Fig. 7
From: A review of unusual VLF bursty-patches observed in Northern Finland for Earth, Planets and Space
S-shaped VLF bursty-patches observed at KAN. Power spectrum density at KAN on 03 February 2021 from 09:00 to 13:00 UT (10:30–14:30 MLT) between 0 and 13 kHz. Dashed and dotted horizontal white lines show, respectively, the local equatorial 0.5 fce and fce for the L-shell of KAN. S-shaped quasi-periodic VLF bursty-patches are observed in multiple groups above 8 kHz from ~ 09:15 UT to 11:20 UT. Each group is indicated by magenta arrows for easier identification. These emissions are characterized by smaller periodic groups of several S-shaped bursts