Tuesday November 6, 2001 dawned mostly sunny and promising Dunedin residents a fine day with northeasterly winds and pleasant temperatures.
The Otago Daily Times that morning was excited about the Melbourne Cup and the chances of a winning run from New Zealand mare Ethereal (it won).
It was then-prime minister Helen Clark’s wedding anniversary but she told NZPA she would not be spending it with husband Peter Davis as they were in different cities.
Brad Thorn had pulled out of the end-of-year All Blacks tour, while there was news that fireworks displays had exceeded noise limits and a "more typical" summer was on the way.
Something else was on the way too.
A spinning, spitting mass of highly charged solar plasma was speeding towards our side of the Earth, following a large eruption from the Sun’s surface about a day earlier.
Not that many people knew that. Including the engineers at state-owned national grid company Transpower.
Officially called a coronal mass ejection (CME), the fastest of these clouds of electrons and protons carrying the Sun’s magnetic field with them, can reach Earth in about 18 hours, disrupting communications and cutting electricity, blowing up transformers and burning-out wires, and effectively rendering anything electrical useless due to the currents they generate inside transmission lines.
University of Otago physics professor Craig Rodger, who leads a $15 million MBIE programme to study space weather’s potential threats, prefers "solar tsunami" to CME.
"We do have this possibility with space weather, at least for coronal mass ejections, that we’ve got half a day-ish, from the explosion on the Sun, to get ready, which is why I really like the phrase ‘solar tsunami’. The ‘earthquake’ occurs, the tsunami is launched."
At 2.53pm that Tuesday, the solar tsunami hit Earth. Transpower’s monitoring systems in the South Island went into alarm mode. Within a minute, a transformer at Dunedin’s Halfway Bush substation burned out and other equipment was tripped at Islington in Christchurch.
However, as far as the public were concerned, nothing untoward had happened. Built-in redundancy in the grid meant the electricity continued flowing. What could have been a highly significant event for the South and the entire country did not even make it into the pages of the ODT.
Prof Rodger has talked to operators in Transpower’s control room about the incident.
"As far as they were concerned, there was no warning. And they were getting alarms coming in from these monitors all over the South Island. This transformer in Halfway Bush had stopped talking to them, and some gear in Islington had gone offline.
"Some older control room people I met a few years ago said they ended up using a web search and found a notice from NOAA in the United States saying there was a really big solar magnetic storm. And they put two and two together, but they really didn’t know."
Vivid and extensive displays of the aurora followed the solar tsunami in both the southern and northern hemispheres.
MSo how big was the November 2001 CME compared with the more run-of-the-mill events, which are still significant enough to cause vibrant auroras?
Engineers and space physicists determine the strength of a solar tsunami, and its impact on a power grid, by calculating how quickly the magnetic field changes. That rate of change of magnetic field is measured in nano-Teslas per minute (nT/min).
"So when the magnetic field is going ‘wibbly-wobbly, wibbly-wobbly’, that makes those currents flow that aren’t meant to be in that power line," Rodger says. "So, the faster it’s going ‘wibble-wobble’, the bigger the current."
The November solar tsunami had a peak rate of change around 200nT/min, about 10 times more than in an average auroral event. It was the biggest event to occur in New Zealand in the past 25 years.
A July 2012 solar tsunami which missed the Earth had a strength of about 1500nT/min (see sidebar), while the infamous Carrington Event of September 1859, the strongest to have affected the planet in recent times, may have been as much as about 5000nT/min, he says.
A Carrington-magnitude event is the planning benchmark for major CME disruption in the future.
"We don’t know how fast the Carrington Event might have been changing the magnetic field because the measurement quality is too low. But in the last few years, the UK government’s scientific advisory panel has made 5000nT/min what they call a reasonable worst-case magnetic storm scenario."
Here, Transpower says its modelling is based on the UK’s and has determined an "extreme storm" to have magnetic field changes of 4000nT/min.
This planning preparation is essential to ensure we know what to do to protect essential electrical and communication infrastructure on which billions of lives depend, and which could cost trillions of dollars to repair or replace.
New Zealand is one of the few countries whose grid has been directly affected by a solar tsunami in recent years. So, with that experience, what are we doing to get ready?
Former prime minister’s chief science adviser Sir Peter Gluckman was made aware of the potentially crippling July 2012 CME — which fortunately missed the Earth’s orbit — by British counterpart Sir John Beddington.
"I kicked it off when I was rung from the UK to inform of a risk of one, to find almost no knowledge in New Zealand and the key services not even aware of it," Gluckman says.
That precipitated the development of New Zealand’s National Risk Register of threats with the potential to affect security and wellbeing.
The entry for space weather says "severe geomagnetic disturbance could negatively impact information and communications technology, global navigation satellite systems and other critical infrastructure".
Meanwhile, Rodger and team are continuing with their MBIE-funded research, and Transpower is steering the electricity sector’s understanding and preparations for such an event.
Unclear at present is whether central government will make a decision as to which agency will lead a response.
MBIE, which has its own space agency for policy and regulation development, might seem as good a bet as any.
General manager of workplace, safety and security Adrian Regnault told The Mix MBIE had been "suggested as a potential agency to lead the emergency response" but no official decision had been made.
"MBIE is currently supporting the development of a discussion paper for the [government’s] Hazard Risk Board on the topic of space weather. This paper notes that a lead risk co-ordinating agency needs to be agreed."
