Magnetic reconnection near the planet as a possible driver of Jupiter's mysterious polar auroras
File(s)2021JA029544R_Merged_PDF.pdf (1.59 MB)
Accepted version
Author(s)
Masters, Adam
Dunn, William
Stallard, Tom
Manners, Harry
Stawarz, Julia
Type
Journal Article
Abstract
Auroral emissions have been extensively observed at the Earth, Jupiter, and Saturn. These planets all have appreciable atmospheres and strong magnetic fields, and their auroras predominantly originate from a region encircling each magnetic pole. However, Jupiter’s auroras poleward of these “main” emissions are brighter and more dynamic, and the drivers responsible for much of these mysterious polar auroras have eluded identification to date. We propose that part of the solution may stem from Jupiter’s stronger magnetic field. We model large-scale Alfvénic perturbations propagating through the polar magnetosphere toward Jupiter, showing that the resulting <0.1° deflections of the magnetic field closest to the planet could trigger magnetic reconnection as near as ∼0.2 Jupiter radii above the cloud tops. At Earth and Saturn this physics should be negligible, but reconnection electric field strengths above Jupiter’s poles can approach ∼1 V m−1, typical of the solar corona. We suggest this near-planet reconnection could generate beams of high-energy electrons capable of explaining some of Jupiter’s polar auroras.
Date Issued
2021-08
Date Acceptance
2021-06-28
Citation
Journal of Geophysical Research: Space Physics, 2021, 126 (8), pp.1-10
ISSN
2169-9380
Publisher
American Geophysical Union
Start Page
1
End Page
10
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
126
Issue
8
Copyright Statement
© 2021. American Geophysical Union. All Rights Reserved. This is the accepted version of the following article: Masters, A., Dunn, W. R., Stallard, T. S., Manners, H., & Stawarz, J. (2021). Magnetic reconnection near the planet as a possible driver of Jupiter’s mysterious polar auroras. Journal of Geophysical Research: Space Physics, 126, e2021JA029544, which has been published in final form at https://doi.org/10.1029/2021JA029544
Sponsor
The Royal Society
The Royal Society
The Royal Society
Identifier
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021JA029544
Grant Number
UF150547
RG160612
URF\R1\201286
Subjects
0201 Astronomical and Space Sciences
0401 Atmospheric Sciences
Publication Status
Published
Date Publish Online
2021-07-14