The Sun wakes up

We are monitoring the sun, which is approaching its maximum activity faster than expected, with very numerous solar storms, much more than 20 years ago.

The weekend science post with Mathilde Fontez, editor-in-chief of the scientific magazine Epsiloon is interested in Sun specialists who are sounding the alarm: our star is very active at the moment.

franceinfo: The activity of the Sun is more intense provided that ?

Mathilde Fontez: Yes, and it’s starting to be seen on Earth: en March, a solar storm caused northern lights in 30 American states. At the end of February, we were even able to see an aurora at Mont-Saint-Michel. Normally, they only form at high latitudes. The fact that we can observe them as far as Normandy indicates very intense solar storms.

And there are also the spots on the surface of the Sun, which researchers monitor, because they reflect the activity of the star. They are going in the same direction: there were 159 in July, 115 in August, that’s a lot, it’s a level not seen in 20 years. So yes, the sun is waking up. We seem to be moving towards maximum activity, within a year. Even by the end of 2023according to some researchers.

Does a solar maximum mean more solar storms?

No more solar flares, yes: the plasma on the surface of the sun agitates and propels jets of matter and radiation into space, which sometimes reach the Earth. This phenomenon is normal: we have known for a long time that the Sun follows a cycle of approximately 11 years, where it goes from a minimum to a maximum of activity.

The first recorded cycle took place between 1755 and 1766. Here we are in cycle 25, which started in 2019. Except that researchers expected the peak to be reached in 2025, it is happening faster than expected. This cycle also seems very intense, especially compared to the previous one, which had been very mild.

What is happening ?

We do not know. I assure you, no one suspects that the Sun is going haywire. What we see above all is that specialists still have difficulty predicting the intensity, the rhythm of the Sun’s activity. We do not understand the physics of the star in detail enough to make reliable predictions. Even with the most advanced models which combine all the data, much like climate models do, it doesn’t work.

This maximum which arrives will therefore be particularly scrutinized by researchers, to try to improve the models. Crossing our fingers that the strongest eruptions do not go towards Earth. Because that’s the point: these bursts of particles can ionize the Earth’s upper atmosphere, and create large-scale radio and satellite failures. Hence the importance of predicting them.


source site-15