Prospects for observing atmospheric gravity waves in Jupiter’s thermosphere using emission

We propose the use of H 3 + thermal emission as a tracer for wave activity present in Jupiter’s ionosphere. We model the effect of atmospheric gravity waves on the ion distribution and the H 3 + thermal emission using a two-dimensional time-dependent model of the wave–ion interaction including ion dynamics, diffusion and chemistry. The model is applied to a broad range of wave parameters to investigate the sensitivity of the observations to the wave amplitude, wavelength, period, and direction of propagation for different latitudes and magnetic field orientations. We find that the impact on the H 3 + emission is optimized for waves with large vertical and horizontal wavelengths that achieve maximum amplitude at or near the hight of maximum H 3 + density (roughly 550 km above the 1 bar pressure level). Larger effect is expected from waves with larger amplitudes. Waves that travel in north/south direction are easier to detect than waves propagating zonally. The model also predicts that the largest signal is to come from waves present at middle latitudes. alysis shows that atmospheric gravity waves with parameters consistent with the Galileo Probe observations can leave observable signatures in the H 3 + thermal emission at 3.4 μm resulting in 5–23% emission variation along the horizontal path of the wave.