2 June 2012 The Land of the Midnight Sun

There are strange things done in the midnight sun

By the men who moil for gold;
The Arctic trails have their secret tales
That would make your blood run cold
From a poem by Robert Service, The Cremation of Sam McGee

Incredible light! Were you wondering about the meaning of the phrase, midnight sun? I mentioned it in my Dalton Highway journal, and had some questions about it. The "midnight sun" refers to the fact that during a certain time of the year, the sun will not set. At midnight, then, you can go outside into full sunlight, if it's not cloudy. What causes this to happen? Well, another definition of the Arctic is the latitude above which the sun will be above the horizon for a full 24 hours for at least one day, and below the horizon for 24 hours for at least one day. Remember when we crossed the Arctic Circle on the way here from Fairbanks? That was the latitude line which happens to be 66.5o N. Being a three hour drive from that point, we at Toolik Field Station are located at 68.6o N latitude. How does the sun get to be above the horizon for 24 hours? Think about the Earth revolving around the sun over the course of a year; it spins on its axis tilted at the sun. This tilt toward the sun causes our seasons. When the Northern Hemisphere is pointed toward the sun it's summertime, and when it's pointed away we experience winter. Click here for a great image from the excellent website from Windows2Universe (http://www.windows2universe.org/earth/climate/cli_seasons.html) Farther north of the 68.6o latitude , the sun stays above the horizon for more than a few days in the summer. Temperatures still change and cool off from day to night as you would expect, especially early in the summer season. That's because the sun is higher above the horizon at noon than it is at midnight, thus the sun's rays are more direct and therefore warmer at midday than they are at midnight. Take a look at the sunrise/sunset chart for this area. sun rise and set table for one year Can you tell when the last sunrise was? When will the next sunset be? It sure is handy to not have to carry a flashlight around!

A really interesting thing about the constant sun is that the sun is at the south at midday, and at the north at midnight. The light shining on the North Slope of the Brooks Range is really at its most beautiful around midnight and later, when the sun is shining on it from the North. We are at Toolik which is located north of the Brooks Range. That's why the light is so beautiful in the picture I took at three in the morning the other day! Here's a photo from the same location, although with a little more snow, taken around 8:30 am on May 28.

Now for a few other pictures I thought turned out well with the light.

and finally

After I mentioned photographing the early light to Dr. Weintraub, he said the light was even better around 2 am. So the next night, on May 30, I got this picture from right outside my dorm.

Wow, I can't wait to get back outside with the camera and see what else I can see!