I'll tell the tale of a Northern trail, and so help me God, it's true.
I'll tell of the howling wilderness and the haggard Arctic heights,
Of a reckless vow that I made, and how I staked the Northern Lights.
— Robert W. Service, "The Ballad of the Northern Lights"
"Will man ever decipher the characters which the Aurora Borealis draws in fire on the dark sky?" Sophus Tromholt wrote in 1885. "Will his eye ever penetrate the mysteries of Creation which are hidden behind this dazzling drapery of color and light?"
Tromholt, a Danish teacher and physicist, was perhaps the first scientist paid to ponder the northern lights. More than a century after his passing, his question is still valid.
Scientists now have tools Tromholt never imagined:
• Satellites so numerous it is difficult to glimpse a still patch of sky;
• Navy-surplus missiles arcing measuring devices through the auroral zone a hundred miles above our heads; and
• Low-frequency microphones that can hear the aurora's voice.
Using those instruments and others, we have learned a few basic facts about the aurora borealis. Among them is that it is a gift from the sun, one that appears almost every dark night if you live in Fort Yukon, or somewhere else near the Arctic Circle.
Auroras appear above Earth at all times as the sun continually spews a solar wind that takes two or three days to cover the 92 million miles to Earth. That breath flows over Earth like a stream curls around a rock. As it licks the planet, the solar wind's particles react with our magnetic field, causing electric power that is the fuel of the aurora.
Why some green, some red?
The aurora's most common form is a pale green halo around the northern and southern ends of the earth. That's why you can see the aurora on almost every dark, clear night in extreme northern places, and why designers of aurora observatories in Fairbanks face their picture windows north. The aurora has other predictable shapes, from blobs that flash on and off to the splash of corona that gives a view from directly under the curtain to the climactic substorm that explodes several times a night. Though scientists have devoted decades to the study of the aurora, some, such as 85-year-old Syun-Ichi Akasofu of the University of Alaska Fairbanks, admit there's more to learn than the sum of what we have discovered.
The electrical discharge created by the solar wind's collisions with reactive atoms clinging to Earth is visible because it is close. Green auroras happen about 60 miles overhead. As the discharge from the solar wind reacts with gases, in this case oxygen, it causes them to glow like a neon light. Akasofu, an aurora expert who was born in Japan but has lived most of his life in Fairbanks, once suggested using auroras as a detector of life on distant planets. He figures that since green and red auroras above Earth occur because plants are exhaling oxygen, auroras above other planets may indicate the same thing.
Red auroras occur much higher than the common green aurora, more than 200 miles overhead. Red auroral displays happen so high they are the only form of aurora seen at the mid-latitudes. Many people observe tinges of red on the fringe of aurora curtains and even more cameras show them. However, the true experience, one you are lucky if you see, is a blood-red sky.
A great red aurora is born of a solar flare — an incredible explosion on the sun — propelled in the direction of Earth by the solar wind. Red auroras are unpredictable, but in the past they have tended to bunch themselves around periods when the solar cycle — an 11-year period of sun activity — features a lot of solar flares.
True red auroras have happened in 1839, 1938 (seen as far south as the Sahara Desert), 1989, 2000 and — as experienced by the photographers responsible for this book — in 2001.
We now gain comfort in explanation, but until scientists acquired the instruments to confirm their intuitions, imagination was the rule.
The Inuit of Labrador, Canada, believed the aurora to be the light from torches of spirits illuminating a pathway to heaven for souls of people "who have died a voluntary or violent death," according to anthropologist Ernest Hawkes, who published an account in 1916.
A story collected by Danish explorer Knud Rasmussen, during an expedition from Greenland to the Pacific from 1921 to 1924, also describes the northern lights as a pathway to the heavens: "Here, (spirits) are constantly playing ball, the Eskimos' favourite game, laughing and singing, and the ball they play with is the skull of a walrus."
Scientists have tried to make sense of reports of people hearing a hiss during a display but have failed to come up with an explanation. Alaska researcher Tom Hallinan, who has heard it himself, said his logical mind had trouble reconciling the sound with the fact that the thin air of the ionosphere — home to auroras — can't carry sound waves. Even if the auroras were buzzing up there, because of delays caused by the speed of sound, the hiss would require several minutes to travel to Earth. Hallinan said the voice of the aurora was "scientifically unreasonable," but the space physicist admitted he was a believer.
But then, our ears are dull instruments. In the 2,000 acres of woods surrounding the University of Alaska Fairbanks, there are sensitive microphones attached to plastic tubes that fan like a spider's legs along the ground. Researchers installed a half-dozen of these systems to detect the low-frequency hum of various disturbances to the atmosphere, the 30-mile shell of gases necessary to keep us alive. Funding came from government agencies interested in detecting nuclear explosions from far away. The scientists found their infrasound microphones recorded other things too, such as the rumble of surf in the Gulf of Alaska 500 miles away, belches of volcanoes and — to their surprise — electronic squiggles on a graph that correspond to a ripping aurora. So, there is proof the aurora is whispering a sound that woolly mammoths — which, like elephants, probably had the ability to hear extremely low frequencies — might have heard as they stomped the North during the last ice age.
