10 May 2024 Aurora

 I was browsing about the news sites when I came across this on the RTÉ.ie pages:-

US authorities have issued the first Severe (G4) Geomagnetic Storm Watch alert in almost 20 years as a powerful solar storm will hit Earth, with one enthusiast saying there's a "good chance" of seeing the Northern Lights in Ireland.

It is unusual for general news sites to carry anything which might be of any interest to radio amateurs or sky watchers. So this had to be something important. Further information could be found at VE3EN's Solarham had it not changed from Solarham.net to Solarham.com, which threw me off the track for a while - thanks to Mike GM3PPE for putting me right there. Anyway there were several big CMEs on the way towards Earth, and in a configuration which suggested that faster ones behind would merge with slower ones in front and produce a stronger effect here. And so it proved.

GM4PMK magnetometer on 10 May 2024

As usual click the image to enlarge if necessary.

I worked 22 stations during the aurora over the 24 hours after the first arrival of the particle stream. 21 were on 50MHz and one on 70MHz. All of them were on Q65 as I could not even attempt to use the microphone due to having the cold and 'flu. This activity covered 10 DXCC and 20 squares, with my best DX being to OE5OLL in JN68 at 1352km. I probably could have done more if I had been feeling better. I also spent some time between midnight and 02:00 local time out in the garden looking at the visual aurora.

50MHz auroral contacts at GM4FVM on 10 and 11 May 2024

All of these contacts were truly auroral with no tone audible, even the fairly close contact with Mike GM3PPE which is only 31km direct but a lot further via aurora. During the time I also had some very useful contacts with Dave, G0ODA on 432MHz and Gordon GM4OAS/M on 2m FM, but no aurora involved there! Having said that, there were reports of auroral contacts on 432MHz, so this was a very powerful event. I did not have 144MHz available at the time and it never even occurred to me to look at 70cm. Possibly a lifetime only chance missed there, but CW was beyond me at that stage.

One unusual feature was a fairly widespread Auroral Es opening across the Atlantic on 50MHz. I listened for about 30 minutes while others worked across the pond but nothing from there was heard here. I have often experienced Auroral Es during smaller openings, but I have never known of a trans Atlantic event.

The one Au contact I had on 70MHz was with G4BRK in IO91 (bringing the total square count to 21). This was my first Au contact on 4m using Q65. I was calling using the Q65-15C variant but Neil and I both noted how wide the signal was. Although many of us started out using Q65-15C during this event, most ended using 30C as it uses less bandwidth. I can see downsides to both approaches so some thought needs to be given as to which one we should use in future. Usually, decisions like this are made in amateur radio by somebody picking something and everybody following, whether that is right or wrong (like using 30 second periods for 2m MSK144 in Europe).

Anyway, this aurora brought a lot of activity much further South than we usually get, and it must have created new DX records for a lot of amateurs. It may well be a new Au DX record for me too. I must look it up.

I shall leave you with some photos I took of the visual aurora as seen from GM4FVM.

73 Jim

GM4FVM

Transatlantic on 6m, the "new normal" on 50MHz?

[Why do you keep writing about Sporadic E Jim?] 

Because there isn't anything else at present.

Not quite true, there have been several auroras. These events all have something in common - I missed them. I got back in on 2 May just in time to catch the last of a good aurora and on 50MHz I managed to work G8BCG in IO70, a distance of 623Km. This is a pretty good result on aurora for me as G8BCG is probably the furthest south I have worked on aurora in the UK. Sadly, I missed everything else in that event.

But it is true that I am not writing about big tropo openings on the higher bands because there have not been any. Maybe soon there will be. Other esoteric modes = zero.

So time to consider again the issue of transatlantic 6m propagation. This is not due to storms positioned 2000km apart across the ocean, as I have been reading recently. I shall stay away from further discussion of what the mechanism might be, other than a final guess.

Since my first transatlantic contact from here with VO1SO back on 18 June 2011, there have been 31 days when I have had 50MHz contacts across the North Atlantic. For this exercise I am excluding Mexico, the Caribbean, Central and South America - this is North Atlantic only. This was done in an attempt to screen out Trans Equatorial Propagation which is tricky to identify.

After that first contact I had to wait a week short of five years until the next one. Then there were two days in 2016, five days in 2017, six days in 2018, two days in 2019, five days in 2020, three days in 2021, none in 2022, and six in 2023. Plus one now in 2024.

There is one feature which applies to all 27 days of contacts across the North Atlantic up until the end of August 2023. All of the contacts in that period were during June, July or August. The earliest was 4 June and the latest was on 24 August. This shows the characteristic lag mentioned in the last posting for Es contacts in general, starting about 17 days before midsummer and ending 65 days after midsummer, making the lag about 7 weeks (see last posting). Not much data for this one so maybe that lag is a bit exaggerated.

What makes the last four contact dates unusual is that they fall way outside the usual pattern. The dates are 27 and 30 November 2023, 1 December 2023 and 1 May 2024. If I needed more evidence that the Es season is getting longer then here it is (if it is Es). Before this week my earliest QSO across the North Atlantic was 4 June. The latest one was 1 May. 

I only made two contacts that day, and I failed to confirm a third one (VE1SKY). There were several stations heard such as K1SIX, K7BV, K1KA, WW1L etc. The point here is that this was a substantial opening even if I only worked two stations.

50MHz contacts at GM4FVM on 1 May 2024.

So what propagation gives transatlantic 6m propagation on 1 May? Is that the same process as in November and December the previous year? When my previous contacts on this path have all been during the period from June to August, it makes me wonder.

Sporadic E which is vastly more sporadic than I have ever seen, or F-layer, or something else???

All the books say that Es is not influenced by the sunspot cycle, and I cannot really see how it could be. Surely not that.

73 Jim

GM4FVM