auroral curtains – The Amazing Sky

September 9, 2015

The Dancing Northern Lights

The lights came out and danced in my sky in the early morning hours.

The early warning signs weren’t calling for anything too impressive for a display last night, September 8/9, but the sky surprised us with a fantastic display of Northern lights.

I shot with one camera – it was very late, or very early! – but shot enough frames to create this short 1.5-minute music video.

I photographed the sequence with a single fixed-camera aimed east toward a bright auroral curtain, showing fast pulsing forms common to the later stages of a substorm. But then a new bright curtain sweeps in from the north and the display brightens even more in a new substorm. The display then fades.

The exposures were taken over an hour from 1:30 a.m. to 2:30 a.m. MDT. Each was a 2-second exposure with an interval of 2 seconds, shot with the Nikon D750 at ISO 3200 and Sigma 24mm lens at f/2, for a total of just over 850 frames.

Music is my Adi Goldstein at AGSoundtrax.com.

March 6, 2015March 6, 2015

Dance of the Northern Lights

My new 3-minute music video compiles still and time-lapse imagery of the aurora I shot in February 2015 from Churchill, Manitoba.

Churchill’s location at 58° North on the shore of Hudson Bay puts it directly under the main auroral oval, the zone of greatest auroral activity. Over the 9 nights, 2 were cloudy, with a roaring blizzard.

But on the 8 clear nights we saw aurora every night. I shot time-lapses on 6 of those nights, shooting about 3,500 frames, most of which appear in the final cut of this movie.

Despite the amazing displays we saw, on no night was the auroral activity index (on a scale of 0 to 9) higher than 2 or 3. These were all “normal” quiet nights for auroras in Churchill. Anyone farther south would have seen little in their sky on most of these nights.

I shot many of the time-lapses with an 8mm spherical fish-eye lens, to create sequences suitable for projection in digital planetarium domes. One other time-lapse sequence (the last in this movie) I shot with a 15mm full-frame fish-eye. Even it is not wide enough to take in the entire display when the Lights fill the sky.

Exposures were typically 10 to 15 seconds at f/3.5 and ISO 1600 to 4000, all with the Canon 6D. I powered it from its lone internal battery. Amazingly, despite temperatures that were considered extreme even for Churchill (often -32° C at night) the batteries lasted 90 to 150 minutes allowing me to take lots of frames with no battery change or perhaps just one battery change. Churchill is very dry and only on one night did I have an issue with the lens frosting up.

Music is by Dan Phillipson, his composition “Into the Unknown,” purchased for royalty-free use through Triple Scoop Music. I edited the movie in Apple Aperture, with a title sequence created in Photoshop. Processing of the original images was with Adobe Camera Raw, Photoshop, and LRTimelapse, with assembly of movie frames done with Sequence for MacOS.

I hope you enjoy it! Do click on the Enlarge button to watch it full screen. It may take a while to start playing.

February 22, 2015February 22, 2015

Green Waves of Northern Lights

Last night the sky exploded with waves of green and pink as the Northern Lights danced in the bitter cold.

With blizzard conditions forecast for the next two days, last night might have been our last for viewing the aurora from Churchill. But if so, we ended on a high note.

The aurora appeared on schedule again at about 9 to 9:30 p.m., following my evening lecture, as it has done every clear night for the last couple of weeks. It began as a sweeping arc to the north, as above, then moved south to encompass the entire sky.

About 11 p.m. the sky burst open with waves of green arcs, but with generous tints of red and magenta that the camera picks up easily. To the eye, the reds are barely visible unless the aurora gets very bright.

Despite the bitterly cold temperatures of -34° C with a -50° wind chill, everyone in the tour group braved the night to take in the sight. And many managed to work their cameras and tripods, no small feat under such conditions, to get great shots.

The groups this week and last saw aurora every clear night, with clear nights on at least 3 out of the 5 nights of each course. Not a bad take, fulfilling everyone’s “bucket list” dream of standing under the aurora borealis.

February 21, 2015

A Cold Night of Auroral Lights

It was a bitterly cold night for watching the dancing Northern Lights.

When Environment Canada issues Extreme Cold warnings for Churchill, you know its cold! With temperatures at -32° C and with high winds last night, the wind chill equivalent was -50° C.

But that didn’t stop us from watching the Lights!

I nicely finished my evening lecture at 9 pm when the Lights appeared on cue. They were faint at first, but then brightened nicely by 10 pm. The show was over by midnight, a well-timed and convenient display.

The 22 participants in this week’s course all bundled up and headed out, onto the second floor viewing deck and out onto the ground for views and photos of the aurora.

This was not a brilliant display – the official activity level was still reading only 1 or 2 on scale of 0 to 9. But it provided us with some beautiful curtains and lovely colours. The hazy appearance is from high clouds and local blowing snow.

The views from the Deck overlooking the boreal forest make for some nice photo opportunities, from a spot largely out of the constant westerly winds.

We have three more nights here, though snow is forecast for the last two. Tonight may be our last night to enjoy the Northern Lights. But all are happy with what they have seen and shot so far.

February 19, 2015February 19, 2015

The Colourful Curtains of the Northern Lights

All-Sky Aurora #1 (Feb 17, 2015)

The Northern Lights have performed beautifully the last few nights, presenting curtains of light dancing across the sky.

Two nights ago in Churchill, Manitoba we were treated to a “storm level” show of aurora, with the Lights all across the sky in green curtains waving and curling before our eyes.

The curtains tower several hundred kilometres up into the atmosphere, from the lower edge at about 80 km up (still high above the stratosphere) to the curtain tops at about 400 km altitude at the edge of space.

The camera picks up the colours far better than the eye can, recording not only the predominant green hues but also shades of pink, magenta and red.

The magentas and reds come from the sections of the curtains at the highest altitudes, from the top of the auroral curtains. Here, where the atmosphere is a near vacuum, sparse oxygen atoms can glow with a red emission line.

However, there must be a blue component as well, leading to the magenta or pink tones, as in my photos here. Nitrogen can glow in blues and purples and might be contributing to the colours.

The top two photos are from Tuesday night, Feb 17, when storm levels of 5 were in effect worldwide.

All-Sky Auroral Curtains #2 (Feb 18, 2015)

Lower down, at about 100 km altitude, the air is denser and oxygen glows with a brighter green hue, which the eye can detect more easily.

The photo above from last night, with an activity level of just 2, also shows most of the sky covered with a faint emission, with a patchy appearance, with dark “holes” also moving and flowing in the time-lapse movies I shot.

Closer to the horizon, and far to the north, the aurora brightens into the more characteristic green snaking curtains.

This image from three nights ago shows an usually coloured aurora at the start of the night, glowing mostly a deeper red and orange.

The green was still off in the distance far to the east. It arrived a few minutes later as green curtains swept in over us.

But the initial red was from low-energy electrons lighting up just high-altitude oxygen. Only when the higher energy particles arrived did the sky light up green.

I shot all these images with an 8mm fish-eye lens as frames in time-lapse sequences intended for use projected in digital planetarium domes, where the 360° “all-sky” scene would be recreated on the dome as it was in real life.

If you are with a planetarium, contact me if you’d like to get aurora clips.

Our second group of aurora tourists has arrived today at the Churchill Northern Studies Centre, and the weather is warming to a high of -20° C. Balmy!

We’re hoping for more fine displays, though the space weather forecast calls for a quiet magnetic field in the next few days.