The Aurora Borealis – Everything you need to know
- What causes the Aurora Borealis?
- What triggers high intensity Auroras?
- What’s the best time of the year to see the Aurora Borealis?
- Where are the best places to see the Northern Lights?
- My top 5 Places to see the Northern Lights
- Can the Northern Lights be seen further south?
- How long do I need to see the Northern Lights?
- Can you actually see the Northern lights with the naked eye?
- Will the Full Moon affect my Aurora viewing?
- What colour are the Northern Lights?
- Can we predict Aurora Borealis activity?
Hey fellow Aurora fans!
After several years of research, kilometers travelled, multiple destinations visited, dark drives down foreign icy roads, snow storms, disappointment, exhilaration, several failures but more successes, here is my two cents on everything Aurora Borealis 🙂
First off, before I start I wanted to elaborate a little on the above. I’ve always held a certain fascination for the Northern Lights. My earliest memory was a documentary on the Discovery channel on Antartica when I was around 12 years old. I found them ethereal and magical and straight away wanted to know more about them and see them.
Being a 12 year old though has it’s drawbacks =) Being completely at the mercy of my parents destination wishlist meant that I wouldn’t really get to chase this dream until a little later on. So that plan was on the back burner for a few years.
So I studied, left school, and started working. At the age of 20, the Northern Lights popped into my little noggin again, and with freedom and a paycheck, I started doing my research and was adamant this time on seeing the Aurora Borealis.
I researched everything from Solar cycles, weather patterns, prediction techniques and annual aurora statistics to ideal destinations under the Auroral Oval.
I’m now 26 and over the last 6 years have seen the Aurora Borealis many times in many varieties and intensities. Those places include Yellowknife (Canada), Skibotn (Norway), Tromso (Norway), Kiruna (Sweden), Abisko (Sweden) and Ivalo/Inari (Finland). I’ve also experienced some failures along the way, and while you can never be guaranteed Aurora displays, I have learnt a few useful things along the way 🙂
What causes the Aurora Borealis?
Aaah the Sun =) The beautiful Sun! Not only does it sustain life on Earth, but it creates one of the most beautiful natural displays known to man. The Aurora Borealis happens due to the interaction between the Solar Wind and the Earth’s magnetic field.
There are a few terms worth remembering just so it’s a little easier to understand.
Solar Wind – A stream of particles originating from the Sun that travels towards us (and other planets alike). It can vary in density (i.e number of solar particles i.e. protons/electrons in the stream), and in speed. Higher speed streams will reach us faster than slower streams.
IMF – Interplanetary Magnetic Field. This is the magnetic field carried with the solar wind. Remember the sun has it’s own Magnetic field, and as the particles leave the Sun, they carry with them magnetic field lines.
Magnetopause – This is a boundary between the Earth’s magnetic field and the Solar Wind. Think of it as a sort of barrier stopping the Solar Wind from reaching us.
The Earth’s magnetic field is pointed North at the Magnetopause (this is illustrated in the image below). Think of a magnet for a second….If the IMF is in a Northern direction, then it will ‘clash’ with our own Northern Magnetic field at the Magnepause and it will repel the solar wind.
However, think of the opposite. If the IMF contains Southern facing magnetic field lines, it will ‘link’ up with our Northern facing Magnetopause and both field will cancel each other out! This in essence opens a portal for Solar wind to enter our atmosphere.
So to sum up, as the Solar Wind approaches and strikes the Earth’s Magnetopause, it causes it to bend and flex. If the IMF in the Solar wind has a southern facing direction, the Solar Wind will eventually causes a ‘break’ in the Magnetosphere and creates two Magnetotails that swing around and behind the Earth. When the Magnetotails from both sides meet up on the otherside, they ‘snap’ and slingshot the Solar Wind particles towards our poles.
The Solar wind particles collide with the Oxygen/Nitrogen atoms in our own atmosphere. These collisions ‘excite’ the Oxygen atoms. When these ‘excited’ Oxygen atoms return to their previous calm state, they emit light in the process. This results in the Northern (or Southern) Lights.
What triggers high intensity Auroras?
