Hello my fellow Aurora hunters and friends!
I admit, it is a bit stupid title for an article. However, lately, I just keep hearing these rather anxious questions: “Are the Auroras ending in Lapland?” Or… “Is 20xx the last year for Auroras“?
The short answer is, of course: “No!”
However, I do want to address these questions seriously, and and if you want to know my thorough answer, just read further!
The Auroras are the result of the solar activity. The solar wind reacts with our upper atmosphere and causes the atoms of oxygen and nitrogen to shine with colourful lights! (The oxygen is responsible for the green and nitrogen for the purple colour). The power and magnitude of the Auroras depend on many factors, for example, how fast and dense the solar wind is.
You are all probably familiar with sunspots. They are important, because are often accompanied by the solar flares. When they occur, they can send some fast-moving solar wind towards Earth, causing bright auroras!
The solar activity follows the 11-year cycle and the amount of solar flares on the Sun’s surface varies accordingly. At the height of the solar cycle we have the solar maximum, a period of high solar activity with a big number of sunspots (and possibly solar flares). However, we also have a solar minimum when there are hardly any sunspots at all, and no solar flares. The last solar maximum happened around 2013–2015 and indeed we had a lot of sparking auroras then. Now, in 2017, we are in transition to the solar minimum which is due to happen around 2019-2020. If you want to read more about the solar cycle business, you can read more in my previous article.
As a result, during the solar minimum, we won’t have many sunspots nor the solar flares that follow them. Thus, one of the important reasons for Auroras will be absent, but, luckily for us, there are other reasons!
The main misconception with the questions, mentioned in the beginning, is that Auroras will stop for the time of the solar minimum. This is not necessarily the case!
Of course, the solar minimum means that we are likely to have less auroras and, in general, they should be less powerful. However, even the brightest auroras are still possible during the solar minimum.
The solar flares are not the only events that can trigger auroras. Luckily for us, there are other causes!
Autumn and Winter 2016 brought us some of the most exciting and powerful auroras of the past years, certainly comparable in power and brightness with ones, happened during the “good ol’ years” of the solar maximum of 2013-2015. And the most astonishing fact is that none of them were caused by solar flares! Instead, they were caused by giant coronal holes.
The coronal holes are dark areas on the Sun’s surface where the magnetic field can reach out to space, instead of folding back into the Sun. As a result, some high-speed can rush away from the Sun. As the Sun makes a full rotation around itself in about 27 days, the coronal holes on its surface rotate as well, coming in and out of our view. When the coronal holes are facing the Earth, the fast solar wind can reach our planet.
One giant coronal hole was born in the Summer 2016. During the last months it has rotated in and out of our view several times and, as a result, we had some amazing auroras in September, October and December 2016! (It did rotate in November as well, but our weather is usually dreadful then). This is how it looked like at its biggest in August-September 2016:
The last time this coronal hole was in our view was just before Christmas, and, giving the 3-4 delay for the sun wind’s travel, the Auroras arrived exactly on Christmas! Me and my fellow Aurora hunters always dream of the Green Christmas (white being a good second) and this year it came true!
Beginning of 2017 also brought us some wonderful auroras and they were all caused by…you’ve guessed it! Coronal holes!
Has anyone noticed the Auroras disappear? I certainly did not!
So, that all sounds really good, but what is ahead of us?
Well, first of all, the coronal hole, which made several passes already, could return again. We might have to expect some new Auroras in the second half of January 2017. Also, there have been some smaller coronal holes popping up, so surprises can happen at any time and we might have an exciting end of 2016–2017 Aurora season as well! And let me remind you that March is usually a particularly good month for Auroras, because they are likely to be more powerful a few weeks around the Equinox time (22.3).
But what about the solar minimum? Well, it will surely come, we cannot stop it, but it will pass as well! When it lasts, we might have a bit fewer Auroras and smaller Auroras, but they are definitely not going to stop!
One thing to keep in mind. In the area of the “Aurora Belt,” which spans over Northern Finland, Sweden, Norway and Russia, seeing Auroras on a regular basis is likely even during the Solar minimum. So if you are really concerned about the Auroras, you might just travel a little bit more North, for example to Saariselkä, Levi, Ylläs, Kilpisjärvi and beyond.
Happy Aurora hunting!