Human beings, hanging out on the surface of Earth, generally don’t have to worry about the goings-on of our Sun. Sure, if it stopped shining, we’d be in for a world of hurt. Heck, in the dark ages, the Sun went quiet for about thirty years, and Europe suffered a mini ice age during what we call the Maunder Minimum. But in general, we’re fine.

While humans on Earth are generally unaffected by the Sun’s variations, our technology, including our power grid, are pretty sensitive to the fits and flares that sometimes come our way, and astronauts off of the Earth really need to worry. Now that our entire economy is reliant on the satellites above the Earth and the power grid on the Earth, we need to be able to forecast when the Sun is most likely going to misbehave so we can put tech and astronauts into safe modes and places.

Humans have known for a long time that the Sun has a 22-year cycle during which its magnetic field flips back and forth in polarity. For roughly eleven years, the Sun’s magnetic field will match the Earth’s alignment, and then for roughly eleven years, it will be oriented the opposite way. It is during the transition between these two states that things tend to get stormy on the Sun, and understanding how things transition is important to making space weather predictions. 

In new research appearing in The Astrophysical Journal and led by Sandra Chapman, researchers find the stormy period actually differs based on if the Sun is going from the north is up to north is down. For unknown reasons, the flip to north-is-down takes longer. According to Chapman: I also think it is remarkable that something the size of the sun can flip its magnetic field every 11 years, and going down-up is different to going up-down. Somehow the sun ‘knows which way up it is’, and this is an intriguing problem, at the heart of how the sun generates its magnetic field.

More Information

University of Warwick press release

“The Sun’s Magnetic (Hale) Cycle and 27 Day Recurrences in the aa Geomagnetic Index,” S. C. Chapman, S. W. McIntosh, R. J. Leamon, and N. W. Watkins, 2021 August 17, The Astrophysical Journal