Kyushu University scientists reveal how a powerful geomagnetic storm in May 2024 triggered mysterious, metal-rich clouds in the upper atmosphere—layers that could disrupt global radio and GPS systems.
Key Points at a Glance
- The 2024 Mother’s Day geomagnetic storm significantly enhanced Sporadic E (Es) layers in the ionosphere.
- These dense, metal-rich clouds formed around 90–120 km above Earth and can disrupt radio signals.
- Researchers observed a rare propagation pattern from polar to equatorial regions during the storm’s recovery phase.
- Ground and satellite data revealed an unprecedented global map of Es activity.
- Findings may help forecast Es layers and improve communication reliability during solar storms.
While the auroras from the spectacular Mother’s Day solar storm of 2024 captured the world’s attention, something even more surprising was unfolding invisibly high above Earth—dense, fast-forming clouds of ionized metals known as Sporadic E (Es) layers. Now, new research from Kyushu University has revealed how this rare atmospheric phenomenon was supercharged by the solar event—and how it may pose a serious risk to communications and navigation systems.
In a study published in Geophysical Research Letters, Professor Huixin Liu and her team have mapped out a never-before-seen global view of Sporadic E activity during the intense geomagnetic storm of May 10–11, 2024. These thin layers, just 1 to 5 km thick and hovering between 90 and 120 km above the Earth’s surface, can interfere with radio waves used in HF and VHF bands—frequencies crucial to aviation, maritime operations, and GPS accuracy.
“Most research during geomagnetic storms focuses on the F layer, which is higher in the ionosphere,” explains Liu. “But we wanted to see if a superstorm like this could affect the lower E layer, which hasn’t been studied much in this context.”
What the team found was remarkable: Sporadic Es were not only enhanced during the storm, but they also displayed a striking migration pattern. Using data from 37 ground-based radars and the COSMiC-2 satellite network, the researchers observed that the clouds first appeared near the poles and gradually moved toward the equator—indicating a high-to-low latitude propagation characteristic that hadn’t been clearly documented before.
“This pattern suggests the cause was likely disturbed neutral winds in the E region of the ionosphere, rather than direct solar activity,” says Liu. “It opens a new chapter in understanding how solar storms ripple through the entire atmosphere—not just the uppermost layers.”
The research team noted that the burst in Es activity occurred not during the storm’s peak, but in its recovery phase—a period usually considered calmer. This finding challenges assumptions about when communication systems are most vulnerable, and underscores the need for updated models of ionospheric behavior during space weather events.
Understanding how these metal-rich layers behave is increasingly important in a world dependent on seamless global communications. HF radio can bounce off the Es layer and travel vast distances, but this becomes a problem when the layer is unstable, absorbing or scattering signals unexpectedly.
With this new data, scientists may soon be able to forecast the likelihood of Es disturbances based on solar storm dynamics—allowing airlines, military operations, and emergency services to better prepare for disruptions. Liu’s team plans to reanalyze past storm data to refine this predictive potential.
“We now know these events are more dynamic and more widespread than we thought,” Liu says. “It’s a reminder that the Earth’s upper atmosphere is not just a passive shell, but an active, responsive system shaped by the space environment.”
As humanity inches toward greater dependence on satellite and radio infrastructure, the ability to forecast and mitigate space weather impacts—especially those once overlooked—is no longer optional. With their findings, Liu and her colleagues have added a critical piece to the space weather puzzle.
Source: Kyushu University
