Monday, 17 October 2016

Wishing Upon A Star

My love for radio began at an early age when I first started to tune the shortwave bands at age eleven. Little did I know then, that I was listening near the peak of the strongest solar cycle in recorded history, monster Cycle 19.

I thought that what I was hearing was normal for shortwave and that it would always be this way ... and it was, for a number of years.

As the solar cycle slowly declined, I began to take a deeper interest in propagation and its relationship with the Sun. After obtaining my licence and getting on the air, the reality set in with the arrival of a rather dismal Cycle 20. Following the vagaries of propagation became almost a hobby in itself, trying to correlate what I was observing with what the Sun was doing and even getting comfortable with predicting what might happen next.

It was particularly exciting during the stronger Cycles (21-23), to watch the dramatic effect of solar radiation on the F layer during the peak winter years of these cycles. With a major interest in 50MHz, watching the solar flux became a daily ritual, along with the fascinating daily rise of the F2 MUF as the Sun peaked over the horizon.

On normal mornings, around sunrise, the MUF would typically start close to 28MHz and slowly begin to rise over the next few hours. Often it would slow and settle-in between 38 and 42MHz, stay there for most of the day and then slowly recede as darkness approached.

I found myself looking forward to and wishing for more solar flares, along with the solar flux boost that inevitably followed.

On these mornings, the MUF would often be at 35MHz or higher, right at sunrise ... and begin climbing. Some days it would shoot-up like a rocket and in a matter of minutes would be at 50MHz or above, bringing thundering signals from the east coast not long after dawn. On other mornings it would climb much more slowly, receding and then advancing again, surging higher and then lower, as it teased its way towards the magicband. It was as if the ionosphere was a living breathing entity, as the solar radiation danced a slow tango with the critical frequency of the moment. Often it would stop at around 48 or 49MHz, stay there for several hours and then collapse ... no 6m excitement that day.

A nice bonus of watching this live interaction between the Sun and our ionosphere, was listening to the communications in the range between 28MHz and 50MHz as I followed the rising MUF. This was, and still is to a lesser extent, utilized on FM by paramedics, fire and police services throughout the U.S. It was not uncommon to hear mobile units enroute to an emergency, with sirens blazing in the background. Southern drawls usually meant that any 6m openings would begin in the southern states or the Caribbean, while Boston or New York accents, would herald an opening to New England or the possibility of trans-Atlantic openings to Africa or Europe. I became even more familiar with the daily interaction of the solar wind and how it affected radio ... and found it fascinating.

But just as the Sun affects propagation so positively, I was recently soberly reminded of how 'unfriendly' it can be ... as it has been in the past and will be again in the future. An article in this month's 'Astronomy', by Bob Berman, discussed threats to global welfare and in particular, a modern day repeat of the Carrington Event of 1859.

This was a double mega-flare and CME, taking only 19 hours to reach earth, compared to the normal 3-day trip. It was the strongest impact on earth ever recorded and one that will be repeated ... and is almost, statistically 'overdue', unless we dodged it in 2012 when a storm of similar magnitude missed the earth.

In Berman's words:

"What would a Carrington-level event do today, with our ubiquitous power lines, transformers, and more than a thousand operational satellites? In 2008, the U.S. government convened a panel of experts, who concluded that such a storm would completely destroy our electric grid. It would require two to 10 years to repair and cost about $2 trillion. We'd be knocked back to the stone age.
That panel panel called Carrington a "low frequency/high consequence" event - the kind humans typically ignore until it happens."

We quickly release how dependent on the hydro system we have become, when our power goes out for a few hours or even a day or two, following a severe weather event. Such an event is certainly 'inconvenient' but soon forgotten when the power returns. Going without power, and its trickle-down effects on our depended-upon infrastructures for several months or longer, would not be just 'inconvenient'. It would be a life-altering.

The Carrington event happened during Cycle 10, on the upward climb to the peak of an average-sized cycle. Solar scientists, for the most part, now predict a general decrease in solar activity over the next few cycles ... a spotless sun may become more the norm. Perhaps it is a good thing that the likelihood of a mega-flare event will be reduced but it seems that a repeat, at some point, is inevitable.

Maybe I'd better stop wishing for flares.