Studying the dynamics of Jupiter using a 3D general circulation model constrained by radio occultation measurements

The shallow layers of the Jovian atmosphere, the only regions accessible to direct investigation through in situ sampling and remote sensing experiments, are the looking glass through which the unknowns of the dynamical structure are revealed. Radio occultation measurements have proved to be a key factor in the study of planetary atmospheres’ thermal structure, dynamics and composition.
During both the extended Juno mission and the upcoming JUICE mission to Jupiter, an unprecedented number of radio occultations are planned to be performed, reaching to a depth of up to 2 bar, with much broader spatial coverage than previously performed. These experiments could be used to better understand the physical properties and dynamics of Jupiter’s atmosphere, not only at the upper cloud level region (~1 bar) but also much deeper (down to 1000s bars), by using these measurements as constraints to general circulation models (GCMs) that simulate the flow on the gaseous planet.

Here, we develop a 3D general circulation model for the dynamical region of Jupiter, driven by a Newtonian cooling scheme with temperature fields derived either from the observed winds (thermal wind balance) or by using in-situ temperature measurements from the Cassini mission’s CIRS or TEXES instruments. The model is used to reproduce the dynamics of Jupiter at the upper levels (mainly the zonal jets) while allowing the dynamics to evolve freely below the cloud level. When the radio occultation experiments will be available for analysis, they could replace or be added to the above thermal profiles used to force the GCM. Combining radio occultations with dynamical modeling of the Jovian atmosphere, will lead to a twofold improvement of the understanding of the structure of the atmosphere at the cloud level and the deep atmospheric dynamics.