The Seven Year Twitch

Strongest solar surge in seven years

The Sun’s recent eruption of activity was crowned yesterday by a robust M-class solar flare that could trigger a significant auroral response in regions north of Earth’s 40th parallel before sunrise

Solar activity is definitely on the upswing after a sustained lull that had some experts wondering whether there would be an appreciable maximum to the current solar cycle. Activity is now expected to intensify over the next six to nine months before dropping off through 2013.

X-Ray output from the Sun’s latest flare:

The sunspot that gave birth to the M-9 flare is now rotating into a position more directly facing our planet, so any pronounced outbursts that occur over the next few days will carry increased potential for radio disruptions and even possible electrical overloads on Earth.

On the plus side, Northern Lights (aurora borealis) could be quite impressive given clear skies at northerly latitudes. The risk of serious consequences from this M-9 flare (such as power outages, damage to satellites or even to ground-based electrical equipment, etc.) is low because the Sun’s most active zone is a good distance from its equator. Still, any time that energetic sunspots rotate into view (especially ones with severely twisted magnetic fields) a reasonable degree of caution is warranted.

The great solar storm of March 1989 knocked out most of Québec’s power grid — and a second round of massive explosions on the surface of the Sun in August of that year brought down various electrical systems in Ontario.

In 1859, the then-recently completed US telegraph network was severely damaged by a solar storm, the intensity of which can only be estimated today. Aurorae were so vivid that people in northern regions were fooled into thinking that morning had arrived. It’s impossible to say precisely how strong a flare it was, but it’s assumed that the disruption to our ionosphere was so profound because the sunspot cluster that spawned the event was directly facing us, casting a massive amount of ionised coronal material from the surface of the Sun squarely in our direction.

Of course, yesterday’s almost-X-class flare could be described as mild when compared with this doozy (below) from November 4, 2003. That flare occurred during a series of eruptions from the Sun that week, some of which are still the strongest solar flares ever recorded with modern instruments. In fact, the week-long storm was so powerful that a new section had to be added to the top of the graph in order to accommodate it. Luckily, much of the output from the storm was not Earth-directed. Had it been, it might have rivaled or surpassed the one that occurred in 1859 — and would surely have had a much more serious impact today due to our reliance on electronic gadgets and upon electricity in general.

The energy of the flare in the chart above appears to be no more than X-20, but it’s widely agreed that the source data from the GOES satellites were clipped at the top end; the interim consensus rendered a verdict of X-28 with some maintaining that it may have been as high as X-32. Later analysis of the series of explosions led NASA to judge the strength of a flare from October 28th as a whopping X-45. It should be pointed out that, until then, NASA scientists thought that they’d probably never see an X-10. For more on the violent spasm of 2003, see the Smithsonian’s Chandra X-Ray Observatory newsletter, March 2004.

There’s increasing speculation about whether we will see anything close to the magnitude of the November 2003 flares (or the 1859 aurorae) during the next year, but only the Sun can say for sure. And Sol just ain’t talkin’.

Making these sorts of predictions is notoriously… well, unpredictable. The 2003 x-28 mega-flare came at a point in the solar cycle when activity should have been quite low — coming, as it did, more than two years after the solar peak of 2001. So, we’ll just have to wait and see.

Best guess? We’ll probably be discussing this again. Maybe soon…

Follow’s coverage



JANUARY 24, 2012 · 11:30 PM

The Earth’s ionosphere is still highly energised from a hit that it received courtesy of an earlier, weaker, flare that triggered our January 23rd geomagnetic storm. Technically, that storm is still continuing. It was the product of a more direct encounter with a solar coronal mass ejection (CME).

It’s actually fortunate that the stronger of the two flares did not occur first; the Earth’s pre-energised ionosphere was thereby strengthened against the effects of the subsequent event. It’s also lucky that the main body of the mass jettisoned by the second flare appears to have missed our planet by about 60 million miles.

Note: These charts are also available with a black background.


Brilliant displays were sporadically visible in North America’s western arctic region, as well as in eastern Siberia, during the early morning hours Tuesday.

But the real show occurred over northeastern Canada, the northern UK and especially Norway (right) on Tuesday night.

Video of the grand display

Some amazing stills, too!



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