November solar superstorm disrupted Earth’s ionosphere and global skies
A cluster of powerful X-class solar flares between November 9 and 14, 2025, jolted Earth’s ionosphere and disrupted global radio signals, NJIT scientists report.
Image credit: Willie Jarl Nilsen
Between November 9 and 14, a single active region on the Sun, AR4274, produced a chain of four major X-class solar flares. The sequence included flares of X1.7, X1.2, X5.1, and X4.0 in quick succession, each releasing vast bursts of energy and radiation. The X5.1 event on November 11 became the strongest flare of the year and produced the strongest Ground Level Enhancement (GLE) event in 20 years.
These flares injected immense quantities of X-ray and ultraviolet radiation into space, temporarily ionizing Earth’s upper atmosphere and destabilizing its ionospheric layers. The ionosphere, a plasma region roughly 60–1 000 km (37–620 miles) above Earth’s surface, plays a key role in reflecting and bending radio waves used for GPS, navigation, and satellite communications.
According to the National Oceanic and Atmospheric Administration, the storm reached G4 on its five-point geomagnetic scale, accompanied by R3 – Strong radio blackouts over Africa and Europe. The disturbance storm time index, a measure of how much the geomagnetic field is compressed by solar wind, plunged from about –40 nT to nearly –250 nT in just a few hours, signaling a major magnetic shock.
As charged particles from the coronal mass ejections swept through Earth’s magnetic field, auroras exploded across mid-latitudes. The northern lights appeared over regions rarely affected by such phenomena, including the central United States and parts of Florida. These lights result from solar particles colliding with atmospheric oxygen and nitrogen atoms, releasing visible energy as brilliant green, purple, and red arcs across the sky.
For space weather scientists, the event was both visually stunning and scientifically invaluable. It offered one of the clearest real-world demonstrations of how solar eruptions affect Earth’s electromagnetic environment and exposed the vulnerabilities of modern technologies that depend on it.
NJIT’s Owens Valley arrays record the storm’s fingerprints
While the flares occurred during nighttime in California, NJIT’s radio telescopes in the Eastern Sierra detected the storm’s atmospheric consequences. The Expanded Owens Valley Solar Array (EOVSA) and the Long Wavelength Array at Owens Valley Radio Observatory (OVRO-LWA) together tracked dramatic radio disturbances as they rippled through the ionosphere.
Normally, the OVRO-LWA data reveal orderly, nearly vertical type III radio bursts, the signatures of electron beams racing through the Sun’s magnetic fields. But following the solar flares, those signals appeared curved, distorted, and chaotic at low frequencies. Such changes are a direct indication that the ionosphere’s density profile was disturbed, causing the radio paths to bend erratically.
Professor Bin Chen, who directs the EOVSA facility, explained that seeing four X-class flares from one solar region within days was remarkable. Yet, he added, the more striking outcome was the chain of effects observed on Earth’s radio environment. The event offered a unique opportunity to link solar emissions with ground-based atmospheric responses in real time.
The newly integrated Owens Valley Solar Arrays system, combining EOVSA’s microwave capabilities with OVRO-LWA’s long-wavelength coverage, provides an unprecedented frequency span for solar and ionospheric studies.
EOVSA records microwaves similar to those used in satellite communications, while OVRO-LWA captures meter and decameter waves similar to FM radio bands. Together, they form one of the world’s most comprehensive radio observatories for studying the Sun and its influence on Earth.
The project, supported by USD 4.2 million from the National Science Foundation, allows scientists to trace space weather events from their solar origins to their atmospheric impacts, bridging a long-missing observational gap between the solar corona and Earth’s upper atmosphere.
Measuring the storm’s impact on modern technology
To quantify how these solar disruptions affect real-world systems, NJIT researchers deployed a new high-precision GPS monitoring instrument beside the Owens Valley arrays. The device, humorously named FLUMPH short for Field-deployed L-band Unit for Monitoring Phase Hiccups—records subtle fluctuations in GPS signal phase during geomagnetic events.
The goal is to observe how plasma irregularities in the ionosphere interfere with satellite-based communications. Variations in electron density can scatter or delay GPS signals, causing navigation errors that ripple through aviation, telecommunications, and finance sectors.
