Fig. 2
From: Proton auroras during the transitional stage of substorm onset
THEMIS ASI keogram and MSP observations. Top panel of a shows the THEMIS ASI keogram constructed along the MSP scan line. The arc band is shown in orange dotted lines. The lower panel of a shows the ASI counts sampled and averaged over the arc band along the MSP scan line. In b, the upper and lower panels show the 557.7 green-line intensities and 486.1 nm proton auroral intensities, versus time and latitude. The arc band is also labeled. Two vertical dotted line throughout the plot denote T0 and T1, the TSSO intervals