• Space weather can lead to widespread damage to energy infrastructure, fires and communications blackouts.
• Experts have forecast a surge in activity – called a solar maximum – in 2025.
• Leading-edge New Zealand research is being carried out into ‘solar tsunamis’.

Solar storms that could lead to a week-long grounding of the world’s aviation industry and cut energy supplies to Kiwis for several days might seem alarmist to some.

But extreme space weather – including patterns dubbed ‘solar tsunamis’ – has had a dramatic impact on New Zealand before and is expected to do so again.

A leading New Zealand figure on the phenomenon said it was a matter of “when, not if” another big solar weather event – beginning from the sun 149 million kilometres away – will make a sizeable impact on Earth.

Caused by activity on the surface of the sun, “day-to-day” space weather can lead to stunning auroras in our night skies. That includes the amazing lights seen in the sky in New Zealand - and around the world - over the past couple of nights.

But more severe space storms could lead to widespread energy supply outages, wildfires from sparking or exploding powerlines or substations, and the forced grounding of planes worldwide due to GPS and communication outages.

The most dangerous point is potentially during a “solar maximum”, the highest rate of solar activity during the sun’s 11-year solar cycle, which is expected to occur again in 2025.

Some of our nation’s planning for and likely reactions to an extreme solar event is outlined in the National Emergency Management Agency’s (Nema) New Zealand Space Weather Response Plan; a document recently shared within the Gisborne District Council’s Civil Defence Emergency Management Group.

Published in June, the report says the “most likely” impact in New Zealand from an extreme solar weather event would be “power cuts which could last for some time”.

Space weather was linked to solar activity, the report stated, “which rises and falls across an 11-year cycle”.

The solar maximum – the next one is forecast to happen next year – was “a period of high activity”.

Space weather and the potential impact on energy infrastructure are currently being studied by the Solar Tsunamis Endeavour Programme, an international collaboration led by the University of Otago and funded by the Ministry of Business, Innovation and Employment.

A graphic in a Gisborne District Council emergency management document outlines what can happen – and what can be impacted – by severe solar weather. Photo / Gisborne District Council

Professor Chris Rodger, head of the solar tsunami project, said while it was getting closer to a solar maximum, history showed Earth could be badly impacted by severe space weather at any time.

“It is when, not if,” he told the Herald.

Storms from the sun can throw out bursts of electromagnetic radiation and charged particles (plasma from the sun) that can impact Earth-based infrastructure systems, especially electricity generation.

Extreme solar storms are rare, but they have previously impacted the Earth

Two of the most notable occurred in 1850 and 1921.

The first – dubbed the “Carrington Event” – resulted in telegraph signals throughout Europe and North America going down. Sparks also flew from telegraph poles.

The Northern Lights are among aurora created by less-extreme space space weather. Photo / 123rf

Brightly coloured auroras were also seen in the night sky around the world.

The 1921 event – dubbed the “New York Railroad Storm” – caused numerous fires around the globe, including several blazes sparked by electrical currents that led to telephone exchanges in New York catching alight.

Telegraph systems around the world, including New Zealand, were also impacted by a surge of electric currents.

In 2001, a transformer in Dunedin was damaged in a solar storm.

And five months ago, Transpower issued a “grid emergency” notice after a storm in space was upgraded to an extreme level.

An extreme space weather event could lead to damage and widespread outages of New Zealand's power grid. Photo / Alex Burton

As a precaution, some South Island transmission lines and North Island substations were removed from service. But, the move did not impact the supply of electricity to consumers.

Rodger said damage to the electric supply, and potentially gas pipelines, was the biggest impact normally linked to severe space weather.

“Then the next impact is systems like GPS could get buggered for a few days. The satellites don’t die, we just can’t talk to them for say three days,” he said.

“If you have got self-driving tractors that use GPS to drive around that would be a problem.

“They also think that in an extreme event the entire global aviation industry could ground themselves for days to a week.

“The thing about an extreme event is that it is not just going to hit New Zealand, it is going to hit everybody. Space weather is on that list of things that by the time we actually care about it, it will be a global event.”

Nasa astronauts carry out a spacewalk with New Zealand pictured in the background. Photo / Nasa

During May’s solar storm, which led to Transpower issuing a grid warning, American owners of a popular brand of tractor were told to stop using self-driving vehicles during crop planting time as the solar storms had impacted the GPS set-up of the tractors.

Farmers who used the technology at that time have been warned crops were planted in places they shouldn’t have been.

“These self-driving magic tractors couldn’t do their job properly because the ionosphere was so messed up,” Rodger said.

In New Zealand, the solar tsunami research project is working alongside Firstgas – the owners of the natural gas pipeline in the North Island – and Transpower in a bid to understand how our energy infrastructure could be impacted by an extreme weather event.

Rodger said there was a gradually growing recognition in New Zealand about space weather.

In 2022, GNS Science opened a new geomagnetic observatory at Antarctica’s Scott Base. One of its roles is to study magnetic storms.

And, earlier this year, Nema completed and circulated its New Zealand Space Weather Response Plan.

The British Antarctic Survey Halley VI research station in Antarctica carries out research into space weather. Photo / James Morris

The plan has three stages: standby, alert and active.

“Standby” is listed as the “default condition”, where Nema will monitor potential space weather events, undertake contingency planning for potential responses and carry out training and other exercises to ensure the plan remains “fit for purpose”.

It could then be upgraded to the “alert” stage if a notification was received from the United States Space Weather Prediction Centre or the Australian Space Weather Forecasting Centre warning of a geomagnetic storm, solar storm or radio blackout that reached certain criteria.

That decision would be made following a meeting between Nema, Civil Defence bosses and a “multi-agency incident management team”.

“The public information management function will focus on likelihood and consequences of disruption to networks, including shutdown of parts of the electricity grid. Nema’s duty public information management function will amplify Transpower’s messaging through Nema’s channels,” the plan says.

A change to “active” could be made where a “significant space weather event is imminent and geographic location has been confirmed”, with that call to be made by the director of Civil Defence emergency management and the national controller, Nema.

Nasa’s Solar Dynamics Observatory captured this image of a solar flare – seen as the bright flash in the lower left – emanating from the Sun earlier this month. Photo / Nasa

Nema would take the leading role in relaying messages to the public.

“This will be impact-focused, including information and advice to the public about what people should and should not do,” the plan says

“In the event of an electricity grid shutdown or major forecast impact, Nema can issue emergency mobile alerts.”

Given the most likely space weather impact on New Zealand could be widespread power cuts, Nema’s plan urged Kiwis to be ready.

“This is a timely reminder to prepare your whare and whānau for emergencies – power outages can happen anywhere at any time,” the plan says.

“Make sure you have emergency supplies including torches and a solar or battery-powered radio, and food that does not need to be cooked.”

Being prepared was a message Rodger encouraged too.

“I don’t want to ... suggest that the sky is falling or saying this is a disaster,” he said.

“In many senses I think New Zealand is in a really good place to start to think about space weather because we have so many hazards already. Whether it is Christchurch and the earthquake or Cyclone Gabrielle knocking most of the North Island ... we have a lot of natural hazards.

This image shows the aurora lights captured over Lake Ellesmere, Canterbury. Photo / Natalie Crowther

“I believe Nema gives advice to people that you should aim to have enough supplies to look after yourself for a time period of three to five days. That is probably really good advice for an extreme space weather event.”

Neil Reid is a Napier-based senior reporter who covers general news, features and sport. He joined the Herald in 2014 and has 30 years of newsroom experience.