A Mild Rant: Not Everything is a Carrington Event

Larry Lambert over Virtual Mirage, one of the more eclectic minds you'll come across in the blogosphere, led us to a post on American Thinker called, "Dodging the Apocalypse" about the recent geomagnetic storms and the apparently truly Epic Coronal Mass Ejection that led to the storm.  Credit where due, the first person I saw writing about this event was the Come and Make It blog.  

The article is by a regular writer there, J.R. Dunn, and while I'm going to do my best to cut him slack, he really triggered me.  The biggest thing is tying this CME to the Carrington Event in 1859, which I've written about a half dozen times before.  For the uninitiated, the Carrington Event was a massive solar geomagnetic storm that happened around the start of the widespread use of electricity.  Widespread electric power was still a half-century away, but the telegraph had led to long wires being used to communicate by what we now call On Off Keying or OOK.  The disruptions to the geomagnetic field around Earth caused open telegraph keys to spark, insulators on poles to arc over, started fires and more. 

The event was witnessed in real time by British astronomer Richard Christopher Carrington.

"Two patches of intensely bright and white light broke out," he later wrote. Carrington puzzled over the flashes. "My first impression was that by some chance a ray of light had penetrated a hole in the screen attached to the object-glass," he explained, given that "the brilliancy was fully equal to that of direct sun-light."

Note that these flashes were so much brighter than the projected image of the sun in his dark room that he thought daylight was somehow getting into the room.  The story itself is amazing.  That evening, when the Coronal Mass Ejection hit, telegraph operators were able to run without batteries; the flare-induced voltages on their wires working better than batteries.  The aurora display was global, even in the deep tropics. 

The American Thinker article quotes "experts" saying the March 13th CME was "was ten to a hundred times more powerful than the one of 1859."  My immediate problem with that is how do we know that number?  The 1859 event happened only one time in human history and it happened in a time when instruments today's experts would use didn't exist.  There are other things that have been attributed to massive Carrington-like storm but the problem of no measurement is compounded by no observers, and the most remote-sounding observations imaginable.  To quote from this blog in 2012 about an increase in Carbon 14 levels being attributed to a Carrington-like storm in the year 774 AD, 

There are a couple of known mechanisms for creating C14 in the atmosphere, one is a massive solar flare.  774 AD was 600 years or so before the first telescopes were used, so there was no Carrington to be watching.

So when a college student from UC-SD found a record of a “red crucifix” in the skies over Britain in that year, Nature published his note.

I've never heard of anyone saying there was a crucifix of any color in the skies back in 1859.  

We've seen this kind of hype more recently.  Back in November of  2003, toward the end of cycle 23, there was a super flare that was genuinely scary and the kind of flare to worry about.  The biggest flare seen since the satellite age started, it was classed as X28 in retrospect - only because it saturated the X-ray detectors on the satellites and they couldn't measure it properly.  Why didn't it harm us? Because it was on the limb of the sun and the CME went 90 degrees to our direction.  So not only does this extremely rare event need to happen, but it has to be pointed at Earth - basically perfectly centered on the sun from where we view.  It's important to remember that during the peak days of cycle 23 we were getting X-class flares a few times every month, and the grid was fine, wasn't it?

I haven't seen anyone say that last week's CME came with an X-class flare or put a number like that X28 on it, but that would be interesting to find out. 

Probably the most obviously wrong thing he said was “We do know that we have two more years before the current solar cycle tops out, and so far, this has been one of the most intense on record.” The best answer to show just how wrong that is to show this plot of just the five most current solar cycles from Solen.info.

The current cycle, 25, is at the bottom left in kind of a brown or olive drab color and ending at 32 "Months after cycle start."  It can be seen that it's higher than the previous cycle (in pink) at pretty much every point and it's currently stronger than cycle 24 was at this point.  It's just that being better than cycle 24 isn't really saying anything impressive.  Cycle 24 was the weakest cycle in the last hundred years.  Cycle 25 is predicted to be stronger than 24 but might not even equal the next stronger cycle, 23.  It obviously isn't cycle 23 level yet (23 is red).  Where he says, “...so far, this has been one of the most intense on record,” it has actually been one of the weakest on record.

This chart, by the way, doesn't include the strongest cycle since the 1780s, cycle 19 from the late 1950s.

It's almost guaranteed that someday there will be something like a Carrington Event again, we just don't and can't know when.  When something has happened once in recorded history, it's hard to assign a periodicity to it.  If that observation about the 774 AD CME is correct, does the 1085 years between them mean anything to predictions?  I don't think we can just say it's a thousand year cycle.  To say a massive CME has something to do with solar cycles isn't much of a reach, given what we know from observing hundreds or thousands of solar flares and CMEs and knowing those track with solar cycles.  

I know alarmism sells but I find it exhausting.  I try to bound problems to give me some feel for how likely some problem is.  In the case of the CME it's not just that probability there's also the probability of it being optimally placed on the sun to do the most damage.  Is that two degrees of solar longitude?  Five degrees?  The probability of independent things like this get multiplied.  If the chance of a big enough CME to cause a disaster is 1 in 100 years and the probability of it being in the right place on the sun is 1 in 180 (two degrees longitude), the probability of both is 1/100 * 1/180, or .0000555 (55.5*10^-6).