Aurora Watching 101

I’m heading home from a trip to northern Sweden to see the Northern Lights or Aurora Borealis.  I spent four nights trying to see the aurora (and about 5 minutes watching an amazing display!) and I came away with some ideas for effective aurora watching.  I’m writing them here in order to help others successfully see the aurora.

The aurora borealis is a beautiful display of colored lights in the sky caused by charged particles from the sun.  It’s rarely seen much below the arctic circle so a trip north is almost always required to see it.  The main challenges of aurora watching are timing your trip during solar activity, having clear skies, avoiding artificial and natural sources of light, battling the cold, staying awake and staying comfortable.

The aurora can be predicted with some accuracy several days in advance based on the position of existing sun spots on the surface of the sun.  As the sun rotates and the earth moves in its orbit, the earth encounters the charged particles coming from sun spots in a predictable way.  My favorite English-language aurora prediction site is here.

However, solar flares and storms can erupt with little notice.  The charged particles from these storms take about 40 hours to travel from the sun to the earth, so these may change auroral predictions (usually for the better) with less than two days notice.  So keep checking the prediction site you use, or sign up for email alerts.

On a longer time scale, solar activity follows an eleven-year cycle of maximums and minimums, so planning your aurora trip can be done years in advance to some extent.  But this cycle is not completely understood.  An above-average solar maximum was predicted for 2012, but has been delayed to 2013 and reduced in expected magnitude.  That being said, 2013 is probably the best time for the next 11 years to see the aurora.

The next thing to worry about is finding a place with little articial light.  Tromso, Norway is often cited as a great place to see the Northern Lights, but it is a major town of 70,000 people and has a large amount of outdoor lighting, making the skies too bright to fully appreciate the aurora.  Tours going outside the city are expensive (about US$100), especially if you want to take them every night.  More remote locations are darker, but there can be transport issues in getting there.  Abisko National Park in norther Sweden is a good combination of isolation and darkness as well as being on a major Swedish rail line.

Natural light in the form of the sun and the moon is the next worry.  The longest nights are in December and January, but these also correspond with the worst weather.  In March the nights are still at least 8 hours of complete darkness, but the weather generally is better.  One week either side of the full moon will mean that the sky will be quite bright with moonlight, including snow-refelcted moonlight.  After the new moon, the moon will start to grow in size and will remain in the evening sky after sunset for about an hour longer each night.  This means that generally the best time is the week before the new moon up through a couple days after it.

Since the best times and places to see the aurora are the winter and early spring in the arctic, battling the cold is a constant struggle.  Dress in layers, as many as you can carry and wear.  On the legs, tights under your trousers as well as snow pants or other insulated trousers over them, for a total of three layers.  On your torso, at least 5 layers of normal clothing including a good jacket are required, or perhaps fewer if one or more is a down layer or otherwise highly insulated.  Thick hat and insulated gloves are also of course required.

Time is an important factor.  The more time you can comfortably remain outdoors the more you will see.  The most comfortable position is lying in the ground.  For this a waterproof ground cloth, winter weight sleeping bag, and blanket(s) are required.  The ground cloth is required as your body heat will eventually melt the snow or ice on the ground no matter how good the sleeping bag, making it wet.

Staying awake as much of the night as possible is also important in order to maximize time spent watching.  Napping during the day will be the biggest aid in this.  Once the aurora starts, it often lasts for several hours, so be prepared to spend those hours awake and outdoors, watching and waiting for something even more spectacular to happen.  If nothing is happening, it’s ok to go inside for 15-30 minutes to keep warm and take a cat nap.  But set an alarm so you don’t oversleep.  Of course, if you can make a team of trusted friends who will  keep watch and tell those indoors of activity, everyone can get more sleep.  But beware, acquaintances met on your trip will often be too mesmerized by the aurora above them to come inside to wake you up.  So know who your true aurora friends are!

For long periods outdoors, snacks and hot liquids in a thermos flask will be useful.  Mixing alcohol and cold is a bad idea, as alcohol impairs judgment and reduces the sensation of cold without actually warming the body.  Falling into a drunken sleep in nighttime arctic temperatures is a recipe for disaster.  Avoid salty dehydrating snacks and excessive caffeinated drinks which cause frequent urination, a hazard when you are cozy inside multiple layers and deep in your sleeping bag!

Weather and auroral predictions are never guaranteed, so there is no substitute for simply spending as much time watching as possible.  A reasonable aurora-watching trip should last at least 4-7 days, longer if possible.  During that time, daytime arctic activities will keep life interesting.  Dog sledding, cross-country skiing, hiking well-traveled trails (that have had the snow crushed down by skis and snow shoes), ice fishing, downhill skiing, and sight-seeing are all good activities.  But in the isolated areas that offer the best watching conditions, nothing beats a good book.

The most important factor is luck, so here’s wishing you the best!


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