WHY OUR SUN'S RELAXING MAGNETIC FIELD REALLY ISN'T A BAD THING FOR YELLOWKNIFE
With the rise of trendy, Pinterest style blogs writing about all the cutest cupcake recipes and your wanderlust desires including seeing the northern lights (you can bring cute cupcakes if you want to), the hundreds (of thousands) of them often get you with click bait article titles. You know, the 'See the Northern Lights Before They Disappear for a Decade' titles. Well, those of course, are not quite true.
"What's going to happen is the aurora will retreat North to where it usually is, but be there more regularly, more routinely. Everybody in the North will see the northern lights more frequently at solar minimum."
- Prof. Eric Donovan, Univ. of Calgary
The northern lights aren't going anywhere
EXCEPT TO BEING BACK OVERHEAD OF YELLOWKNIFE MORE CONSISTENTLY
Here's what all these brand new space weather expects, who also bake delicious cupcakes, are leaving out. The sun goes through roughly 11 year sunspot cycles, and at the height of this cycle - solar maximum - the sun's surface is peppered with sometimes hundreds of sunspots, which can cause solar flares, and if we're lucky, coronal mass ejections along with them. Coronal mass ejections are often responsible for increased geomagnetic activity on earth, which is, very often, what brings the aurora down to southern latitudes. But more on this in a second.
During solar minimum, the sun has very few sunspots, and sometimes none at all, as we have seen a few times in the last year even. Without sunspots, the sun cannot release any solar flares or coronal mass ejections - which actually keeps the northern lights more closely around the polar regions, which helps explain why during solar minimum, people at southern latitudes would take notice of seeing the northern lights much less. Yellowknife, however, at 68°N geomagnetically is within a single degree of sitting directly underneath the centre of the auroral oval on nights of the most average auroral activity.
WITH STRONG GEOMAGNETIC STORMING, THE AURORAL OVAL PUSHES SOUTH
While a lot of the time this means the auroral oval merely expands over Yellowknife, it can in more extreme circumstances, leave Yellowknife (very temporarily) altogether.
What you're seeing in the image at the right (or below on mobile, thank you very much, responsive web design) is our view from Yellowknife looking south during a night of intense geomagnetic storming. Much, much further south, the aurora in these moments would be appearing as right overhead or much higher on the northern horizon - which makes the northern lights, in these circumstances, visible from places like Calgary, like Vancouver, the states of Minnesota, North Dakota etc.
"The normal solar wind will not disappear and coronal holes will still be present from time to time ...The aurora will always appear at locations close to the auroral oval."
So, if you're wishing to continue to watch the northern lights from your backyard in the northern United States on a regular basis, solar minimum should be of concern to you. If you're hoping to get right underneath them, and are considering travelling north to somewhere like Yellowknife, solar minimum is as perfect a time as ever. Maybe even better.