Solar storm causes significant GPS errors across the United States

A severe solar storm that struck the Earth in November of last year caused significant positioning errors in global navigation satellite systems, according to a new study. Researchers reported that the disturbances resulted in errors exceeding 33 feet, a magnitude sufficient to disrupt precision agriculture and autonomous transportation sectors across the continental United States. The findings were detailed in a paper published in the journal Geophysical Research Letters, highlighting the tangible impact of space weather on terrestrial technology.

The event was identified as the strongest solar storm in over two decades. Such storms occur when the Sun releases a surge of charged particles that, upon reaching the Earth’s magnetosphere, can interfere with communications satellites and radio signals. The November storm was intense enough to delay the launch of a NASA spacecraft bound for Mars. On the ground, the activity wreaked havoc with GPS systems for hours. Scientists noted that the storm pushed the Aurora Oval, a ring-shaped area of pronounced activity around the geomagnetic north pole, southward toward the equator. This movement triggered a horizontally extended band of intense density gradients in the upper atmosphere, which caused fluctuations in signal travel times and led to significant positioning errors at mid-latitudes.

The study indicates that the intensity of the observed irregularities correlated with the brightness of the auroras, with greater brightness corresponding to more intense irregularities and deteriorating GPS accuracy. While the November storm occurred after the primary farming season, avoiding immediate agricultural losses, the researchers warned of the potential economic impact had it struck during peak activity. They noted that a similar superstorm in May 2024 was estimated to have cost farmers half a billion dollars in damages. The authors emphasised the need for a better understanding of space weather phenomena to improve predictive capabilities through coordinated observations and physics-based modelling, ultimately reducing disruptions to radio frequency applications.