A portrait of the infamous STEVE arc of hot flowing gas associated with an active aurora, here showing his distinctive pink colour and the fleeting appearance of the green picket fence fingers that often show up hanging down from the main arc. It then subsided in brightness and structure, giving the impression the show was over.īut that’s exactly when STEVE can - and this night did! - appear. The main aurora reached a peak in activity about 11:30 pm MDT, when it was bright and moving along the northern and northeastern horizon. Moonlight from the waxing gibbous Moon low in the southwest illuminates the scene.Īs the NLCs faded, the auroral arc brightened, promising a good show, in line with the predictions (which don’t always come true!). A display of a Kp-5 aurora near its peak of activity on August 7, 2022, taken from home in southern Alberta, over the wheatfield next to my acreage. But early August was the latest I had ever sighted NLCs. They are common in June and July from here (we are also in an ideal latitude for seeing them). These are high altitude water-vapour clouds up almost as high as the aurora.
I captured the above panoramas of the aurora early in the night, when we also were treated to a late season display of noctilucent clouds low in the north. This was the latest I had seen NLCs from my latitude of 51° N.
This is a telephoto lens panorama of a low and late-season display of noctilucent clouds in the north on August 7, 2022. However, at Kp5, the amount of energy being pumped into the magnetosphere and atmosphere around Earth is high enough to trigger (through mechanisms only beginning to be understood) some of the unique phenomena that occur south of the main aurora. So with Kp5, the aurora always appeared in my sky this night to the north, though certainly in a fine display, as I show above. The panorama takes in the northern stars, from the Big Dipper and Ursa Major at left, to the W of Cassiopeia at top right of centre, with Perseus below Cassiopeia, and Andromeda and Pegasus at right. An arc of a Kp-5 aurora over a wheatfield from home in southern Alberta. However, on August 7, the Kp Index was predicted to reach Kp5, on the Kp 0 to 9 scale, so moderately active, but not so active it would bring the aurora right over me at latitude 51° N, and certainly not down over the northern U.S., which normally requires Kp6 or higher levels.
The main auroral band typically lies over Northern Canada, at latitudes 58° to 66°, though it can move south when auroral activity increases. Where I live in southern Alberta we are well positioned to see a variety of so-called “sub-auroral” phenomena - effects in the upper atmosphere associated with auroras but that appear south of the main auroral arc, thus the term “sub-auroral.” An arc of a Kp-5 aurora early in the evening just starting a show, but with a fading display of noctilucent clouds low in the north as well. On Augwe were treated to a fine aurora and a superb showing of the anomalous STEVE arc across the sky.
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