Aurora Lessons

Swoosh, Northern Lights Over Kirkjufell, Iceland

Neon Night, Aurora and Glacier Lagoon, Iceland

We are slightly past the peak of the 11-year solar cycle, still in the window for the best opportunity in the next 10 years to see and photograph an aurora (the aurora activity will decrease each year until 2032, and won’t approach the current level until the middle of the next decade). Though I don’t have the aurora expertise of someone who has lived an entire life in the high latitudes, since my first experience in 2019, I’ve traveled to Iceland many times and have enjoyed enough aurora success to consider myself qualified to share my own aurora insights.

First, some aurora science

Our planet is continuously bombarded by solar energy. When this perpetual solar wind encounters Earth’s atmosphere, a narrow range of wavelengths (infrared and visible) passes through to warm our bodies and light our way. But other wavelengths in the solar wind interact with the atmospheric molecules they encounter, stripping electrons to create a charge imbalance (ions).

Instead of penetrating our atmosphere where they would create havoc on Earth’s surface, most of these charged ions are intercepted by the magnetosphere, our planet’s protective magnetic shield. Continually buffeted by solar energy, the magnetosphere is teardrop shaped—picture the shape of a falling raindrop that’s squished out front and stretched behind by the air it rushes through. In the case of our magnetosphere, the battered side facing the sun (daylight) is compressed, while the night side that’s shielded behind Earth is thinned and stretched much far into space. The thick sunward side of the magnetosphere deflects the charged particles and channels them to upper regions of Earth’s leeward (night) side.

While many of these ionized molecules stream toward the farthest, most extended part of the magnetosphere and eventually away from Earth and deeper into the solar system, some are drawn Earthward along magnetic field lines created by our planet’s north and south magnetic poles, creating an oval of charged particles lower into the atmosphere above the poles. It’s these energized particles that we see as an aurora, and why the aurora display is most prominent near the poles.

The aurora’s color depends on the molecules involved, and the altitude of their activity. Green-emitting oxygen molecules at relatively low altitudes are the most plentiful, making green the most common aurora color. Less common is red, which we see when charged particles strike oxygen at very high altitudes, as well as nitrogen, hydrogen, and helium at lower altitudes. Blue and purple are also possible, depending combinations of altitude and the molecules involved. When an aurora is active enough to extend into the highest reaches of the atmosphere, it becomes visible at lower latitudes. Since the people at the lower latitudes are seeing only the highest extremes of the aurora region, it appears mostly red. (An aurora image that shows a predominantly green aurora above a low latitude landscape is likely a fake.)

Aurora activity is measured by the Kp- (or K-) index, 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—decent, but far from perfect, and improving as the forecast day draws near. 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.

The solar cycle (more aurora science)

The size of the aurora oval, and therefore the extent of the area on Earth’s surface where an aurora is visible, varies with the amount of activity on the sun and how much of it reaches us. In times of extreme solar activity, not only will the intensity of the display at higher latitudes will be greater, the aurora display will be visible at lower latitudes.

Through centuries of observation, solar scientists have identified an 11-year cycle of solar activity tied to the reversal of the sun’s magnetic poles: every 11 (or so) years, the sun’s north and south poles flip. With this solar reversal comes an increase in sunspots (storms on the solar surface) that spawn the solar flares and coronal mass ejections that hurtle energetic particles Earthward to ignite an aurora. And though strong aurora displays are possible at any time during the solar cycle, their occurrence is most frequent around the 11-year max, and least frequent around the 11-year minimum.

For anyone with aurora dreams of their own, all this is especially relevant right now (late 2024), as the sun is about at its 11-year peak. It’s impossible to know exactly what month the absolute peak will occur, but the activity is still increasing and it’s safe to say that it will probably peak sometime in the next year or so. Whether you join me in an Iceland photo workshop, find some other workshop or tour, or just plan a trip on your own, the time for action is now.

Lessons learned

Download an aurora app to your phone. I use Aurora Forecast Pro; since this is the first aurora app I used (recommend by experienced aurora chasers), and provides all the info I need and has never let me down, I’ve never used anything else.
Learn how to control your camera (expose, compose, and focus) in the dark.
Spend some time before dark to find a foreground to go with your aurora, and look for spots with views in multiple directions. The northern lights are so spectacular, it’s easy to just show up and forget to compose the scene. And while the northern lights tend to concentrate in the northern sky, an intense display can appear in any direction.
Bring extra batteries (more than you think you’ll need) and keep them warm. (In extreme cold, li-ion batteries can go from 50% charged to exhausted in minutes.) It’s best to store batteries next to your body, and/or and or close to a heat source, like a hand-warmer pouch. And when a battery runs down, it may be reusable once it’s warmed.
Wings of Angels, Aurora Above Dyrhólaey, Iceland

Bundle up. The best aurora photography usually happens in the coldest weather—high latitudes during the long nights of winter. In other words, you could be in for the coldest temperatures you’ve ever experienced. Few things will shorten or distract from a great shoot faster than cold, dress accordingly. In addition to a robust, hooded down jacket, in January in Iceland, I’ve managed to stay comfortably toasty beneath a wool base layer, heavy down jacket, wool hat, balaclava, heavy gloves over thin liner gloves, wool socks, and insulated boots. And rechargeable hand-warmers are a godsend.
Monitor your exposure constantly. Unlike Milky Way and most other night photography, aurora exposures can change by multiple stops in minutes, and sometimes seconds. An exposure that worked to capture the aurora’s color and bring out foreground detail one minute, may completely blow out the aurora the next.
Stay alert and keep your head on a swivel. An aurora can ramp from zero to sixty in seconds, and a strong display can color the sky in all directions, often with head-spinning suddenness. My Wings of Angels image was captured on Iceland’s south coast, facing south.
I can’t give you the ideal exposure settings because the brightness of an aurora is so variable. To capture the detail (prevent blurring) of an extremely dynamic aurora (that can change as quickly as fast-moving clouds), keep your shutter speed in the 5 to 10 second range, and control the light with your ISO and aperture. Also note that a very strong aurora can actually illuminate the foreground enough to make a noticeable difference (natural light painting). (All of the aurora images in the gallery below used shutter speeds between 4 and 15 seconds.)
I always use auto white balance (shooting raw), and adjust later.
Don’t forget to set the camera aside and take a few minutes to truly appreciate the majesty of the sight above you.