Mapping Jupiter's Mischief

Abstract

AbstractNew results (Grassi et al., 2020, https://doi.org/10.1029/2019JE006206) from analysis of Juno Jovian Infrared Auroral Mapper (JIRAM) 4‐ to 5‐μm observations provide updated latitudinal abundance profiles and measurements of the spatial distribution of H2O, NH3, PH3, GeH4, and AsH3 in Jupiter's troposphere near the 3‐ to 5‐bar level. The observed compositional variations provide new constraints on processes shaping chemical abundances in the cloud‐forming region of the troposphere, including vertical and horizontal atmospheric mixing, meteorology and cloud formation, transport‐induced quenching, and photochemistry. Along with recent results from the Juno Microwave Radiometer (MWR) for NH3 and H2O abundances far below the clouds, the JIRAM measurements of key disequilibrium tracer species can also be used to explore the coupled dynamics, chemistry, and bulk composition of Jupiter's deep atmosphere. The heavy element abundance inventory on Jupiter is a key constraint for the development and assessment of giant planet formation models. Combined with prior ground‐based, spacecraft, and in situ observations, the Juno results suggest near‐uniform (∼2–4 times) enhancements over protosolar abundances for several heavy elements in Jupiter's atmosphere, giving new clues about the composition of the material accreted, the timing and location of formation, and the internal evolution of Jupiter over the history of the solar system.