Diurnal variation of spherics
- Hi all
With Spectrum Lab and crossed loops I've been monitoring the signal averaged across two 500Hz bands around 18.8kHz and 14.25kHz. These bands are largely free from transmitting stations, and it seems that they provide a good proxy for lighning activity as detected at my site.
The diurnal variation of signal strength in the bands (when averaged over a few days to smooth out 'local' thunderstorm activity) show three distinct peaks centred on 0600Z, 1200Z and 1700Z, and a minumum at 0200Z. These curves are very similar in shape with published curves for global thunderstorm activity. It seems I'm actually measuring quite distant activity - from RDF it looks like the peaks are due to storm activity in the Asian, African and American regions, respectively, and this is also consistent with the published data.
If anyone is interested, I can provide these plots. It would be nice to compare with similar data from other sites. I'm curious as to how representative the curves are of global activity, and how much influence the day and night propagation characteristics of the Earth-ionosphere waveguide has on the amplitude of the curve.
BTW I'm in Tasmania, Australia (43S, 147E).
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