Confirmation that the Sun has more than one solar cycle.
Space weather is always changing and this week scientists from Stanford University have published a paper confirming, as suspected, that there is more than the 11-year solar cycle.
Coronal Holes – A clue to when the Northern Lights might appear?
Coronal Holes – The basics
As we enter the period of the Solar Cycle when the Sun’s activity increases, we can expect to see the number and strength of geomagnetic storms increasing. Most of these storms will come from Coronal Mass Ejections (CMEs), but sometimes displays of the aurora are generated by Coronal Holes.
Coronal Holes are regions of the Sun that are less dense and cooler than the plasma that surrounds them. Importantly, according to the Space Weather Prediction Center in Boulder, Colorado, they are regions of “open, unipolar magnetic fields” which allow High-Speed Streams of solar wind to escape into space.
When these increased solar winds are directed towards the Earth, the particles collide with the gases in our atmosphere creating energy which manifests itself as the Northern Lights.
How do the Northern Lights appear?
What is the Solar Maximum?
The Aurora Borealis manifests itself in a huge ring above the Earth's Geomagnetic North Pole which is referred to as the Auroral Oval. You might expect this oval to be visible from the same altitude around the globe but because it is centred on true north rather than the geographical North Pole, this is not the case.
For example, fairly minor geomagnetic activity, let's say Kp3 will cause the lights to appear at a latitude of around 65°N to watchers in Northern Scandinavia but in central parts of North America it will likely be visible as far south as 50°N.
The best way to illustrate...
The Ovation map is created using real time....
Essentially, the OVATION Aurora Forecast Model is closest science has come to accurately....
Top image credit: NASA
The Aurora Oval & the Ovation Map
How likely am I to see the Northern Lights?
We'd love to give you an exact statistical answer to this most-asked question but the truth is that we simply cannot say.
The Northern Lights are Mother Nature's creation and as such we can't even use historical data to predict how likely you are to witness a display. The Sun's activity varies, cloud cover varies, solar winds vary and these and other factors can all influence the likelihood of seeing the Aurora. Indeed, accurately predicting an Auroral display is only possible a few hours at best before it happens because the interaction of solar wind with the Earth's magnetic field is crucial. So, while we may know that the Sun has thrown a Coronal Mass Ejection our way, we don't know how it will react when it reaches us.
What we do at The Aurora Zone is seek to maximise....
Hence, if they don't appear before we return you to your warm accommodation, you may wish to stay out longer...
Why are the Northern Lights sometimes coloured differently?
The majority of auroral displays are predominantly green for two reasons, the first of which is that the human eye detects green more readily than other colours. This is why photographic images of the Northern Lights will often show colours that were not visible at the time to the naked eye.
However, the main factor in determining the colours of any given display is the altitude at which the solar particles collide with our atmosphere. Different gases prevail at different altitudes and in varying concentrations and it is the collision which “excites” these gases that determines the colour of the aurora.
Not seeing red
We don’t see red in the Aurora Borealis too frequently and the colour tends to be associated with intense solar activity.
Reds appear in the Aurora when solar particles react with Oxygen at higher altitudes, generally above 150 miles. At this height the Oxygen is less concentrated and is “excited” at a higher frequency or wavelength than the denser Oxygen lower down making reds visible.
Yellow and pink
Very occasionally, you can see yellow and pink in an Auroral display which are associated with only high solar activity as they are simple a mixture of red with green or blue.
50 shades of green
Most solar particles typically collide with our atmosphere at an altitude of around 60 to 150 miles where there are high concentrations of oxygen. When the Oxygen is “excited” at these altitudes it causes the Aurora to appear in shades of green. Coupled with the eye’s greater ability to detect the green colour spectrum this makes it the most predominant and frequent Auroral colour.
Blue is the colour
Blue and purple are also colours which are seen less frequently and again, they tend to appear when solar activity is high. In this case, the colours are caused by particles colliding with our atmosphere at an altitude of 60 miles or less. At these heights, it is a reaction with Nitrogen that causes the Aurora to be tinged with purple or blue and most commonly, you will see these colours towards the lower parts of the display.
Does a full moon ruin your chances of seeing the Aurora Borealis?
In our opinion, the answer to this much-asked question is no.
We’ve discussed this issue with numerous Northern Lights guides and photographers and the consensus is that a full moon only impacts on a weak Auroral display and only when it is directly, or almost directly, behind that display. Indeed, the majority of Northern Lights photographers welcome the presence of a full moon as it adds another dimension to their Aurora imagery.
