There’s a big wave of excitement rolling through the aurora community right now, and that wave is called “Solar Maximum”. I’m sure you’ve seen your local and national press announcing headlines like “Aurora to be seen all over the UK this week”, or “Aurora visible in mainland US tonight”, and these announcements are becoming more and more frequent. And, they’re becoming frequent because of the current stage of Solar Cycle 25 – Solar Maximum. So, I thought it would be useful to talk through what “Solar Maximum” means and why this is getting us all excited!
For the purpose of this blog I’m going to talk about the Solar Cycle lasting eleven years. There has been some exceptions with lengths from around nine to thirteen years, and an extremely rare one over 70 years. However the average is around eleven years. And the cycle happens due to how active the sun’s magnetic field is. We then split this eleven years into two halves, so we get two periods of five and a half years. These five and half year periods have different names, one is called Solar Minimum, and the other Solar Maximum (I hope you’re still with me)!
The two periods, minimum and maximum are determined by the presence (or lack of) of sunspots within the sun’s magnetic field. During Solar Minimum sunspots fall to a minimum, and for Solar Maximum, sunspots reach a maximum. For first five and a half years, sunspot activity gets weaker and weaker, and then this builds for the next five and a half years. The peak of each cycle is the actual point of Solar Minimum, and Solar Maximum, however we refer to each five and a half period as Solar Minimum and Solar maximum too.
I started leading tours for Lights Over Lapland here in Abisko in the winter of 2016. Solar Minimum had just begun, and so the sunspot numbers became less and less over the coming years. The peak of the Solar Minimum occurred in 2019 when sunspot numbers were staggeringly low, an incredible two hundred and eight one days were recorded where there wasn’t a recorded sunspot on the sun facing the earth. We are now firmly in the grip of the current Solar Maximum, and that means lots of sunspots. For the whole of 2022 there was just one day in the year where there wasn’t a recorded sunspot.
So what are sunspots and why are they important?
A sunspot is a knot in the sun’s magnetic field, the big ones can even be seen from Earth using binoculars and special filters and a projection method (don’t look directly at the sun using any equipment)! To give an idea of size on average they are about the size of Earth, the largest can be up to twelve times as big! Sunspots look darker than the sun because the strength of the magnetic field makes them cooler, the sun’s heat can’t escape as fast from the sun itself. The magnetic field is basically tangling itself into a big knot, and sometimes under certain conditions this can cause an eruption from the surface of the sun called a solar flare. Occasionally, from an eruption of a solar flare we get a Coronal Mass Ejection, or a CME. This is a huge bubble of radiation and charged particles which is hurled into space. Hopefully it’s in an earthward direction, if so then big auroras can happen, and could be seen as far south as lower US states and southern Europe, and Australia and New Zealand!
The table below shows the sunspot numbers from 2010 to the present. Lights Over Lapland began offering aurora tours in Abisko in 2010, which also coincided with the last Solar Maximum. In 2010 there were fifty-one spotless days, to a total of only three spotless days over the next five years. If we then look at the years after 2016 you can see the spotless day count increase significantly, reaching a peak of 77% days in 2019. Then as the sun’s magnetic field becomes stronger the numbers begin to decrease again, bringing us to only one day since the beginning of 2022.
If we’re really lucky, the next three years we will see sunspots facing Earth for 100% of the duration, and then we will creep into the next Solar Minimum.
YEAR SPOTLESS DAYS PERCENTAGE
2010 51 14%
2011 2 <1%
2012 0 0%
2013 0 0%
2014 1 <1%
2015 0 0%
2016 32 9%
2017 104 28%
2018 221 61%
2019 281 77%
2020 208 57%
2021 64 18%
2022 1 <1%
2023 0 0%
Why is this important for aurora hunters?
Having guided a full Solar Minimum I still experienced many bright full-sky auroras. However, with the sheer quantity of sunspots during Solar Maximum, the chances of seeing an enhanced, turbo-charged, full-sky rippling and dancing aurora becomes much greater. The biggest auroras I have seen have been over the last two seasons, with the previous 2022/3 season being the best. It’s possible for the Earth to be bombarded by several CMEs over a short period and things can go absolutely crazy. This is unlikely to happen during Solar Minimum, however there are other solar conditions that can still cause big bright auroras, so don’t write this off.
If you are thinking about visiting the Arctic to witness the amazing phenomenon of the aurora borealis, then I would strongly advise you to look at visiting over the next two to three years. The peak of Solar Maximum is forecasted for 2025 and myself and all the guides at Lights Over Lapland would love to host you and help you try and see something truly magical. Go on, you know you want to!