The Sun is currently experiencing an unusually intense period of activity. In August, the number of sunspots recorded reached a level unseen in nearly 23 years. What does this surge reveal?
These sunspots, dark areas on the Sun's surface, are visible signs of increasing solar activity. They appear when electromagnetic eruptions cross the star's magnetic field. Scientists use their number to track the solar cycle's progression, a regular process lasting about 11 years, marked by phases of minimum and maximum activity.
Last August recorded a daily average of 215.5 sunspots, far exceeding the initial predictions that anticipated only 107.8. This overactivity suggests that the current solar cycle, the 25th since observations began, could be much more intense than expected.
This peak in activity doesn't surprise some experts who had already noted deviations from predictions. Since 2022, the number of sunspots has steadily increased, even surpassing the maximum values of the previous cycle, cycle 24. In August 2023, a peak was reached with 337 visible sunspots in a single day, a record since 2001.
This heightened solar activity impacts not only our understanding of the Sun's cycles but also has tangible effects on Earth. Geomagnetic storms, caused by solar eruptions, can disrupt communication systems, damage satellites, and even cause large-scale power outages.
In May, a geomagnetic storm of unprecedented strength in 21 years dazzled the skies in many parts of the world with spectacular polar auroras. A few days later, the Sun released a solar flare of magnitude X8.7, the most intense since 2017, further highlighting the dangers of this solar maximum period.
There was an average of 215.5 visible sunspots on the Sun's surface each day in August. This timelapse image shows each visible black spot crossing the Sun during this period.
Credit: SDO/Şenol Şanlı/Uğur İkizler
Scientists remain cautious about the future development of this cycle. Although forecasts have been revised, indicating a probable activity peak in 2024, uncertainty persists. It's possible that the activity may continue to intensify, extending the solar maximum over several months, or even years.