Heating of Jupiter's Thermosphere by Dissipating Acoustic Waves

Thunderstorms in Jupiter's atmosphere are likely to be prodigious generators of acoustic waves, as are thunderstorms in Earth's atmosphere. The contribution of viscous heating to the thermal balance of the thermospheres of both planets by dissipating acoustic waves is largely unknown. Accordingly, we have used a numerical model to study the dissipation in Jupiter's thermosphere of upward propagating acoustic waves. Model simulations are performed for a range of wave periods and horizontal wavelengths believed to characterize these acoustic waves. Whereas dissipating gravity waves can cool the upper atmosphere through the effects of sensible heat flux divergence, it is found that acoustic waves mainly heat the thermosphere by viscous dissipation. Though the amplitudes and mechanical energy fluxes of acoustic waves are poorly constrained in Jupiter's atmosphere, our calculations suggest that dissipating acoustic waves can locally heat the thermosphere at a significant rate and might thereby account for the high temperatures of Jupiter's upper atmosphere.