After losing his Pacific Palisades neighborhood in the fires that swept through Los Angeles in January, Kent Tobiska, the CEO and chief scientist at Space Environment Technologies, is reconsidering a part of his work.
Specifically, he’s rethinking the danger posed by geomagnetic storms.
Instead of worrying only about rare storms like the 1859 Carrington event, a powerful geomagnetic storm that disrupted telegraph lines, Tobiska, former director of Utah State University’s Space Weather Center, said researchers and policymakers should consider the potentially serious consequences of smaller geomagnetic disturbances.
For example, consider May 10 and 11, 2024, when dozens of solar flares sent at least five coronal mass ejections (CMEs) toward Earth.
“The CMEs merged, amplifying one another, to create a major event,” Tobiska said at the American Meteorological Society (AMS) annual meeting in New Orleans in January, when the L.A. fires were still spreading. “We were all surprised at how big it got.”
Similarly, the Palisades Fire wasn’t caused by a wall of fire but by the embers from small fires carried by high winds.
“All these spot fires turned into a massive urban burn of unimaginable proportions,” Tobiska said. “These disasters that we’re facing result from the combination of multiple factors.”
$500 million loss
The May event, the largest geomagnetic event to strike Earth in two decades, has come to be known as the Gannon storm in memory of Jennifer Gannon, a National Oceanic and Atmospheric Administration Space Weather Prediction Center research scientist.
For such geomagnetic storms, a complicating factor creating potentially far-reaching impact is the terrestrial economy’s increasing reliance on space-based infrastructure.
Now, researchers are examining the impact on the fields of precision agriculture, satellite operations, aviation and the electric grid.
While the analysis is not yet complete, reports presented at the AMS meeting revealed a particularly striking impact on agriculture.
The Gannon storm occurred in the middle of planting season in the 12 midwestern states that produce nearly one-third of the world’s corn. Many farmers, already behind schedule due to rainfall, were forced to delay planting further because the storm disrupted the global navigation satellite systems that guide their tractors with centimeter-level accuracy, allowing them to distribute seeds and fertilizer in precise locations. Making matters worse, because few tractors relied on space-based navigation during the previous storm of similar magnitude, the Halloween storms of 2003, many farmers did not have a viable contingency plan.
Since delays in planting are associated with lower yield and revenue, an initial “back of the cocktail napkin” analysis indicates corn farmers lost $500 million due to the Gannon storm, Terry Griffin, Kansas State University associate professor of agricultural economics said at the AMS meeting. “That’s a conservative estimate, it’s clearly going to be more than that.”
Mass satellite migration
The Gannon storm also revealed vulnerabilities in space traffic management.
During a 2003 Halloween storm, roughly 1,000 satellites were in Earth’s orbit. As the altitudes of the satellites decreased due to enhanced atmospheric drag, operators sent instructions to each satellite to fire thrusters and raise its orbit. About 10 satellites at a time were moving to higher altitudes, according to a study, “Satellite Drag Analysis During the May 2024 Geomagnetic Storm” published in Journal of Spacecraft and Rockets in August by PhD candidate William Parker and assistant professor Richard Linares of the Massachusetts Institute of Technology’s Department of Aeronautics and Astronautics.
Fast forward to the Gannon storm, when more than 10,000 active satellites were traveling alongside 37,000 pieces of orbital debris larger than 10 centimeters across. To prevent collisions in low-Earth orbit, satellite constellation operators have adopted automated collision-avoidance systems.
Unfortunately, the automated systems only work if operators can predict where satellites will be in 12 to 24 hours. But space weather models aren’t that precise.
Forecasts of the arrival time of coronal mass ejections, which increase drag in low Earth orbit, tend to be accurate within 10 hours. As a result, individual satellites can be dozens of kilometers from where operators thought they would be a day earlier.
That’s particularly dangerous when thousands of satellites are maneuvering simultaneously.
During the Gannon storm, nearly 5,000 satellites were propelled to higher altitudes by autonomous guidance systems firing thrusters. Similar activity occurred five months later during the October geomagnetic storm.
