On Energy and Density of Jovian Lightning

Jovian lightning, first detected by Voyager 1 in 1979, has been extensively studied by missions like Galileo, Cassini, and Juno, revealing its occurrence in water clouds. We quantitatively compare Jovian lightning energies across radio, optical, and microwave spectra, highlighting their comparison with terrestrial lightning. Report on radiofrequency detections, such as Galileo probe measurements or whistlers observed by Voyager 1 suggested that Jovian lightning radiates significantly more energy than terrestrial lightning, with estimates ranging from hundreds of kilojoules to several gigajoules. These results can be, however, also interpreted as a high energy tail of a distribution similar to terrestrial lightning. Optical detections from spacecraft like Voyager, Galileo, and Juno reveal lightning energies spanning eight orders of magnitude, from $$10^5$$ to $$10^{13}$$ J, with a lognormal distribution similar to terrestrial lightning. Microwave observations by Juno’s MWR instrument detected weaker lightning signals, with energies between 1 and 1 kJ. Transient Luminous Events (TLEs), such as sprites or elves, have been observed on Jupiter, with ultraviolet energies estimated at $$10^9$$ J, far exceeding terrestrial counterparts. Lightning densities vary widely, with radio-based estimates up to 40 events/km $$^2$$ /year and optical measurements closer to 0.04 events/km $$^2$$ /year. This difference may be caused by attenuation of light in the clouds. Therefore, optical emissions would be substantially more intense compared to the terrestrial lightning while the radio emissions and lightning density would be comparable to Earth. These findings enhance the need for a better understanding of Jovian atmospheric electricity.