Abstract/Summary

Jupiter's polar aurorae deliver significant heating at the poles, thought to spread across the planet through atmospheric winds. Additionally, ground-based Keck observations have revealed a large-scale high-temperature region, spatially distinct from the aurorae. Here, we investigate the origins and characteristics of the feature using Keck data, in-situ Juno spacecraft measurements, and solar wind modeling. Juno exited the magnetosphere on approach to Jupiter, coinciding with modeled high-speed solar wind impact that compressed the magnetosphere. This hot feature may be dynamic, transported equatorward by winds following auroral activity enhancements from magnetospheric compression akin to a large-scale traveling ionospheric disturbance on Earth, or driven by the inner magnetosphere particle precipitation. Exploring the dynamic case, we calculated equatorward velocities ranging from 0.46 to 2.02 km, similar to those seen at Earth. Our study underscores the importance of the solar wind at all planets, exemplified by its ability to alter Jupiter's upper-atmospheric energy balance globally.