A key topic of discussion for the UK public safety communications sector will always be ‘response’.
That is, the ways in which technology can be leveraged to improve both public safety, as well as the safety of those on the frontline. The ongoing development of the technology itself also falls within this discussion meanwhile, which nowadays invariably means broadband, drones, AI and so on.
Another key area which probably gets less coverage however is ‘resilience’ (or, the measures in place through which the technology is enabled and maintained). For example, radio networks will only continue to work if their base stations are protected from damage, for instance from natural disasters.
Regarding the latter, the most common difficulties, at least in the UK, are likely to be either chronically inclement weather or extreme heat. Indeed, this article was written during a lull between Storm Jocelyn and Storm Isha, the latter of which affected the supply of power to large parts of the UK.
The natural world has more things to throw at us than just floods and wildfires however, some of which are not even of this Earth. One of these is what meteorologists refer to as ‘space weather,’ which according to experts at the Met Office has the potential to seriously disrupt communications technology and therefore public safety services.
Eyes on the storm
The concept of ‘space weather’ as it’s now recognised first came into existence in 1859, following what’s known as the ‘Carrington Event’. This is named after Sir Richard Carrington, an English astronomer who demonstrated the existence of solar flares and their effect on the Earth in terms of electrical interference.
Discussing the legacy of Carrington in greater detail, head of space weather at the Met Office, Mark Gibbs, said: “He was observing sunspots and saw a bright flash, which was a solar flare.
“Less than a day later, there was an aurora with red skies as far south as the Caribbean. As a rule of thumb, the further south the aurora goes, the more intense is the [solar] storm.”
He continues: “The Carrington event was a one in 100-year [occurance]. We use it as our reasonable worse-case scenario for when we’re doing the national security risk assessment in relation to space weather.
“These kinds of events have been around ever since the Earth has existed. The difference is that now, modern technology is vulnerable to it. As we increase our dependence on technology, we’re also potentially increasing our vulnerability to space weather.”
For those who might not know, a solar flare is the name for an expulsion of electromagnetic radiation from the surface of the Sun. This is often associated with what’s known as a coronal mass ejection, or ‘CME’, which is an ejection of magnetically charged matter, known as plasma, from the outermost part of the Sun’s surface (that is, the corona).
As mentioned, space weather such as this appears on the National Risk Register, posing as it does a threat to elements of the critical national infrastructure. (This threat was codified by a landmark report published by the Royal Academy of Engineering in 2013).
Gibbs explains why this is the case, mentioning two specific incidents taking place within the utilities sector. He says: “There was a famous space weather storm in 1989, which we would categorise as a one in 50-year event. This caused the collapse of the power grid across the whole of Quebec.
“That essentially saw safety systems within the power grid itself shutting the system down to prevent damage. It took 92 seconds to shut down the grid across the whole of the province.”
A decade and a half later in 2003 meanwhile, there was another event (one in 30 years, this time), which caused a complete power blackout across Malmo in Sweden. According to Gibbs, the Swedish power company explicitly stated that if it had a forecast of the event in advance, it would have been able to prevent any disruption.
Asked to explain in the simplest possible terms why these events are so disruptive, he says: “Coronal mass ejections are plasma bubbles exploding off the surface of the Sun. They carry with them the local magnetic field.
“They break away from the Sun and travel 93 million miles to the Earth,. If the magnetic field in the plasma is aligned with our magnetic field, then most of the energy will pass around.
“But if it comes in the opposite way up, the two magnetic fields combine together, and you get that energy enter the Earth’s magnetic field. That’s when you get the aurora.”
According to Gibbs, this has the potential to affect what’s known as the aurora electrojets, which are electric currents in the ionosphere.
“On the surface [of the Earth], there is an equal and opposite current set up,” he continues. “That current is trying to flow through the ground, with the route of least resistance often being up through an electrical transformer, then the power line and back down to Earth again.”
This can prove extremely damaging to the equipment involved, hence the networks mentioned above essentially shutting themselves down to avoid any potential damage.
Impact on emergency services
Space weather clearly has the potential to cause real disruption to critical national infrastructure, for instance the means through which energy is distributed. Should such an incident occur, this also would clearly have a profound impact on the emergency services.
There is also another scenario more directly relevant to the UK public safety comms technology sector however, in which radio communication itself is compromised.
Krista Hammond is a meteorologist and space weather forecaster, also working at the Met Office. Outlining the potential impact on communications technology, she talks about two possible scenarios.
“During a space weather event, there would also be a disruption to communications, in particular high frequency radio such as that used by the military and aviation. There could be disruption to some satellite comms, and satellite anomalies were something we started to notice during the incident in 2003.”
Dealing with satellites in the first instance, Hammond says that according to the Royal Academy of Engineering report, approximately ten per cent of satellites would likely see anomalies resulting in interruptions of services “from hours to days.”
Going into detail about the mechanics behind the disruption of satellite comms as well as HF radio, Hammond says: “As Mark said, space weather effects the Earth’s ionosphere. For instance, solar flares cause it to heat up, change density and so on.
“This is important, because of the role that the ionosphere plays in way-beyond line-of-sight high frequency communications, with the radio signal reflecting off it.
“If the properties [of the ionosphere] change, it can potentially scatter or absorb the radio signals rather than being reflected to be picked up by a receiver. So, if we have a particularly strong solar flare, that could cause radio blackouts in the area where it’s affected.”
Changes to the ionosphere also effect satellite communications according to the same principles, just with the signal emanating from space rather than the ground.
She continues: “That obviously includes GPS/Galileo signals, which are used by many organisations, including the emergency services. At that point, we would learn just how dependent our lives are on satellite-based communications.
“For GNSS to work, you need to triangulate the signal,” says Hammond. “So, you need at least three satellites to get a lock on GNSS. You only have to lose some of [the satellites] to lose track of where things are.
“The more we become dependent on technology that’s reliant on GNSS, the more vulnerable we are to changes in that accuracy.”
While undoubtedly a somewhat intermittent threat, space weather still has potentially serious consequences for the UK. That being the case, a natural question that arises is how easy are these events to predict? And more to the point, just how much danger are we actually in?
According to Hammond, forecasting space weather is still what she refers to as an “evolving science.” The reason for this is simply the sheer scale of the endeavour, coupled with the distances involved.
For instance, the energy emitted by a solar flare travels at the speed of light, meaning that by the time the event is even observed on the surface of the Sun, the effects are potentially already being felt on Earth.
Discussing the prediction piece, Hammond says: “We’ve got forecasters on duty 24/7. It’s now one of the forecasting benches in the Met Office, like the shipping forecast.
“We’re looking for sunspots, which is where the solar flares originate from. You can’t really tell for certain if we’re going to get a space weather event from the sunspot, but we can get an idea there is a risk.”
How about in terms of readiness on the ground, meanwhile? What can emergency services actually do to prepare?
Gibbs says: “This has been on the national risk register since 2011, so local resilience fora will be aware of it. They will therefore also have plans to deal with the effects of it, like power disruption or communications issues
“The question is, looking at those plans, will they work with the specific effects of space weather? At the same time, will they also be able to cope with multiple effects happening simultaneously?”.
Article originally published in the BAPCO Journal.
