Comparing Northern Alberta to Coastal BC on Longwave

For five consecutive nights last week I made observations of six NDBs. The methodology was a refinement of that used for my December post on the same subject. This time the raw data came from two NDBs in Alberta and four along the BC coast. Each carrier was sampled every 5 seconds from 0000z to 1600z and then for each frequency 120 consecutive linearized values were averaged to smooth the data with advice from Nick Hall-Patch on the best way to do this based on his medium wave work. Here is the result from the first night for all six stations...

As expected, all of the signal levels rise rapidly at dusk when the entire path is in darkness and they fade back into the noise at dawn. The apparent 20-minute periodicity is presumed to be an artifact of the 10-minute averaging. For completeness, here are the other four nights...

Since the four stations on the BC coast are clustered fairly close to the longitude of my receiver location in grid CN88, I expected their curves to have some commonality not shared by the two Alberta stations to the east of here so I averaged the two groups into two separate curves for each night...

Seeing no reason to believe that spatially grouping the signal sources was of any value, I looked at how individual beacon signals behaved from night to night...

I see no source of profound geophysical insight from the above but at least they confirm some basic DXing wisdom. "Listen, listen, listen." For example, if I had tuned for 368 Sandspit BC on the 23rd at 1200 I might have concluded that it could not be heard here but checking back at 1345 would have shown it to be putting in a decent signal. Even returning at 1200 on any of the following nights would have found it to be 7 to 15 dB stronger.

This next graph simply averages each of the above signals over the five nights...

In my logbook I noted that the A index was at 19 on 2019-01-25 at 1505 due to a recent brief period of active conditions in the middle of this study so I produced these to graphs to see if any one day was significantly different from the others...

If the event did have any effect over these paths it's buried in the noise but this might be interesting to do again during a major geomagnetic storm, if there are enough NDBs left on the air by then.