The ever-changing planet. Atmospheric variations in the Jovian atmosphere as seen by radio observations with Juno and the VLA.

Abstract:

Radio observations by NASA's Juno/MWR, NRAO's Very Large Array (VLA), and the Atacama Large Millimeter Array (ALMA) capture thermal emission originating from the atmospheres of gas giants, modulated by the presence of trace gases in the atmosphere. By matching the observed radiation to atmospheric models in which we vary the distribution of trace gases, we can reconstruct the atmospheric structure in the probed region. The inversion of the data is based on disturbing a thermal equilibrium model for a given atmospheric temperature profile that calculates the mixing ratio of trace gases and their condensation pressures. We can reveal the underlying dynamics shaping the planet's troposphere based on how the structure of the atmosphere changes with time and location.

For this, we combine ground-based VLA observations with overlapping observations from the Juno spacecraft (December 2016, February 2017, February 2018, and December 2018) and present our best fit models to the radio observations. The combined VLA and Juno observations allows us to disentangle spatial from temporal variations and reveals a stable, well-mixed deep troposphere, a region characterized by mixing and above that a turbulent weather layer that is highly variable both temporally and spatially. Set by the 53-day orbit cadence of Juno, the repeated observations show evidence for long-lasting changes to cloud condensation affecting the typical Zone-Belt structure, tracing climatological changes seen in the visible deeper down into the planet.