The solar maximum is coming faster than expected. We still don’t know why

The sun changes its activity in successive solar cycles, lasting 11 years each. During each cycle, the activity of our star increases for several years, reaching its maximum, and then decreases for several years until it reaches its minimum. It is not clear what causes solar cycles and why they last 11 years. However, for decades scientists have been able to calculate when subsequent periods of solar activity begin and end and confirm the approaching maximum by observation. During the greatest activity, numerous spots appear on the disk of our star and the influence of the solar wind on the Earth increases.

From data including: NASA shows that the current solar cycle began in December 2019, so it will probably last until the end of 2030. Observing the behavior of the Sun, scientists calculated that maximum activity should most likely occur in July 2025. Now it turns out that probably won’t happen. How a team of scientists led by Robert Leamon of NASA and Scott McIntosh of NCAR (National Center for Atmospheric Research) disagrees with these calculations.

Researchers note that the Sun appears to be preparing to enter maximum faster than in previous cycles. Therefore – as the team calculated – our star should reach its maximum a year earlier, i.e. in mid-2024. Moreover, solar activity and the number of sunspots during this period should, according to researchers, exceed scientists’ expectations twice.

Leamon and McIntosh note in their study that the moment of transition from one solar cycle to another is not sudden and abrupt, but gentle and slow. The moment of the cycle change is calculated based on the ratio of the number of new to old sunspots. And although the 24th cycle officially ended in December 2019, the last sunspots disappeared from the disk of our star until December 2021. However, the exact reasons for the earlier maximum occurrence (and the predicted increased solar activity) remain unknown.

What does this mean for us?

Each solar maximum is associated with significantly greater emissions of radiation and matter sent into interplanetary space. Some of this matter in the form of plasma constantly hits the Earth’s magnetic field (solar wind) at enormous speed. However, stronger flares on the Sun trigger coronal mass ejections, which – after reaching Earth – are responsible for the formation of brighter auroras and magnetic storms.

The increase in solar activity translates into an increased number of magnetic storms, which in turn may pose a threat primarily to artificial satellites in orbit, but also in extreme cases to infrastructure on the planet’s surface (including power stations). It is believed that powerful magnetic storms like those in 1859 and 1989 would cause a global catastrophe today. Fortunately, the vast majority of coronal mass ejections end only with beautiful aurora borealis, often observed even in northern Poland.