Steve – The Amazing Sky

August 11, 2022August 11, 2022

A Showing of STEVE

On August 7, 2022 we were treated to a fine aurora and a superb showing of the anomalous STEVE arc across the sky.

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.

The main auroral band typically lies over Northern Canada, at latitudes 58° to 66°, though it can move south when auroral activity increases. 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.

An arc of a Kp-5 aurora over a wheatfield from home in southern Alberta. 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.

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.

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. These often appear right over me. That was the case on August 7.

This is a telephoto lens panorama of a low and late-season display of noctilucent clouds in the north on August 7, 2022. This was the latest I had seen NLCs from my latitude of 51° N.

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. These are high altitude water-vapour clouds up almost as high as the aurora. They are common in June and July from here (we are also in an ideal latitude for seeing them). But early August was the latest I had ever sighted NLCs.

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. STEVE appeared later this night. Moonlight from the waxing gibbous Moon low in the southwest illuminates the scene.

As the NLCs faded, the auroral arc brightened, promising a good show, in line with the predictions (which don’t always come true!). 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. It then subsided in brightness and structure, giving the impression the show was over.

But that’s exactly when STEVE can — and this night did! — appear.

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.

Sure enough, about 12:15 am, a faint arc appeared in the east, which slowly extended to cross the sky, passing straight overhead. This was STEVE, short for Strong Thermal Emission Velocity Enhancement.

STEVE is not an aurora per se, which is caused by electrons raining down from the magnetosphere. STEVE is a ribbon of hot (~3000°) gas flowing east to west. STEVE typically appears for no more than an hour, often less, before he fades from view.

A fish-eye view looking straight up. On this night the green fingers lasted no more than two minutes.

At his peak, STEVE is often accompanied by green “picket-fence” fingers hanging down from the main pink band, which also have a westward rippling motion. These do seem to be caused by vertically moving electrons.

This night I shot with three cameras, with lenses from 21mm to 7.5mm, including two fish-eye lenses needed to capture the full extent of sky-spanning STEVE. I shot still, time-lapses, and real-time videos, compiled below.

Amateur photos like mine have been used to determine the height of STEVE, which seems to be 250 to 300 km, higher than the main components of a normal aurora. Indeed, previous images of mine have formed parts of the data sets for two research papers, with me credited as a citizen scientist co-author.

A closeup of the STEVE arc of hot flowing gas associated with an active aurora.

STEVE is a unique example of citizen scientists working with the professional researchers to solve a mystery that anyone who looks up at the right time and from the right place can see. August 7-8, 2022 and my backyard in Alberta was such a time and place.

A dim Perseid meteor (at top) streaking near the Milky Way on the night of Aug 7-8, 2022, taken as part of a time-lapse set for the STEVE auroral arc in frame as the pink band.

As a bonus, a few frames recorded Perseid meteors, with the annual shower becoming active.

For a video compilation of some of my stills and videos from the night, see this Vimeo video.

A 2.5-minute music video of stills, time-lapses, and real-time videos of STEVE from August 7-8, 2022.

Thanks! Clear skies!

— Alan Dyer, amazingsky.com

May 8, 2018May 19, 2018

STEVE Puts on a Show

Steve Auroral Arc over House #2 (May 6, 2018)

The strange aurora named Steve put on a show on Sunday, May 6.

The past weekend was a good one for Northern Lights here in Alberta and across western Canada.

Aurora and Milky Way over Red Deer River

A decent display lit the northern sky on Saturday, May 5, on a warm spring evening. I took in that show from a favorite spot along the Red Deer River.

The next night, Sunday, May 6, we were hoping for a better show, but the main aurora never amounted to much across the north.

Instead, we got a fine showing of Steve, an unusual isolated arc of light across the sky, that was widely observed across western Canada and the northern U.S. I caught his performance from my backyard.

Popularized by the Alberta Aurora Chasers Facebook group, Steve is the fanciful name applied to what still remains a partly unexplained phenomenon. It might not even be a true aurora (and it is NOT a “proton arc!”) from electrons streaming down, but a stream of hot gas flowing east to west and always well south of the main aurora.

