Northern Lights Ramping Up Intensity, More Chances To See Them Expected

The northern lights, seen as far south as Florida and Texas in recent days, may be ramping up in intensity over the next 50 years as the sun enters a little-known phase of heightened activity, some scientists believe.

One of nature’s most beautiful natural phenomena, the aurora borealis is triggered by powerful solar flares and coronal mass ejections, or CMEs. These charged particles, carried to Earth by solar winds, collide with gases in our atmosphere that emit light and create the aurora.

Traditional thinking is that solar activity naturally waxes and wanes throughout the 11-year solar cycle, swinging from a calm period known as solar minimum to a more intense period marked by the intense activity seen in the past year and a half known as solar maximum.

Solar Cycle 25 reached maximum last fall, in a year that saw a powerful G5 storm in May that triggered aurora displays around the world but also disrupted GPS technology, stalling tractors during the spring planting season. Another powerful storm sent the northern lights far south in October 2024, and the recent displays were stronger than that, according to NOAA.

Tuesday and Wednesday’s widespread displays fit the same pattern.

The intensity of the Solar Cycle 25 maximum has surprised space weather scientists and forecasters. It has been one of the most active on record, and they’re not quite sure why.

“It’s one of the many mysteries to unravel,” space weather forecaster Shawn Dahl explained in an October 2024 briefing with reporters after solar maximum was officially reached.

At the time, Dahl and others said intense geomagnetic storms could continue well into 2025 and perhaps 2026, creating more northern displays outside the Arctic range well into 2025 and perhaps 2026.

A Tie To 100-Year Cycle?

Some solar scientists think they’ve solved the riddle — that space weather isn’t influenced by a single solar cycle.

Their theory, published earlier this year in the journal Space Weather, is that the solar maximum is tied to the lesser-known Centennial Gleissberg Cycle, a longer-term period of solar activity that spans 80 to 100 years.

The cycle is named after German astronomer Wolfgang Gleissberg, who discovered the longer-term cycle hiding, in effect, behind the 11-year cycles of rising and falling solar activity about 70 years ago.

That suggests that whether one solar cycle is stronger than the other is not random, but part of the larger whole.

“Usually, over four solar cycles, the intensity of solar activity will increase,” Kalvyn Adam, a former researcher with the National Center for Atmospheric Research and lead author of the study, told Space.com. “Then it will reach its peak, and then it will go down over another four solar cycles.”

The researchers suggest this cycle may have “just turned over” and is starting anew, which is why solar maximum in Solar Cycle 25 was more difficult to pin down than initially expected.

Longer Cycle May Be Ramping Up

Previous research, including a 2023 study and a 2024 paper, has suggested the CGC, as the long-term cycle is known, may have played a role in increased sunspot activity. But the new study is the first to suggest that the longer cycle’s minimum may be over.

If they’re correct, the ethereal curtains of green, red, pink, purple and yellow lights that have delighted people around the world could become more commonplace.

Pretty sky paintings aside, the research, funded with an Air Force Office of Scientific Research grant, has broad implications for the military, as well as others using satellite technology.

“This changing space climate will have implications for the design and operation of future satellite missions,” the authors said.

‘Too Early’ For Conclusions

There’s broad disagreement among solar scientists about the validity of the theory.

It’s “too early” to draw conclusions about the role of the CGC, Scott McIntosh, formerly of the National Center for Atmospheric Research at the University of Colorado Boulder and now at space weather company Lynker Space, told LiveScience.

McIntosh also suggested the paper may overestimate the effects of the CGC.

Lisa Upton, a heliophysicist at the Southwest Research Institute, told Scientific American that scientists have limited data to work with.

“It’s kind of debatable whether or not this is a physical phenomenon versus a statistical phenomenon,” Upton said.

Even if the Solar Cycle 25 maximum is unrelated to the Centennial Gleissberg Cycle, there’s a good chance that the next couple of solar cycles, at least, will be more active than over the last decades, according to Upton.

That’s because Solar Cycle 24 in the 2010s was underwhelming, one of the weakest on record.

“We, as humans, have a short memory, and a lot of people have been wowed and amazed by what’s been going on in the last year or two on the sun,” Upton told Scientific American. “There’s this tendency for us to forget this longer-term variability in what the sun is doing.”

• Related: 2024 Was The Year Of The Sun, Going Dark In A Total Eclipse And Sending Dazzling Northern Lights Far South