Some train track circuits are at the mercy of distant storms on the Sun’s surface, researchers found, which could cause train signals to jump from red to green and vice versa as a result of extreme space weather.
The Sun is a dynamic star, with stormy outbursts that fling radiation millions of miles into the solar system. Some of this radiation bombards Earth, where it can disrupt our technology and cause bright aurorae in the sky. Space weather can even knock out electric grids and create blackouts, as noted by NOAA’s Space Weather Prediction Center.
Solar storms are more frequent at the moment due to where we are in the 11-year solar cycle, causing problems for satellite operators. And as research published today in the journal Space Weather reveals, a significant solar storm could cause train signals in the United Kingdom to reverse themselves.
“Our research shows that space weather poses a serious, if relatively rare, risk to the rail signaling system, which could cause delays or even have more critical, safety implications,” said study lead author Cameron Patterson, a physicist at Lancaster University, in a university release. “This natural hazard needs to be taken seriously. By their nature, high-impact, low-frequency events are hard to plan for, but ignoring them is rarely the best way forward.”
Solar superstorms—whenever they happen—have the capacity to knock out important electronics on Earth, from GPS systems to, yes, train signals. Previous research by a team including Patterson found that signaling failures (and reversals) could happen in the other direction, turning green train signals to red. These “right side” failures, as the team calls them, could cause significant delays in a rail network, as trains that are supposed to be moving instead lurch to an unexpected stop. But the newly suggested scenarios—“wrong side” failure—are obviously much more worrisome.
It’s not clear when the next extreme solar storm will occur, but the team found that an event as powerful as the 1859 Carrington Event, a massive geomagnetic storm triggered by an eruption on the Sun, would cause extensive problems with train signals.
“As our understanding of the space weather hazard improves, it’s possible to consider how to reduce the risks,” said study co-author Jim Wild, a physicist at Lancaster University, in the release. “In the future, we could see space weather forecasting being used to make decisions about limiting railway operations if an extreme event is expected, just as meteorological forecasts are used currently.”
The team found that an electric field caused by a one-in-a-century space weather event could cause “a significant number” of wrong side failures, depending on the number of trains in operation at that time.
You can keep up to date on space weather at NOAA’s Space Weather Prediction Center, which tracks solar phenomena and their potential impacts on Earth.
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