Iceland - Part 1

Aurora!

Our recent trip to Iceland was wonderful! Although we enjoyed the beauty of many interesting places within the Icelandic countryside, the primary goal of the tour was to view the aurora borealis in dark skies above rural Iceland.

On the night flight to Iceland I reserved a window seat on the north side of the plane hoping to see an auroral display from high altitude. I did see stars from the plane window, but no aurora.

There are at least three requirements for favorable aurora viewing. First, the sky should be dark and free of clouds or bright moonlight. Second, the Sun needs to be active enough to generate gusts and concentrations of solar wind headed toward Earth. Third, northern observers need to be close enough to Earth's north pole to view the auroral oval.
 
Dark Skies:
Our tour provided five opportunities to view the northern lights from dark rural locations. The entire population of Iceland is about 322,000. About 200,000 people live in and around Reykjavik. The rest of the population is spread out, and there aren't many people living in the countryside. Consequently, few lights spoil dark skies away from the city. Both our viewing locations were well away from the Reykjavik area. At our second viewing location, Hotel Ranga, the sky was dark all the way to the horizon in almost all directions. Our tour was planned to happen near the time of new moon, so moonlight was not a problem. The sky was dark at our observing sites, but it was not always clear.

Active Sun:
For some unknown reason auroras seem to be frequent around the equinoxes. Our trip started a week past the autumnal equinox. Unfortunately, the Sun was not very active during most of our Iceland visit. It woke up only once during the 5-day observing window.

Northern Location:
Our two viewing sites were located at about 64 degrees north latitude, slightly south of the arctic circle. These are the most northern locations I've visited so far. If auroras were visible, we would see them high in the sky, or at least well above the northern horizon.

Our first viewing opportunity on October 1st was clouded over and rainy. It had been completely cloudy and rainy since our arrival in Iceland two days earlier. Furthermore, there was no auroral activity that night, so, even if the sky had been clear, we would have seen nothing. This initial observing opportunity passed with no result. Our tour leader told us not to be discouraged. He had never failed to see auroras on any of his previous Iceland tours.

The first two auroral viewing nights were spent at Hotel Hekla near Selfoss. Here are two pictures of Hotel Hekla.

Rain and clouds continued throughout the day on October 2nd, our next viewing opportunity. A coronal mass ejection from the Sun was headed toward Earth on October 2nd, and it was predicted to spark good auroral activity this night. We were all gloomy because we thought continuous clouds were going to block our one chance to see the aurora.

During dinner, at roughly 8:00 pm, our tour leaders suddenly rushed out onto the dining room porch. Word quickly spread that an aurora was visible! Yes! Incredibly, unexpectedly, the completely overcast sky had cleared and pale green curtains of light were waving above. Enthusiastic cheers erupted. I quickly finished dessert, put on warm clothes, grabbed my camera and tripod, and went outside to watch the aurora. One initial view to the northeast looked like this.

The yellow/orange glow on the horizon came from hot house lights somewhere in the distance. In the beginning, the auroral display was persistent and easily visible, but not strikingly bright. The camera captured more color than the naked eye. To my eyes, auroral colors seemed pale green, almost white. Scattered clouds drifted by in the scene below. The Pleiades cluster and the constellation Auriga can be seen above the horizon.

The aurora continually changed shape and brightness. A bit later the view above foreground trees looked like the next picture. The Pleiades, Aries, Triangulum, and parts of Andromeda and Pegasus can be seen.

Overhead, a curtain feature appeared, with Delphinus, Aquila, and Sagitta above the curtain on the right.

Up to this point my camera was focused properly at infinity. Afterward, somehow, the focus changed. Maybe I unknowingly bumped the focus ring. Maybe the temperature changed. I should have checked for precise focusing at regular intervals throughout the evening. But I was too enthralled by the light show, and I didn't think to check focus. From here on my star images were slightly bloated and unfocused. For example, look at the next image.

Can you see the stars are not quite sharp? They aren't drastically out of focus, but they're not as sharp as they should be. (This imperfection really, really annoys me!) The constellations Lyra and Cygnus are in the lower right. 

The last picture above illustrates one of my camera's shortcomings. The aurora was actually changing shape while this 30-second exposure was proceeding. So the detailed structure I could see with my naked eye is smeared into a blur in the image. A two-second exposure would have captured the detail, but my camera does not have an ISO setting above 1600. The short exposures I tried did not capture enough light to properly show auroral detail. (All pictures here were captured with a tripod-mounted Nikon D40 camera, an 18-55 mm lens set at 18 mm, an ISO of 1600, and exposures 30 seconds long.)

I developed a serious case of camera envy on this trip. Before leaving I knew my camera was not top of the line, but I had no idea it was at the low end of the capability spectrum. Some tour members carried around close to $20,000 worth of high end cameras with sophisticated expensive lenses. Whoa! I can only dream of owning these amazing devices. On the other hand, thanks to my generous son-in-law, I had a superior, rock solid tripod.

Up to this point in the evening I was completely thrilled by the celestial light show. Then it got even better. Swinging around towards the northeastern horizon I saw this view.

In a short time the lights changed again. (Why, oh why didn't I check for better focus??)

Things were happening all over now. I swung around towards Lyra for this bright display.

A bit of purple color emerged in this image towards Corona Borealis and Hercules.

Things got more exciting in the north.

Since my camera wasn't sensitive enough to capture detail in short exposures, I decided to frame constellations accompanied by auroras. The following two images of Ursa Major came out fairly well.

The following animation, composed of four consecutive exposures, shows how the aurora changed over a period of just two minutes!

Soon after these last images were taken I noticed my pictures becoming increasingly dim and fuzzy. I knew the reason. Dew had formed on the camera lens. Earlier in the evening a mild dry breeze kept dew off the lens. But now the breeze was gone. By this time I had been taking photos for about 3 hours. I was getting cold and tired, so I decided to stop imaging and simply watch the lights play. The time was approximately 11:15 pm.

The sky then exploded with light! It seemed like most of the sky was covered with auroral light bright enough to light the ground below. The lights were changing shape, twisting, curling, and wavering. It was hypnotic, gorgeous, jaw-dropping. I was absolutely thrilled to have seen this phenomenon at least once in my life! Now I had personally witnessed the kind of display that inspired Robert Service to write in The Ballad of the Northern Lights:

      "And the skies of night were alive with light, with a throbbing thrilling flame;
      Amber and rose and violet, opal and gold it came.
     It swept the sky like a giant scythe, it quivered back to a wedge;
     Argently bright, it cleft the night with a wavy golden edge.
     Pennants of silver waved and streamed, lazy banners unfurled;
     Sudden splendors of sabers gleamed, lightning javelins were hurled.
     There in our awe we crouched and saw with our wild, uplifted eyes
     Charge and retire the hosts of fire in the battlefield of the skies."

    "And on we went on our woeful way, wrapped in a daze of a dream,   
    And the Northern Lights in the crystal nights came forth with a mystic gleam.
    They danced and they danced the devil-dance over the naked snow;
    And soft they rolled like a tide upshoaled with a ceaseless ebb and flow.
    They rippled green with a wondrous sheen, they fluttered out like a fan;
    They spread with a blaze of rose-pink rays never yet seen of man.
    They writhed like a brood of angry snakes, hissing and sulpher pale;
    Then swift they changed to a dragon vast, lashing a cloven tail."

Although two of the three remaining observing opportunities were cloud free, there was no further auroral activity on our trip. Thank goodness we were fortunate to win the aurora jackpot on one special night!

Below are three more animations showing how the aurora changed over the course of a minute or two.