Svalbard’s Total Eclipse

Totality on 20th March 2015, Spitsbergen, Svalbard, by Ivar Marthinusen.
Marthinusen_eclipse

The total solar eclipse above the mountains of Svalbard.

Last Friday was an extraordinary day. Eclipse day.  I awoke to mostly clear weather and couldn’t quite believe our luck.  As I walked down through Longyearbyen towards the university (UNIS) just before seven o’clock, there was a large lenticular cloud hugging the summit of the mountain across the fjord, and some wispy, pink cirrus clouds up high.  Otherwise the sky was blue.  I met my friend Pål (pronounced Paul) at UNIS, an optics specialist in the atmospheric physics group, and we went across to the old aurora station in Adventdalen.  Visiting scientists were there setting up their equipment for imaging and spectroscopy, and the Norwegian broadcaster NRK was preparing for a live broadcast. Pål set up his telescope and camera. The clouds disappeared and the sky became a perfect blue, the sun shining strong and clear and reflecting brightly around the snowy mountain landscape.  

Sunspotter

The image of the eclipse on the Sunspotter

After nine a group of students arrived. Up and down Adventdalen people were gathering. It was freezing – probably around -20C – and I was wearing full down clothing.  People walked around between small groups, trying to keep warm and anticipating “first contact”.  Then, at about twelve minutes past ten local time, there it was.  The moon touched the sun and we watched it gradually move across, people tracking the progress through their eclipse glasses.  We also had a Sunspotter, a folded Keplerian telescope which projected an image of the sun onto a small screen.  People gathered round to watch.

Gradually the sun shrunk down to a small crescent, then a sliver. At this point it became noticeably darker, though still quite light. “It’s just like looking through sunglasses,” I heard a student nearby exclaim.  Except we weren’t wearing sunglasses.  Then, a strange strobe-like effect began, clearly visible as flickering light-and-dark on the snow.  These were the shadow bands – rippling waves of light caused as the final, almost point-source, sliver of light is focussed and defocussed as it passes through warmer and cooler air currents in the atmosphere.  People talk about watching out for the shadow bands because they are easy to miss.  Experts recommend putting a white sheet on the ground because they are most visible on a flat, white surface.  There they were obvious – we had a landscape of pure white snow all around.

Incredibly quickly, after seemingly only a few pulses of the strobe, there was sudden brightening, the diamond ring effect, and then darkness.  Totality.  The moon was completely blocking the sun and I looked up at it with naked eye. I could see the pink tinge of the chromosphere (so called because of this distinctive pink colour) and prominences, though the fine structure of the prominences was more visible by telescope than by eye.  I think I just saw the colour. The solar corona glowed silver, a ring around the dark shape of the moon stretching short, silky fingers outwards into the black. It looked fairly symmetrical to me, not highly pinched in any direction.  It was like the sun had taken on the moon’s sheen, an eerie, ethereal silver.  It was beautiful.  I looked around at the mountains. The darkness was not pitch black, more a navy blue, perhaps from all the snow to reflect the light.  The mountains could be seen clearly and the horizon all around gave out a yellow glow.  People stood staring up in awe.

Ellingsen_totality

The moment of totality. Pink prominences can be seen.

All too soon there was another bright burst of light and the sun was back. I fumbled in my mittens to open my eclipse glasses again and looked up to see the newly exposed crescent of the sun as the moon moved on its way.  I took a deep breath as people around whooped and began discussing how incredible it was.  I couldn’t quite believe that I had witnessed a total solar eclipse.  I felt elated.  It had all worked perfectly.  I was in Svalbard, the weather cleared, the heavens aligned.  To be in such a phenomenally beautiful setting in the wide valley, with the mountains around, the snow, the light – it was special.

After totality we watched the sun return to us in full, everyone talking excitedly about what they had seen.  Then at twelve past midday the moon made last contact and was gone.  Everyone packed up and left, leaving Adventdalen deserted once more.  Apart from the scientists taking measurements from inside the old aurora station building, Pål and I were the least to leave, clearing the place up like at the end of a party.

A lecturer at UNIS last week compared a partial and total eclipse thus: “it’s like a kiss on the cheek versus a night of passion.”  It’s true.  I saw the partial eclipse near London in 1999 (I didn’t go to Cornwall) but I wasn’t prepared for the difference.  What I found most interesting, most incredible, this time was the sudden transition from light to dark, from crescent to corona.  It was the way the land went dark almost instantaneously that really struck me – one minute strobing shadows, then a bright flash, then darkness. Then the sun as you have never seen her.  I have seen pictures of the corona before but, just like viewing the aurora, to witness it as part of the landscape gives and new depth to the experience, something that I am exploring in my upcoming book, Seeing the Light.

I am truly grateful to have been there in Svalbard to see the eclipse.  I’m pleased that there was so much excitement and activity in the UK, and that so many people were able to get a glimpse of the splendour of this celestial event for themselves by viewing the partial eclipse.  But I urge you to remember that if you saw the partial it was just a glimpse, and I hope that one day you will have the opportunity to see totality for yourself too.

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This blog was first published on the International Year of Light UK website on 23th March 2015 as Notes from the North – Part 4

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Plasma physicist and adventurer, Melanie Windridge, is on an expedition to the frozen wilderness of Svalbard to witness the northern lights. In a series of letters, she shares her experiences as she walks in the footsteps of the earliest polar explorers and battles the elements in pursuit of science. In her fourth post she has a front row seat to one of the biggest events of the International Year of Light – a total solar eclipse!

