November 14, 2004

Wondering when to look up? Ask the web!

Last week, the night sky over North America (and elsewhere) put on a pretty spectacular show of Northern Lights. I was lucky to have them pointed out to me during the second major wave on Nov. 9, but I missed the apparently more impressive Nov. 7 display.


Determined not to miss them again, I scoured the web for information. I was not disappointed. You can't predict the Northern Lights with full certainty, of course, but the following sites will improve your odds.

"Meta" sites (sites that collect, (re-)analyze, display, etc. original data and information)

  • My first find was a personal website: Aurora Sentry. The site collects a bunch of interesting information and has links that I eventually followed to other useful sites. If you're looking for a quick visual fix on auroral activity, this is a good place to start. Graphical data from CANOPUS, the NOAA, and are displayed on the home page.
  • The second site I came across was, which is sponsored by NASA. This site seems to be updated fairly frequently with a fairly novice-friendly textual analysis of what's going on up above. There's information on the sun's activity down the left side, and the site covers non-auroral events as well.
  • I'm a little less clear on the nature of this site, but Solar Terrestrial Dispatch tracks a lot of similar data. One of the original products of this site is the Visible Auroral Oval, which "estimates the VISIBILITY of auroral activity from any location in the northern hemisphere, assuming a dark moonless sky and low light pollution." This site also has the Auroral Activity Observation Network, which really came alive with sighting postings during the recent activity. You can even buy some "advanced auroral activity and space weather monitoring software"

"Original data" sites (the "heavies"):

  • If, like me, you live in Canada, you'll be interested in, a contribution from Natural Resources Canada and the Canadian Space Agency. Their basic forecast is pretty simplistic, but if you start scouring around you can find more detailed information (e.g. their station-by-station review/forecast graph.)
  • The National Oceanic and Atmospheric Administration (NOAA) in the U.S. seems to provide a lot of the data that other sites rely on for their analysis. In particular, the NOAA's Space Environment Centre has everything from satellite-derived auroral oval maps to an aurora calculator. The calculator tells you how to cross-reference the planetary Kp index, a measure of geomagnetic activity over a 3-hour period, against your location. The further south you go, the higher the Kp needed to see the aurora borealis in your neck of the woods. The NOAA has a three-day plot of the estimated planetary Kp index.
  • Finally, there's the aforementioned CANOPUS program, funded by the Canadian Space Agency. CANOPUS has heaps of data, including its own auroral oval graphic.

So you're armed with more data than you know what to do with. Now what? Well, if you think a sighting is likely, check the weather, head somewhere dark, and look up!'s sky clocks are a pretty handy visual aid for hour-by-hour visibility forecasting.

Finally, if you're like me and you missed the best of the recent Aurora Borealis in and around Ottawa, check out these amazing photos taken by Roy Hooper at Gatineau Park. Incidentally, cameras are apparently more sensitive than our eyes to the aurora, so consider snapping a few photos to see what you get, even with a fairly quiet display of the Northern Lights.

Posted by anatole at November 14, 2004 05:00 PM

Do you know Roy, or did that turn up in a web-search, too? He was a friend of mine back when I was in Ottawa ... we ran a BBS together :)

Posted by: beltzner at November 16, 2004 03:10 AM

Crazy small world. Roy came up in a web search too. :) He has some really nice photographs on his site. Are you still in touch?

Posted by: Anatole at November 16, 2004 11:33 AM

Mike and I don't keep in touch as well as we should.

Posted by: Roy at November 17, 2004 11:26 PM