Did you see the Northern Lights in May and October, where aurora displays were seen worldwide? It could be just the start of the Northern Lights being seen across the U.S. and Europe, and far beyond, on several more occasions, according to an expert aurora chaser who can predict when impressive aurora displays will appear almost down to the minute.
Aurora is typically seen in polar regions at around latitudes of 70 degrees north and south, but during extreme geomagnetic conditions — usually when coronal mass ejections (clouds of charged particles ejected from the sun) arrive at Earth one after another or in tandem — the auroral oval can bulge, with displays then potentially seen as far as 25 degrees north and south.
Northern Lights: Geomagnetic Storms
The Kp index measures geomagnetic activity, with higher numbers indicating more intense aurora-producing solar storms. “If you look back at decades of data, you will find that in the typical solar maximum period, when the sun is at its most active over a three to four-year period, you get about 10 powerful Kp 8 and Kp 9 storms,” said Wil Cheung, who gives highly accurate aurora alerts to his followers on his popular Wil Photography channel on Instagram and Facebook, in an interview. “But we’ve only had two or three Kp 8 and Kp 9 storms in this cycle so far.”
According to NOAA, during a Kp 8 to Kp 9 storm, “the aurora will move further towards the equator, and it will become very bright and active. These events create the best aurora, and the extended auroral oval will be observable by most people. At these levels, the aurora may be seen directly overhead from the northern states of the U.S.”
That’s saying nothing of much more common Kp 6 and Kp 7 storms, which NOAA says: “the aurora will move even further from the poles and become quite bright and active. At this geomagnetic activity level, it might be possible to see the aurora from the northern edge of the U.S.”
Northern Lights: Solar Maximum
The recent increase in aurora displays at more southerly latitudes is due to the sun reaching solar maximum, a peak in the 11-year solar cycle. This solar maximum is increasing the frequency and intensity of Northern Lights displays, with a higher probability of intense geomagnetic storms for the next six months to a year. This current solar maximum is more intense than the last one in 2013, which is why we are seeing more noticeable Northern Lights at lower latitudes that for many decades.
For Cheung, this means that the stunning light shows that captivated audiences in May and October of this year are just the beginning. “I think some people would be surprised to know that the events in May and October were not one-off events, that there could be five or six more to come,” he said. That insight comes from comparing data on geomagnetic storms from previous solar cycles.
Northern Lights: Real-Time Forecasting
Cheung’s expertise in aurora forecasting has been honed over the past decade, during which he has seen the Northern Lights an astounding 370 times. “The first thing to realize about the Northern Lights is that it’s not something you can literally just walk out of your house and look up by complete chance,” he said, emphasizing the need for careful planning and preparation.
Cheung relies heavily on real-time data from satellites and specialized apps, but he gets forecasts for bursts of auroral activity that are accurate to the minute. How? For starters, it’s essential to know that NOAA’s Aurora Dashboard, which includes forecasts for geomagnetic storms, is based not on real-time data but on models.
Northern Lights: Key Moments
Knowing when a geomagnetic storm will begin — and how intense it will be — is all about knowing when a CME reaches Earth and begins interacting with the atmosphere. The only advance warning space weather forecasters get is from NASA’s DSCOVR and ACE satellites, which orbit Earth about a million miles out. They measure a CME’s speed and magnetic intensity, which is critical in calculating how the solar wind is about to change. Depending on the speed of the CME, the satellites give about 15-30 minutes warning of a significant space weather event — and the resulting displays of aurora.
Real-time forecasting can, therefore, be done just a few minutes before it happens. “There are key moments in the cycle of the phases of the aurora to be outside for,” said Cheung. “There are satellites that can help us predict it in real-time, but you also have to have low light pollution, clear skies and dark-adapted eyes — it’s hard work being in the right place at the right time. Don’t expect the Northern Lights to come to you.” However, if they are forecast come to your region, Cheung’s feed — which is aimed mostly at those in the U.K. — has some incredibly accurate predictions.
Northern Lights: Best Places And Times
Despite the flurry of aurora at southerly latitudes, the best and most reliable way to see the Northern Lights is to travel north, in the northern hemisphere, between September and March (when there’s sufficient darkness).
The best destinations are Alaska, northern Canada, Greenland and northern Scandinavia (Norway, Finland, Sweden and Iceland). “That’s where the auroral oval sits,” said Cheung, adding that the “super storms” experienced lately remain relatively rare. “If you want to maximize your chances of seeing the Northern Lights, then really you have to go north — and September and March, around the equinoxes, are the best months to go.”
Wishing you clear skies and wide eyes.