Assistant Professor Lindsay Goodwin and her team at NJIT’s Center for Solar-Terrestrial Research lead this effort. By pairing GPS phase data from FLUMPH with radio observations from OVRO-LWA, researchers can analyze both the cause and the consequence of solar disturbances in a single dataset.
Goodwin described the November storm as a textbook example of a direct hit from a solar eruption. Many solar flares eject plasma clouds that miss Earth entirely, but this series was ideally aligned, allowing scientists to witness the full chain of space-weather effects.
These simultaneous datasets are helping refine models that predict when and how solar activity interferes with navigation systems. As dependency on GPS, communications satellites, and power grids grows, such monitoring is increasingly vital for infrastructure resilience.
A peak-year reminder of the Sun’s power
The November solar storm occurred near the height of Solar Cycle 25, the current 11-year period of heightened solar activity. Each solar maximum brings increased risk of large flares and coronal mass ejections, capable of sending billions of tons of plasma hurtling toward Earth at speeds exceeding 2 000 km/s (1 240 mi/s).
While this event stopped short of historical extremes, it served as a vivid reminder of Earth’s exposure to solar energy bursts. The last storm of a similar scale, in March 1989, caused a nine-hour power outage in Quebec. The infamous Carrington Event of 1859, much stronger, set telegraph systems ablaze and remains the benchmark for worst-case scenarios.
Today, our dependence on satellite communication, GPS, and orbital infrastructure means a comparable event could have far-reaching consequences. Power grid surges, navigation disruptions, and radiation hazards to spacecraft are all plausible outcomes of such storms.
Goodwin emphasized that studying these episodes is essential for preparedness. By combining ground-based radio data, GPS monitoring, and spaceborne instruments like NASA’s Solar Dynamics Observatory, scientists can improve forecasts and minimize risks to modern systems.
With the Sun expected to remain active into 2026, more flares of similar magnitude are possible. Continuous monitoring and data sharing between observatories will be crucial to understanding and mitigating their effects.
The scientific significance of NJIT’s observations
Beyond tracking immediate effects, NJIT’s observations advance the broader study of the Sun’s middle corona, the region between 1.5 and 10 solar radii where solar magnetic fields restructure and CMEs accelerate. This zone has long been difficult to observe directly, but the combination of EOVSA and OVRO-LWA provides a new window into its dynamics.
By measuring radio emissions across both microwave and long-wavelength bands, scientists can map how high-energy electrons move through magnetic fields and how these processes cascade toward Earth. This capability connects solar physics with atmospheric science in unprecedented detail.
The Owens Valley Solar Arrays now stand as one of the world’s most advanced community radio facilities dedicated to solar research. Their multi-frequency data not only enrich space-weather science but also serve as a global early-warning tool for potential disruptions.
For researchers, the November storm produced one of the richest data troves in years. It links solar flare emissions, ionospheric disturbance signatures, and geomagnetic variations in a single coherent sequence—a benchmark case study for the solar maximum.
As Professor Chen summarized, this integration allows scientists to follow a solar flare’s journey from its birthplace on the Sun to its ultimate interaction with Earth’s upper atmosphere, a comprehensive view that was never before possible in such detail.
References:
1 NJIT Scientists Track Recent Solar Flare Disruptions in Earth’s Ionosphere – NJIT – November 21, 2025
I’m a science journalist and researcher at The Watchers, contributing to the Epicenter edition, where I cover peer-reviewed scientific research and emerging discoveries across Earth and space sciences. With a background in astronomy and a passion for environmental science, I’ve worked in shark and coral conservation in Fiji, conducting reef and shark-behavior research, contributing to mangrove restoration, and earning PADI Open Water and Coral Reef Certifications. I bring a blend of scientific rigor and storytelling to illuminate the discoveries shaping our planet and beyond.
If this solar event transpired from 11/9 thru 11/14, what affect would it have on short term atmospheric weather directions/conditions like a polar vortex and other weather patterns. I find it interesting that two weeks later we are having cold weather outbreaks in the upper midwest and in other northern climes that were not projected in long term weather forecast estimates based on historical recorded data.
I live in Minneapolis, Minnesota and was enjoying the mild weather conditions here!
Doug Van Thorre
Interested by-stander