Variability of Jupiter's IR H3+ aurorae during Juno approach. Issue 10 (25th May 2017)

• Record Type: Journal Article
• Authors: Moore, L.; O'Donoghue, J.; Melin, H.; Stallard, T.; Tao, C.; Zieger, B.; Clarke, J.; Vogt, M. F.; Bhakyapaibul, T.; Opher, M.; Tóth, G.; Connerney, J. E. P.; Levin, S.; Bolton, S.
• Is Part Of: Geophysical research letters. Volume 44:Issue 10(2017)
• Page Start: 4513
• Page End: 4522
• Publication Date: 2017-05-25
• Subjects: Jupiter -- aurorae -- ionosphere; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL073156
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We present ground‐based observations of Jupiter's H3 + aurorae over four nights in April 2016 while the Juno spacecraft was monitoring the upstream interplanetary magnetic field. High‐precision maps of auroral H3 + densities, temperatures, and radiances reveal significant variabilities in those parameters, with regions of enhanced density and emission accompanied by reduced temperature. Juno magnetometer data, combined with solar wind propagation models, suggest that a shock may have impacted Jupiter in the days preceding the observation interval but that the solar wind was quiescent thereafter. Auroral H3 + temperatures reveal a downward temporal trend, consistent with a slowly cooling upper atmosphere, such as might follow a period of shock recovery. The brightest H3 + emissions are from the end of the period, 23 April. A lack of definitive signatures in the upstream interplanetary magnetic field lends supporting evidence to the possibility that this brightening event may have been driven by internal magnetospheric processes. Key Points: For the first time, Jupiter's auroral temperatures are mapped, while the upstream solar wind magnetic field is measured in situ Maps of northern and southern H3 + aurorae show significant variability in four observations spaced across 11 days Auroral H3 + intensifications are found to be dominated by density enhancements rather than temperature increases