The body of knowledge on the Solar wind and it’s relationship to our planet and the Northern Lights is far from complete. But relationships have been deduced and there are things we do know with relative certainty. Before we answer this question lets specifically look at the ways in which the Solar Wind reaches us.
- Coronal Holes – Coronal Holes are dark regions on the Sun’s Corona (sort of it’s own atmosphere) where temperatures are cooler. They act as ‘funnels’ for the Solar wind to escape the Sun and travel towards us. Coronal Holes are generally responsible for High Speed Solar Streams (and also Low speed streams). The intensity of Northern Lights caused by these streams are dependent on the IMF of the Solar Wind Stream, the number of solar particles in the stream (plasma density), and the duration of time the stream is hitting us.
- Coronal Mass Ejections (CME) – CME’s are sudden high speed ejections of large amounts of solar wind and magnetic field lines from the Suns surface. They are sporadic and unpredictable and originate from Sunspots on the sun’s surface. They are classed by intensities, B, C, M and X. The latter being the most powerful. Typically they also take 24-48 hours to reach us. So when news arrives of decent CME’s Aurora hunters all over the world await with baited breath and hope for clear skies =)
So what conditions can cause Geomagnetic Storms? Here are a few examples:
- Solar Wind Streams with good southern IMF – Solar Streams with a decent southern Bz (Southern IMF of approx -5nT or less), with moderate to high Particle Density (approximately greater than 5 protons/cm3), that last for extended periods of time, can cause Geomagnetic Storms and cause intense Aurora displays. Therefore contrary to popular belief, fantastic Auroras are not just the result of CME’s from our Sun.
- CME’s – CME’s of class C, M and X (C being the weakest, M more powerful and X are real whoppers and only happen a couple of times a year) can trigger geomagnetic storms. The higher class CME’s are more likely to spark high intensity Auroras i.e. M and X, CME’s are intensified when they carry negative IMF’s too.
There are situations when weaker CME’s or weaker Solar Wind streams can still cause some amazing Auroras! Say for example that a good Solar Wind Stream is approaching Earth with a Southern IMF, this will in effect ‘weaken’ the Magnetic Field and allow Solar Wind to enter our atmosphere. Imagine now…there is also a CME on the way behind the Stream. Even a low class CME (say B or C) could be intensified due to the fact there is already a ‘portal’ open.
So as you can see, if’s not an exact Science. I’ve learnt to get a feel for conditions and can now predict with relative confidence when to expect something decent. I hope this helps you too!
What’s the best time of the year to see the Aurora Borealis?
This is one of the most common questions I get asked about the Northern Lights. The basic answer is that, although the Aurora Borealis is always present at the northern and southern magnetic poles, we can’t always see them because of daylight hours getting in the way during the summer months at such extreme latitudes. Therefore the best time to try and see this natural phenomenon is anytime between late August – early April when the window of opportunity with regards darker skies is higher.
Statistically speaking (I like my statistics) there seems to be higher Auroral activity around the Equinoxes, that is around the months of late September and late March. This is to do with slight variations of the Earth’s tilt axis relative to the Sun’s tilt. During the equinoxes the Earth’s magnetic axis more suitably aligns with that of the Sun’s and larger deviations into negative Bz are more likely, therefore facilitating Solar Wind particle transfer into our atmosphere. Suffice to say, activity does tend to be higher around these months.
This is NOT to say that spectacular Aurora’s are not possible in the interim months, in fact I have seen fabulous displays in other months. But since I don’t get to travel as much as I’d like, I like to give myself the best chances and stick to those times.
My personal preference is February/March, due to the fact weather tends to stabilize in Northern Scandinavia after December.
Where are the best places to see the Northern Lights?
There is no one right answer for this one as there are many places you can see the Northern Lights. As long as you are situated far enough North (or south if you are thinking of the Aurora Australis) then you stand a chance of seeing the Aurora. North of 63/64 degrees latitude roughly is a good place to see them.
