Missed seeing the northern lights near you? The biggest storm may be yet to come.
Recent aurora displays have been just a warm-up.
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Coming off its solar maximum, the sun becomes a complex, muddy mess. As tendrils of the next solar cycle move in, it can merge with the old solar cycle. McIntosh said the two systems have different polarities and can get tangled with each other. When the systems merge, the pluses and minuses start to realign to make the simplest configuration. But as it goes through this intricate spaghetti rearrangement, enormous amounts of energy are released.
“When these hybrid systems pop through the surface, they almost instantly unwind to try and reduce the stress,” McIntosh said.
The result is very, very large storms — maybe even bigger than the one on May 10.
How intense will the upcoming years be?
If you ask a scientist, this solar cycle is pretty average or even below it from a numbers perspective. That’s not necessarily a bad label for aurora chasers.
So far, monthly sunspot numbers for this summer have reached about the peak of an average cycle, according to data from the Austrian Space Weather Office at the GeoSphere Austria. Before this summer, the number of sunspots have been below the average.
As far as coronal mass ejections from the sun, the data shows 31 storms impacted Earth last year. This year, Earth is expected to receive about 40 to 50 hits. Another 40 to 50 are expected to hit Earth in 2025. In a world of perfect statistics, that would mean an impact about once per week on average. In reality, eruptions often bombard Earth together to create a strong geomagnetic storm.
“It’s quite fascinating that we get all these current [coronal mass ejection] impacts and aurora events,” even though sunspots are still below an average cycle compared to the ones since 1750, said Christian Möstl, head of the Austrian Space Weather Office.
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Seven G4 storms have hit since the beginning of this solar cycle, which is average for this stage in the current cycle, space weather forecaster Sara Housseal said. If the season remains on par with past equitable cycles, Housseal said the average cycle has about 20 G4 storms, meaning we could have a decent number of G4 storms left in the tank. If you follow numbers from the National Oceanic and Atmospheric Administration, an average cycle sees around 100 G4 storms, although that may be optimistic.
“Activity is still on the rise towards solar maximum, so we should continue to see more G4s and possibly G5s before the cycle is done,” Housseal said.
Then there’s the chance this cycle could end up above average. The fact that we already had one G5 storm in May when the solar cycle wasn’t even at peak “speaks volumes about how active this cycle could potentially still be,” said Shawn Dahl, the service coordinator for NOAA’s Space Weather.
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For a stronger than average cycle, Earth could get hit by about 60 or even 70 coronal mass ejections. “During such a cycle maximum, aurora at low latitudes could be an almost common sight, happening every other month or so,” Möstl said.
Models show the solar cycle will be relatively short at around 10.5 years, Leamon said. He added the “last best flare” may occur in the first quarter of 2028, although predictions will continue to be refined.
https://www.washingtonpost.com/climate-environment/2024/08/18/aurora-activity-solar-storms-sunspots/
