Auroras could appear next week as solar activity increases

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Colorful auroras could appear again soon in parts of the United States — including northern states and the upper Midwest, from New York to Idaho — due to a solar storm that could impact Earth, according to the National Oceanic and Atmospheric Administration . Space Weather Prediction Center.

The center, a division of the National Weather Service, issued a modern geomagnetic storm warning, known as G2, for Friday and Saturday. Unlike G5, or extreme geomagnetic storm, which took place on May 10thModerate thunderstorm warnings are not uncommon, according to the center.

But the aurora-causing solar flares and coronal mass ejections currently emitted by the Sun are the result of the same sunspots that triggered solar activity in May, according to Dr. Ryan French, a solar physicist at the National Solar Observatory in Boulder, Colorado. .

Coronal mass ejections are large clouds of ionized gas called plasma and magnetic fields that erupt from the Sun’s outer atmosphere. When these explosions are aimed at Earth, they can cause geomagnetic storms or large disturbances in Earth’s magnetic field.

As the sun approaches solar maximum – the peak of its 11-year cycle, predicted for this year – becomes more active and researchers have observed increasingly intense solar flares erupting from the fiery orb.

Increased solar activity causes auroras that dance around Earth’s poles, known as the northern lights, or aurora borealis, and the southern lights, or aurora australis. When energized particles from coronal mass ejections hit Earth’s magnetic field, they interact with gases in the atmosphere to create different colored lights in the sky.

The Sun rotates on its axis once every 27 days, which scientists have learned by tracking sunspots. These dark regions, some of which may be Earth-sized or larger, are driven by the star’s strong, ever-changing magnetic fields.

The large, complex clusters of sunspots on the Sun’s surface that drove the increase in solar activity in May survived their rotation around the Sun. The European Space Agency’s Solar Orbiter mission, which is currently studying the back of the Sun, was able to monitor the progress of sunspots while they were out of sight of Earth’s telescopes.

Now, sunspots are returning to the Earth-facing side of the Sun, meaning the chances of dazzling auroras could increase over the next week, experts say.

The birth of solar storms

While it’s typical for sunspot clusters to survive two to three rotations around the Sun, they typically decay after one rotation and become less active, French said.

The sunspot cluster that is now returning is still capable of producing X-class flaresthe largest of solar flares, but the frequency appears to have decreased, he said.

French observed two Class X seizures per day for about six days in May.

“It’s probably the biggest cluster of Class X explosions we’ve had in a 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.”

Now, sunspots are producing flares every two days, so the frequency has decreased and the complexity of the sunspot cluster has decreased, French said.

Earth is predicted to “just reach the threshold” of the coronal mass ejection currently en route, French said.

Sunspots will face Earth most directly between Tuesday and Thursday, French said.

“Any larger eruptions during this period, and a few days outside of this window, could cause an eruption coming towards us and that could cause a geomagnetic storm,” French said. “The frequency of things is decreasing, but you only need one to cause a huge geomagnetic storm. Whether this one will be big enough to cause something similar to what we saw in mid-May, I think is unlikely.”

Keep an eye out for auroras during the Tuesday through Thursday window, as well as a few days afterward, French said. Auroras can be visible to millions of people, but the location depends on whether any coronal mass ejections affect Earth.

A panel of experts typically declares the peak of solar maximum well after it has passed, so scientists cannot say whether solar maximum is occurring at this time. But the chances of solar activity are expected to increase over the next two years, French said.

“The thing about solar cycles is that sometimes they have a double peak,” said Shawn Dahl, services coordinator at the Space Weather Prediction Center. “Sometimes the southern hemisphere (of the Sun) or the northern hemisphere peaks first.”

Near the peak of solar maximum, sunspots tend to congregate around the equator. But the sunspot clusters that were active during the past month were in the sun’s northern and southern hemispheres, Dahl noted.

Although scientists can track active sunspot clusters, others can appear at any time during the period leading up to solar maximum.

“We could have a new group of sunspots appear right in front of us,” Dahl said. “We have no way of knowing what is about to happen until we see it. This is how it will be throughout this year, until next year and until 2026.”

Lessons learned from solar storms

The storm of May 10 was historic, but fortunately it did not reach the level of the Carrington Event of 1859, which caused telegraph stations to light up and catch fire and remains the most intense geomagnetic storm on record.

Before May 10, the last G5 storm to hit Earth occurred in 2003, resulting in power outages in Sweden and damaged transformers in South Africa.

Since then, governments have taken steps through legislation, research and operations to mitigate the potentially negative impacts of solar storms, Dahl said.

The May 10 solar storm was the most successfully mitigated space weather storm in history, Dahl said.

“All this work and preparation has led to this moment, and the nation could not be more prepared for a space weather storm,” he said.

With these events, there is always the possibility that communications, the electrical power grid, navigation and radio and satellite operations will be affected. During the May 10 storm, power grid and satellite operators kept satellites in order and properly in orbit and managed the build-up of intense geomagnetic currents in grid systems.

Extreme solar storms can cause swelling in Earth’s atmosphere, which changes the level of drag satellites experience, so it’s harder for operators to keep them within their specific trajectories, according to the European Space Agency.

“There were a lot of effects that people won’t hear about because things were successfully mitigated where we didn’t see as many direct impacts,” Dahl said.

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