Polar Circle


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polar circle

[′pō·lər ′sər·kəl]
(geodesy)
A parallel of latitude whose distance from the pole is equal to the obliquity of the ecliptic (approximately 23°27′).
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Polar Circle

 

one of the two parallels of latitude 66°33′ (angle of inclination of the earth’s axis to the plane of the ecliptic) from the equator. The polar circle in the northern hemisphere is called the arctic circle, and the polar circle in the southern hemisphere, the antarctic circle. On the summer solstice (June 21 or 22) the sun does not set north of the arctic circle, and on the winter solstice (December 21 or 22) it does not rise. The number of days during which the sun does not go below the horizon or does not rise above it increases as one approaches the pole, at which point day and night each last six months. A similar phenomenon is observed in the southern hemisphere. Refraction of light somewhat complicates this phenomenon, increasing the length of the polar day at the expense of the polar night and increasing the number of days on which the sun does not set. The polar circles are considered the boundaries of the frigid zones.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
With temperatures of -10degC in October (when the event takes place), the Polar Circle Marathon dubs itself the "coolest marathon on earth".
Headlines ( Article MRec ), pagematch: 1, sectionmatch: 1 The Arctic or Polar Circle (as determined in 1865) cuts through Santa's Village, a sprawling snow-covered village that seemed to have leaped straight out of a child's storybook.
He added he could understand why Russia is adamant allowing airplanes to cross their airspace, knowing that there are many military installations across the whole area encompassing the Polar Circle.
The marathon is run on a gravel, snow-covered track that connects the ice sheet with the small town of Kangerlussuaq, just north of the Polar Circle. Around 50 runners are taking part in this year's race on October 28-29.
He added: "Today's initiative with Armani Hotel Dubai has really given a huge boost in our fundraising effort prior to departing for the Arctic next week for the Polar Circle Marathon, which will in turn make a real difference to kids' lives in Vietnam as all money raised will directly go to the Sunshine School".
Chapple-Hyam knows what it takes to win the Empress Stakes as he saddled Polar Circle to land the spoils under Jimmy Fortune in 2007.
According to the US Geological Survey (USGS), one fifth of the world's undiscovered oil reserves lie in the polar circle, including 13% of oil and 30% of gas.
Unfortunately it is above the Polar Circle. Speaking seriously, the sailing sport develops with the growth of welfare.
18 (in Kharp in the Nenetz territory within the polar circle).
The Class 1 Icebreaker was originally built in Norway in 1990 as MV Polar Circle and was chartered by the Royal Navy in 1991 before being commissioned as HMS Polar Circle.
A LEADING frozen food manufacturer has invited yours truly to a desolate island, within touching distance of the Polar Circle, to write about cod farming.
As a presenter for the Russia Today news channel, Martyn Andrews has experienced every diverse inch of the country, from living with Eskimos in the Polar Circle to basking on the beaches of the Black Sea.