When scientists begin to observe the sun a bit more closely than usual, a certain kind of unease sets in. A G3 geomagnetic storm watch was recently issued by NOAA’s Space Weather Prediction Center. Although it hasn’t caused widespread panic, which is rare, it has quietly unsettled those who work as managers of satellite systems and power infrastructure. On a five-point scale, G3 is the third level and is categorized as “Strong.” It is not catastrophic. However, it’s also not ignorable.
The sun must be viewed as a chaotic system that frequently launches magnetized plasma into space rather than as a steady, glowing ball in order to comprehend what is truly taking place. Approximately a billion tons of charged particles embedded in magnetic fields can be carried by these coronal mass ejections, or CMEs, as they swiftly approach Earth. In less than eighteen hours, some of the most intense have arrived. Most require several days. That window is a warning as well as an odd kind of tension.
It’s not precisely the particles that cause a geomagnetic storm to be dangerous. It is the result of a collision between Earth’s magnetosphere and a southward-pointing solar magnetic field. The invisible systems supporting contemporary infrastructure suddenly start to feel the strain as the two fields interact and energy is transferred. The ionosphere is filled with surging currents. Heat and expansion occur in the upper atmosphere. Because of the increased drag experienced by satellites in low-Earth orbit, engineers must recalculate trajectories that were previously flawless. There’s a feeling that space, which most people overlook as an operational environment, can suddenly become unstable.
A G3 event indicates a particular and somewhat concerning situation for power grids. Voltage adjustments might be required. False alarms can be set off by protection devices, which are systems made to stop cascading failures. This may seem like a small annoyance until you realize that a misread alarm can take important assets offline at the wrong time. Utility company engineers are aware from experience that geomagnetically induced currents, or GICs, are real and flow through pipelines and transmission lines like unwanted electricity. Millions of people in Quebec lost power for nine hours during the 1989 blackout, which was brought on by a much more serious G5 event. No one wants to get close to that ceiling.
There are challenges unique to satellite communications. Surface charging can accumulate on spacecraft parts; in other words, the satellite builds up static electricity in ways that can harm delicate systems or interfere with electronics. GPS precision deteriorates. Aviation and maritime operations continue to use HF radio, but it becomes sporadic. It’s possible that all of this goes unnoticed by regular users, but it’s also possible that navigation mistakes accumulate subtly over time, impacting flight paths and logistics in ways that are hard to identify later.
It’s important to note how commonplace a G3 event is in terms of statistics. According to NOAA, there are about 200 of these occurrences every solar cycle, or about 130 days over the course of eleven years. This is what the sun has always done. The extent to which our civilization now relies on systems that are susceptible to it has changed. The size and connectivity of power grids have increased. Constellations of satellites are denser. Everything from surgical instruments to shipping containers has GPS built in.
It’s difficult not to feel that the infrastructure discourse hasn’t fully caught up with the reality of space weather as this situation develops. Utility companies and NOAA engineers are ready, executing procedures and modifying systems. It’s still unclear if the larger investment in grid resilience is where it should be.
