Left (a)–(d): Magnetic local time distribution of impulsive events per hour as recorded at selected AUTUMNX locations. Right (e)–(h): Distribution of magnitude of 8-min B_z ranges around identified impulsive events per 100 nT bin. Vertical scales vary between magnetometers to better convey diurnal trends. Total event numbers are indicated in bold gray for each magnetometer, with corrected geomagnetic latitude indicated in dark red indicated underneath. Blue shading indicates negative impulses, red shading positive.