However, there is a slight catch to these numbers, in that I’m not talking about standard geographical latitude, but Corrected Geomagnetic Latitude. The Earth’s magnetic field is not perfectly aligned around our geographic poles, it deviates slightly. Therefore this ‘Corrected Geomagnetic Latitude’ is the true latitude you need with regards our magnetic field (and therefore Auroras). This is why in Europe, you need to be in Northern Scandinavia to see the lights, but in certain places in Northern US and Canada, you don’t need to be at such a high latitude. So, to sum up, North of 63/64 Corrected Geomagnetic latitude and you’re set =)
All you need to do is click on a location on the maps linked above, and you’ll be given latitudes, most importantly the corrected magnetic latitude. If the location is greater than 63/64 you will be able to see the Northern Lights there (if there’s activity and clear skies).
For some people, this might not be particularly helpful as we need specifics, easy to access towns that are close to convenient airports etc. So a more tailored answer for Aurora chasers is that any of the cities underneath the green band in these images, are good locations to spot the Northern Lights.
As for my own personal recommendations? Here is my top 5 places to see the Northern Lights. All tried and tested and I’ve had success in each one. They’re fantastic places to try your luck! I’ve listed them in order of my preference and given reasons why.
My top 5 Places to see the Northern Lights
Here are some of my suggestions for where to best see the Aurora Borealis from. These are tried and tested. Feel free to get in touch if you have other towns in mind and would like some advice.
- Ivalo, Finland
I visited Ivalo and the surrounding area in March 2012 when working with Aurora Hunters for a week. The landscape in this part of Finland is vastly different to that of Abisko in Sweden and parts of Norway. It is much flatter, but so beautiful in a different way!
The landscape has a very winter wonderland type feel to it, with snow capped trees, and snow mounds everywhere. Really beautiful =) The people in Ivalo and the Inari region are so friendly and welcoming. Ivalo itself is a relatively small town, with everything you need, supermarket, local pub all within walking distance. I stayed at the Hotel Ivalo for a week. The hotel is basic but more than adequate, with clean rooms and decent food. The best part about this hotel is its lovely location in Ivalo. It sits right off the River Ivalo, literally, 20 seconds walk behind the hotel down a gentle slope onto the beautiful frozen river (On the picture to the right the Hotel is on the left hand side!) Not only is this a hub for daily activities such as snowmobiling and cross country skiing, but makes a good location to view the Northern Lights if you cant get out of the city!
Being a small town, Ivalo doesn’t actually have that much light pollution, which means Aurora viewing is entirely possible within the city. In fact I was witness to a wonderful display right on River Ivalo behind my hotel for about 2 hours with several of the hotel guests.
Of course this was a happy little extra, there are other options that involve heading outside the town, to some gorgeous locations in perfect darkness. One company I can highly recommend myself is Aurora Hunters. Andy Keen and his team of Aurora hunters will do their utmost to drive you to clear skies and Auroras, even if it means driving for hours to the Russian border! They provide entertainment, warm drinks and will help out with your photography equipment too! They also know all the beautiful locations to help you get the most out of your photography, I owe some of my best shots to Andy Keen 😉
- Pros – Winter wonderland landscapes, amenities in town, low light pollution, plenty of activities, Aurora tour guides. Furthern inland, therefore colder with more stable weather patterns.
- Cons – Staying inside the city does have some light pollution, but as long as the Aurora Borealis isn’t too weak you will see them. So tours may be required.
- Abisko, Sweden
Abisko is a lovely little arctic town in the North of Sweden, nestled between Kiruna and Narvik in Norway. The scenery is beautiful with the famous Lapporten mountain range in sight, and wonderful frozen lakes nearby. The small town is offered some protection from cloudy weather due to the Norwegian mountain range, so some say there are clearer skies in this region than others in the area. I myself have noticed that it can clear up in a very short space of time in Abisko!
I stayed at the Abisko Mountain Lodge and I really can’t say enough good things about the place. Service, food, location is all top notch, and the best part of all? You just need to step outside your room/cabin into darkness to see the Northern Lights, so you can be ready at a moments notice. So there is no need to pack your car and head out into the dark night and sit in the cold for hours on end (as I’ve done many times!). This really is a bonus to this type of accommodation Your window of opportunity for viewing is so much higher when you can just step outside. If you’re up for something special, you can also take a chairlift up to the Aurora Sky Station for some amazing views over the beautiful Abisko region, and hopefully a great view of the lights!
- Pros – Beautiful scenery, excellent food, wonderful hosts, no need to go anywhere to see the lights, activities organised from the lodge.
