Stereoscopic observations of Jovian decametric radio arc s associated with ultraviolet auroras

Auroras in Jupiter’s polar regions show complex activity over a broad range of electromagnetic wavelengths. One of the auroral radio components, decametric radiation (DAM), dominates the frequency range from a few to 40 MHz and is produced at a frequency very close to the local electron cyclotron frequency. Since Juno first began detecting sporadic DAM arcs on May 5, 2016, during the approach to Jupiter, the DAM radio arcs have been monitored in a frequency range of 3.5 to 40.5 MHz by several observatories. These include Juno at Jupiter, Cassini at Saturn, STEREO A at 1 AU, WIND at Earth, and Earth-based radio observatories (Long Wavelength Array Station One (LWA1) in New Mexico, USA, and Nançay Decameter Array (NDA) in France). We have carried out a visual survey of the spectral data to identify concurrent DAM radio arcs, from May 5, 2016, through September, 2017 (Cassini’s end-of-mission). We found six events for which two or more observers clearly captured the same group of arcs. In one of the events on December 3, 2016, Juno first captured a group of the DAM arcs around 4:00 UT and two intense arcs were later recorded in NDA spectrograms at 6:30 and 7:45 UT. On the same day from 13:44 to 14:24 UT, the Hubble Space Telescope (HST) observed a bright auroral arc at ultraviolet wavelengths with an emitted power of 20 to 25 GW, suggesting a possible link to the concurrently observed DAM arcs. In this paper, we show results from the stereoscopic DAM radio observations and compare with the ultraviolet auroras captured by HST.