14MHz ground wave at night.

An interesting phenomenon recently has been the near-continuous reception of my daughter's WSPR beacon by G0LUJ throughout the night time, when propagation via the ionosphere has died completely.

Although my daughter's elevated vertical and my own are identical in every way, G0LUJ does not generally hear my beacon.  This is probably due to slightly higher ground to my NE, whereas the alternative, marsh site is flat all the way around.

I thought it may be interesting to plot the strength of the WSPR signal heard by G0LUJ, to see if it conformed to any discernible pattern.

SNR of MW6PYS as heard at G0LUJ (RX antenna/site details not published)

The fairly sharp peak around 22:15UT coincides nicely with a significant, brief disturbance in the geomagnetic field to Kp=5.  The second, broader peak towards dawn looks like the the early dawn effect.

This is quite interesting, because the first peak probably reveals the extent of a weak but definite propagation enhancement. 

It seems the ground wave, steadily received at around -27dB is 'overtaken' by modest and transient ionospheric propagation due to the geomagnetic disturbance, increasing the received signal strength by 8dB (or 6 times the ground wave signal strength) at peak.