The sun will briefly set in America's northernmost city this weekend, something that hasn't occurred there in 85 days.
On May 10, Utqiagvik, Alaska, had a sunrise at 2:45 a.m. AKDT, as noted in the tweet below from that day. Since then, the sun has not dropped below the horizon in this city located north of the Arctic Circle.
That will change this weekend when the sun briefly sets early Sunday morning (Aug. 2) at 1:52 a.m. AKDT.
This nearly three-month period without a sunset in Utqiagvik is not unusual and it happens every year.
During the Northern Hemisphere's spring and summer, the sun's most direct rays shine over areas between the equator and Tropic of Cancer, about 23.5 degrees north latitude.
Because the Northern Hemisphere tilts toward the sun in the spring and summer, areas north of the Arctic Circle – within 23.5 degrees of the North Pole – experience more than two months when the sun never dips below the horizon, evoking the popular phrase "Land of the Midnight Sun."
Despite all this possible sunshine, average highs in Barrow – now known as Utqiaġvik – reach a yearly peak of only 47 degrees in July, not only due to its northern latitude, but also its proximity to the Arctic Ocean. Barrow experiences 187 cloudy days a year because of dominant east winds off the ocean, according to data from NOAA's National Centers for Environmental Information.
From mid-November through late January, the sun doesn't rise north of the Arctic Circle, due to the tilt of the Earth away from the sun's most direct radiation.The opposite occurs from mid-November through late January, when the sun doesn't rise for about two months north of the Arctic Circle.
It's a common misconception that Utqiagvik and areas north of the Arctic Circle are completely dark during this period.
Civil twilight, defined as the point when the sun is 6 degrees below the horizon, allows sufficient light to see objects outside. This civil twilight period is about 6 hours long near the beginning and end of polar night but shrinks to about three hours in the heart of the polar night just before Christmas.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
No comments:
Post a Comment