New research reveals unprecedented atmospheric changes during May’s geomagnetic superstorm

On May 11, a magnificent aurora borealis surprised astronomers in the southern United States. That same weekend, a GPS-guided tractor missed its target.

What do northern lights visibility and damaged farm equipment in the Midwest have in common?

A geomagnetic storm of unique power, according to two papers co-authored by Virginia Tech’s Scott England.

“The northern lights are caused by energetic, charged particles hitting our upper atmosphere, which are impacted by many factors in space, including the sun,” said England, associate professor in the Kevin T. Crofton Department of Aerospace and Ocean Engineering.

“During solar geomagnetic storms, there are a lot more of these energetically charged particles in the space around the Earth, so we see a brightening of the aurora borealis and the region over which you can see them expands to include places like the lower 48 contiguous states that don’t typically see this spectacle.”

England and a team of academic and industry collaborators tracked the May 11 atmospheric event using NASA’s GOLD instrument, and it turned out to be the most powerful geomagnetic storm recorded in the past 20 years.

Their findings were published in Geophysical Research Letters Two studies, both co-authored by England, found unprecedented changes in the location and spread of particles in the upper atmosphere. The second study, by first author and Virginia Tech alumnus J. Scott Evans, documented changes in composition and temperature.

Among the data collected, England noted that he first observed “charming swirling patterns” and a dramatic movement of air away from the aurora, causing huge vortices to form that moved the air in a spiral larger than a hurricane. Specific observations included:

• Unpredictable motion of low-energy charged particles around the equator toward the aurora
• Charged particles that can be divided into two categories: low energy and high energy, the latter of which can injure humans working in space and damage electronics
• Temperature and pressure changes likely to cause the observed eddies and swirls
• Changes in location and propagation of low-energy particles, which can negatively impact GPS, satellites and even the power grid

“As the aurora gets stronger, you see more light, but at the same time, more energy is entering the atmosphere, which makes the atmosphere near the poles very hot, which starts to push air away from the poles and toward the equator,” England said.

“These data raise many questions, such as: Did something really different happen during this geomagnetic storm compared to previous ones, or do we just have better instruments to measure the changes?”

Additionally, what might these changes mean for human-made technology orbiting this region of the atmosphere?

More than a northern lights show

Earth’s upper atmosphere, which extends from 60 to 400 miles (96 to 640 kilometers) above us, borders space and is the staging area for satellites and the International Space Station. The upper atmosphere is made up of some of the same particles as the lower atmosphere, where we live and breathe.

But this region of space also has another facet, the ionosphere, which can be compared to an electric blanket, highly charged and constantly fluctuating. These charged particles in the ionosphere are one of the elements that make this region of space so dynamic. It is common for the temperature and composition of the upper atmosphere and ionosphere to change. In fact, this happens predictably during the day and night and even changes over time, with the seasons.

According to England, the particles in Earth’s atmosphere are influenced by many spatial factors, including solar activity. During a solar geomagnetic storm, an intense burst of radiation from the sun changes the composition and speed of particles in Earth’s atmosphere. So why have the northern lights been visible in places all over the world in recent months where they have never been seen before?

“The number of sunspots, flares and storms changes in an 11-year cycle that we call the solar cycle,” England said. “The number of flares we see has been gradually increasing over the last few years as we approach the peak of the solar cycle.”

In addition to the visibility of the northern lights, geomagnetic storms have many impacts on our technology. Because radio and GPS signals travel through this constantly fluctuating “electrical blanket,” changes in this layer of the atmosphere can disrupt signals and hamper navigation and communication systems such as GPS.

Various factors related to Earth and space weather can impact this crucial layer, but much remains to be learned about why changes occur in the upper and lower atmosphere and how they might impact life as we know it.

“These storms can also increase the electrical currents that flow around the Earth, which can impact technology that uses very long cables. In recent years, the electrical grid has been affected by excessive current flowing through the cables. During the largest geomagnetic storm on record, the Carrington event in 1859, these events caused telegraph systems, which were cutting-edge technology at the time, to catch fire,” England said.

Scientists suspect that a storm similar to Carrington in 1859, if it happened today, could cause an internet apocalypse, knocking large numbers of people and businesses offline. While the May 11 storm didn’t cause drastic disruptions, with the peak of the solar cycle predicted for July 2025, we’re still about a year away from knowing those potential effects.

“One of the reasons we study geomagnetic storms is to try to build models to predict their impacts,” England said. “Based on the solar cycle, we expect the conditions we see this year to persist for about two years.”