Van Allen Probes EMFISIS Waves
Spooky Whistlers 2013-10-23

The Van Allen Probes B EMFISIS Waves instruments detected these signals with three orthogonal magnetic antennas (Bu, Bv, Bw) during UTC hour 00 (the witching hour) of October 23, 2013. This is a set of five different six-second intervals concatenated together. The featured signal is high-dispersion whistlers, generated by lightning discharges in the atmosphere and then "streatched" by propagating along magnetic field lines through sufficient space plasma to slow down the lowest frequencies into an ominous drawn-out bass rumble. (Just in time for Halloween!)

The animation shows a frequency-time spectrogram of the data with a moving cursor that indicates the time position of the audio track.