The thing to remember about the moon is that in relation to the vastness of space, it is absolutely tiny. Have a look at the night sky and note the minuscule fraction of that sky that is occupied by the moon. In our experience, it is only weak Auroras that are diminished by the light of the moon and, very often, a weak Aurora is more frustrating than no Aurora at all because waiting and hoping for a smudge of green light to develop into something spectacular can be hugely frustrating.
If that weak Aurora is positioned directly in front of a full moon then there is likely to be a loss of clarity but, in our experience, any half-decent Aurora display will remain clearly visible even when the moon is at its fullest.
A full moon in the Arctic sky is a wonder in its own right and we’d urge you not to be put off travelling because of it.
Image credit: NASA/JPL/USGS
The Aurora Hunter’s Worst Enemy
Contrary to what you may have read or heard elsewhere, the Aurora Hunter’s worst enemy is not a full moon. In fact, most Aurora hunters, guides and photographers rather like having a full moon in the sky because it is in itself a thing of great, great beauty and only really impacts negatively on weak Auroral displays.
No, the thing that Aurora hunters don’t like is cloud, especially, thick, dense blanket cloud cover which renders the night sky, and hence the Northern Lights, invisible. On such nights, you have to be prepared to drive for hours and hours in search of either clear skies or breaks in the cloud and even if you do find a gap, you are still relying on geomagnetic activity to provide the Northern Lights.
Obviously, the ideal situation for Northern Lights viewing is a completely clear sky but broken or limited cloud cover will provide some interesting contrast to an Auroral display. It’s just those frustrating nights when the cloud hangs heavy that causes the professionals to stomp around the house like bored kids on a rainy day during the school holidays.
When is the best time to see the Northern Lights?
If we could answer this question we would be rich beyond our wildest dreams!
As a naturally occurring phenomenon, the appearance of the Northern Lights is notoriously difficult to predict any further in advance than about two days before it happens, if it does then happen. So much is dependent on solar activity, the position of the Earth’s geomagnetic field and the weather. What we can say is the aurora season begins in late August and runs all the way through until early April. During this time, if you have a clear sky and you’re underneath the auroral oval in one of our destinations, you have a fantastic chance of seeing the Aurora Borealis.
Top image credit: NASA/SDO/AIA/Goddard Space Flight Center
The Solar Cycle - Solar Maximum/Solar Minimum
Our Sun goes through an activity cycle that lasts approximately 11 years and sees it pass through Solar Maximum (highest solar activity) and Solar Minimum (lowest solar activity). The Northern Lights are more prevalent during Solar Maximum the last of which occurred in June 2014.
Generally speaking, the Aurora Borealis will remain very active for 2 to 3 years on either side of Solar Maximum which effectively means that the current maximum has just passed its halfway stage.
There is further research to suggest that more significant solar events occur in the declining period following Solar Maximum which bodes well if you are planning a trip in the next couple of years.
Image credit: NASA/SDO
The Best Time of the Year
As far as we are aware (and we’ve searched long and hard) there is no definitive research to suggest that any particular time of year brings with it a greater preponderance of Northern Lights. Auroras occur throughout the year but the light summer months render them invisible to the eye so we have to focus on the rest of the year.
All we can do then is rely on our years of experience chasing the Aurora. So, roughly speaking and with absolutely no guarantees, here are our thoughts on the subject.
January to March
January to March
These are probably the three most popular months for Aurora hunting because they bring long dark nights and plenty of snow to play in during the daylight hours while you wait for darkness to fall.
In the Arctic, January is a time of renewal as the sun reappears above the horizon but it can be very, very cold indeed. Nevertheless, it is sometimes said that the Aurora is more likely to appear on colder nights so perhaps we could recommend January to hardier souls.
Generally speaking, February sees the weather slowly improving and in March, the temperatures begin to rise although it can still get pretty nippy, especially at night.
There is some speculation that the spring and autumn Equinoxes (around 20 March and 20 October) bring greater solar activity. Combine this with slightly warmer temperatures and improving weather (with the possibility of less cloud cover) and you may feel compelled to go Aurora hunting in late March or very early April. The daylight hours will be stretching out by then so you’ll have to be prepared for some late nights but this can be a very rewarding time of year in The Auroral Zone.
April to August
April to August
To see the Northern Lights you need dark skies and from early April until late-August, the Aurora may be blazing across the Arctic firmament but it is visible only to scientific equipment. Sadly, during the warmer months of summer, the skies are just too light for the human eye to see the show.
