The bucket list item; when those aurora alerts or the news reports with a chance of the northern lights it, people begin flocking north in hopes of clear, dark skies and a brilliant magical show of the aurora dancing in the sky.
This usually leads to a lot of repeat questions for those heading out into the dark wilderness on their first hunt of the northern lights, which leads to this (very long) post, with my end goal here to answer the most common questions, give you information and maybe even help you find the chance to check this item off the list.
I've thought about writing multiple times over the years, and after the other night's display and numerous texts, DMs, emails, messages, etc. asking these questions, I decided it's time.
Again, this is a long one, so if you're looking for something specific, I'm just going to outline the key points from the beginning so you can scroll where you need to go, otherwise, grab a coffee and toast, kick back and get ready.
- What is the Aurora Borealis?
- Knowing when to go.
- apps & group recommendations
- how to read the data
- why the equinoxes are the "best"
- location scouting
- dark sky parks & Preserves in MI
- why do people gather at the water?
- expectations v reality
- the naked eye
- what to bring with you
What are the northern lights?
The northern lights: Aurora Borealis are caused by charged particles emitted from the sun hitting the earth's magnetic fields and atmosphere. Once they enter the atmosphere, they collide with the gas molecules, mainly oxygen and nitrogen, ionize the particles and release energy in the form of light, creating the northern (and southern) lights.
Colors are determined by a.) the gas type being ionized: oxygen creates green and red while nitrogen creates blue and purple. Additionally, the color, as well as the intensity, are affected by the altitude where the charged particles from the sun (solar winds) collide with the atmospheric gases. The lower the altitude, the more intense and brilliant the colors will be displayed.
I don't want to write pages on the science of the northern lights, however, if you are interested in the science behind the lights (which is actually pretty cool), I recommend checking out these articles:
- https://spaceplace.nasa.gov/aurora/en/ (this one is great for kids!)
Knowing When to Go.
This is the hard part - even after 10+ years of chasing these guys, I still miss out (and I still hang out in the dark until sunrise, coming home empty-handed). Even when all the numbers say yes, sometimes she says no. But there are definitely some key factors to watch for, for the chance of seeing them.
- Clear skies - this is #1, it could be the greatest auroral display of all time, but if it's raining, you aren't seeing it.
- kP index: on a scale of 0-9, this measures the geometric activity level. I don't usually bother until we hit a 4 if the other numbers strongly align, or a 5/6 if I'm going just off the current kP. If you're below the 45th parallel, I wouldn't really consider it until I saw 5/6 then I'd read further data
- bZ: this one gets me. Everything else can line up, but a north-facing bZ will kill it all. bZ measures the interplanetary magnetic field direction (north/south), which interacts with earth's magnetic field. When bz faces southward it has a chance of entering our atmosphere, creating the possibility of northern lights. When facing north, it glides past us. An easy way I remembered this originally is "north, no. south, lights are coming down"
- Solar Wind Density: the number of particles in the solar wind, the more particles, the more strength and chance.
- Solar Wind Speed: the speed at which the particles are traveling toward Earth. Faster speed = more compression in the atmosphere = higher solar wind density.
- Aurora Oval Map: this one is the one if nothing else. This map gives a visual representation of the possible strength and distance at which the aurora can be viewed.
- Red = very strong, drop everything and go.
- Yellow = moderate, yes, you should go.
- Green = normal, go... just go.
- Many apps have either a grey area or a red line past the green - this shows where there's a viewing on the horizon possibility.
- Solar Storms - these are geomagnetic storms caused by coronal mass ejections (CMEs) or high-speed solar winds that interact with the earth's magnetic field. G-level storms are the lowest and most common, other levels include R(moderate), S(strong), and X(extreme). X-level storms could have significant impacts and effects on satellites, telecommunications and power grids.
With all the key components aligning, while rare, a G5 storm could be seen as far south as the tropics and is often seen in the southern US/mid-European areas.
I do want to note here: forecasts have a very short-term accuracy. I know most apps have a "long-term forecast", but there's no way of knowing in 26 days it'll happen... I usually keep watch of the next 12-36 hours max.
I often see questions of simply "will they be out tonight?" to "I'll be at [location] on [weeks-months from current date], what are my chances?" And the answer is there isn't one. Your best bet is when you're there or when you have the opportunity to go searching, look at the data and ultimately guess.
