A couple of posts back I wrote about Nature’s gifts, natural phenomena that sometimes augment the ordinary enough to defy belief. In that post I cited reflections, relatively ubiquitous phenomena that improve nearly every scene they touch. Toward the other end of the commonness continuum are auroras, colorful lights that dance randomly in the frigid darkness high above Earth’s extreme latitudes.
While everyone has seen reflections, many live their life without ever witnessing an aurora. For most of us, viewing an aurora requires travel at the absolute worst time of year for travel, and then venturing outdoors in the darkest, coldest hours of the day. And even then, there’s no guarantee of success. Some nights the aurora simply doesn’t show up, other (many) nights auroras perform their dance behind a curtain of clouds.
So what’s the deal?
Despite all appearances to the contrary, auroras aren’t magic. Our planet is continuously bombarded by solar energy; a narrow range of these wavelengths (infrared and visible) battles all the way through Earth’s atmosphere to the surface to warm our bodies and light our way. But other wavelengths in the solar wind interact with atmospheric molecules they encounter, stripping their electrons to create ions, which causes a charge imbalance in the atmosphere.
Instead of penetrating the atmosphere to generate havoc on Earth’s surface, most of these ions are intercepted by the magnetosphere, our planet’s protective magnetic shield. The magnetosphere is a teardrop-shaped barrier surrounding Earth—battered by the relentless solar bombardment, its sun-facing side is spread out and compressed to about 6 to 10 Earth radii thick, while the shielded side behind Earth (from the Sun’s perspective) is stretched up to 60 Earth radii into space behind us (beyond the Moon’s orbit).
As Earth rotates inside the magnetosphere, the daylight side at any given moment looks through the wide, compressed region, while the night side peers out toward the extended region. Particles ionized by the sun are pushed by the solar wind from the daylight side of the magnetosphere to the upper regions of the polar latitudes on Earth’s leeward (night) side.
The result of these atmospheric machinations is an accumulation of ionized molecules dancing high in the night sky, creating an atmospheric oval of geomagnetic activity that waxes and wanes with solar activity and the intensity of the solar wind.
The aurora’s color depends on the molecules involved, as well as their location in the magnetosphere. The most plentiful and frequently activated molecules vibrate in the green wavelengths, but reds and blues are possible as well, depending on the intensity and altitude of the activity.
Known colloquially as the northern or southern lights, and more technically the aurora borealis in the Northern Hemisphere and aurora australis in the Southern Hemisphere, to see them you need all of the above: the correct location on or near Earth’s surface, activity in the magnetosphere, and dark, clear skies.
As with terrestrial weather, great effort is taken to predict the aurora, but there’s no such thing as an aurora “sure thing”—the best we can do is put ourselves in position to be as close to the auroral oval on nights with the greatest chance for activity. Planning a winter trip to the high latitudes (the higher the better), like Iceland, is a good start—then just pray for an active sun and clear skies.
Another key to successful aurora chasing is access to and comprehension of the Kp- (or K-) index. The Kp-index is a 0-9 scale of atmospheric electromagnetic activity, with 0 being little or no activity (get some sleep), and 9 being the most extreme activity (don’t forget the sunglasses). Many governments and scientific organizations issue regular Kp forecasts that seem about as reliable as a weather forecast—pretty good, but far from perfect. There are many websites and smartphone apps that will provide you with up-to-date Kp forecasts for your current location—some will even issue alerts. On my iPhone I find the Aurora Pro app essential for both planning and real-time aurora chasing.
Last week, armed with all this aurora knowledge, loads of preparation, and a healthy dose of hope, Don Smith and I embarked on the first of this year’s back-to-back Iceland photo workshops ready for action. We’ve had pretty good luck in all of our previous visits, but are wise enough to Nature’s fickle ways not to be too cocky.
After having (what from all reports was) a beautiful display erased by clouds the workshop’s first night, we were blessed with a truly magnificent show at Kirkjufell the next night. Not only did the sky behind the mountain light up, the colorful lights careened about the sky in all directions. On our ride back to the hotel, Don and I agreed that this show rivaled the Glacier Lagoon aurora show on our first trip to Iceland that we considered the best we’d seen so far. The group was happy and life was good.
Departing Snaefellsnes Peninsula for Vik the next morning with a tremendously successful aurora shoot already in the bank, I thought to myself that wishing for anything more would be downright greedy. And since Vik lacks the really great north-facing views that are ideal for photographing the aurora, I wasn’t counting on another northern lights shoot that night.
Nevertheless, because the sky was clear and the aurora forecast was decent, after dinner in Vik we went aurora chasing anyway. Rather than opt for the more sure but mediocre north-facing view, we instead drove to Dyrhólaey, a coastline/ocean vista with nice views in all directions except north. Our rationale was that a truly great display can be viewed in any and all directions, and since we already had our northern lights success in the books, why not just go for broke?
Smart move. An aurora was already blasting so strongly when we arrived that we started photographing the instant we rolled off the bus and didn’t make it out of the parking lot for about 15 minutes. And while the previous night’s aurora display at Kirkjufell rivaled our best ever, this one easily topped it.
Once ensconced at the vista, we spent most of our time photographing westward, where the view up the coastline was the best available, and from where a persistent series of brilliant red and green beams radiated. Very much aware that the show was great in all directions, at one point I glanced southward, out over the Atlantic, and just had to photograph what I saw.
There really wasn’t a lot happening in the foreground, but a few small islands (more like large rocks) saved the day. I took several frames facing south, but chose the one I’m sharing today because it I find its beautiful angel wing shape truly unique.
After using my brand new Sony a7R V at Kirkjufell the previous night (it performed wonderfully), for this entire shoot I used my Sony a1. For both shoots, because the aurora spanned most of the sky, I shot almost exclusively with my Sony 12 – 24 f/2.8 GM lens at 12mm—and would have gone wider if I could have. With the aurora changing continuously, I shot wide open and used ISOs between 3200 and 6400 to keep my shutter speed at 10 seconds or faster. I’m thrilled with how clean these high ISO images were from both cameras, and won’t hesitate to use either one for any future aurora shoot.
Here are my answers to the two aurora questions I hear most frequently:
Absolutely stunning Gary! Love the angel wing and the way the stars shine through . . . I love all your aurora shots with reflections to boot! Hope the rest of your time in Iceland is equally amazing. Looking forward to shooting Death Valley with you!
A factoid that blew my mind was that the Northern Lights can extend 400 miles and more above the earth.
That’s crazy! Wow.
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