A strong solar storm has been delighting aurora photographers across New Zealand. Photo / NOAA; Paul Wilson, NZ Photo Trips
A strong solar storm has been delighting aurora photographers across New Zealand. Photo / NOAA; Paul Wilson, NZ Photo Trips
Last weekend was an exceptional one for aurora hunters. A once-in-a-decade geomagnetic storm from the Sun led to a rare type of aurora not seen in New Zealand in years.
The larger-than-expected storm follows a trend that is expected to reach its peak in the next 12 months, when expertspredict it could be possible for sightings as far north as the Hauraki Gulf.
“It was the biggest aurora display in many years. So big, the corona formed. [Which is] very, very rare for New Zealand,” said photographer Larryn Rae.
“It’s the first time I have ever seen or captured this and the first and only of this current solar cycle so far,” said the photographer from Wanaka.
Rae was hardly the only New Zealander to notice the unusually strong NOAA forecast. There was a major geomagnetic storm on the Sun on the night of December 1, which resulted in a spectacular aurora forecast for the weekend.
“It was the first time I have seen a corona in more than 10 years,” said Dunedin-based astronomer Dr Ian Griffin.
The director of Tūhura The Otago Museum says he was out observing the storm from the Otago Peninsula.
The rare Aurora Corona seen from New Zealand's South Island. Photo / Paul Wilson
“The storm was caused by a number of explosions on the Sun’s surface (called coronal mass ejections, CMEs) arriving at the same time and magnifying the impact of the storm.”
The solar CME which appeared at the beginning of the week turned out to be far stronger than first forecast.
Rae says he will always keep an eye out on the space weather forecast when there are aurora-causing ejections but “even then they can’t predict exactly how large the aurora will actually be until that energy hits the monitoring ACE Satellite in space”.
Th Aurora Corona, Otago Museum Director Ian Griffin said was the first seen in 10 years. Photo / Ian Griffin
High point in the Solar Cycle bringing solar flares and auroras
The larger-than-expected storm follows a trend that is predicted to reach its peak in the next 12 months. At this point, it could be possible for sightings as far north as the Hauraki Gulf.
While autumn and spring equinoxes are known to be good times to look out for the aurora, the displays are also affected by longer time cycles. We are currently at the tail end of the decade-long solar cycle, which can bring spectacular aurora results.
“There’s something called the solar cycle coming into effect at the moment,” said Dr Griffin.
“The number of sunspots increases and decreases in a fairly regular 11-year pattern. We are presently heading towards the next ‘solar maximum’, which will probably occur either next year or the year after.”
The aurora corona is an extremely rare phenomenon, not normally seen in New Zealand. Photo / Larryn Rae
With the peak set for next year, he says it will be an exciting time for astronomers and photographers.
“It is not surprising we are seeing more auroras - and more powerful auroras,” he says.
The “solar maximum” is turning out to be more powerful than first predicted.
“We may see auroras in places where you wouldn’t expect to see them, like Auckland, over the next year or so!”
