Missed seeing the northern lights near you? The biggest storm may be yet to come.
Jordan Pegram, who wanted to cross off seeing the dancing lights from her bucket list, started driving west of Richmond to a cloudless dark area that May evening. “My first experience seeing the northern lights was truly mind-blowing,” Pegram said. “I never thought it would happen in south-central Virginia of all places.” People often spend thousands of dollars to travel to see the northern lights, but in recent months, many have seen the aurora without having to move much beyond their backyard. In the United States, geomagnetic storms have brought auroras to people from California to Texas to Florida. If you haven’t seen the aurora or are bouncing like an excited electron to see more, bigger events may be on their way over the next few years. Advertisement “The next three or four years, we should see some fine displays of aurora,” said Bob Leamon, a solar physicist at the University of Maryland Baltimore County and NASA. On May 10, when Pegram saw her first aurora, Earth was hit by the biggest geomagnetic storm in about two decades, with the most widespread aurora in probably 500 years. Just like Earth experiences thunderstorms, the planet also experiences stormy weather from the sun called geomagnetic storms. That solar punch often originates from explosions on the sun’s surface called coronal mass ejections, expelling charged particles laced with the sun’s magnetic field. Advertisement Such solar eruptions can affect satellite operations, interfere with radio frequencies and even disrupt power grids. The particles also travel along Earth’s magnetic field lines into our upper atmosphere, where they excite air molecules that release various colors of photons known as the aurora. Search now End of carousel But, in some years, changes on the sun mean Earth has a higher likelihood of seeing geomagnetic storms. About every decade or so, the sun’s north and south magnetic poles flip, which affects the solar activity seen at the surface. This “solar cycle” means some years are more active on the sun’s surface than others, usually measured by the number of dark blotches called sunspots. More visible sunspots mean more active, magnetically complex regions on the sun that can spawn flares and explosions. Not all of these sun’s eruptions hit Earth, but it’s like adding more darts to a dart board game — there are more chances one will land. Like assembling puzzle pieces, scientists are seeing some clues that the Sun is near its solar maximum. One way is to measure the number of sunspots, which has been steadily increasing since 2019 when the new solar cycle started. On Aug. 8, at least 299 sunspot groups were visible — the highest number since July 2002. When the monthly average number of sunspots peaks, that’s the sunspot maximum. Advertisement Another telltale but subtle sign is that rumblings of the next solar cycle will start to creep in, space weather scientist Scott McIntosh said. In July, scientists announced that they detected evidence of the next solar cycle moving in. When the cycle does reach the other side of the maximum, it will be good sign for aurora chasers. The biggest geomagnetic storms tend to occur in the year or two after reaching the maximum, a phenomenon known as the Gnevyshev gap, said McIntosh, vice president of space operations at Lynker and formerly the deputy director of the National Center for Atmospheric Research. It’s what comes in the next few years,” he said. “The storms get more complex, more frequent, and that makes them a bit more impactful for Earth.” Advertisement 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. “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. If you ask a scientist, this solar cycle is pretty average or even below it from a numbers perspective. Advertisement 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. 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. Advertisement 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. 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. Advertisement 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. – This Summarize was created by Neural News AI (V1). Source: https://www.washingtonpost.com/climate-environment/2024/08/18/aurora-activity-solar-storms-sunspots/