Solar storms can penetrate Earth’s magnetic field, knocking out power

For thousands of years, people have gazed upon the vivid auroras, dancing across the night sky. But these beautiful displays are more than just a pretty sight. They are a warning sign of a hidden danger – induced geomagnetic currents.

Auroras are caused by particles from the sun crashing into the Earth’s magnetic field. The same forces can suppress the magnetic field, resulting in tremendous currents that can reach the ground.

New research shows that the angle at which these solar flares hit Earth is crucial to protecting infrastructure.

“Auroras and geomagnetically induced currents are caused by similar space weather triggers. The aurora is a visual warning that electrical currents in space can generate these induced geomagnetic currents on Earth,” explained Denny Oliveira of NASA’s Goddard Space Flight Center and lead author of this new study.

Head-to-head blow

Earth’s dazzling auroras result from two processes: solar storms unleashed by the sun and magnetic field compressions caused by interplanetary shocks. These shocks occur when a fast solar wind overcomes a slower current, creating a shock wave.

Both can cause dangerous currents to flow through the Earth, potentially damaging electrical infrastructure. Bigger events bring bigger threats, but even small shocks pose a risk.

“The auroral region can expand greatly during strong geomagnetic storms,” ​​Oliveira added. “Normally, its southernmost limit is around 70 degrees latitude, but during extreme events it can drop to 40 degrees or even further, which certainly happened during the May 2024 storm – the most severe storm in two decades.” .”

The researchers found that frontal shocks are likely to create the strongest induced geomagnetic currents, leading to “powerful ground-level electrical currents threatening submarine pipelines and cables.”

This is because frontal shocks can compress the magnetic field more.

How was the corner found?

The researchers examined how the angle and timing of solar strikes affect the induced geomagnetic currents. To understand the connection, the researchers looked at two sets of data.

One was a collection of recorded interplanetary shocks, while the other was a reading of electrical currents taken from a natural gas pipeline in Mäntsälä, Finland. This pipeline is located in a region that often sees auroras during times of strong solar activity.

They used data from the interplanetary magnetic field and the solar wind to calculate the angle and speed of each impact. And then divided them into three categories: high-prone, medium-prone, and near-frontal.

Research has shown a clear relationship between the angle of impact and actual force. The more head-on a solar flare hits, the stronger the jolt of electricity traveling to earth. This electrical surge usually occurs in two bursts: one immediately after the initial shock and the other during a subsequent substorm—a smaller geomagnetic disturbance. Surprisingly, these peaks were strongest at midnight, when Mäntsälä’s north pole faced the sun directly.

The study’s authors say scientists can predict the angle of an impact up to two hours before it hits. This can provide time to take precautions such as power reduction on certain lines.

“Although Mäntsälä is in a critical location, it does not offer a worldwide view. In addition, Mäntsälä’s records are missing several days in the investigated period, which forced us to discard many events in our companion database. It would be good for energy companies around the world to make their data accessible to scientists for studies,” Oliveira concluded in the press release.

The findings were published in the journal Frontiers in Astronomy and Space Sciences.