Fig. 21From: A new five-wavelength photometer operated in Tromsø (69.6°N, 19.2°E)Spectra of normalized amplitude for the five emissions (20 Hz data) between 02:12:00 UT and 02:24:00 UT on January 23, 2018. The horizontal dashed lines denote the 99% significance level. The vertical dotted lines denote oscillations of 1/16.74 Hz (i.e., period being 16.74 s)Back to article page