Scientists from the American Geophysical Union have shown that geomagnetic storms caused by space weather can interfere with railway signaling. This insight was highlighted by Space Weather and underscores how solar activity can ripple through to the ground.
In July 1982, a routine rail signal in Sweden unexpectedly turned red instead of green. The unusual behavior was traced to a geomagnetic disturbance originating millions of miles away, a storm that began roughly 150 million kilometers from the Sun. The basic fact remains: bursts of solar energy can flip the Earth’s magnetic field, triggering geomagnetic storms when solar material interacts with it. Those storms can drive electrical currents across the planet, potentially damaging power lines, pipelines, railroad corridors, and other critical infrastructure.
Researchers have built a computational model to estimate how strong a geomagnetic storm would need to be to disrupt two British railway lines and to gauge how frequently such events might occur. The analysis indicates that moderately intense solar flares occur on roughly a 30-year cadence. Even stronger storms, which are projected to occur about once every century, have the capacity to disrupt almost any signaling system in place.
The outcome of this work informs both scientists and regulators about the vulnerability of rail networks to space weather. It also provides practical guidance for train operators on when to implement protective measures and how to minimize risks to signaling reliability for passenger and freight services alike. The findings are backed by ongoing observations and cross-disciplinary research, with attribution to the contributing investigations (Source: American Geophysical Union) and corroborating data from space weather monitoring networks (Source: Space Weather).