The Aurora Cycle: When and Where to Witness the Northern Lights
While there’s a certain mystical quality behind Alaska’s awe-inspiring Aurora Borealis, the Northern Lights form great bands of incredible illumination that actually have much more to do with magnetism than with magic. And believe it or not, their activity is even (perhaps surprisingly) fairly predictable.
First, you need to understand the science behind lights themselves. The Northern Lights phenomenon is created when the Earth’s magnetosphere is disrupted by the sun’s powerful winds and massive eruptions, creating geomagnetic “storms” that send atoms, electrons and protons dancing and smashing togethter, ramping up radiation, and turning oxygen and nitrogen molecules into bursts of bright light. These vibrant and changing lights can groove on for minutes or even for hours. They appear as disparate dancing bands or big flowing blankets, spanning the color spectrum from often-seen greens and yellows to the really rare reds. And the Northern Lights can appear crazy close to you (about 50 miles above Earth) or feel far, far away (200-plus miles).
But what about the science and circumstance of predicting aurora sightings? In the late 1800’s, scientists started recognizing patterns in the appearances of these amazing lights. They noted that the lights most often showed up in what is known as the “auroral zone”, about 3-6 degrees wide in latitude and about 10-20 degrees from the geomagnetic North Pole. That location range makes Alaska prime time aurora country, especially in the 65-70 degrees north latitudes. Fairbanks, Alaska is an aurora hot spot at 64 degrees north while the more remote communities north of there, from Coldfoot (67 degrees north) to North Slope towns of Prudhoe Bay (70 degrees north) and Utqiagvik/Barrow (71 degrees north), can be even better.
After honing in on the auroral zone, scientists also started recognizing that the sun had its own patterns of solar energy activity. In fact, there’s an 11-year solar cycle in which the sun’s energy flaring crests and wanes. So, basically, when the sun’s energy is peaking, so is aurora activity. When the sun is somber, the opportunities for aurora sightings get slimmer. The last peak of the solar cycle came in 2014, which means the next peak should arrive in 2025. But that doesn’t mean you can’t find an amazing aurora display any year, including this year! The sun also has a reliable routine of revolving around its axis every 27-28 days. That can mean that if a great aurora display appears on a certain night, there are good odds it will be replicated 27-28 days later due to sunspots and sun positioning.
The University of Alaska Fairbanks’ Geophysical Institute is the aurora authority for Alaska. It notes that the window to see the best aurora displays is between 9 p.m. and 3 a.m., though the closer to midnight the better. Its data also indicates that aurora activity over Interior Alaska is stronger at the equinox, and that, combined with usually clearer skies during Alaska’s spring, makes February to early April the best months to see the lights. Of course, there are also less scientific factors that can increase the likelihood of finding the lights. One phase of the phenomenon that’s easy to predict: they are a lot easier to see when it’s dark outside. In fact, aurora activity takes place year-round in Alaska, but it’s tough to tell when sky is bright all summer. So that means the best months to see the northern lights in Alaska are late August to April when the Midnight Sun takes its seasonal nap and daylight hours decrease.
And you don’t need a Ph.D. in solar sciences to become an accomplished Northern Lights chaser. Some decent wi-fi will do just fine. There are numerous websites (the aforementioned UAF Geophysical Institute’s site is among the best), social media pages and smartphone apps hosted by professionals and amateurs in aurora viewing, that employ satellites, charts, weather patterns, sun cycles and comments sections to help aurora hunters increase their odds of finding the lights. There are also professional guides that specialize in northern lights tours. And upon request, some Alaska hotels will alert their guests if the aurora starts rocking.
Even on the darkest of winter nights, it helps to get out of urban areas to see the Northern Lights. Manmade, ambient city lights can dull or even obscure an otherwise vibrant display of aurora borealis. And even if the northern lights forecast calls for heavy aurora action, it won’t matter if the sky is filled with clouds that can all but block this fabulous light show.
One misconception about the Northern Lights is that they only come out when it’s cold. Not true. Many have lucked out on a warm fall night in the Interior, wearing a T-shirt and shorts while watching the lights dance in a dusky sky.
Ultimately, however, there’s no such thing as a sure thing when it comes to predicting and finding aurora borealis. It is a prediction, after all, so there’s a little luck involved. That said, the science of the lights and the other factors listed above can certainly increase – or decrease – the likelihood of finding these awe-inspiring lights when they come to life on a dark Alaska night.