The National Emergency Management Agency (Nema) has also been mooted as a possible leader, but its answers to The Mix didn’t reveal any clear directive to take charge.
Director John Price says the National Civil Defence Emergency Management Plan 2015 can be used to address the consequences of an emergency, including a solar tsunami.
"The ‘Get Ready’ website has details about how to prepare for potential impacts from a space weather event, such as loss of telecommunications, internet and electricity.
"Since a coronal mass ejection might have a range of different impacts depending on the nature and size of the event, relevant agencies including Transpower and MBIE are carrying out their own planning in accordance with their responsibilities within the National CDEM Plan. Nema is in regular contact with them."
When it comes to forecasting space weather, agencies in the United States, Japan, Canada, Australia, throughout Europe and in South Africa issue advisories or warnings of disruptive solar radiation events.
In New Zealand, MetService provides a range of forecasts and warnings as part of its public services contract with the minister of transport.
Senior meteorologist Chris Noble says those offerings are reviewed periodically and space weather could be something MetService became involved with in future.
"It’s an area that does need some attention, whatever that might end up looking like."
It’s not only power lines that can be badly affected by magnetically induced currents. The same can happen in long natural gas and oil pipelines. GPS (global positioning systems), on which the aviation sector relies, can also be disrupted.
Airways New Zealand says in case of a solar tsunami it has alternatives to GPS to keep passengers and pilots safe in the 30 million sq km of airspace it controls.
Chief information officer Geoff Peck says the contingency is to revert to traditional navigation by methods such as radar.
"We maintain a network of contingency technologies ... in the event of a GPS outage. For security reasons we are not able to provide specific details."
Transpower has been leading electricity industry work on solar tsunami and their potential effects.
In August last year, the industry’s chief executives’ forum set up a working group comprising Transpower, Meridian Energy, Genesis Energy, Mercury Energy and Contact Energy.
Transpower’s general manager of operations, John Clarke, says the grid company has worked with the University of Otago and Prof Rodger to understand CMEs and model their impact on equipment.
This work may be even more important at present, as we head towards an approximately 11-year solar-cycle maximum in the next year.
"The likelihood of an extreme CME is closely correlated to solar activity. However, an extreme CME could occur at any time. While there is no imminent danger, this is an opportunity to remind all New Zealanders that no infrastructure can be 100% reliable in a natural disaster or other major event.
"Our research suggests we should have at least 12 hours warning of an extreme solar storm hitting Earth to begin putting our plans in action ... to protect equipment and minimise the impact on consumers."
Some of the power grid might have to be switched off for up to 30 hours to minimise the risk of extended blackouts due to damaged equipment, he says.
Transpower has been measuring geomagnetically induced currents since the Halfway Bush incident in 2001. Measurements have been fed into models to work out how to allow for a reduction in these currents in lines and transformers.
Rodger says one of the advantages of preparing for a solar tsunami compared with other natural hazards is there is likely more time to do so.
"But we all recognise we don’t want to be in a situation where NOAA or Nasa, or the European Space Agency, put out a press release saying a Carrington-like event is going to hit the Earth in 12 hours. That is not the time to be building the plane. We’re not going to be able to create those plans on the fly.
"You’ve also got some time to warn people if one is on the way and to bring those plans into play to shut down the network for a time."
After a planned blackout, it might take a day to bring power back on in the South Island and up to two and a-half days in the North Island, he says.
"That’s if there’s no damage. It’s almost like rebuilding a computer network. A blackout where all the equipment survives is a lot less bad than a blackout where everything is broken afterwards.
"The worst worry is if you have significant pieces of equipment, like transformers, burned out during the storm, because you can’t re-energise something that’s gone.
"We don’t have a lot of spare transformers and you have to order them in advance. There’s the suggestion it would take months to build new transformers. And if there’s a global event, New Zealand wouldn’t necessarily be at the front of the queue."
Kiwis would need to dig deep and, like after a major disaster such as an earthquake or flood, be ready to look after themselves for several days during a preventive power shutdown, Rodger says.
"It’s like the message comes out and says, ‘look, everybody, in six hours’ time the electricity is going to go. We hope to be back talking to you in three to five days’."
Solar storms causing disruption on a massive scale
September 1-2, 1859: The Carrington Event remains the most intense solar tsunami/coronal mass ejection (CME) to have affected Earth in recent times. The storm created incredible auroral displays as close to the equator as Queensland and Hawaii, blew up telegraph lines and pylons, and created strong enough currents for some operators to use the system without batteries.
May 13-15, 1921: The "New York Railroad Storm" was the strongest solar tsunami of the 20th century. It sparked fires around the world, and damaged telegraph links in the United States and undersea telegraph cables.
August 1972 solar flares: An intense series of solar flares caused widespread disruption to electricity and communication grids across North America and caused the accidental firing of naval mines in North Vietnam. The CME’s 14 and a-half hour travel time from the Sun to Earth is the fastest recorded.
March 9-13, 1989: Significant communications blackouts were experienced, along with a serious failure of Quebec’s electricity network that lasted nine hours. In August, another solar tsunami brought trading to a halt on the Toronto Stock Exchange.
November 6, 2001: A solar tsunami burnt out a transformer at Transpower’s Halfway Bush, Dunedin, substation, and generated vivid auroras.
July 23, 2012: A near-miss for the Earth from a CME believed to be of similar magnitude to the Carrington Event but which was ejected from the side of the Sun facing away from us. If it had hit Earth, it would have caused several trillions of dollars of damage and disruption.
