Last week you may have caught the news of two large coronal mass ejections (CMEs) occurring within a few days of each other, hitting Earth with a good dose of radiation. The two CMEs were the result of the catchily titled AR2158 sunspot, and their power was placed within the ‘extreme’ bracket of the scale used by astronomers.
On the night, many people saw the beauty in the event – thanks to it resulting in a fantastic Northern Lights display – whilst others predicted that it would lead to a nightmare of doomsday proportions.
In the end, the only ones really impacted were amateur (ham) radio enthusiasts. The HF signals used in ham radio transmissions propagate by ‘bouncing’ off the ionosphere, the atmospheric layer impacted by geomagnetic activity. This is a good thing for amateur radio enthusiasts, allowing communication over much longer distances than usual.
It was therefore far from the cataclysmic existential risk some had made it out to be – but there is just cause for concern, thanks to the potential future impact of such an event on wireless, and the consequences for wider society.
The most famous solar event is the Carrington Event of 1859, a powerful solar storm that produced the largest geomagnetic storm ever recorded. Aurora Borealis sightings near the equator were noted, whilst a famous anecdote states that gold miners in Denver woke up at 1AM and began their morning routines due to the brightness.
We’ve seen written testimony discussing Northern Lights events like this throughout history; the reason the Carrington Event is remembered is partially due to our increased understanding by 1859, but also the impact on the early telegraph systems we had by this point. These systems failed, pylons sparked and operators suffered electric shocks.
Fast forward to 2014, and we are witnessing another peak in solar activity. After a major solar superstorm narrowly missed Earth in 2012, a NASA study in the December 2013 edition of Space Weather estimated the chances of a Carrington-level event hitting earth by 2022 at 12%. That said, I’m dubious of how you assign statistics to something that has only happened once.
Such an event could induce huge currents in east-west wires – the longer the wire the bigger the effect. That could cause significant disruption in USA and continental Europe – though less in UK where our powerlines mostly run North-South. Transformers failing, power networks collapsing, fires and other unpleasant effects could result. With no power water supplies and sewage systems - and of course communication networks – could stop working if not specifically design to take such effects into account.
However, just as we take into account and mitigate risks of terrorism to wireless infrastructure, the impact such an event could have on communications infrastructure is something we must take in to account when planning wireless.
Why? A 2013 report from Lloyd’s investigating the risk of such a storm estimated between $0.6 – 2.6 trillion in costs from US power shortages alone, with lower end estimates relying upon utility businesses being prepared for an event.
We contributed to arguably the most authoritative study on this issue: a report by a Royal Academy of Engineering committee on the impacts of so-called Extreme Space Weather on engineered systems and infrastructure. This included a group of eminent space scientists together with representatives of major services such as power networks and aviation, with Real Wireless representing the interests of wireless communication networks.
One interesting finding was that, although Carrington events are very extreme, even more typical activity should result in measurable impacts on mobile network quality around once a week. We recommended that systems needed for critical applications should carefully examine their use of synchronization systems based on GPS, which could be vulnerable.
The full report is available here.
We can’t prevent such an event, it will probably happen one day in the not too distant future, all we can do is ensure we are prepared to mitigate any impact it may have. We hope that the Royal Academy of Engineering report will provide a basis for proper planning to minimise the potential consequences.