The Sun provides the charged particles that create aurorae at Ganymede, but those same charged particles also hit Earth’s atmosphere and create aurorae. That’s nice and pretty. It’s a lovely side effect of space weather, but not all space weather is so friendly.

Larger coronal mass ejections can cause big problems here on Earth. Back in 1859, a solar storm hit Earth and caused what we call the Carrington Event, which impacted the telegraph system from Melbourne, Australia to New York. We’re even more reliant on electronics and satellites today. In 1989, another event caused blackouts in Canada. And we were missed by a huge coronal mass ejection in 2012 by just nine days.

Okay, that’s kind of scary. So what do we do? First, how much lead time do we have between a solar event and it hitting Earth and possibly wreaking havoc? It ranges from just several hours to a few days. That’s really not a lot of time, although if we have systems in place to warn us, we can shut down satellites and prepare electrical systems for the potential impact. That could help.

What we really need, though, is a way to predict sunspots and solar flares and all these other types of activity that could affect us here on Earth. Except, we don’t understand how sunspots form. We don’t have a complete picture of the inner workings of the Sun. We know it’s made of distinct regions, and one of those regions is the convection zone — super-hot, turbulent, roiling plasma that takes up the outer 30 percent or so of the Sun’s diameter. Within that zone are convection cells, but we’re not sure how they work. We have some hypotheses, one of which involves circular swirls, similar to what we model in moisture transfer in storm cells here on Earth. However, we have never found evidence of these circular cells. So, that’s great.

Enter Dr. Geoffrey Vasil and his team, who have developed a new, strong theoretical framework for modeling our Sun and those convection cells. Instead of the traditional circular cells we see in so many diagrams, Vasil has proposed that the cells are, per the press release: …tall spinning cigar-shaped columns ‘just’ 30,000 kilometers across.

Vasil goes on to explain: You can balance a skinny pencil on its point if you spin it fast enough. Skinny cells of solar fluid spinning in the convection zone can behave similarly.

By changing the model, the team has managed to properly account for this rapid rotation, which can suppress larger-scale convection and create a more varied pattern of movement in the upper third of the Sun. This new model could help us better understand the Sun’s behavior when it comes to electromagnetic activity, like those sunspots, flares, and ejections. And any further understanding of the Sun might just help us predict a solar storm and help us prevent damage to all our electronic infrastructure and the clouds of satellites happily working away above us.

This work appears in the Proceedings of the National Academy of Science.

More Information

The University of Sydney press release

“Rotation suppresses giant-scale solar convection,” Geoffrey M. Vasil, Keith Julien, and Nicholas A. Featherstone, 2021 August 3, PNAS