High-Spatiotemporal Resolution Observations of Jupiter Lightning-Induced Radio Pulses Associated With Sferics and Thunderstorms
Abstract
Jupiter lightning discharges produce various kinds of phenomena including radio wave pulses at different frequencies. On 6 April 2019, the Juno Waves instrument captured an extraordinary series of radio pulses at frequencies below 150kHz on timescales of submilliseconds.
Quasi-simultaneous multi-instrument data show that the locations of their magnetic footprints are very close to the locations of ultrahigh frequency (UHF) sferics recorded by the Juno MWR instrument. Hubble Space Telescope images show that the signature of active convection includes cloud-free clearings, in addition to the convective towers and deep water clouds that were also recognized in previous spacecraft observations of lightning source regions.
Furthermore, the detections of 17 very low frequency/low-frequency (VLF/LF) radio pulses suggest a minimum duration of lightning processes on the order of submilliseconds. These observations provide new constraints on the physical properties of Jupiter lightning.
Plain Language Summary Jupiter lightning illuminates clouds and produces a strong pulse at radio wavelengths. Juno's radio observatory (consisting of two onboard instruments) in a broad radio range made several detections of extraordinary radio pulses on 6 April 2019.
The high-temporal observations of such radio pulses detected below 150kHz indicate variations of the lightning related processes on the order of submilliseconds. Observations of these radio pulses and direct lightning-induced radio emissions at 600MHz come from the same area, very close to deep water clouds detected by the Hubble Space Telescope (HST) in the Jovian atmosphere.
The coordinated Juno-HST lightning observations provide a new way of understanding the lightning processes and lightning source regions associated with the cloud features at Jupiter.