Polar Night

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polar night

[′pō·lər ′nīt]
The period of winter darkness in the polar regions, both northern and southern.

Polar Night


a night lasting more than 24 hours, occurring in polar regions north of the arctic circle and south of the antarctic circle. At points in the northern hemisphere with a geographic latitude ϕ, the sun will not rise above the horizon at certain times of the year. This occurs whenever the sun, in its apparent annual motion along the ecliptic, enters an area of the sky that is not visible at that given latitude. At such times, the

Table 1
Geographic latitude (degrees)Polar night (24-hour periods)Polar day (24-hour periods)

sun is located south of the parallel of declination δ = —(90° — ϕ). At points along the arctic circle the sun will not rise once each year; this occurs on the winter solstice (December 21 or 22), when the sun is at maximum south declination δ Θ = –23°27’. As ϕ increases, the arc of the ecliptic in the region of the sky that is not visible also increases. The polar night lengthens, and at the pole itself, it is six months long, lasting from the autumnal equinox to the vernal equinox. At points along the antarctic circle the sun will not rise on the summer solstice (June 21 or 22), and at the south pole the polar night lasts from the vernal equinox to the autumnal equinox.

The refraction of light complicates this phenomenon, and as a consequence the polar night becomes somewhat shorter. Table 1 gives lengths of the polar night and polar day at various geographic latitudes of the northern hemisphere (with refraction taken into account).


References in periodicals archive ?
Customers can choose from three stylish colors: Polar Night (black), Ivory White and Sky Blue.
Angela Weidenbach, from specialist tour operator Eclipse-Reisen, expects Spitsbergen to offer a very special natural experience: On the last day of the year, Europe s most northerly archipelago is subjected to a deep polar night with 24-hour darkness.
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That sea, the luminosity of the mountains, the monochrome, sub-zero, being aboard a ship in the polar night, in the middle of the ocean utter mesmeric gorgeousness of it all.
cosy, milies The holiday village nestles in the forest and, as I snuggled up in my warm bed, with only the calls of snowy eagles and an occasional wolf howl to break the silence of the deep, dark polar night, the hustle and bustle of normal daily life seemed like a world away.
In the Finnish arctic the sun does not rise, the polar night lasting 51 days.
2] during the autumnal and winter polar night, and it disappears by sublimation in spring and summertime.
There are plenty of other activities on offer in the winter season and a slightly higher-octane excursion is a snowmobiling polar night safari.
The second day ended with a Carnival after a full day of deliberations, while the third day along with intense discussions gave the delegates a chance to dress up in white to the theme of Polar Night.
Moreover, on the Polar Night, NUML team member, Ikhlas Tariq, was officially requested to sing, who then put out the magic into the night and every one appreciated not only with an applaud but with the standing ovation.
Each year, more and more tourists are opting for their own Arctic adventure, and my group has elected to come in winter, during the Polar night season, when the sun doesn't rise and the only light comes from the moon peeking from behind the clouds.
The area can be defined as north of the Arctic Circle (66[degrees] 33'N), the approximate limit of the midnight sun and the polar night.