- Cons – Can’t think of any!
- Kiruna, Sweden
Kiruna itself isn’t the most picturesque town, but does have a large selection of hotels, and many activities. My recommendation here if you’re not planning on staying in Abisko, is to head out to the Ice Hotel which is just a 15-20min taxi/drive from Kiruna.
Alternately you could stay in Kiruna and take nightly tours out to see the lights. But that will prove more expensive.
- Pros – Good base, lots of activities leave from Kiruna, plenty of hotel selection. Easy access to Abisko and Ice Hotel.
- Cons – Kiruna is a relatively large city and suffers from moderate light pollution, so you’d need to find a darker spot, either by tours, or renting a car and driving outside the city.
- Tromso, Norway
It’s almost a little painful for me to place Tromso 4th on the list. Tromso as far as cities go is an absolute gem. It is a gorgeous city nestled in the Arctic North. I’ve been there 4 times and loved it just as much as the time before. Some call it the Paris of the North and this title is well deserved. It is a beautiful, bustling town with every possible amenity you could think of. Restaurants, hotels, pubs, cinemas, shopping malls the lot.
The Clarion Collection hotel is a lovely nautical themed hotel (ask for a room with a view of the harbour they’re wonderful). Very fairly priced, good food, and free chocolate waffles and coffee all day are a real plus when you return from the cold.
My personal reservation with Tromso is twofold, it is the largest Arctic city I have visited, so has the worst light pollution. It is also a coastal town, and close to the Gulf Stream, therefore temperatures are milder than you would expect, but as a result suffers more from cloudy skies.
You would likely need to drive outside the city limits to find darker skies, and further inland if cloudy, to find clearer skies (along the E8). Alternately you could take nightly tours outside the city of which there are many. But I personally have had great success with Kjetil Skogli, a local photographer and Aurora hunter who also works tirelessly to find clear skies and Auroras if it’s at all possible. He drove us 3 hours out to Skibotn where I was treated to one of the best displays I’ve ever seen, despite a snow storm back in Tromso.
- Pros – Beautiful city, all amenities, numerous tours and tourist activities, good Aurora guides.
- Cons – Heavy light pollution, tends to suffer from cloudy weather
- Yellowknife, Canada
I’ve placed Yellowknife 5th on my list mostly because it’s across the pond from me 😉 So for us Europeans perhaps it’s slightly more out of reach, but for all of you over on the other side of the Atlantic I can’t say enough good things about this place, in particular the Blachford Lake Lodge which is where I spent my 5 nights in Yellowknife.
The lodge is on its own private plot of land and is accessible only by Bush plane, but oh my was it worth it! The landscape is absolutely astonishing. So beautiful and desolate at the same time, with wonderful safe forest trails surrounding the property. The lodge itself is top notch and has all the luxurious commodities you would need. The Chef is professionally trained and apart from the Abisko Mountain Lodge, I don’t remember the last time I’ve eaten better!
- Pros – Amazing location with stunning scenery, private (no chance of overcrowding tourists), food to die for.
- Cons – Hard to get to, no roads so you’re completely at the mercy of the weather.
Some other recommended locations are:
- Norway – Lyngen, Alta, Kirkenes, Malangen
- Finland – Inari, Nellim, Utsjoki
- Sweden – Jukkasjarvi
- Alaska – Fairbanks, Bettles
- Canada – Churchill (Manitoba), Gillam (Manitoba)
Can the Northern Lights be seen further South?
Another common question is from people wanting to know whether they can see the Aurora Borealis from a little further south. This is entirely possible to a certain extent. I mentioned earlier that a good location for Northern Lights viewing was approximately North of 63/64 Corrected Geomagnetic Latitude, and in my opinion it is if you want to see the Aurora as brightly as possible, in all its glory, directly above you. (Personally I prefer to be bang underneath it at 65-67 Corrected Geomagnetic Latitude).
But this isn’t to say it’s not possible to see the Aurora to a different degree further south.
The general rule of thumb is that the further south you are from the Auroral band, the further North, and the lower, the Aurora will appear on the horizon. Keep travelling going South and eventually it dips beneath the horizon and we can no longer see it.