Thus Steve is “backronymed” as Strong Thermal Emission Velocity Enhancement.

To the eye he appears as a grey arc, not doing much, but fading in, slowly shifting, then fading away after 30 to 60 minutes. He doesn’t stick around long.

The camera reveals his true colours.

Steve Auroral Arc over House #1 (May 6, 2018)

This is Steve to the west, displaying his characteristic pink and white tints.

Fish-Eye Steve #1 (May 6, 2018)

But overhead, in a fish-eye lens view, he displayed ever so briefly another of his talents – slowly moving fingers of green, called a picket fence aurora.

It was appropriate for Steve to appear on cue, as NASA scientists and local researchers who are working on Steve research were gathered in Calgary to discuss future aurora space missions. Some of the researchers had not yet seen Steve in person, but all got a good look Sunday night as they, too, chased Steve!

I shot a time-lapse and real-time videos of Steve, the latter using the new Sony a7III camera which can shoot 4K videos of night sky scenes very well.

The final video is here on Vimeo.

Steve Aurora – May 6, 2018 (4K) from Alan Dyer on Vimeo.

It is in 4K, if you choose to stream it at full resolution.

With summer approaching, the nights are getting shorter and brighter, but we here in western Canada can still see auroras, while aurora destinations farther north are too bright and lack any night skies.

Plus our latitude south of the main auroral oval makes western Canada Steve country!

October 7, 2017

The Aurora Starring Steve

"Steve," the Strange Auroral Arc (Spherical Fish-Eye Projection)

I’ve assembled a music video of time-lapse clips and still images of the fine aurora of September 27, with Steve making a cameo appearance.

The indicators this night didn’t point to a particularly great display, but the sky really performed.

The Northern Lights started low across the north, in a very active classic arc. The display then quietened.

But as it did so, and as is his wont, the isolated arc that has become known as Steve appeared across the south in a sweeping arc. The Steve arc always defines the most southerly extent of the aurora.

Steve faded, but then the main display kicked up again and began to fill the sky with a post-sub-storm display of pulsing rays and curtains shooting up to the zenith. Only real-time video can really capture the scene as the eye sees it, but the fast time-lapses I shot do a decent job of recording the effect of whole patches of sky turning on and off.

The display ended with odd pulsing arcs in the south.

Here’s the video, available in 4K resolution.

Alberta Aurora (Sept. 27, 2017) from Alan Dyer on Vimeo.

Expand to fill the screen for the best view.

Thanks for looking!

May 12, 2017May 12, 2017

Meet Steve, the Odd Auroral Arc

Red Auroral Arc #1 (May 10, 2015)

Stargazers in western Canada will have seen him – Steve, the odd auroral arc.

There’s been a lot of publicity lately about an unusual form of aurora that appears as a stationary arc across the sky, isolated from the main aurora to the north. It usually just sits there – motionless, featureless, and colourless to the eye, though the camera can pick up magenta and green tints.

We often see these strange auroral arcs from western Canada.

In lieu of a better name, and lacking a good explanation as to their cause, these isolated arcs have become labelled simply as “Steve” by the aurora chasing community (the Alberta Aurora Chasers Facebook group) here in Alberta.

In a gathering of aurora chasers at Calgary’s Kilkenny Pub, aurora photographer extraordinaire and AAC Facebook group administrator Chris Ratzlaff suggested the name. It comes from the children’s movie Over the Hedge, where a character calls anything he doesn’t understand “Steve.” The name has stuck!

The 270° panorama from March 2, 2017 shows Steve to the west (right) and east (left) here, and well isolated from the main aurora to the north.

This is the view of that same March 2, 2017 arc looking straight up, showing Steve’s characteristic gradient from pink at top though white, then to subtle “picket-fence” fingers of green that are usually very short-lived.

The view above is Steve from exactly 6 months earlier, on September 2, 2016. Same features. I get the impression we’re looking up along a very tall but thin curtain.

Another view of the September 2, 2016 Steve shows his classic thin curtain and gradation of colours, here looking southeast.

