By Dave Jensen, W7DGJ

The Sun's activities can either be beneficial to our interests or completely disruptive. Let's compare the current (and quite pleasant) Cycle 25 to what is recalled about Cycle 10 and the effects of one solar storm on our planet. I certainly hope we will never again experience a Cycle 10, but it is certainly within the realm of possibility that we will. And, in fact, one may be timed to come along soon.

The Sun has a huge impact on the airwaves -- as we have all experienced. If you've been a ham for awhile, no doubt you've hammered away on a favorite frequency during other sunspot cycles and were happy to have QSO'd across a few States. Sure, radio was still fun -- even then. But wow, how cool it is to be riding the wave of a good sunspot cycle. Lots of new QRP radios come out in these good times, because it doesn't take a kilowatt and a half to cover the globe. Experts may disagree on where exactly we are now, but most say that we'll see the peak of Cycle 25 this year. I'm personally pleased to have been around to ride that wave.

10 meters has been a blast, hasn't it?

Sunspots Point to Good Times - They Don't Have an Impact Themselves

I always thought it was the sunspots that created a more reflective F layer in our ionosphere, allowing HF radio signals to travel further. But I've learned that it is a lot trickier than that . . . Sunspots themselves aren't directly causing this improved propagation. Instead, they point to increased solar activity -- flares and coronal mass ejections, UV and X Ray radiation. This provides us with a "solar wind" that is the key to these effects in our ionosphere. The charged particles (ions and electrons) in these solar winds enables the ionosphere to bend or reflect radio waves, allowing long-distance communication by bouncing signals back to Earth beyond the line of sight. 

While periods of a high number of sunspots show us that our ionosphere has become more charged, it can also point to impending solar storms which -- on the other hand -- can cause huge disruptions. These storms can lead to complete radio blackouts or wild, unexpected changes in propagation.

As an example, let's talk about the big one. This "big one" came in Cycle 10 and was called the Carrington Event. It was quite a phenomenon and it took place on September 1st, 1859. In that year we had so little electric/electronic infrastructure that the effects were far less than the damage we would see today. Still, the effects of the Carrington Event on Morse Code operators working their telegraphs was surely mysterious at the time.

The Carrington Event

Richard Carrington, a British amateur Physicist and Astronomer, loved to monitor the sunspot cycle, and it was in Cycle 10 when he sat at his telescope remarking to his wife that he had just seen an amazing flare on the surface of the sun.

Carrington quickly grabbed his drawing tools and paper and set about replicating what he had seen. It was the single largest flare-up and bigger than anything he thought was possible on the surface of the Sun. He suspected that there would be a "sun-terrestrial connection" and 17 hours later he was proven right.

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The entire sky lit up with the aurora in Kingston, Jamaica. People all over the USA were awakened by the bright light thinking that morning was on its way. Miners working in the gold fields of Australia wrote, "We saw a great reflection in the southern heavens and in about half an hour, a scene of almost unspeakable beauty presented itself. Lights of every imaginable color were issuing from the heavens, one color fading away only to give place to another if possible more beautiful than the last, the streams mounting to the zenith. It was a sight never to be forgotten."

Things were not so rosy In telegraph offices. The huge amount of ionization in the atmosphere caused fires to ignite along telegraph lines; many offices had small fires as their telegraph paper caught fire. As these offices all ran on battery power, it was amazing to some operators that they could completely disconnect their power source and still maintain a connection via Morse Code as the solar storm left such a significant charge on their wires that they didn't need batteries.

In one Boston-to-Portland connection, the Morse operator in Boston told his Maine colleague to disconnect from batteries completely. "My current is very strong at times, and we can work better without the batteries, as the aurora seems to neutralize and augment our batteries alternately, making current too strong at times for our relay magnets. Suppose we work without batteries while we are affected by this trouble."

Could it Happen Again?

Moving forward a century or two and you'd find an event like this could be tragic. In fact, the circumstances we might face have been foreshadowed by earlier solar storms -- nothing of the intensity of the Carrington Event, but nonetheless they have shown us what can happen if solar storms of this magnitude hit our modern day electronics.

During the height of the Cold War, there was a sudden blackout in radio communications due to a large solar flare. It was May 23, 1967, and unfortunately the USA thought that this blackout (which extended across the NORAD region and into Great Britain) was the result of a Russian radio jamming attempt and pending nuclear attack. Bombers were loaded and missiles readied before astronomers relayed news of the solar flare at the last minute to the government. 

The Vietnam war was especially fierce in August of 1972 and just a few years from ending . . . At this time, a solar flare caused a number of magnetic sea mines off the coast of Vietnam to explode on their own, which must have been very unnerving for anyone in the vicinity. Even worse, the geomagnetic disturbance interfered with instruments used by the USA military to detect nuclear detonations. For some reason, the level of solar winds caused these devices to indicate that a nuclear bomb had been detonated. It's quite scary to think of the implications of this kind of disruption!

Let's Keep Our Fingers Crossed

I love a good sunspot cycle. I'd love to hear in the discussion forum if you think that Cycle 25 has met the hype (you know, from the ARRL and other ham radio columns) or if you think it was just kind of average. As I said, I enjoyed what it did to 10 meters, but I wasn't overly impressed with the other effects. I'd say it is a good one, but perhaps not as life-changing as it was hyped up to be. If you feel differently, let me know in the discussion forum that is attached at the bottom. But, let's all keep our fingers crossed that the pleasant rate of our Sun's activities never crosses the line again into the radiation that occurred during the Carrington Event.

Lloyd's of London did a study as to the economic effects of a Carrington-level event on just the USA, and found that it would hit our economy with a cost of $774 billion to $3.35 trillion. As you might imagine, satellites would malfunction in such a storm and, without access to an atomic clock for precise timings, mobile networks would cease to work. Without connections to satellites, scientists would struggle to monitor the phenomenon and we would, for a time, be literally in the dark. Even hams might be off the air in such a phenomenon. 

VY 73 for now,

Dave W7DGJ

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