The origins of patchy aurora at Jupiter

Auroral emissions play a critical role in coupling the magnetosphere and atmosphere at magnetized planets. At Jupiter, isolated auroral patches equatorward of the main auroral oval have been associated with magnetospheric injections, yet the key conditions driving these emissions remain unclear. Here we combine in situ particle and wave measurements and remote-sensing auroral observations from Juno to uncover the origins of Jupiter's patchy aurora. By examining both low-altitude and equatorial crossings, our results reveal that not all injections lead to auroral enhancements. Instead, auroral patches arise directly from electron precipitation driven by wave-particle interactions, while injections play a supportive role in facilitating wave growth and electron precipitation. These findings highlight the central role of plasma waves in auroral generation and in coupling Jupiter's magnetosphere and ionosphere, providing broader implications for wave-driven auroral processes across planetary magnetospheres.