Contemporaneous Observations of Jovian Energetic Auroral Electrons and Ultraviolet Emissions by the Juno Spacecraft. Issue 11 (29th November 2019)

• Record Type: Journal Article
• Authors: Gérard, J.‐C.; Bonfond, B.; Mauk, B. H.; Gladstone, G. R.; Yao, Z. H.; Greathouse, T. K.; Hue, V.; Grodent, D.; Gkouvelis, L.; Kammer, J. A.; Versteeg, M.; Clark, G.; Radioti, A.; Connerney, J. E. P.; Bolton, S. J.; Levin, S. M.
• Is Part Of: Journal of geophysical research. Volume 124:Issue 11(2019)
• Page Start: 8298
• Page End: 8317
• Publication Date: 2019-11-29
• Subjects: Jupiter aurora -- electron precipitation -- ultraviolet emission -- Juno -- UVS -- JEDI; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2019JA026862
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We present comparisons of precipitating electron flux and auroral brightness measurements made during several Juno transits over Jupiter's auroral regions in both hemispheres. We extract from the ultraviolet spectrograph (UVS) spectral imager H2 emission intensities at locations magnetically conjugate to the spacecraft using the JRM09 model. We use UVS images as close in time as possible to the electron measurements by the Jupiter Energetic Particle Detector Instrument (JEDI) instrument. The upward electron flux generally exceeds the downward component and shows a broadband energy distribution. Auroral intensity is related to total precipitated electron flux and compared with the energy‐integrated JEDI flux inside the loss cone. The far ultraviolet color ratio along the spacecraft footprint maps variations of the mean energy of the auroral electron precipitation. A wide diversity of situations has been observed. The intensity of the diffuse emission equatorward of the main oval is generally in fair agreement with the JEDI downward energy flux. The intensity of the ME matches exceeds or remains below the value expected from the JEDI electron energy flux. The polar emission may be more than an order of magnitude brighter than associated with the JEDI electron flux in association with high values of the color ratio. We tentatively explain these observations by the location of the electron energization region relative to Juno's orbit as it transits the auroral region. Current models predict that the extent and the altitude of electron acceleration along the magnetic field lines are consistent with this assumption. Key Points: We compare precipitated electron flux measured with JEDI to the auroral intensity and FUV color ratio observed with UVS at Juno's footprint The different UV auroral features generally map well with the corresponding structures measured in the precipitated electron energy flux Comparison of energy flux at the two levels reveal a diversity of situations probably related to the location of the acceleration region