The sun is experiencing an 11-year period of unusually strong activity that began in 2002. In the last three months, three very large solar flares have been reported, the latest of which disrupted communications and the Global Positioning System (GPS) for a short time. Solar flares can affect more than communications, however; it can also cause disruptions to power grids. The length of such a disruption is unlikely to be enough to cause serious damage, though it may be a matter of concern in countries with weak spots in their power grids, or in countries with aging infrastructures.
Solar flares, tossed off by the sun as it experiences solar storms, are a bit like waterspouts during an ocean storm, except instead of tossing a vast quantity of seawater into the air, solar storms toss flares of high energy particles and radiation into space, where they travel until they hit something. Occasionally that something is planet Earth.
This last Saturday, March 29, a sunspot called AR2017 erupted in a massive solar flare. This is not a new occurrence in the last year, as there have been large solar flares in January and February as well as a few in October of 2013. The largest recent flare was a level X6.9 last August. Last year’s flares disrupted radio signals for a short time. The latest flare, only an X1 level occurrence, still managed to cause similar disruptions of radio signals as well as the GPS network for several minutes. The flare is projected to possibly cause a geomagnetic storm in the next few days as well.
This kind of reaction is small potatoes compared to what a coronal ejection could do. In coronal ejections, super-hot plasma from the sun can be thrown outward toward Earth, causing much wider perturbations to the planet’s magnetic field and to the orbits of communications satellites. Luckily, the AR2017 sunspot seems to be diminishing for now, though it may throw off a few more solar flares before it subsides.
The March 29 flare, however, is expected to have further effect as its material reaches Earth and bombards our atmosphere on Wednesday. NASA projects further disruptions in GPS services and possible overloads to power grids and high frequency communications on April 2 due to the effects of high energy particles tossed Earth’s way by the solar flare.
Scientists at NASA have discussed in the past how larger events such as X3 and higher level solar flares could affect global communications and power grids on Earth. The planet’s atmosphere and magnetic field absorb much of the material thrown out by such flares, keeping them from physically harming humans; but should one hit a weak point in the atmospheric envelope, more of the radiation could get through to affect the layer wherein GPS and other satellite signals and communications travel.
X-rays and UV radiation from flares are the main culprits for communication breakdown, since communication signals travel at levels closer to space and with less protection than terrestrial life has from the products of solar storms, and UV rays can cause a slowing drag on satellite orbits.
Luckily, the effects of such flares is likely to be temporary. Coronal mass ejections, on the other hand, throw out much more stellar material and can cause geomagnetic storms which could have much greater effect on communications satellites unprotected in their high orbits. If blasts of power from such an ejection were to affect weak points in power grids, though, it would be an isolated event. Scientists admit to the possibility, though such effects have yet to cause widespread damage. It is certain however that modern reliance on technology makes failures in the communications networks of Earth unsettling.
On the plus side, the solar flares from this sunspot reached their peak in 2013 and are now subsiding. Solar flares can indeed affect communications and power grids as well as satellites and the attendant GPS signals, but for now it seems these systems have escaped the worst ravages of the solar storm.
By Kat Turner