The global distribution of ultra-low-frequency waves in Jupiter's magnetosphere
File(s)
Published version
Author(s)
Manners, Harry Arthur
Masters, Adam
Type
Journal Article
Abstract
Jupiter's giant magnetosphere is a complex system seldom in a configuration approximating steady state, and a clear picture of its governing dynamics remains elusive. Crucial to understanding how the magnetosphere behaves on a large scale are disturbances to the system on length‐scales comparable to the cavity, which are communicated by magnetohydrodynamic waves in the ultra‐low‐frequency band (<1 mHz). In this study we used magnetometer data from multiple spacecraft to perform the first global heritage survey of these waves in the magnetosphere. To map the equatorial region, we relied on the large local‐time coverage provided by the Galileo spacecraft. Flyby encounters performed by Voyager 1 & 2, Pioneer 10 & 11 and Ulysses provided local‐time coverage of the dawn sector. We found several hundred events where significant wave power was present, with periods spanning ~5‐60 min. The majority of events consisted of multiple superposed discrete periods. Periods at ~15, ~30 and ~40 min dominated the event‐averaged spectrum, consistent with the spectra of quasi‐periodic pulsations often reported in the literature. Most events were clustered in the outer magnetosphere close to the magnetopause at noon and dusk, suggesting that an external driving mechanism may dominate. The most energetic events occurred close to the planet, though more sporadically, indicating an accumulation of wave energy in the inner magnetosphere or infrequent impulsive drivers in the region. Our findings suggest that dynamics of the system at large scales is modulated by this diverse population of waves, which permeate the magnetosphere through several cavities and waveguides.
Date Issued
2020-10-01
Date Acceptance
2020-09-05
Citation
Journal of Geophysical Research, 2020, 125 (10)
ISSN
0148-0227
Publisher
Wiley
Journal / Book Title
Journal of Geophysical Research
Volume
125
Issue
10
Copyright Statement
©2020. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
The Royal Society
The Royal Society
Grant Number
UF150547
RG160612
Subjects
Meteorology & Atmospheric Sciences
Publication Status
Published
Article Number
e2020JA028345
Date Publish Online
2020-09-22