Some Canadians looking to the sky this weekend could be in for a treat as two solar flares that erupted on the sun on their way to Earth, potentially bringing some intense displays of the northern lights.
The Space Weather Prediction Center in the U.S. National Oceanic and Atmospheric Adminsitration (NOAA) said on Thursday that a strong geomagnetic storm watch has been issued Oct. 4 to 6 due to a pair of coronal mass ejections.
The anticipated light show will be among a bounty of aurora borealis viewings seen this year. They are due to the sun’s magnetic field, which is at its peak of its 11-year cycle and putting out more solar storms, resulting in more frequent displays of northern lights.
“Up to now, this peak is exceeding predictions significantly and it hasn’t reached the top yet,” David Knudsen, the head of the University of Calgary’s department of physics and astronomy, told Global News on Thursday.
On Tuesday, scientists recorded one of the strongest solar flares of the cycle, considered an X7, which was then outperformed two days later with an X9 on Thursday, the biggest since 2017.
According to the Stanford Solar Center, solar flares typically range from B — considered too small to harm Earth — up to X, which can trigger planet-wide radio blackouts and long-lasting radiation storms.
When these flares interact with the Earth, they cause geomagnetic storms which are then given a classification of G1 to G5 in terms of strength, with G1 seeing potential weak power grid fluctuations and a G5 having the potential to cause some grid systems to experience complete blackouts. The geomagnetic storm hitting this weekend has been given a G3 classification.
But while there can be concerns for power grids, there is still excitement among sky watchers for what these storms could mean at night.
“The next two nights, there’s opportunity expected,” Chris Ratzlaff, an aurora chaser, told Global News on Thursday. “And then over the next probably three or four as this X9, we start to understand what that looks like, it could extend well into the weekend.”
Ratzlaff gave a probability of about 35 per cent that Calgary, for example, will potentially see the northern lights, in particular the afternoon and evening on Friday and early to mid-morning of Saturday.
According to mapping by NOAA, several parts of Canada may see the aurora with the highest likelihood stretching across the territories, and from B.C. to Quebec, though parts of southern Ontario may have less luck. Much of the Maritimes, according to the forecast also have a lower likelihood of viewing.
Erica Grow Cei, spokesperson for NOAA, told the Associated Press that there was still the potential for storms to intensify or weaken.
“There’s still a fair amount of uncertainty,” Cei said.
Given the activity in the sun, it’s not the first time Canada has had such an opportunity to view the lights. Unusually strong solar storms in May produced spectacular aurora displays across the Northern Hemisphere, but NOAA has said this weekend may be slightly lower in terms of light shows due to fewer ejections of the high energy plasma that drives them.
—with files from Global News’ Sarah Offin and The Canadian Press