2025 Geomagnetic Superstorm Disrupted GPS Accuracy Across the US

On Nov. 11, 2025, Earth was hit by a severe geomagnetic storm triggered by solar flares and coronal mass ejections from an active sunspot region. The storm produced widely seen auroras, but it also disturbed Earth's ionosphere and disrupted radio signals. A study in the journal Geophysical Research Letters found the storm scrambled GPS signals across parts of the United States where such disruptions had never been recorded.

The auroral oval, the ring around Earth's magnetic poles where auroras occur, normally sits between about 65 and 75 degrees geomagnetic latitude, but expands toward the equator during strong storms. This makes the ionosphere, Earth's charged upper-atmosphere layer, turbulent, causing satellite signals to scintillate, or rapidly fluctuate in amplitude and phase, reducing GPS accuracy. Scintillation is usually strongest near the poles and equator, but intense storms can push it into the normally stable mid-latitudes.

To study the November storm, researchers combined aurora-camera observations with ground-based GPS receiver networks across the US and Canada. They found the auroral oval migrated toward the equator and electron precipitation, charged particles raining into the upper atmosphere, intensified across a wide range of longitudes, producing strong scintillation across much of the continental US, coast to coast and as far south as Florida. The disturbance pushed GPS positioning errors above 10 meters (about 33 feet) for hours.

GPS underpins more than driving directions; it supports security, autonomous transportation, precision agriculture and financial transactions. A more severe storm in May 2024 struck during planting season, and its GPS errors are estimated to have cost American farmers over $500 million. Because November 2025's storm fell outside farming season, the authors say a similarly costly disaster may have been averted.

The authors wrote that if the November superstorm's onset had occurred during farming season in the US, it could have caused significant losses for American farming and transportation industries, underscoring the need to understand the storm-time ionospheric irregularities that drive scintillation.