Our Violent Sun

 
 

What dangers do solar flares pose to our highly technological society? Séan Mooney ignores common wisdom by taking a look at the sun in this article about solar weather.

 

Water, medication, and batteries: these are typical items that NOAA, the United States National Oceanic and Atmospheric Administration advise we have at the ready in case the Earth is struck by an extreme solar flare. Such a natural disaster might not be at the top of most people’s minds, but it is a cause for concern.

The sun is a rotating sphere of electrically charged plasma. Its activity is not constant, however. The sun goes through an 11-year cycle, oscillating between highly active “solar maxima” and very quiet “solar minima.” Given that the Sun has been smashing atoms together for 4.5 billion years now, it adheres remarkably well to this 11-year cycle. There are complex magnetic fields on the Sun which, during active periods, are more likely to become tangled together. Over time, these tangled magnetic fields can snap, resulting in a solar flare. There are several components to a flare, such as X-rays and high-energy particles, but the most concerning element is the release of about a billion tonnes of extremely hot plasma. This release is known as a coronal mass ejection. This material explodes out into space at one million km/h, and it can lead to a geomagnetic storm on Earth as it sweeps by us, giving rise to the aurora, also known as the Northern or Southern Lights.

“The sun goes through an 11-year cycle, oscillating between highly active “solar maxima” and very quiet “solar minima.””

On September 6th 2017, one of the biggest solar flares in 40 years shot out from a group of huge sunspots, each many times bigger than Earth. Most coronal mass ejections are not emitted in the direction of Earth, and on this occasion we were fortunate too. When solar flares do hit our planet, though, the consequences can be quite severe. The Carrington Event refers to the biggest flare on record which did impact Earth, in 1859. It was so powerful that the Northern lights became more than just Northern for a time, with reported sightings of them from places as far south as Cuba. A solar flare on par with the Carrington Event is thought to occur every 500 years, but with limited data, it is difficult to say for certain.

“This material explodes out into space at one million km/h giving rise to the aurora.”

There is no doubt that our society is inextricably bound to technology, and all technology needs power. If a severe solar storm similar to the Carrington Event happened today, it would induce a current in the electrical grid, causing transformers around the globe to short-circuit. Such transformers can take months to replace, meaning that a major flare could plunge vast swathes of the planet into darkness for quite some time. The list of industries likely to be impacted is wide-ranging, from transportation to healthcare and everything in between.

We have our atmosphere to thank for the fact that when the Sun spits a plasma glob at Earth, we enjoy the aurora instead of a dose of radiation. This protective envelope does not extend to our satellites, however. A major flare could cause irreparable damage to satellites, which facilitate telecommunications, banking transactions, and navigation. If a drop in GPS coverage seems trivial, consider what it might be like to sit on an aeroplane which has just lost its navigation system. So much of the technology we take for granted is not possible without functioning satellites and ground-based electronics, yet very little is being done to safeguard all of this.

“If a drop in GPS coverage seems trivial, consider what it might be like to sit on an aeroplane which has just lost its navigation system.”

Earth has been careening into massive solar storms throughout its history, but before we harnessed electricity this was never a problem. The worst flare we have been hit by since entering the electrical era caused localised blackouts and short disruption in telecommunications. Given the current state of our technology, however, the estimated cost associated with such a flare exceeds the €1 trillion mark. That a solar flare will strike at some point in the future is a statistical certainty. Sufficient preparation is required, but this is no small task.

The species of great ape to which we belong is proficient at many things, but we need look no further than climate change to see that our ability to assess existential risk is not our strong suit. All hope is not lost, however. Our perilous position is recognised by some, and both the UK and the USA have made efforts in recent years to put “space weather” response plans in place. Relevant mitigation measures are being engineered into infrastructure, and alert systems are in place which should provide at least 12 hours’ notice of an incoming solar flare. This should be sufficient for us to take action to protect electrical transformers and satellite electronics.

“Both the UK and the US have made efforts in recent years to put “space weather” response plans in place.”

Only time will tell if these preventative measures are enough. Given the highly technological nature of our society, we need to take this threat as seriously as we take that posed by other natural disasters like floods, earthquakes, and volcanoes. As with all disasters, the time to prepare is beforehand. It is easy to sensationalise something as dramatic as a solar flare and its fallout, but a sober analysis of the dangers posed reveals that the threat is very real indeed. Highlighting this simply brings awareness to the dangling sword of Damocles so that we have a plan for when the lights go out.

 

 

 

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