Concurrent Jovian S‐Burst Beaming as Observed From LWA1, NDA, and Ukrainian Radio Telescopes.

This paper describes the statistical property of Jupiter's millisecond burst (S‐burst) beaming for Io‐related decametric (Io‐DAM) sources from a ground‐based radio telescope network. To do so, we performed simultaneous observations of Jovian Io‐DAM S‐bursts from 15 January through 4 May 2016 for a total of nine events using several radio telescopes. These radio telescopes include the Long Wavelength Array station One (LWA1) in the United States, Nançay Decameter Array (NDA) in France, and three large radio telescopes (UTR2, URAN2, and URAN3) in Ukraine. We conducted a cross‐correlation analysis of the S‐burst spectrograms in a frequency range of 10.5 to 33 MHz over effective baselines of up to 8,950 km. We found that the beaming of the S‐bursts is formed on the flashlight‐like structure within an east‐west beam width of 2.75" for Io‐A/C, 2.63" for Io‐A', and 2.75" for Io‐B/D. In parallel, the flashlight‐like beam was completely filled because the results from all usable pairs of telescopes supported this model. Hence, these beam widths directly correspond to the minimum cone thickness where a radio source emanates over large solid angles from the same direction of Jupiter, as opposed to a localized radio source emitting over small solid angles along active magnetic flux tubes that are tied to Io's orbital motion in Jupiter's rotation frame (beacon‐like structure). Additionally, this cross‐correlation technique shows a practical benefit of producing statistical profiles of S‐bursts. Plain Language Summary: In our solar system, Jupiter is second only to the Sun in its intensity as a radio source. One of the radio sources tied to Jovian auroras dominates at the decameter wavelength, exhibiting fine structures (called S‐bursts) in a timescale of milliseconds. While spacecraft equipped with a low‐frequency radio system is insufficient to capture S‐bursts in a broad frequency bandwidth and a long‐term period, Earth‐based radio telescopes offer high‐resolution observations of Jovian S‐bursts. Using five world‐class large radio telescopes in the United States, France, and Ukraine, we performed the common S‐burst observation campaign in 2016. We found that S‐burst beaming is wide enough to cover the maximum baseline of 8,950 km between radio telescopes in the United States and Ukraine. This result provides a nature of Jovian S‐burst beaming lasting on the order of the milliseconds. Key Points: S‐burst long baseline analysis was performed using five powerful radio telescopes on the groundStatistics of nine Io‐related events show that S‐burst beam is formed by a flashlight‐like beam structureThe cross‐correlation analysis can isolate the S‐burst frequency‐dependent distributions from those of the other emissions [ABSTRACT FROM AUTHOR]