September and October
September and October
These are the months we would recommend to anybody who prefers to avoid the extreme cold of an Arctic winter. September brings a fleeting autumn but the colours can be absolutely magical but best of all is that you can often see two Auroras for the price of one.
September and October are usually the only months when the Northern Lights are visible at the same time as the lakes and rivers remain open. The beauty of this is that you will often see the Northern Lights overhead and reflected in open water at the same time. It can be a truly spectacular sight and one that doesn’t occur after the big freeze sets in and the waterways freeze and become covered in the first snows of winter.
It’s probably worth mentioning that the last two autumns have given us some absolutely stunning Northern Lights and 2014 caused one of the very best guides in the business to describe it as “the best in my lifetime”.
November and December
November and December
November is very much a time of change in the Arctic and heralds the arrival of the first major snow of the winter. It’s amazing to watch the landscape change so rapidly, it’s as if autumn becomes winter almost overnight. The snow does bring quite a bit of cloud cover but the shorter days also bring darker skies which increases the amount of time during which the Aurora might be visible.
The other thing about November and December is that it’s almost a time of celebration in the likes of Finnish and Swedish Lapland because they just love snow and all things winter like dog sledding and snowmobiling and ice fishing and reindeer pulled sleigh rides and any other number of fun winter activities.
The Best Time of Day
First and foremost, to see the Northern Lights, the skies must be dark. This immediately rules out daylight hours and, contrary to popular opinion, it is not pitch black in the Aurora Zone for the entire winter. Indeed, despite the sun not appearing above the horizon, even the shortest day, 21 December, brings 3 to 4 hours of grey/blue light which renders the Northern Lights invisible to the naked eye.
Once darkness falls, the Aurora can be visible at any time of day and we have seen them as early as 4pm and as late as 6am (that was quite a night!). Nevertheless, the optimum time seems to be around 9.30pm to 1am and that is when we concentrate the majority of our searches.
As ever with Mother Nature, these things are impossible to predict and autumn 2014 has been unusual in that the lights have appeared earlier than usual and often, very often, billowed across the night sky into the very early hours.
The secret to seeing the Aurora Borealis is patience. If your snowmobile or minibus or snowshoe search is unsuccessful then it is very often the people who brave the cold night rather than those who sneak off to a warm bed who have a tale to tell at breakfast time.
Where Is The Best Place To See The Northern Lights?
If we had a pound for every time we have been asked this question...
Imagine if there was one best place to see the Northern Lights! Overnight it would become the Costa del Aurora with high-rise Northern Lights viewing hotels and people in the street handing out leaflets offering a free drink with every Aurora chase.
Mercifully, the unpredictable nature of the Aurora means that it retains its mystical allure and it’s fair to say that you stand as much chance of seeing them from a vantage point in Norway as you do from a frozen lake in Finland.
Southern Lights, Northern Lights, Extra-Terrestrial Lights
The lights appear in both the northern and southern hemispheres and even on other planets but from an Aurora hunting point of view, only the Northern Lights are a genuinely viable option.
The Southern Lights or Aurora Australis occur most frequently over Antarctica which really only appeals to a few research scientists and penguins. When the Aurora Australis is very active then the lights may be visible from Australia, New Zealand and South Africa but these occasions are few and far between and certainly don’t justify travelling to such places purely in search of the Southern Lights.
The lights also appear near the magnetic poles of other planets and if you search the internet you can find images of Auroras above the likes of Jupiter and Saturn. Unfortunately, we’re not likely to be sending people into space on Aurora hunting missions any time soon so our focus remains firmly on Earth’s northern hemisphere and Northern Scandinavia especially.
Essentially, the Aurora is most frequently visible in Northern Scandinavia in a band that stretches between 66°N and 69°N and it is very difficult to be any more exact than that. Yes, the band expands when geomagnetic activity is higher but most commonly, the lights are fairly localised to an area just above the Arctic Circle that we call the Aurora Zone.
So, to give yourself the best chance of witnessing a magical light show you need to find somewhere in that band that is far removed from any significant light pollution (you need to escape the confines of cities such as Tromso or Reykjavik and the night lights of larger ski resorts such as Levi and Yllas) and be prepared to wait because when it comes to Aurora hunting, patience is very often a virtue that goes rewarded.
The best advice we can give you is to get yourself into that Auroral band and hope that there is some geomagnetic activity and limited broken cloud cover. This is where you will have the best chance of seeing the Northern Lights.