Can you feel the aurora?

Aurora, seen from my QTH, 2015 October 07

As we await a G2 geomagnetic storm in the next few hours,  this recent research output is worth thinking about:

https://www.sciencedaily.com/releases/2019/03/190321083637.htm

Kp between 5 and 7 expected tonight (23/03/19).  Image: http://www.aurora-service.eu/aurora-school/all-about-the-kp-index/

More geomagnetic anomalies!

Last evening saw the onset of what was predicted to reach G1 geomagnetic conditions.  Unfortunately, things didn't get quite that rough, but a nice disturbance did take place, as shown below:

Image: IRF/Kiruna

At 19:26UT, N1ECP in Maine was the last station I heard on 14MHz WSPR.  I was actually watching the screen at the time, and the waterfall became quite dead, with not even much by way of partial traces appearing. I did notice the occasional strong WSPR signal burst (looking like a meteor scatter signal at VHF) that lasted only three of four seconds, followed by a natural 'whooshing' noise.

Aurora visibility at 23:30UT.  Image: NOAA.

At 21:14UT, 8P9HA appeared and, over the coming few minutes built up to -20dB SNR/2500Hz.

Shortly thereafter, HC6PE appeared.  He built up to a remarkable -08dB SNR/2500Hz at 22:10UT.  Keep in mind the geometry of his station and mine, relative to the sunlit atmosphere, no part of which has been visible from Wales at this point for maybe 2 hours or so:

Path to HC6PE and terminator at 22:10UT, 2018 December 01.  Image with permission, DX Atlas.

My RX spots at the times relevant to this post.

Not only this, but you will note that WC2S - all the way from Los Angeles - makes an appearance, if only just, at -29dB SNR/2500Hz, at 22:32UT.

Even more intriguingly,  K6MCS appears shortly thereafter, but only briefly.  You may recall this post concerning K6MCS making an identical sort of appearance in early January this year.

The paths are interesting to consider.  The model for the aurora shows a small patch further to the south in the Atlantic than the main oval.  These appear regularly, so they don't seem to be artefacts of the model, though that is a possibility that needs checking out with NOAA.  If this patch is real, it might indicate a limited area that could have facilitated propagation to HC6PE.

The path for K6MCS seems to go through dense regions of the aurora.  Clearly, with so many (as of this morning, 300) WSPR stations active on 14MHz, there remains something to explain about how that station seems to make a regular appearance under disturbed conditions.

As always, any ideas welcome under comments!

The curious case of...ZL/K6KWI

WSPR always throws up something unexpected.  Last night, it was a New Zealand station (with the great callsign of ZL/K6KWI - indicating Neil's Kiwi origins) at 14MHz, throwing out a very high, 50W signal.

The strange thing was that I was the only station who heard him around that time (18:20UT) outisde the US and Antarctica, despite the very high output.  Oddly, though it appears on the map, I can find no reference at all to the HB9 spot in the WSPR database, either in TX or RX in relation to Neil's station:

The terminator is correct for the time of the spot.  I am not sure as to the path taken, as ZL is very near the precise antipodean point to the UK, and the geometry of the greyline seems to make either (or both) paths just as likely.  I tend to think it was a path involving antipodean focusing, which was just about enough to enhance the signal to detection limits (I heard him at -26dB).

I didn't hear Neil again until 06:52UT this morning, where a few other stations in Europe were also now hearing him.

Certainly something to look out for in coming days, if the very high winds of up to 130km/h over the next 24 hours permit!