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Simultaneous Observation of an Auroral Dawn Storm with the Hubble Space Telescope and Juno

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journal contribution
posted on 09.09.2021, 09:28 by BG Swithenbank‐Harris, JD Nichols, F Allegrini, F Bagenal, B Bonfond, EJ Bunce, G Clark, WS Kurth, BH Mauk, RJ Wilson
On July 13, 2016, the Hubble Space Telescope observed the onset of a dawn storm in Jupiter's northern ultraviolet aurora, while the NASA Juno spacecraft simultaneously traversed the dawnside outer magnetosphere. This represents the first concurrent auroral and in situ magnetospheric observations of the onset of a dawn storm at Jupiter. Mapping the auroral emission to the magnetosphere reveals the dawn storm corresponds to a source region at ∼60 Jupiter radii, and the eastward edge propagates toward local noon at speeds exceeding corotation. Particle observations from Jovian Auroral Distributions Experiment (JADE) and Jupiter Energetic particle Detector Instrument (JEDI) reveal the presence of enhanced hot plasma density in the outer magnetosphere during this interval, and pitch angle distributions measured with JEDI reveal pronounced field-aligned proton and heavy ion motion. Juno magnetometer (MAG) signatures reveal a reversal in the azimuthal magnetic field at the time of storm onset, suggesting acceleration of the hot plasma population above typical sub-corotational speeds. JEDI also detects a region of energetic particles which persists throughout the day following the storm, a feature which is not observed during subsequent perijoves. We interpret this dawn storm as the result of reconnection at earlier local times, possibly associated with a disruption of the azimuthal magnetodisk current.

Funding

Science and Technology Facilities Council. Grant Number: ST/N000749/1

History

Citation

Journal of Geophysical Research: Space Physics, Volume 126, Issue 4, April 2021, e2020JA028717

Author affiliation

School of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Journal of Geophysical Research: Space Physics

Volume

126

Issue

4

Publisher

Wiley for American Geophysical Union (AGU)

issn

2169-9380

eissn

2169-9402

Acceptance date

09/02/2021

Copyright date

2021

Available date

09/09/2021

Language

en

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