Solar radiation storms happen when a large-scale magnetic eruption from the sun accelerates charged particles in the solar atmosphere to very high velocities. This can cause protons to get accelerated to large fractions of the speed of light, meaning they can travel the 150 million km from the sun to the Earth in just tens of minutes. Once they reach the Earth, the rapidly moving protons break through the magnetosphere that shields Earth from lower-energy charged particles to land near the north and south poles.
A major disturbance in the Earth’s magnetic field, known as a geomagnetic storm, can cause radio blackouts, power outages, and beautiful auroras. However, they are not generally harmful to humans as the planet’s magnetic field and atmosphere protect people from the worst of these storms.
Some past solar storms include the 1989 Quebec storm, which knocked out the province’s power for nine hours; a 1972 storm, which triggered dozens of mines off the coast of Vietnam where the U.S. military was stationed; and the 1859 geomagnetic storm, known as the Carrington Event. Carrington caused the aurora borealis to shine so bright that it could be seen as far south as Colombia. It was caused by a wave of magnetized plasma, which was launched from the Sun and travelled at a speed of over 2,000 km per hour before hitting Earth, prompting the Earth’s magnetic field to release terawatts of power in response.
The risk of a major solar storm now is much higher than over a decade ago as the Sun is reaching its peak activity cycle, increasing the likelihood of a geomagnetic storm. The main difficulty in mitigating the risk of a solar storm is the lack of ability to predict when it might happen. Predictions for the solar cycle vary significantly, with some scientists putting the odds of a roughly Carrington-level storm at about 1 percent, while others have gone as high as around 25 percent.
Nour Rawafi, the project scientist for NASA’s Parker Solar Probe mission, explained, “Honestly, we don’t know” how likely it is to be hit by a similarly severe storm. Rawafi believes that it does not really matter, as while humans will be fine most of the time, it will only take one incident to change everything, and it is only a matter of time. “There is no way around it… We are living with the Sun,” stressed Rawafi.
In October 2024, the U.S. National Oceanic and Atmospheric Administration (NOAA) issued a solar storm warning after an outburst from the sun was detected for an event that could have affected power grids. NOAA notified power plant operators and orbiting spacecraft to prepare for the storm, as well as alerted the Federal Emergency Management Agency – the organisation that manages post-disaster response - about potential power disruptions. While the geomagnetic storm resulted in a widely visible aurora borealis, it had little additional impact. However, the NOAA warning suggests just how difficult it is for scientists to predict the potential impact of a storm.
One of the biggest worries is the lack of preparedness for a solar storm in the modern age. When a geomagnetic storm hit New York in 1921, it knocked out the city's lights. However, if a strong storm occurs in the present day, it could have a more detrimental effect due to the widespread reliance on technology. Power-grid infrastructure is extremely vulnerable to the impact of solar storms, for example, and long-term blackouts could cause safety issues at nuclear facilities.
If nuclear plants lost their off-site electricity for months at a time, it could prevent them from operating safely. While emergency diesel generators could power cooling pumps for several days, any longer blackouts could spell trouble. No nuclear plant in the U.S. has ever lost off-site electricity for more than a week. In 2012, the U.S. Nuclear Regulatory Commission warned that a severe solar storm could collapse the country’s power grids and may even lead to reactor core damage at multiple nuclear plants. The unknown risk of geomagnetic storms suggests that nuclear plants and other at-risk facilities must do more to mitigate the potential risk of a solar event.
The main cause for concern with solar storms is the lack of understanding and predictability about these types of events. The world is largely unprepared for geomagnetic storms to hit Earth and potentially trigger widespread, long-term blackouts. However, researchers are growing increasingly optimistic that artificial intelligence might help them to better understand and plan for these types of scenarios, helping to mitigate the risk of solar storms.
A recent journal article showed that one forecasting tool was able to predict the orientation of the magnetic field by assessing data from the four hours of a storm. The combination of the human sighting of a solar event and the use of machines to analyse data could provide greater insight into the potential impact of a storm. However, we are still largely in the dark when it comes to solar storms, and both governments and energy companies must be prepared for such an eventuality to occur at any moment.
By Felicity Bradstock for Oilprice.com