Fig. 3
From: Proton auroras during the transitional stage of substorm onset
Comparison of electron aurora and proton aurora. Top panel reproduces the THEMIS ASI counts averaged over the arc band as shown in Fig. 2a. The 2nd panel and 3rd panel shows the green-line electron aurora and 486.1 nm proton aurora intensities, sampled and averaged at the same arc band. The scan time (30 s) of each MSP data point is marked by a horizontal bar. The bottom panel shows the proton auroral intensity integrated over the entire MSP latitudes. TSSO epochs T0 and T1 are marked by dotted lines