Recent Science Results on Jupiter’s Atmosphere from the JunoCam Instrument

Abstract:

JunoCam, the visible imager on the Juno mission’s payload that was designed primarily for public-outreach purposes, continues to produce images of Jupiter’s cloud system at very high resolution that provide unexpected scientific benefits. Juno’s polar orbits continue to observe regions of the planet that have not previously been detected at such high resolution by any previous spacecraft. As originally described at the 2019 fall meeting of the AGU, work on the characterization of waves and wave-like cloud features has been published (Orton et al. 2020 JGR, doi 10.1029/2019JE006369). We will describe the results of quantifying the characteristics and likely origins of bright white compact (~50 km) clouds informally dubbed “pop-up” clouds by the JunoCam team. In concert with ground-based observations, particularly by the amateur community, we tracked the continued interactions of small anticyclonic ovals drawn into the counterclockwise circumferential flow around Jupiter’s Great Red Spot (GRS) and an interaction that draws off high-altitude reddish haze into strips (commonly called “flakes”) on its western edge. Continued observations of the constellations of compact circumpolar cyclones, with the northern group’s central cyclone increasingly illuminated by sunlight. Observations of the south-polar group yielded surprises, with the original unequally sided pentagon becoming a hexagon – with a cyclone filling in an open area, then a pentagon again over the course of 110 days (three close approaches of the spacecraft). In another collaboration with an amateur astronomer, Clyde Foster (S. Africa) we observed the morphology of an unexpected upwelling in late May of 2020, now known as “Clyde’s Spot” and, again in concert with a several ground-based observations, tracked its evolution. We also tracked ~40-50 m/s winds around the sinuous jet bounding the South Polar Hood, an upper-level haze generated by auroral-related chemistry. Other dynamical modeling of two-dimensional Euler fluids reveals similarities between the morphology of Jupiter’s cloud tops and simulated vorticity maps. Lightly processed and raw JunoCam data continue to be posted on the JunoCam webpage at https://missionjuno.swri.edu/junocam/processing. Citizen scientists download these images and upload their processed contributions.