When I started that piece, two weeks ago today, I had a simple conclusion I was going toward, but I kept wondering how many people understood the language we speak in the corner of the ham radio I world I'm talking about. Not just a word or two, like paper chaser, or grid square, but enough to follow what I'm saying.
Here's where I'm going.
A few months ago we had propagation or band openings that I honestly didn't expect. In much of March and April, I'd get guys in South America: Argentina, Brazil, Chile, Uruguay, and Paraguay for example, stronger than locals - very high signal to noise ratios - and all of them (including the very strong local guy) off the back of my beam. That means in principle, they'd be 25 dB stronger if I was pointing the antenna toward them, which would turn their 25 to 30 dB SNR to 50 to 55 dB (except the software can't measure that high an SNR).
Even better, those openings lasted a good long time. I'd hear those south American station for maybe an hour. One of my best catches in the period was a guy on the Falkland Islands off the SE tip of South America. I spent the better part of a half hour calling him to get a contact before he answered, and he was easy to copy for an hour.
March through April aren't considered months that have very good propagation so this was outstanding. The sporadic E (Es) propagation we expect to liven things up typically picks up as April turns to May and then Es is very good by the start of June and through July.
There's a website and utility called
PSKReporter that I
can use to show everything my station heard within some time period, from 15
minutes up to 24 hours. I made a comparison plot to show a friend two days,
April 29 and May 1st. Each and every red drop (think upside down drop) is a
different station. These plots were made around 8 or 9AM and represent a few hours out of the
previous day; the purpose was to show the day to day variation of what was
phenomenal coverage.
If you study the two you see interesting things like Monday had the Caribbean from Haiti through the Lesser Antilles, but Wednesday had none of that bunch. Conversely, Wednesday had western US states including Colorado, possibly Nebraska and over to Arizona and California, as well as several heard in Mexico and Guatemala while Monday didn't. So while they don't match exactly, they're similar in an overall sense. They don't match but they rhyme.
Considering I only expected things to get better, that's pretty mind-boggling. Only it didn't get better - it took a nose dive.
I use a different website to tell me what everyone else is hearing, a site in Spain called DXMaps. A plot from June 2nd can help me explain.
What I want to draw your attention to is that mess of red lines in the NE US.
Someone came up with the term "Red blob" and it's pretty descriptive. Every
one of the little boxes with call signs represent people reporting hearing or
contacting the other end of the red line (and some of the red lines don't have those boxes, but you need to look really zoomed in to see that). In that blob area, the red report
lines are so dense you can't even see the map underneath the lines. But notice
that the lines don't cross into Florida, except for one guy reporting (or
being reported by) a few stations in Texas.
For virtually all of June and the last week or two of May, I'd see a display like this on DXMaps and hear nothing in the blob or even from the overall direction of the blob. The vast majority of the time I'd hear or copy nothing except for one or two guys in peninsular Florida. Maybe within 50 to 100 miles, but rarely beyond the state line with Georgia or Alabama
Another thing that happens is that I'll finally copy someone from up in the blob area, or at least well beyond Florida and I'll copy one or two of their 15 second transmissions, meaning the opening was around 45 seconds long. With the FT8 mode, each side sends two 15 second transmissions and they're an exchange of information. That means the shortest possible contact is 60 seconds - once you both know you're there, so it's really closer to needing 90 seconds of opening than 60. More is always better.
Earlier this week, I had the station on earlier than usual (before noon) and I noticed the red contact traces were extending into Florida. I took that as a clue that maybe it would be better in the morning than the afternoon, and so far that has worked. In March and April, the band didn't really get open until 3PM or later, my time. For a while that seemed to be moving later in the day, now it seems to be moving earlier.
Putting all this together, this is supposed to be the best time of the year and it's the worst best time I can remember. It's the peak of the solar cycle, and while it's not a particularly good cycle, it's better than the last one. Most people think the peak of the solar cycle should be good for propagation, but that isn't the case for this year. I don't know what to expect going forward.
To me, this data shows how little we understand the world around us (here including the solar system).
ReplyDeleteIn many ways we are really just scratching the surface in physics, biology, and chemistry.
This is a great reason for humility, which many in those fields are lacking...
Jonathan
I don't want to say nobody understands it as well as they imply, but I sure don't.
DeleteI haven't done any research on the topic, but I do have a thought...
ReplyDeleteSolar activity usually reacts with the upper atmosphere to enhance the ability to bounce signals. But maybe stuff in the interplanetary environment that the earth routinely runs into also does that.
The strong solar storms of early May cleared out some of that stuff; and flare activity has been rather low lately. So these might combine to give lower-than-usual signal strengths.
I haven't heard others discuss how the interplanetary and interstellar environments can affect the earth - but it sure seems likely to be under-appreciated.
(While writing this comment, I read an interesting article related to the interstellar environment affecting the earth millions of years ago - published just last month. Not directly related to this, but shows that some surprising interactions are possible.
https://www.nature.com/articles/s41550-024-02279-8
)
I saw reference to that Nature Astronomy article somewhere else, but with no link, so thanks for that.
DeleteThere's been a lot of discussion of why propagation isn't as good as earlier in the solar cycle and the consensus is it's more than just since this spring and goes back a couple of years. It's generally thought to be solar cycle related, but not specifically to that big storm in early May or any other solar storm in particular - propagation has been below average since farther back in the solar cycle.
One issue is that there are different kinds of propagation involved and it's really difficult to know exactly how a radio signal you hear got to you. Back in January, for example, I contacted New Zealand and Australia on 6m. That's midwinter here and midsummer there. Midsummer is a time when sporadic E (Es) is much more common than midwinter but Es isn't capable of that long a distance without multiple bounces off the the ionosphere and the ground, so just how did it get here? There are known ways that a sporadic E patch will feed the radio signal up into the F-layer instead of back down to the ground, and its feasible it went from the E layer to the F layer on the way out of New Zealand and stayed in the F layer until my end. Or changed layers more than once in the several thousand mile route.
Lots of "could be" explanations without much ability to pin it down to a real cause and effect relationship.