Simulations of Potential Radio Occultation Studies of Jupiter’s Atmosphere using the Juno Spacecraft

Abstract:

The potential extension of NASA’s Mission Juno could provide multiple opportunities to conduct radio occultation measurements of Jupiter’s upper atmosphere and ionosphere from 2023 through 2025. Using X-band and Ka-band signals, Juno would be able to provide both ionospheric electron density profiles and atmospheric temperature-pressure profiles down to altitudes with pressures up to 500 mbars. The potential occultations would cover a wide range of latitudes including the auroral regions of Jupiter, which have not been measured in previous missions. Occultations of the neutral atmosphere would provide additional reference temperatures for T-p profiles used in retrievals of data from the Juno Microwave Radiometer (MWR). Additionally, occultations of the auroral regions could verify previous MWR data that suggests the auroral zones have significantly higher electron densities than the non-auroral ionosphere. This study shows simulated occultations displaying the doppler shifts caused by ray bending in the atmosphere and ionosphere due to the refractive effects at X and Ka-band. Variation in signal intensity due to refractive defocusing, antenna mispointing and absorption from ammonia are also shown.

This work was supported by NASA Contract NNM06AA75C from the Marshall Space Flight Center supporting the Juno Mission Science team members at SwRI and Georgia Tech and under NASA contract NNN12AA01C supporting team members at the Jet Propulsion Laboratory, California Institute of Technology.