Before aurora forecasts
Daryl Pederson and Calvin Hall know the feeling of discovery that kept the turn-of-the-century drift miner hacking at frozen gravel through the dark winter: If one keeps at it, there is always a chance a thumb-size nugget will show. In the photographers' case, if they subject themselves to enough nights of silent devotion and cold discomfort, the aurora will reward them with a spontaneous composition different from the others. Since the aurora borealis occurs most often as a halo over the North Pole, the closer one gets to the top of the world, the higher the probability of photographing it — and the better chance of feeling a cold powerful enough to sap batteries and nip fingers.
Longtime residents of the zone of great aurora viewing know the price these men have paid to capture the aurora on plastic film and wafer-stored pixels. Both men's careers extend back to the days before aurora forecasts and cloud-free probabilities appeared on pocket devices.
Pederson remembers at first convincing a few friends to join him on frigid hilltops after he'd slugged a Red Bull at 11 p.m. He had enthusiastic takers early on, but almost no one repeated the experience. Most of his aurora expeditions have been solitary endeavors, as they have been for Hall.
Although the two men have been friends sharing a unique bond over the years, they have almost never worked together. But they feel now as if they are standing side-by-side, tripods clinging to frozen ground, as they talk on mobile phones, each sharing updates on aurora activity at his chosen location.
Pederson figures that he misses capturing a great aurora image nine out of every 10 attempts. But 10 percent is pretty good, he figures, especially when the effort rewards him like it did a November night long ago. He pulled on his parka and ventured from his Girdwood home late at night to see the snow glowing red. The hills reflected one of those auroras that made his heart beat as if he was a hunter hearing twigs snap at the approach of a bull moose.
Up on a hillside above Turnagain Arm, Pederson shot for an hour in a state he describes as "stunned" before clouds began obscuring his subject. He then packed his gear and drove an arc around Cook Inlet to the tiny town of Hope. There, he found the perfect spot. A faint moon provided definition for his foreground — snow crystals twinkling like a field of rubies. He felt the thrill of thumbing his cable shutter, knowing he was capturing something new and majestic. Looking toward the lights of Anchorage, Alaska's largest city just across Turnagain Arm, he thought of the thousands sleeping through the magic.
Hope clouded over five minutes later. Thinking of his day job that would commence in a few hours, Pederson drove home. There, he took a hot shower and pondered his magical night. As dawn lit his living room window, he by habit looked upward. The aurora was still active, mixing with the first scattered rays of dawn. He ran out on his deck wearing only a towel. There, he shot for 20 minutes until the morning light quenched the display. His hair had frozen into a helmet, but he had the rarest of prizes on his rolls of film, along with the delicious anticipation that accompanied the wait for development. He remembers that November night of 2001 as his "walk-off grand slam."
Pink vapors
That same unusual night, Hall was also out in pursuit, a bit farther north than his friend. He remembers the hint that this evening would be different — the fog created by the vapors of an unfrozen river seemed to be glowing pink.
As the night progressed, the red aurora revealed itself, painting the sky much farther south than usual. With shooting locations stored in his mind's eye, Hall remembered the Matanuska Glacier. He'd long hoped to shoot there, but it took a robust display to show itself that far southward. He knew this might be his night, so he drove to the glacier overlook on the Glenn Highway and witnessed the grand finale of the aurora night of the century.
He fired away until daylight. Like Pederson, he remembers the aurora that resulted from that solar storm as his best ever.
"The range of colors I saw in that time was the most amazing of my career. There was a partial moon, then the twilight coming in from the eastern sky, and that combination created an ever-changing sky, from rich reds and blues and greens and orange to light pastels of blues and pink and green and yellow in continually changing shapes and shades."
In addition to capturing images they might sell, both photographers have gained much more from their aurora hunting — an appreciation for the beautiful, harsh place they live in and the creatures that share all those unpeopled acres.
Remembering a night he was alone on a ridgetop, Hall swears coyotes on a neighboring ridge howled just as a big auroral display flared up. As the aurora awakened at 3 a.m., the coyotes sang again, this time from Hall's ridgetop.
"I could hear them take a breath between howls."
Pederson, too, appreciates the feeling of unity aurora chasing has given him. He remembers standing in his bunny boots to begin a night of patience on the shore of Cook Inlet. There, his heart skipped a beat as a beluga whale exploded a breath of fishy air into the night. The sonic eruption was perhaps 50 feet away, but seemed closer. As the aurora showed itself and he framed his composition, Pederson imagined smiling white whales sharing the black night, invisibly chasing salmon below the same surface that reflected a ballet of aquamarine light from the heavens.
Copyright 2015 "The Northern Lights", Sasquatch Books. Used with permission. Ned Rozell is a science writer for the Geophysical Institute at the University of Alaska Fairbanks and the author of four books. Daryl Pederson, an Anchorage-based nature and studio photographer, has been creating images of the northern lights for more than 30 years. Calvin Hall is a Palmer-based photographer. His work includes time-lapse 3-D for IMAX and National Geographic movies, underwater salmon video and commercial work for the Alaska Railroad, Google and others.