Published: 2015-11-19 11:51:00
Updated: 2015-11-20 12:37:21
Posted November 19, 2015
Updated November 20, 2015
By Tony Rice
When Greg Fishel visited Barrow, Alaska, in March, the sun set at 9 p.m. after just over 13 hours above the horizon. This small town along Alaska’s northern coast is known for its extremes and has become ground zero for climate-change research.
Records over the past 60 years show that Alaska has warmed at a rate more than twice that of the rest of the United States. One extreme in this northern most town that hasn’t changed is the huge variance of sunlight Barrow sees in a given day.
The sun will rise on Barrow today, Nov. 19, at 1:09 p.m Alaska Standard Time and set just SIX minutes later. Temperatures are forecasted to hover around -20 Fahrenheit throughout the day. The upper edge of the sun wont be visible above the horizon again until Jan. 23, 2016 at 1:10 p.m., or 65 days of Polar Night.
Barrow sees the opposite extreme during summer months. Residents see their last sunset for just before 1:00 a.m on May 11 followed by constant sunlight through the months of June an July, or around 80 days of Polar Day.
Other areas of the world above about 70 degrees latitude in Canada, Greenland, Finland, Norway, Russia and Sweden also experience this lack of sunlight during winter months. The duration of Polar Night varies greatly with latitude.
Tromsø, Norway, is situated just above 70 degrees north latitude. The city will see the sun set on Nov. 27 followed by about six weeks of polar night. Just 3 degrees south, just above the arctic circle, residents of Bodø, Norway, never experience Polar Night.
Atmospheric refraction bends the suns rays sufficiently to allow each day to receive some sunlight, less than an hour’s worth from Dec. 19 through Christmas Eve. However, Bodø does experience the “midnight sun” with the sun never setting during the month of June through-mid July.
At the northern extreme, the North Pole, the sun sets around the September Equinox and doesn’t rise again until the March Equinox. The South Pole experiences a similar (but reversed) six month periods of Polar Night and Day.
Back here in Raleigh, we will see 10 hours 11 minutes of daylight. We will lose 1-2 minutes each day. That loss of daylight slows to less than a minute as the next solstice approaches on Dec. 21.
After that we will again slowly regain daylight gain before adding 1-2 minutes of sunlight to January days.