“What we see is pretty reliable satellite mass migration in response to these geomagnetic storms,” Parker said. “Half of all the satellites are maneuvering in a way that we cannot predict, because these are unplanned maneuvers being made on board the satellite during a geomagnetic storm.”
Further complicating the picture are communications disruptions caused by geomagnetic activity. During major storms, many satellites go into safe mode, shutting down nonessential systems, which may limit communications with the ground.
Aviation impact
In May, airline meteorologists were alerted to potential communications and satellite-navigation disruptions by the warnings issued by the National Oceanic and Atmospheric Administration Space Weather Prediction Center in Boulder, Colorado.
The Wide Area Augmentation Systems (WAAS), which relies on ground stations to calculate small variations in GPS signal accuracy, was disrupted by the Gannon storm. WAAS experienced a loss of Localized Performance with Vertical Guidance, a feature that helps aircraft to descend within 200 feet of a runway, at roughly 2,000 airports in the continental United States and Alaska from May 10 to 12.
“That doesn’t mean you can’t land,” said Karen Shelton-Mur of the FAA Office of Commercial Space Transportation. “But it definitely makes operations less efficient.”
In addition, pilots flying between the U.S. and Europe noted communications anomalies near southwestern Greenland. And one transoceanic flight was rerouted due to loss of high-frequency (HF) communications.
“Some aircraft struggled to maintain HF communications from Greenland to the Canadian Coast,” said Rondeau Flynn, Coalition of Airline Pilots Associations Aeromedical committee chairman and an American Airlines pilot.
As for radiation exposure to air travelers caused by solar energetic particles, “there was really no threat,” Flynn said, noting the 2003 Halloween storms produced more radiation at civil aviation altitudes.
Power outages
In the U.S., the impact on the electrical grid during the storm was minimal.
Electric reliability coordinators, who monitor power flows, voltages and the status of power-generation equipment, participated in a conference call with the Space Weather Prediction Center six hours before the first CME reached Earth.
“This enabled system operators to proactively kick off their geomagnetic disturbance operating procedures and conservative operations protocols, which includes such actions as scheduling additional generation, canceling some transmission maintenance and increasing the monitoring of geomagnetically induced currents and system performance,” said Donna Pratt, North American Electric Reliability Corp. (NERC) performance analysis manager.
While there were reports of unusual transformer heating and distortions of the electrical waveform, “no major outages were reported,” Pratt said.
Ongoing research
It will take years to complete analysis of the Gannon storm. Researchers investigating disruption to global navigation satellite systems are delving into subsectors to examine the impact on agriculture, drilling, surveying and construction.
Evidence shows the storm did little to disrupt most terrestrial activity.
“In my opinion, this was the most prepared for and successfully mitigated extreme space weather storm in history,” said Shawn Dahl, Space Weather Prediction Center forecaster.
Thinking ahead, though, Tobiska said it’s important to consider the potential consequences of future geomagnetic storms.
“When we look at a hurricane, sometimes it’s not the winds quite so much but it’s the massive flooding that causes damage,” Tobiska said.
A geomagnetic storm could, for instance, be exacerbated by national security concerns. Solar Convergence, a tabletop exercise conducted in September by the Homeland Security Department Cybersecurity and Infrastructure Security Agency (CISA), considered an extreme space weather event concurrent with a cybersecurity attack.
“That raised a number of interesting challenges in trying to respond to the space weather event, while simultaneously dealing with the uncertainty of a nefarious actor using the space weather incident to their advantage,” said Chris Cannizzaro, head of CISA’s Space Systems and Services branch.
After another space weather tabletop exercise in May led by Johns Hopkins’ Applied Physics Laboratory, Defense Department and intelligence officials who participated recommended a future classified exercise to explore the potential impact on national security of geomagnetic storms.
In addition to disrupting GPS and high-frequency communications, geomagnetic storms can interfere with radar signals, making it harder to spot aircraft, ships or missiles at long range.
“If I were an adversary, I would launch an attack during a big space weather event,” Tobiska said.
This article was first published in the February 2025 issue of SpaceNews Magazine with the title “Weathering the storms.”
