Saturn’s auroral processes: insights from the Cassini Grand Finale

Saturn’s auroral emissions display a variety of features reflecting different regions of the magnetosphere. The ‘main’ aurora is usually dominated by a dawn arc mapping to outer, closed field lines. It can be complemented by arcs and spots, sometimes pulsating, at high latitudes, likely occurring on field lines open to the solar wind. Diffuse patches or arcs are also detected at lower latitudes corresponding to particles precipitating from the inner regions. The dawn arc itself has a highly variable intensity and structure, modulated by rotating features and storm-like expansions. We review Saturn’s auroral features and the driving mechanisms in light of the measurements made during the high latitude, low altitude Grand Finale orbits. We focus on the intensity and position variability observed on small spatial scales and how the underlying mechanisms can contribute to the global magnetospheric dynamics.