Green curtains of light ripple over glowing teepees, and the whole sky seems to reflect in the lake below. Korean astrophotographer Kwon O Chul made these northern lights photographs near Yellowknife, the capital of Canada's Northwest Territories and one of the best places on Earth to watch the aurora borealis.
Yellowknife, a northern lights capital
Yellowknife sits on the northern shore of Great Slave Lake, about 400 kilometres south of the Arctic Circle. It was founded in 1934 after gold was found nearby, became the capital of the Northwest Territories in 1967 and has around 20,000 people. The city takes its name from the Yellowknives Dene; in the Tłı̨chǫ (Dogrib) language it is Sǫǫ̀mbak'è, "where the money is".
For aurora watchers, geography is everything. The region lies beneath the auroral oval, the ring around the magnetic pole where the lights appear most often, and its flat land far from the ocean usually means clear skies.
Aurora Village and its lit teepees
Several of Kwon O Chul's photographs were taken at Aurora Village, a popular viewing site outside Yellowknife. Its lit teepees give the pictures their warm orange points beneath the green sky, and they show how vast the display is: a tiny human structure under a sky full of light.
The other striking frames use water. A calm lake doubles the aurora, so the light fills both the top and bottom of the image. Watch the same kind of display in motion in the Aurora Substorm recording, which its creator presents as real-time video, and in our companion video feature.
For another way of photographing the whole sky, see Vincent Brady’s panoramic setup, and for a journey made just to see the lights, read about Ben Pierce’s Alaska trip.
What makes the northern lights glow
The aurora begins with the Sun. Energy carried by the solar wind is transferred into Earth's magnetic field, and electrons are accelerated along the field lines towards the polar regions. High in the atmosphere they collide with oxygen and nitrogen atoms and molecules, exciting them; as these return to their normal state, they release light. NOAA's Space Weather Prediction Center explains the process in its aurora tutorial.
The colour depends on which gas is glowing and at what height. The familiar green of Kwon O Chul's photographs comes from oxygen, the most common auroral colour.
Tips for photographing the aurora
- Use a tripod and long exposures. A camera gathers far more light than the eye, which is why photographs often look brighter than the naked-eye view.
- Find a foreground. Teepees, trees or people give the sky a sense of scale.
- Look for still water. A calm lake or pond doubles the display.
- Check the forecast. NOAA's Space Weather Prediction Center publishes aurora forecasts, and clear, dark skies matter as much as solar activity.
Sources
- My Modern Met, Kwon O Chul's Yellowknife auroras: https://mymodernmet.com/kwon-o-chul-yellowknife-auroras
- NOAA Space Weather Prediction Center, aurora tutorial: https://www.spaceweather.gov/content/aurora-tutorial
- Wikipedia, Yellowknife: https://en.wikipedia.org/wiki/Yellowknife
- Video: Aurora Substorm (Vimeo)
- Photographs: Kwon O Chul
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