Aurora Borealis aka Northern Lights


SPACEWEATHER

stickerThis first page takes you along a quick and simplified introduction to the aurora, our planetary defense system. It both makes life possible as it can be a threat to our electrified society. Under the other menu items you will find an extensive load of information either written by myself for sometimes more easy explanatory reasons or deep linked to other sites. So this sub site of my website is sort of first line of information with a function of a relay/distribution station to more information. That way I can honour the sources of copyrights to text and illustration.

People often ask me where and when to go to for the Aurora. When is quite simple: always and in the dark. That would be from roughly half august till half april on the Northern Hemisphere and half march till half october for the Southern Hemisphere. The Aurorae are the result of Earths defense mechanism against galactic radiation and charged particles sent out from our Sun into Space. So basically the Aurorae will be there on a regular basis though not non-stop. No threat, no defense from our atmosphere. By the way: There are very few spots to watch the southern lights of Aurora Australis so forget about that unless you live in the most southern area of South America or Tasmania.

Where is quite more complicated for two reasons. First you have to be somewhere around the arctic circle, preferably north of it so about 66 degrees north or higher. A bit to the south is fine too but not too far otherwise you will only look at it sideways and you'll miss the impressive stuff.
But before continuing: read this about chasing the lights! That is, in most cases, plain bullshit.
There are only a few locations where that works. The second reason are the weather gods. Clouds are the major spoilers. When they are thin they can provide you with psychedelic effects when Aurora shows up for her performance but this is not what you want. The light can be very faint and pale and you won't be able to see it with the thinnest of clouds.

So before planning your trip be advised about the local climate. Furthermore you have to go away from the city lighting. Remote rural areas are preferred. The less light the better and you can measure this by looking at a clear sky and make an estimate of the amount of stars that you see. You're pretty close when the sky looks like grainy from stars. But also the moon can make spotting the lights difficult. The moon is a huge lightsource in any dark sky area and spoiles the faint lights. And the lights are more often faint and pale then strong and colourfull.

When you have no experience looking for the Aurora and she is just faintly visible then look for a cloud that still shows you stars. Clouds are not transparent but the Aurora is. The problem is that your eyes are not sensitive enough to see colours when the light is to faint, your colour sight has a threshold and the intensity of the lights need to cross that threshold for your eyes to see the colours. Your camera however is. That faint white cloud will jump out of your camera in bright green and sometimes other colours (most often purple and red) if it is the Aurora.

Real Aurora
The aurora to the naked eye at a low to moderate intensity
Look at the stars inside the "cloud"

For good weather information and the determination of the darkness on my location I use the app Clear Outside. Find it on the left side of your screen on a computer and under the menu on a smartphone. The darkness is in the orange field on the top and expressed as the Bortle value. The lower the better.

And then the issue of money. I can hardly advice you about that. Scandinavia is expensive. I go to Finnish Lapland and I have put some links in my links menu about this. I don't give about luxury but about quality. I love the Guesthouse Borealis and amongst the many Safari Companies there is one that stands out in their effort to let you experience the Aurora. Lapland Welcome does have a timeframe but hardly keeps to it if there is any chance that, making it later than planned, will help to spot the lights.

I stay in the city of Rovaniemi which has its own airport and I fly with Finnair for the simple reason that hardly any other airline goes there with the connection at Helsinki that is usefull to me. My favourite time there is September and March around the equinox. The clouds are somewhat better before and after the huge snow deposits but the weather there is extremely inpredictable due to 3 colliding systems. On the other hand... that takes care of sudden clearings quite often.

Last but not least... It is a gamble. An expensive one. Take a week at least and go every night. Go out to a dark sky area, Bortle 4 or lower, and when in winter season don't go alone as temperatures in the winter can be extremely low already or drop in seconds to minus 30 degrees Celcius or lower. If for some reason you are not able to leave a populated area behind you, Lights above the city are possible for sure but they are rare as they have to be quite strong. They can last for hours but 30 seconds for 1 night has been my part as well.

The apps in short

Parameters to keep an eye on with regards to the conditions of the solar wind and Earths magnetic field.
First of all: they are no guarantee. They tell you some parameters but how our magnetosphere and ionosphere and the Earths magnetic field will react to the solarwind remains not fully clear. If you want to know more on this specific subject go to the menu item 'In Depth'.

The better site and app is www.poollicht.be or SpaceWeatherLive as a phone app. Same site, it is in many languages so you'll find out quick enough what is what.

The first Tab Poollichtactiviteit (polar light activity):
Snelheid (speed): 400=normal 900=very fast (speed of the solar wind)
Dichtheid (density) <10 low >60 very high (density of the solarwind in particles per cubic centimeter)
BZ <0 south <-20 strong south (extra explanation)
Bt >=10 moderate >=30 very strong (Interplanetary magnetic field )
Hemisferisch vermogen (Hemispheric power) >50 GW well visible lights

The second Tab Zonneactiviteit (solar activity):
Interesting data but... you need discipline and keep following it. It takes the solar wind roughly and on average 3 days to reach Earth so if you see that a so called Coronal hole is facing Earth directly than be vigilant for the first Tabs data in those three days.

The Bz value needs an extra explanation. When the solar wind is send out from the sun it is ejected or streaming into space by magnetic powers. This gives the solar wind its own magnetism. This can be directed north or south. To connect well with the magnetic field of the Earth which is north, the solar wind needs to be south oriented. So by this theory you can forget about the Aurora when the solar wind is magnetically directed north. This is where things get fuzzy. I have seen Aurorea eminating from north oriented solar winds. And also I have NOT seen Aurorae when the solar winds magnetic field was oriented south AND other parameters were high enough.

There is a thing with the density as well but as we cannot yet explain that to our satisfaction I will leave this one to rest.

So... this messes up the 'forecasts' and quite severely sometimes too. On the other hand... this gives the lights their mysterious personality. See it like a fishing trip. You never know what and how much you are going to catch.

If any.

My review about Lapland Welcome on Google
Google is a bit stubborn from time to time so if it is copy and paste: https://www.google.com/maps/contrib/110415910932146560106/place/ChIJ8dyneGs1K0QRYzhAdtiEjXo/@59.3011973,14.9990634,5z/data=!4m6!1m5!8m4!1e1!2s110415910932146560106!3m1!1e1?hl=nl&entry=ttu

Maybe we'll meet in Rovaniemi from 19 march till 31 march 2025. See you there!

Latest revision:
20-10-2024, 11:48 UTC

Very special thanks to:
Safari Company Lapland Welcome
Guesthouse Borealis
My special friend Anthony Picken
Dutch Aurora Hunter Wesley Hogervorst

Take this page with you on your phone!QR Aurora info

Weather and Bortle classification

This is an app (CLEAR OUTSIDE) for both iOS and Android. Very detailed info on your current location. The lower the bortle number the darker your location is at night.

app clearoutside