Thanks, Iceland!

Very usefully, a number of WSPR stations have started operating permanently in Iceland over the past few weeks.  Iceland sits right under the typical edge of the auroral oval, allowing some interesting investigations of geomagnetic effects on propagation.

A couple of the stations do not hear so well for some reason.  Luckily, another two - TF4M and TF1A - are working efficiently and to a very similar level, allowing some fine scale changes across locations to be revealed.

Last evening provided a chance to see the effects of a G1 storm.

This was the magnetometer data from Kiruna:

Image courtesy IRF/Kiruna.

 And this is how my 1W at 14MHz was heard in Iceland:

Well, a clearer example of the effects of a deep southerly swing in the Z component could not be wished for!

You will notice that TF1A, who is a little further south than TF4M, suffers a stronger attenuation.  TF4M was probably located within the auroral region, whilst TF1A lies at its inner edge.  Perhaps that explains the difference.

Of course, this strong disruption of HF signals is not universal, and the results above only apply to the UK-Iceland path.  As I've previously reported, many geomagnetic disturbances lead to HF propagation enhancement for other paths, notably to the western half of the USA.

I was lucky enough to enjoy four nights of clear skies with aurora in TF-land in 2011, despite every daytime being completely rain-soaked!  The image below was taken just north of Selfoss (looking SSW, i.e. towards the edge of the auroral oval):

UPDATE.

I ran WSPR again on the following evening (24-25 July 2018), where the field was disturbed in a complex manner over most of the evening and all of the early morning.  Here was the situation at Kiruna:

And the reception of my signal at TF4M now looked like this, which is pretty much the inverse of the previous evening. 

Update (2)

Another run during the following, geomagnetically quiet evening (2018 July 25-26), reveals what's going on with the propagation.  As you can see below, with darkness now becoming deeper in very late July, normal ionospheric 14MHz propagation is shutting down in the later evening, with TF4M returning no spots from me until well into my local dawn period, where the sun, and not the aurora, allows ionospheric propagation to resume.  Yes, I did check TF4M was running all night!  He is currently running 24/7.

Clearly, and as previous academic studies have reported, active geomagnetic conditions give rise to auroral Es, which supports propagation at a higher frequency than would otherwise be the case (in this case, there is no quiet-state, night-time propagation to the station in question). 

In reading the paper, note how far things have come since the 1990s, and how much information the WSPR network potentially provides to us all.  It's a shame there are so few WSPR transceivers in the polar regions, though.  It seems to me that all research stations in the Arctic regions should have WSPR tranceiver capability, which poses little by way of resource implications or technical challenge, thanks to the simple antennas that are required.

The geomagnetic condition:

And, below, the spots issued by TF4M for my signal.  I think you can see the difference between a quiet and active geomagnetic field!  Note also the very large difference in SNR during early daylight, about 500 times weaker following active conditions, as compared to the morning after quiet conditions.