The week of Oct 10th, 2021, provided many Canadians and US residents with an extraordinarily light show. People in many Canadian cities such as Vancouver, Calgary and Winnipeg, as well as US residents of Seattle, New York, and parts in between, were able to see a multi-day Northern Lights display.
The National Weather Service’s Space Weather Prediction Center (USA) initially predicted this geomagnetic storm as a G3 but ultimately downgraded it to a G1. Figure 1 shows the storm’s geographic range across Asia and North America, with the highest intensity in the Great Plains (i.e. Prairies) region.
Despite a downgrading of this Coronal Mass Ejection (CME)1, it still proved to be a spectacular presentation. Large cities could see these northern lights (CME events), providing they were not clouded over. Of course, rural residents got an even more spectacular view, and as a result many Northern Light enthusiasts went out to the countryside to take photos.
The following photo is one such example of a broad sky view, fully engulfed with northern lights during that week.
Another exciting aurora picture comes from northern Manitoba. Here in the following picture, we see perhaps an image of a Sky Dancer in the aurora.
A surprising component of this CME event is that solar astronomers believe that the sun’s 11-year cycle has been at a minimal activity level for some years. So this CME ejection surprised them.
The ejected material in a CME is a magnetized plasma consisting primarily of electrons and protons. Many of the colours of the aurora come from the sun’s plasma particles interacting with oxygen at relatively lower altitudes of 100 – 300 km. The classic green glow is produced at this level, and the colour is produced when plasma particles interact with oxygen. The red aurora display, is also from interacting with oxygen, but this time it is from altitudes as high as 600 km. Blue and purple aurora colours, on the other hand, come from plasma exciting the nitrogen found at the 600 km heights.
The following figure shows the purple and blue colours from high-altitude plasma interactions with the earth’s atmosphere.
Here are some links to many more Northern Light pictures from the week of Oct 10th:
- Manitoba Aurora and Astronomy
- A pan-Canadian view of Northern Light pictures during this week
- Incredibly bright aurora borealis lights up Alberta’s night sky
- Brilliant auroras light up North America from Alberta to Nebraska
- https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections
We have published several stories about Northern Lights on our web pages in the past. These at times reference our GLACIER Facility, which is just west of Thompson, and other times, we bring to the reader’s attention some other interesting feature about the Northern Lights. For this story, the Northern Lights have presented themselves early and much farther south than commonly seen. And, of course, we comment on the various features of this phenomenon.