As a side note: spring and fall equinoxes are considered prime aurora viewing "seasons", while they can and do occur all year, the equinoxes provide a special advantage on the earth's magnetic field alighting in a way more likely to interact with the solar winds. Also between the fall and spring equinox, you have long, dark nights.
Spring really ramps up with the refreshing clear skies after winters cloudiness as well.
Websites & Apps
Windy - for clouds and weather
Aurora Alerts App - for data & forecasts
Space Weather Live App - for up-to-date notifications, including solar flares, local kP relevance, Gstorms, etc.
Space Weather Live - I use the app, but this is handy to know.
Soft Serve News - before apps, Facebook groups and everything else, I LIVED on this website.
AK University - this was the other site I lived on, I specifically love the different information it has at easy access for learning and further understanding.
Location & Location Scouting
Michigan is home to many recognized dark sky parks and preserves [you can find the official list here], which are great in general, but I also recommend checking them out, especially when you're first starting because
- They usually have easy-to-navigate viewing areas.
- There will often be other people, which could also offer the opportunity to learn.
You don't need a dark-sky park or preserve to see the northern lights - finding the right area, perhaps closer to you or with more of the scenery you envision for photo opportunities is also possible. When scouting for locations search for a place that meets the following requirements:
- Dark sky, with very little to no light pollution for miles ahead. A big city can shine for hundreds of miles, whereas small towns will shine less.
- North facing, regardless of the event in which the aurora is directly overhead and reaching south, you still want a north view, that's where it'll begin and you can move from there should the show get bigger.
- Unobstructed view, not only do you want it to face north, you want a clear view of the northern horizon. Getting a little elevation here doesn't hurt either.
When scouting locations, I highly recommend checking them out first and at least once during the daylight hours to watch/learn any possible safety hazards, know your trail, and make sure you're aware of the location and surroundings.
"Why do people go to the water?" This is a question I see often so I want to address it as well. I think a lot of people have the misconception you must go to the lakes because so many of us shoot over them, but it's not true. The biggest reason is they offer the trifecta of what to look for in location scouting: dark spaces, no obstructions, and no lights for miles. But these things can be found in other locations.
Expectations v Reality
A key thing I try to tell anyone heading out with stars in their eyes and only photographs as a source is to manage their expectations of what reality will actually look like. Oftentimes, especially at our latitude, the aurora will appear more as a greenish, white haze or cloud in the sky/above the horizon. And while you may sometimes be able to see the pillars, pulsing, curtains, and movement, the colors aren't as bold, brilliant, or visible to the naked eye as they are in photographs.
The fact, photography, and our vision are very different. In fact, in the dark, our eyes would have to choose, be able to see, or have color. Obviously, you'll pick the ability to see and that's why often your night vision has an easier time in grayscale than it does identifying colors. That's not to say with a strong enough storm the brightness won't overtake and make seeing some colors easier (March 23rd, for example, you could see some colors)
What to bring with you.
- A red light headlamp
- Camp chair
- Snack bag
- Coffee & water
- Neck pillow
- Camera & tripod
- Portable phone charger
When it's warm:
- A coat/jacket/hoodie
- Sweat pants (that fit over jeans, leggings, or whatever I'm wearing)
- Extra socks & tennis shoes
When it's cold:
- Hothands - for my feet/hands, and my camera lens if it starts getting too frosty
- Snowpants (regardless of snow)
- Thick mittens - to go over my thin gloves when I'm not taking pictures)
- Really, any and all winter apparel
- You'll also want to bring extra batteries if you're taking photos - the cold will deplete them much quicker than warmer evenings.
This should really be general practice for any sort of outdoor ventures, hiking, night anything, etc... but just in case:
- Always tell somebody where you are going and tentatively when you'll be back.
- Stay on designated trails and paths.
- Bring a friend if possible
- Scope out rural/unmarked areas in daylight - especially if you are going somewhere new, remember, especially in Northern Michigan & the UP we get a lot of snowfall and have seasonal, unmaintained roads that people can and HAVE gotten stuck and stranded on in the winter!
- Bring a real flashlight - because I'd rather a little light pollution and lose my dark eye adjustment than a person.
- Make sure your phone is charged
- Stay alert - it's easy to get off course and disoriented, especially in winter and in the dark.