Looking southwest on September 2, 2016, Steve takes on more rippled forms. But these are very transient. Indeed, Steve rarely lasts more than 30 minutes to an hour, and might get bright for only a few minutes. But even at his brightest, he usually looks white or grey to the eye, and moves very slowly.

Here’s a classic Steve, from October 1, 2006 – a white featureless arc even to the camera in this case.

So what is Steve?

He is often erroneously called a “proton arc,” but he isn’t. True auroral proton arcs are invisible to the eye and camera, emitting in wavelengths the eye cannot see. Proton auroras are also diffuse, not tightly confined like Steve.

Above is Steve from August 5, 2005, when he crashed the Saskatchewan Summer Star Party, appearing as a ghostly white band across the sky. But, again, the camera revealed his true colours.

Steve Auroras in 2015 from Alan Dyer on Vimeo.

Here are a couple of time-lapses from 2015 of the phenomenon, appearing as an isolated arc overhead in the sky far from the main auroral activity to the north. I shot these from my backyard in southern Alberta. In both clips the camera faces north, but takes in most of the sky with a fish-eye lens.

In the first video clip, note the east-to-west flow of structure, as in classic auroras. In the second clip, Steve is not so well-defined. Indeed, his usual magenta band appears only briefly for a minute or so. So I’m not sure this second clip does show the classic Steve arc.

The origin and nature of Steve are subjects of investigation, aided by “citizen science” contributors of photos and videos.

Local aurora researcher Dr. Eric Donovan from the University of Calgary has satellite data from the ESA Swarm mission to suggest Steve is made of intensely hot thermal currents, and not classic electrons raining down as in normal auroras. He has back-acronymed Steve to mean Strong Thermal Emission Velocity Enhancement.

Learning more about Steve will require a unique combination of professional and amateur astronomers working together.

Now that he has a name, Steve won’t be escaping our attention any longer. We’ll be looking for him!

March 4, 2017March 4, 2017

Auroras from Alberta

Aurora Self-Portrait (March 2 2017)

The solar winds blew some fine auroras our way this past week.

Oh, that I had been in the North last week, where the sky erupted with jaw-dropping displays. I could only watch those vicariously via webcams, such as the Explore.org Northern Lights Cam at the Churchill Northern Studies Centre.

But here in southern Alberta we were still treated to some fine displays across our northern sky. The image below is from March 1, from my rural backyard.

Fish-Eye Aurora (March 1, 2017) — A full-frame fish-eye lens image of the aurora on March 1 with curtains reaching up into the Big Dipper.

The Sun wasn’t particularly active and there were no coronal mass ejections per se. But a hole in the corona let a wind of solar particles through to buffet our magnetosphere, stirring up geomagnetic storms of Level 4 to 5 scale. That’s good enough to light our skies in western Canada.

Aurora over Frozen Pond — A 160° panorama of the main auroral oval to the north on March 2 about 11:40 pm MST.

Above is the display from March 2, taken over a frozen pond near home. I like how the Lights reflect in the ice.

This night, for about 30 minutes, an odd auroral form appeared that we see from time to time at our latitudes. A wider panorama shows this isolated arc well south of the main auroral oval and forming a thin arc stretching across the sky from west to east.

Aurora Panorama with Isolated Arc — A 220° panorama of the isolated arc to the west (left) and east (right) and the main auroral oval to the north.

The panorama above shows just the western and eastern portion of the arc. Overhead (image below) it looked like this briefly.

Isolated Auroral Arc Overhead — The overhead portion of the isolated arc at its peak.

Visually, it appeared colourless. But the camera picks up this isolated arc’s usual pink color, with a fringe of white and sometimes (here very briefly) a “picket-fence” effect of green rays.

Isolated Auroral Arc West — The western portion of the isolated auroral arc at its peak.

This is the view of the isolated arc to the west. Erroneously called “proton arcs,” these are not caused by incoming protons. Those produce a very diffuse, usually sub-visual glow. But the exact nature of these isolated arcs remains a mystery.

As we head into solar minimum in the nest few years, displays of Northern Lights at lower latitudes will become less frequent. But even without major solar activity, last week’s displays demonstrated we can still get good shows.