Fig. 4From: Simultaneous ground-based optical and SuperDARN observations of the shock aurora at MLT noonGreen line emissions of the shock aurora at 557.7 nm observed at YRS station on 7 January 2005. Auroral sequence images were shown with cadence of 30 s during 09:22:00–09:30:30 UT. A MLAT-MLT coordinate grid was plotted in each frame. SI onset is marked by the black arrow in the first rowBack to article page