Fig. 4From: Eastward-expanding auroral surges observed in the post-midnight sector during a multiple-onset substormMagnetic variations observed at TRO and ABK. Magnetic variations in the X, Y, and Z components observed from 23:50 to 00:45 UT (from 01:05 to 02:45 MLT) on March 8–9, 2013. Vertical dashed-dotted lines show the start and end times of the magnetic variations associated with the EEASs, determined by visual inspection. The dashed lines are the same as those in Fig. 2 Back to article page