So how can you know if its possible for you to see it from your location?
Check out the latitude maps I linked earlier again:
Roughly look at the location in question, and then see where you’re positioned relative to the coloured lines in the image. These are the KP Index lines. They roughly tell you what KP Activity number the Aurora needs to have, for you to be able to see it at the location in question.
The current KP Activity index can be seen here.
How many nights do I need to stay to see the Northern Lights?
The more the better! This is a little obvious, but really I always say the same thing. For most people trips to the Arctic Circle are a rarety, and expensive. All things considered I feel that since we’re going through the effort to travel so far, we might as well give ourselves the best shot! I strongly advise anyone that is serious about wanting to see the Aurora, to stay ATLEAST 3-4 nights. More really is better. There may be activity, but cloudy skies, or clear skies, and no activity, so stay as long as is possible.
According to the scientists in Kiruna, Sweden, you have about an 80% of seeing the auroras if you stay in the area for at least 3 days. This is likely too for any destination at similar latitudes (like those listed above).
Can you actually see the Northern lights with the naked eye? Or is it all camera trickery?
The definite answer is YES! Yes you absolutely can see the Aurora with the naked eye. You can more than see it, when it’s active enough it’s so bright, intense and fast that your eyes won’t be able to keep up! You’ll want to stop time just to take it all in.
The problem is, there’s a common misconception that because Aurora photography can sometimes use long exposures to enhance the Aurora’s, that this is infact untrue to life, and it isn’t. When the Aurora borealis is weak, long term exposure photography is handy because it allows the camera to capture light over time, and as result you get a nice green band in your photos, much brighter than perhaps you can see yourself.
But this is just because the Aurora is weak. Infact it may appear to you (when your eyes have fully adjusted to the dark) as a pale green/ almost white band of light in the sky, immobile, and very faint. SO much so that you might think to yourself, is that it? Is that the famous Aurora Borealis?
Take the two shots below as examples, the left shot was a 2 second exposure, the right an 18 second exposure!
The left hand picture looks almost identical to the naked eye as the photo, whereas the right hand picture really looks nothing like it did in real life and infact appeared to me as a very VERY faint, and pale band in the sky. Just remember, photos with short exposures are more true to life, longer exposures enhance what we see.
It’s important to note, the Aurora Borealis is present in a great variety of intensities, from it’s lackluster weaker form, to it’s in your face, vibrant, dancing from one side of the sky to another in 2 seconds flat form. The latter will literally take your breath away, so much so the camera might be the last thing on your mind. You will just want to stare and take it all in.
So please, don’t be put off by any weak Aurora’s you may have seen, or any stories about how it’s all long exposure trickery. The Northern Lights are by far the most beautiful natural phenomenon I’ve witnessed. You just have to be lucky and catch her right 😉
Below is some video footage I captured of the Northern Lights in Yellowknife, Canada back in March 2008. I’ve sped it up quite a bit as the display was over 2 hours long! But rest assured the movement is very fast at normal speed too! Apologies for the grain, it’s actually read video footage, not time lapse images.
Will the Full Moon affect my Aurora viewing?
Short answer, not much. I used to be put off by the Full Moon, and always booked my Aurora hunting trips around the New or Crescent Moon, but there really is no need for this and it really limited the times I could travel!
Contrary to popular belief and suggestions, the Full Moon or Gibbous Waning moon will only affect your viewing of the Northern Lights if they are WEAK. In which case, it will make it harder to see the pale green bands in the sky. But honestly? If the Aurora has any decent level of activity it really matters very little, and it’s those impressive Auroras you really want to see =)
I actually PREFER the brighter moon phases as the Moon lights up the landscape beautifully and brings out all the details in my photographs. Just remember, even the Full Moon pales in comparison to a moderate to active Aurora, and it gives beautiful photographs 😉
I guess what it boils down to is preference, and for us photographers what it is you’re after from your shots. If you want a nicely lit landscape, the Half to Full Moons actually help us out (as long as the Aurora is of moderate activity). If you want more of a Star-field, or want to capture the Milky Way and the Aurora Borealis, then plan your travels around a New or Crescent Moons as the moonlight does obscure the star field.
What colour are the Northern Lights?
