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On the Relation Between Auroral Morphologies and Compression Conditions of Jupiter’s Magnetopause: Observations from Juno and the Hubble Space Telescope

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journal contribution
posted on 18.11.2022, 11:20 authored by ZH Yao, B Bonfond, D Grodent, E Chané, WR Dunn, WS Kurth, JEP Connerney, JD Nichols, B Palmaerts, RL Guo, GB Hospodarsky, BH Mauk, T Kimura, SJ Bolton

Jupiter displays the most powerful auroral emissions in our solar system, which result from strong energy dissipation in Jupiter's surrounding space environment. Although mass and energy in Jupiter's magnetosphere mostly come from the innermost Galilean moon Io's volcanic activity and Jupiter's rotation, solar wind perturbations can play crucial roles in releasing magnetospheric energy. The systematic response of the aurora to a solar wind compression remains poorly understood because of timing uncertainties. Here we report the analysis of a set of auroral images from the Hubble Space Telescope with contemporaneous in situ magnetopause detections from Juno, allowing for a more direct comparison. By analyzing the dawn side main auroral emission, we distinguish two non-mutually exclusive types of auroral enhancements: auroral dawn storm (ADS) featured with latitudinal extension in limited longitudes, and a long-lasting main auroral brightening with limited extension in latitudes while extending over a large longitude range. Only the latter systematically appears under a compressed magnetopause, while the dawn storms could occur whatever the state of the magnetopause. The results could provide important constraints to improve theoretical models and numerical simulations. During expanded magnetopause conditions, Jupiter's aurora displayed either quiet or dawn storm morphology. The result is consistent with recent discovery of the initiation of ADSs in midnight and post-midnight, possibly driven by magnetic reconnection plasma instabilities in night magnetotail. Our results show that some typical auroral morphologies could be used as a diagnostic of solar wind conditions at Jupiter.

Funding

NASA's New Frontiers Program

Belgian Federal Science Policy Office, BELSPO

PRODEX Programme of ESA

International Space Science Institute in Beijing, ISSI-BJ

National Key R&D Program of China. Grant Number: 2021YFA0718600

National Science Foundation of China. Grant Number: 42074211

Key Research Program of the Institute of Geology & Geophysics CAS. Grant Number: IGGCAS-201904

NASA. Grant Number: 699041X

History

Author affiliation

Department of Physics and Astronomy, University of Leicester

Version

AM (Accepted Manuscript)

Published in

Journal of Geophysical Research: Space Physics

Volume

127

Issue

10

Publisher

American Geophysical Union (AGU)

issn

2169-9380

eissn

2169-9402

Copyright date

2022

Available date

18/11/2022

Language

en