A team of scientists has revealed that the first signs of the next solar cycle of our Sun have already been detected, even though it is only currently halfway through its 11-year cycle. Researchers from the University of Birmingham announced the findings at the Royal Astronomical Society’s National Astronomy Meeting in Hull.
The Sun is now in the full swing of its 25th recorded solar cycle, known as Cycle 25, which began in 2019. Solar maximum is the period when there is an increased level of activity of sunspots, solar flares, and coronal mass ejections. These phenomena boost emissions toward Earth; the result will be frequent and more visible aurorae at lower latitudes.
According to researchers led by Dr. Rachel Howe, very faint signs of Cycle 26 are already noted in the analysis of internal sound waves of the Sun. The waves allow experts to measure the Sun’s rotation, which shows a series of bands that rotate at somewhat different speeds. These bands, known as solar torsional oscillations, seem to move toward the equator and the poles of the Sun during an activity cycle.
“We’re likely seeing the first traces of Cycle 26, which won’t officially start until about 2030,” Dr. Howe explained. The team’s findings are based on helioseismic data collected since 1995 from various solar observatories, including the Global Oscillation Network Group (GONG) and space-based instruments.
The solar cycle is mainly driven by the complex dynamics of the Sun’s magnetic field, created during the process called the solar dynamo. It is governed by plasma motion within the Sun. Essentially, in one cycle, a flop, that is, the exchange of magnetic north and south poles, must take place, occurring during the maximum of a solar cycle.
At solar minimum, there is a low count of sunspots because the magnetic field is stable and thus often takes a dipole structure, so there is a minimum amount of solar activity. As the solar maximum is approached- and we are doing so the numbers of sunspots go up since the solar magnetic field is more complex and twisted, which in turn leads to a rise in the frequency of solar flares and coronal mass ejections. The next solar maximum is expected to be between the end of 2024 and the beginning of 2026.
According to Roger Dube, a physics professor at the Rochester Institute of Technology, as we get closer to the maximum activity, the sunspots fire off solar flares, the peak activity happening in mid-cycle. Solar flares are caused when the magnetic fields of the Sun get twisted. If the magnetic fields break, it can lead to a solar flare. Solar flares are electromagnetic storms on the surface of the Sun. By Earth’s standards, these are huge, about the size of a planet, and the electromagnetic effects can be intense even as far away as Earth. It is not uncommon for these flares to emit so much solar plasma into space in the form of a Coronal Mass Ejection, or CME.
This early detection will, in this case, aid in understanding the behavior of the Sun and in forecasting its influence on Earth. Solar cycles impact space weather, which affects operations on Earth and in space of satellites radio communications, and even the power grid.
If scientists can continue to track these early signatures, their results may improve predictions of solar activity and its effects on Earth, perhaps strengthening our ability to take readiness steps and possibly even mitigating the consequences of space weather. Dr. Howe added, “With more data, I hope we can learn more about the role these flows play in plasma and magnetic fields’ intricate dance that makes up the solar cycle.”
The discovery puts the persistent observation of the sun in the long term and the ceaseless effort by the scientific fraternity into perspective on revealing the secrets of our closest star.