The most common colour of the Aurora Borealis is shades of green. Different colours start to appear depending on what elements are interacting with our Earth’s magnetic field. As the Solar Wind becomes trapped in our Magnetic Field at the poles, the solar particles collide with atoms and ions in our atmosphere and become ‘excited’. It is the settling down of this excited state that results in the emission of ‘light’. If the excited particles in question are Oxygen, we typically see the green/yellow light, however, if the Oxygen particles are at very high altitudes, a more seldom seen Red light colour is emitted at the top of the Aurora. If it’s Nitrogen particles, we are more likely to see a blueish tinge to the Aurora. Purples, whites, blues occur often in coronas (coronas appear as almost spindle looking shapes directly above, as if reaching directly down to you), but overall green is the most common =) There isn’t a geographical place where specific colours occur, its all totally random and depends on the activity of the Auroral oval over different parts of the world.
Can we predict Aurora Borealis activity?
A lot of people message me with dates they have in mind to travel to certain destinations, and they ask if there’s anyway to know if there will be Auroras (often times these dates are months in advance!)
The truth is, predicting the Northern Lights is a tricky business and there’s never an absolute guarantee. Predictions are always most reliable the closer we are to the dates in question (much like the weather).
To be specific, it takes approximately 24-48 hours for solar wind to travel the distance from the Sun to Earth (depending on the speed of the Solar Wind or Coronal Mass Ejections (CME). So relatively accurate predictions can only really be made in that time frame, 2-3 days ahead. Here are a few useful resources for gauging general Aurora activity currently and over the next few days:
Geographic Institute at Fairbanks University – A popular general prediction model. Good used as a general guideline but not updated everyday. Predictions are made for 5-6 days ahead, however if an event occurs on the Sun, this prediction model will not account for new activity due to it’s update intervals. Take with a pinch of salt.
SWPC Prediction Center – Ovation Model – A good realtime model showing the Aurora Borealis’ current oval over the Earth. The brighter the green (or white) in the model, the more intensely the Aurora can be seen over the estimated geographical location underneath.
SWPC KP Model – The Kp model is an indication of fluctuations in the horizontal component of our geomagnetic field, also referred to as the Kp value over a 3 hour period. Kp values of 3+ are considered to be conducive to Geomagnetic storms and more intense Auroras. However, Kp’s as low as 1/2 can sometimes spark some wonderful Auroras, especially if you’re situated directly underneath the Auroral band. This is because there could be isolated substorms that do not last for a long enough period to register as a high Kp number, so the average will be lower.
Astronomy North – These guys tend to be pretty accurate with predictions and likely monitor events on the sun as well as current solar wind data.
Longterm forecasts tend to be unreliable, but there are ways to see what potential long term activity COULD be. There is a method known as the Carrington rotation (you can see an example of this on the Gedds page) which is based on the Suns rotation pattern. The Sun fully rotates on its own axis every 27 days. If there is an active Sunspot that is causing Solar Flares or CME’s, there’s a chance that 27 days later, that same Sunspot could still be there and could dish out similar levels of activity.
The problem with longterm forecasts, is that Sunspots decay and die, and their activity wanes. So the Carrington rotation is not always reliable, and when the Sun rotates completely and is facing the Earth again, a particular Sunspot might not be there anymore.
Aurora Borealis activity is never guaranteed, unfortunately it’s a little like playing the lottery. Many people are blessed with days of fantastic displays, while others leave their holiday destinations only to hear of Auroras the day they left. (Personal experience! Very frustrating).
The most important thing to remember with the Aurora is that you need to be patient. She could make you wait hours but it will be totally worth the cold and frustration when she finally puts on a show for you.
I personally use a combination of current Solar activity and Solar Wind readings from the ACE satellite, and generally know when to head outside to within an hour of activity. But the above should get you on the right track 🙂
Here are some photographs I’ve taken over the last 5 years or so, all of which are in the locations listed above. I hope you enjoyed my article! Feel free to ask any questions and I’ll try and answer =) You can find my full Aurora stream here
All photographic images and written content are copyright protected and are the property of Natalia Robba. If you’d like to order some prints, use my photographs, or republish my written content, please email me at firstname.lastname@example.org to request permission.