Fig. 8
From: A review of unusual VLF bursty-patches observed in Northern Finland for Earth, Planets and Space
‘Bird’ VLF bursty-patches observed at KAN. Power spectrum density at KAN on 19 January 2021 from a 09:00 to 13:00 UT (10:30–14:30 MLT) and from b 12:00 and 12:10 UT, between 0 and 12 kHz. Dashed and dotted horizontal white lines show, respectively, the local equatorial 0.5 fce and fce for the L-shell of KAN. ‘Bird’ VLF bursty-patches are observed in two distinct occasions from 09:05 to 10:15 UT between ~ 8.5 and 10 kHz and from 11:45 to 12:30 UT between ~ 9 and 10 kHz. These events show several bursts that have a distinctive cartoon bird shape. We also note some hiss-like VLF bursty-patches observed either between bursts or at the end of the events