Fig. 6From: ULF impulsive magnetic response at mid-latitudes to lightning activityThe correspondence between the temporal evolution of the impulsive background and SRS for the 10/04 during the time interval 18–24 LT (D component). The upper panels show hourly quasi-3D spectra in the range 0.1–6 Hz. The middle panels show the averaged spectra for the hourly intervals corresponding to the upper panel. The bottom panels show the superposed waveforms of all recorded impulses.Back to article page