Read parts 12 and 3 of her adventure.

Anticipating Aurora & Eclipse

“You should be here earlier in the winter. When it was colder,” said Knut, the Sami reindeer herder in his gruff, accented English. “Now it’s warm weather, rain, we can’t see the northern lights.”

“We haven’t seen them at all since I’ve been here,” I replied. “That’s nearly a week. It’s been cloudy every day.”

“When it’s so warm it [the northern lights] doesn’t come.”

“When is the best time to see it?”

“December or January. When it’s very cold.”

We were out in the hills with the reindeer somewhere around Karasjok, a few hours’ drive inland from Alta, near the Norwegian–Finnish border. That was March last year. I was in northern Norway researching a book I am writing on the northern lights. I am a plasma physicist and the aurora is plasma, so despite my academic interests in nuclear fusion (I was the IOP Schools’ Lecturer in 2010 on this subject), the northern lights have long fascinated me.

In Norway I was finding out about Sami culture and their folklore. “My parents told me that it was the spirits of the dead peoples, our relatives,” said Knut. “They were watching us.”

Since that trip I have visited Canada, America and Iceland – speaking to physicists, visiting tiny observatories, learning about space weather, geology and geomagnetism. And it all culminates this year – 2015, the International Year of Light. I’m going to Svalbard, the Norwegian archipelago in the high Arctic and the most northerly place in the world with a permanent population (though the people are outnumbered by polar bears). I’m going to see two of the most spectacular phenomena involving light on Earth – the northern lights and a total solar eclipse. Let’s just hope it’s not cloudy.

Svalbard_Arctic_map

Map looking down on the North Pole and Arctic Circle. Svalbard is marked with the red arrow.

For me, the chance to see both these phenomena together is a lucky coincidence. Solar eclipses happen around once every year or two somewhere around the globe. A solar eclipse occurs when the Moon passes between the Sun and the Earth, thereby blocking the light of the Sun. Although the Moon passes between the Earth and the Sun once during each monthly cycle – the new moon – most times they don’t line up exactly. The Moon’s orbit around the Earth is tilted with respect to the Earth’s orbit around the Sun, so the shadow of the Moon often misses the Earth. Thus eclipses happen infrequently.

This total eclipse (which occurs on 20 March) happens to coincide beautifully with the research for my aurora book, when I will be in Svalbard chasing the lights in an unconventional way. The first two weeks I will spend skiing east–west across the largest island of the archipelago, Spitsbergen, dragging my equipment and food in a pulk behind me, camping out in the snow, hoping to witness a good auroral display out in the Arctic wilderness. I will be with a guide, and we will be looking out for polar bears.

It will be more difficult than usual because it will be mostly dark. When I arrive on 16 February, the island will just be emerging from polar night, the sun rising for the first time since October last year. But the sun comes back quickly and by the end of my ski journey 10 days later there will be about seven hours of daylight. If I’m lucky I might catch a glimpse of the dayside aurora, only visible during polar night, for which Svalbard is particularly known.

Svalbard hosts some major research facilities including the European Incoherent Scatter Scientific Association radar, the aurora station at the Kjell Henriksen Observatory and a satellite station. It’s a good place to study the northern lights because the island’s high latitude position gives it an interesting perspective. The Earth’s dipolar magnetic field is not aligned exactly with the axis of the Earth (and indeed the geomagnetic field varies and wanders), meaning that the magnetic poles are not aligned exactly with the geographic poles. The dipole is tilted towards Canada.

Svalbard is located underneath the northern polar cusp, where the Earth’s magnetic field opens out into space like a funnel and charged particles directly from the Sun can enter and reach the Earth’s atmosphere. Here they excite atoms in the air, which then release this extra energy as light of characteristic colour. This direct funnelling from the Sun side of the Earth results in daytime aurora, which is less bright than night aurora and usually red in colour, since the incoming particles have lower energy. But how, you might be wondering, do charged particles get round to the night side of the Earth and create the northern lights there? And how are they accelerated to the higher energies required for those more vivid, colourful displays? That is the magic and mystery of the true aurora, something I will be exploring in my book.

As for the solar eclipse, I don’t know what to expect. But I do know that the town will get very busy with visitors from all over the world. Solar eclipses are not just beautiful, they offer a short window to make important scientific measurements. Einstein’s theory of general relativity was confirmed using observations made by Sir Arthur Eddington during the 1919 total eclipse.

Hopefully the weather will be kind and I will glimpse the solar corona and the complex, ever-changing magnetic field pattern, imagining the solar wind particles travelling to Earth and causing the aurora. I will be thinking about how it affects us on the technological, disruptable level we call space weather and also about how studying light has enabled us to increase our understanding of the universe.

Yet phenomena such as these also touch us on a personal, spiritual level. It interests me that even now, while understanding the physics, we still feel the wonder – even the spirituality – of these natural events. Standing captivated under a wide sky, watching the heavens move in a graceful, barely-choreographed dance, it’s easy to see the inspiration behind those old Sami tales.

aurora_Alta14_square

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This blog was first published by the Institute of Physics on 4th February 2015 at http://www.iopblog.org/melanie-windridge-northern-lights/

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Dr Melanie Windridge

info 'at' melaniewindridge.co.uk
 @m_windridge /DrMelanieWindridge m_windridge