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Murphy's Law: Anything that can go wrong, will go wrong.
Finagle's Law: Anything that can go wrong, will—at the worst possible moment.
Ralf's Laws of Observational Astronomy: There are never clouds in the sky unless the setup is complete.
Have you ever noticed that it is often clear during our meeting nights at the Ontario Science Centre? The Universe is having a laugh.
At the last meeting (on January 8) at the Ontario Science Centre, I sat beside Bill. You know, SuperGenius. He was trying to twist my arm to ride shotgun and watch for 'coons while he chased the elusive aurora borealis. Eh? While I had heard about a big Earthbound coronal mass ejection from an X-class solar flare and the anticipated category G3 geomagnetic storm, I was not really prepared to leap.
Didn't have my long johns on! So Bill started pitching Stu. He was keen. Stu in turn recommended a spot in Port Perry. I promised to keep in touch and let them know my plans. But I would go home first. We kept an eye on Bill's iPhone, monitoring the KP index estimates (around 3) and Clear Sky Charts (partly clear).
KP index, from 0 to 9, is a planetary value based on a weighted average of K-indices from a network of observatories. The K-index is a quasi-logarithmic measurement in the disturbance in the Earth's magnetic field. The KP index is often estimated since there is a delay receiving data from some observatories. The higher the value, the more the mag field is being rattled by the Sun. Three and below is considered quiet; above 4 is considered intense. And a strong KP usually means aurora is visible.
By the way, the Jan 8 category G3 storm prediction would have meant a KP index of 7!
The next question then becomes: where? That is, from what latitude will the aurora be visible? Everyone knows that, generally, the further north you go, the better the chances you'll see the "northern lights."
Light pollution issues aside, generally the auroral oval does not appear at middle or low latitudes.
Once home, I hopped on the interwebs and tried to accumulate some good data. What was the sky going to be like, in terms of cloud cover? How intense was the auroral activity, what was the past and predicted KP index? And how low did it go, that is, was the aurora in mid- or lower-Ontario?
In short order, I had about a dozen or so web sites open. Some old favourites like spaceweather.com and the Aurora Sky Station. I was particularly interested in the tools provided by the National Oceanic and Atmospheric Administration, some of which I had consulted before.
Got myself into the Space Weather Prediction Center resources, reviewed the Auroral Map, the Solar X-ray Flux chart, and the familiar Estimated Planetary K index histogram. But then I found something new...
I was looking at a realistic top-down representation of the planet, as if I were floating over the north pole. Countries and regions outlined, it showed the lit sun-ward side of the planet and shadow opposite, reminding me of sun-clocks.
It was clearly adjusted for the season, with most of Nunavut and Greenland in darkness. A mystical fuzzy green ring floated around the north pole. The legend at the bottom left of the display showed colour chips to help one gauge the probability of visibility. There was also a thin red arc called the View Line slicing through the Canadian provinces. It updated automatically two times a minute. Wow.
Updated link:
http://www.swpc.noaa.gov/ovation/
The OVATION Aurora tool appears to be new. It is clearly marked as a "Test Product." The description notes the "Auroral Forecast product is based on the OVATION Prime model which provides a 30-40 minute forecast on the location and probability of auroral displays for both the northern and southern polar regions." So, with this new tool at hand, I made the call. There was a 50% chance of seeing aurora on this evening. But it was not extending very far south. The View Line hovered around Hudson's Bay. I was not going to drive there tonight.
Sadly, Stu's early morning report echoed the prediction.
I hope you have better luck aurora spotting!
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