The sun would have passed the minimum of a secular cycle of magnetic activity (duration 70-100 years) known as Gleissberg cycle. In the next 50 years, the magnetic activity of our star could therefore increase, leading to a greater frequency and intensity of geomagnetic storms and northern lights here on earth. To affirm it is a new study led by Kalvyn Adams of the University of Pennsylvania and published in the magazine Space Weather.
Tendentially, when we talk about “solar cycles” we refer to the so -called Schwabe cyclea cycle of about 11 years which regulates the solar magnetic activity directly related to the abundance of sudden spots on the surface of our star. The Gleissberg cycle, longer, causes one modulation of the intensity of the eleising cycles: in other words, “decides” how “strong” the SCWABE cycles are. At the moment we are close to the maximum of the Undecenial cycle (the 25th since we record the sun activity) but close to the minimum of the Gleissberg cycle: this should lead to an average strengthening of the hidden cycles in the next half century.
It is important to be aware of the expected behavior of our star since geomagnetic storms, in addition to causing splendid auror, can disturb or completely put satellites completely out of use, with potentially devastating consequences on our interconnected world.
What the study on the cycle of Gleissberg of the sun
The study examined the data collected by Poes satellites (Polar Operational Environmental Satellites) of the Noaa. These satellites monitor the earth in onepolar orbit and in doing so they cross a particular region of the Earth’s magnetosphere known as Anomaly of the South Atlanticin which the intensity of the Earth’s magnetic field is lower. Scientists monitored the flow of charged particles within this region, discovering that it is first increased between 1998 and 2021 and subsequently decreased between 2022 and 2024. Since in the Gleissberg cycle to an increase in the flow of particles charged in this anomaly is associated with a decrease in solar activity and vice versa, the measurements of Adams and colleagues would indicate the exceeding the minimum of the Gleissberg cycle.
What are the effects of the increase in solar activity
A trend of increasing the intensity of the solar magnetic activity has consequences that are not limited to solar spots only. The greater the magnetic activity, the more likely it is that the sun releases Expulsions of Coronal Mass and energy brilliantwhich can cause severe geomagnetic storms on earth, which can cause serious damage to satellites in orbitbut also to Electric infrastructure On the ground, due to the electric currents induced in the earth’s crust. Having exceeded the minimum of the Gleissberg cycle, it is expected that in the next 50 years the intensity of solar activity increases significantly. However, as Professor told Ansa Mauro Messerottiprofessor of Space Meteorology at the University of Trieste, there is no certainty of this increase: for example, the scientific community has no unanimous consensus on the duration of the Gleissberg cycles.
What is the Gleissberg cycle
The eleising cycle of magnetic activity of the sun, associated with the presence of sunspots, takes the name of Schwabe cycle. This is the cycle that we always hear about, but it is not the only one to whom our star is subject. In fact, there are Cycles of much longer durationfrom centuries to millennia. Scientists, in the study published in the magazine Space Weatherdetermined that our star has recently passed the minimum of Gleissberg cyclewhich is the one that lasts including between 70 and 100 years. The effect of the Gleissberg cycle is that of Modular the intensity of the eleising cycles.
Let’s try to explain it with a simple analogy. Imagine that the eleising cycle is like a melody that is repeated every 11 seconds. Now in a 70-100 second time span, increase and decrease the volume of music over time. The melody remains the same every 11 seconds, but there are periods in which it feels stronger (more solar activities) and others in which it is weaker (less solar activities). The Gleissberg cycle therefore represents one Slow modulation of the intensity of a faster cycle: We have recently passed the minimum volume phase of our melody.
