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Colorful weather in parts of the United States, including northern and upper Midwestern states from New York to Idaho, due to a solar storm that could affect Earth, according to the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center The polar lights may reappear soon.
The center, a division of the National Weather Service, issued a modern geomagnetic storm watch, known as G2, for Friday and Saturday. Observations of moderate storms are not uncommon, unlike the G5, or extreme geomagnetic storm, that occurred on May 10, according to the center.
But solar physicist Dr. of the National Solar Observatory in Boulder, Colorado. According to Ryan French, the solar flares that cause aurora and the coronal mass ejections currently emitted from the sun are a result of sunspots that trigger solar activity in May.
Coronal mass ejections are large clouds of ionized gas and magnetic fields, called plasma, that erupt from the sun’s outer atmosphere. When these bursts are directed towards the Earth, they can cause geomagnetic storms or major disturbances in the Earth’s magnetic field.
The Sun is becoming more active as it approaches solar maximum (the peak of its 11-year cycle expected this year), and researchers have observed increasingly intense solar flares from the fiery sphere.
Increased solar activity causes dancing auroras around the Earth’s poles, known as the northern lights, or aurora borealis, and the southern lights, or aurora australis. When energetic particles from coronal mass ejections reach the Earth’s magnetic field, they interact with gases in the atmosphere, creating different colored lights in the sky.
The Sun rotates around its axis every 27 days, and scientists learned this by tracking sunspots. These dark regions, some of which can reach Earth size or larger, are driven by the star’s powerful and ever-changing magnetic fields.
Large, complex clusters of sunspots on the sun’s surface that caused increased solar activity in May managed to survive their rotation around the sun. The European Space Agency’s Solar Orbiter mission, which is currently studying the backside of the sun, has managed to track the progression of sunspots while out of view of telescopes on Earth.
Experts say sunspots are now returning to the Earth-facing side of the Sun, which means dazzling aurora displays could increase next week.
The birth of solar storms
It’s typical for sunspot clusters to survive two to three orbits around the sun, but they usually decay and become less active after one orbit, French said.
He said the now-returning sunspot cluster is still capable of producing Class X explosions, the largest of the solar flares, but the frequency appears to have decreased.
The French observed two Class X flares per day for approximately six days in May.
“It’s probably the highest cluster of Class X flares we’ve encountered in the last few decades,” French said. “This current solar cycle appears to be more active than the 2014 peak, but not as active as the 2003 peak.”
French said sunspots now produce outbursts every two days, so the frequency is decreasing and the complexity of the sunspot cluster is decreasing.
Earth is predicted to “catch the tip” of the coronal mass ejection now underway, French said.
Sunspots will look more directly at Earth between Tuesday and Thursday, French said.
“Larger eruptions that could occur during this period and over a few days outside of this window could cause an eruption coming toward us, which could cause a geomagnetic storm,” French said. “The frequency of events is decreasing, but you only need one to cause a major geomagnetic storm. I think it’s very unlikely that this will be big enough to cause something matching what we saw in mid-May.
French said to keep an eye out for auroras Tuesday through Thursday and for a few days afterward. Auroras can be seen by millions, but their location depends on whether any coronal mass ejections are impacting Earth.
A panel of experts usually declares the peak of the solar maximum long after that peak has passed, so scientists cannot say whether the solar maximum is occurring at this time. But French said an increase in solar activity is expected over the next two years.
“The thing about solar cycles is that sometimes they have a sort of twin peak,” said Shawn Dahl, service coordinator for the Space Weather Prediction Center. “Sometimes the (sun’s) southern hemisphere or northern hemisphere peaks first.”
Near the peak of solar maximum, sunspots tend to cluster around the equator. However, Dahl noted that the sunspot clusters that were active last month were in the sun’s northern and southern hemispheres.
Scientists can track active sunspot clusters, while others can appear at any time toward solar maximum.
“We could have a new group of sunspots appear right in front of us,” Dahl said. “We have no way of knowing until we see it coming. It’s going to be like this throughout this year, next year, and even into 2026.”
Lessons learned from solar storms
The May 10 storm was historic, but fortunately it did not reach the level of the 1859 Carrington Event, which caused telegraph stations to spark and catch fire and remains the most intense geomagnetic storm ever recorded.
Before May 10, the last G5 storm to hit Earth occurred in 2003, resulting in power outages in Sweden and damaged power transformers in South Africa.
Dahl said that since then, governments have taken measures through legislation, research and operations to reduce the potential negative effects of solar storms.
The May 10 solar storm was the most successfully mitigated space storm in history, Dahl said.
“All of this work and preparation led to this moment, and the nation could no longer be prepared for a space weather storm,” he said.
There is always the possibility that communications, power grid, navigation, radio and satellite operations may be affected by these events. During the May 10 storm, power grid and satellite operators kept satellites in steady orbit and managed to generate intense geomagnetic currents on grid systems.
Extreme solar storms can cause Earth’s atmosphere to swell, which changes the level of drag satellites experience, making it more difficult for operators to keep satellites within their specific orbits, according to the European Space Agency.
“There were a lot of impacts that people wouldn’t hear about because things were successfully mitigated where we couldn’t see much of the direct impacts,” Dahl said.
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