made live:	03 Aug 2017 12:41 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/517470

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1002/2017JA024214

Programmes:

BAS Programmes > BAS Programmes 2015 > Space Weather and Atmosphere

ISSN:

21699380

Additional Keywords:

Jupiter, aurora, plasma injections, HST, wave-particle interactions

Date made live:

03 Aug 2017 12:41 +0 (UTC)