Juno‐UVS approach observations of Jupiter's auroras

Gladstone, G. R.; Versteeg, M. H.; Greathouse, Thomas; Hue, V.; Davis, Michael W.; Gérard, Jean‐Claude; Grodent, Denis; Bonfond, Bertrand; Nichols, J. D.; Wilson, R.; Hospodarsky, G. B.; Bolton, S. J.; Levin, S. M.; Connerney, J. E. P.; Adriani, A.; Kurth, W. S.; Mauk, B. H.; Valek, P. W.; McComas, D. J.; Orton, Glenn S.; Bagenal, F.

doi:10.1002/2017gl073377

Cited by 29 publications

(36 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As in UV images [ Grodent et al ., ; Gladstone et al ., ; Connerney et al ., ], the main oval (both south and north ones) shows a narrow single arc in about one half of the oval and multiple arcs plus broad diffuse emissions in the other half. However, as Juno's UV and IR images were not obtained at the same instant in time, during this perijove pass, we urge caution in direct comparison of the two.…”

Section: Main Ovalmentioning

confidence: 98%

Infrared observations of Jovian aurora from Juno's first orbits: Main oval and satellite footprints

Mura

Adriani

Altieri

et al. 2017

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

The Jovian Infrared Auroral Mapper (JIRAM) is an imager/spectrometer on board NASA/Juno mission for the study of the Jovian aurorae. The first results of JIRAM's imager channel observations of the H3+ infrared emission, collected around the first Juno perijove, provide excellent spatial and temporal distribution of the Jovian aurorae, and show the morphology of the main ovals, the polar regions, and the footprints of Io, Europa and Ganymede. The extended Io “tail” persists for ~3 h after the passage of the satellite flux tube. Multi‐arc structures of varied spatial extent appear in both main auroral ovals. Inside the main ovals, intense, localized emissions are observed. In the southern aurora, an evident circular region of strong depletion of H3+ emissions is partially surrounded by an intense emission arc. The southern aurora is brighter than the north one in these observations. Similar, probably conjugate emission patterns are distinguishable in both polar regions.

show abstract

Section: Main Ovalmentioning

confidence: 98%

Infrared observations of Jovian aurora from Juno's first orbits: Main oval and satellite footprints

Mura

Adriani

Altieri

et al. 2017

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…This includes the H 2 bands (Werner, Lyman and Rydberg), as well as the Lyman‐ α series. Juno‐UVS successfully provided the first views on the nightside Jovian auroras (Bonfond et al, ; Gérard et al, ), provided new constraints on the vertical distribution of Io's footprint tail emissions (Szalay et al, ), and has monitored the overall auroral activity during approach (Gladstone et al, ). It has also made regular observation of the sky during cruise, used to characterize the instrument (Greathouse et al, ).…”

Section: Observation Of the Io Footprintmentioning

confidence: 99%

Juno‐UVS Observation of the Io Footprint During Solar Eclipse

et al. 2019

Self Cite

View full text Add to dashboard Cite

The two main ultraviolet‐signatures resulting from the Io‐magnetosphere interaction are the local auroras on Io's atmosphere, and the Io footprints on Jupiter. We study here how Io's daily eclipses affect the footprint. Previous observations showed that its atmosphere collapses in eclipse. While remote observers can observe Io's local auroras briefly when Io disappears behind Jupiter, Juno is able to follow the Io footprint in the unlit hemisphere. Theoretical models of the variability of the energy flux fed into the Alfvén wings, ultimately powering the footprints, are not sufficiently constrained by observations. For the first time, we use observations of Io's footprint from the Ultraviolet Spectrograph (UVS) on Juno recorded as Io went into eclipse. We benchmark the trend of the footprint brightness using observations by UVS taken over Io's complete orbit and find that the footprint emitted power variation with Jupiter's rotation shows fairly consistent trends with previous observations. Two exploitable data sets provided measurements when Io was simultaneously in eclipse. No statistically significant changes were recorded as Io left and moved into eclipse, respectively, suggesting either that (i) Io's atmospheric densities within and outside eclipse are large enough to produce a saturated plasma interaction, that is, in the saturated state, changes in Io's atmospheric properties to first order do not control the total Alfvénic energy flux, (ii) the atmospheric collapse during the Juno observations was less than previously observed, or (iii) additional processes of the Alfvén wings in addition to the Poynting flux generated at Io control the footprint luminosity.

show abstract

“…We have provided a best estimate pre‐JOI SW moments data set for the community to use in their modeling endeavors (applications of bow shock or magnetopause models, or comparisons with propagated SW conditions from Earth) or for coordinated investigations with remote measurements of Jovian aurora. Our data set has already been used in the auroral studies of Gladstone et al () and Nichols et al (), and the hot flow anomaly study of Valek et al (). We expect this new interval of SW parameters to greatly expand future investigations with telescopic measurements of Jupiter.…”

Section: Discussionmentioning

confidence: 99%

“…Early results from Juno related to the SW's influence at Jupiter include the detection of a large hot flow anomaly near the dawn bow shock (Valek et al, ), a compressed magnetosphere prior to crossing Jupiter's bow shock (McComas, Szalay, et al, ), evidence of magnetic reconnection and an open magnetosphere along the dawn magnetopause (Ebert et al, ), and significant enhancements in the main aurora ultraviolet power in response to an interplanetary shock (Nichols et al, ). This paper quantifies the SW conditions during Juno's approach to Jupiter and documents the analysis to derive a customized data set already used by multiple first‐results papers (Gladstone et al, ; Nichols et al, ; Valek et al, ).…”

Section: Introductionmentioning

confidence: 99%

Solar Wind Properties During Juno's Approach to Jupiter: Data Analysis and Resulting Plasma Properties Utilizing a 1‐D Forward Model

et al. 2018

Self Cite

View full text Add to dashboard Cite

The Jovian Auroral Distributions Experiment ion sensor (JADE‐I) on board the National Aeronautics and Space Administration's Juno mission measured solar wind ions for ≈40 days prior to the spacecraft's arrival at Jupiter, simultaneous with numerous telescope observations of the Jovian aurora. JADE‐I is a thermal plasma time‐of‐flight instrument designed to measure Jovian auroral and magnetospheric ions. This study provides a solar wind parameter data set for the approach phase that may be used in coordinated studies with remote measurements of the Jovian aurora, to compare with models that propagate solar wind conditions from Earth and to apply to Jovian bow shock or magnetopause models. While multiple bow shock crossings were predicted during Juno's approach, there was only one observed suggesting a compressed magnetosphere that was shrinking as Juno approached. However, the calculated ram pressure at the bow shock was near the median value of those 40 days, rather than being in an upper percentile.

show abstract

Juno‐UVS approach observations of Jupiter's auroras

Cited by 29 publications

References 45 publications

Infrared observations of Jovian aurora from Juno's first orbits: Main oval and satellite footprints

Infrared observations of Jovian aurora from Juno's first orbits: Main oval and satellite footprints

Juno‐UVS Observation of the Io Footprint During Solar Eclipse

Solar Wind Properties During Juno's Approach to Jupiter: Data Analysis and Resulting Plasma Properties Utilizing a 1‐D Forward Model

Contact Info

Product

Resources

About