I
never knew there are places on earth where the sun does not rise. It has not
even occurred to me that there are places where the sun does not rise. I got to
know that there are such places on earth when I stumble upon a story on the
web.
The
story was done by Kari Leibowitz (http://www.theatlantic.com/author/kari-leibowitz)
and published on July 1, 2015
The story is about her experience in Tromsø, Norway. The story inspired me
to put together this post.
Like
me, you may not have known that there are places where the sun does not rise,
so I am sharing this post with you.
Kari spent a
year in Tromsø, Norway, where the “Polar Night” lasts all winter—and where
rates of seasonal depression are remarkably low.
Located over
200 miles north of the Arctic Circle, Tromsø, Norway, is home to extreme light
variation between seasons. During the Polar Night, which lasts from November to
January, the sun doesn’t rise at all. Then the days get progressively longer
until the Midnight Sun period, from May to July, when it never sets. After the
midnight sun, the days get shorter and shorter again until the Polar Night, and
the yearly cycle repeats.
But the Polar Night was what drew Kari to
Tromsø in the first place.
Kari first
learned of Tromsø two years ago(2013), as a recent college graduate looking for
more research experience before applying to graduate school for social
psychology. In search of an opportunity that would allow her to explore her
interests in positive psychology and mental health—and satisfy her sense of
adventure—she stumbled upon the work of Joar Vittersø, a psychologist at the
University of Tromsø who studies happiness, personal growth, and quality of
life.
After reaching
out to him via e-mail, Kari learned that the University of Tromsø is the
northernmost university in the world. It seemed like the perfect place to test
just how adventurous she really was, while also providing a unique population
for a psychology research study.
Tromsø is a
tiny island, roughly the same size as Manhattan, and is home to approximately
70,000 inhabitants, making it the second-most populated city north of the
Arctic Circle. With everything a person could “need”—a mall, three main
shopping streets, and a few movie theaters—but nothing extra, Tromsø felt more
like a small suburb than a city. Surrounded by mountains and fjords on all
sides, it also felt isolated and wild.
Almost
everyone she spoke with—in casual conversations, at parties, over
psychology-department lunches at the university—had a theory as to why their
city flourished during the Polar Night. Some people swore by cod-liver oil, or
told her they used lamps that simulated the sun by progressively brightening at
a specific time each morning.
In Tromsø,
the prevailing sentiment is that winter is something to be enjoyed, not
something to be endured. According to her friends, winter in Tromsø would be
full of snow, skiing, the northern lights, and all things koselig, the
Norwegian word for “cozy.” By November, open-flame candles would adorn every
café, restaurant, home, and even workspace. Over the following months she
learned firsthand that, far from a period of absolute darkness, the Polar Night
in Tromsø is a time of beautiful colors and soft, indirect light. Even during
the darkest times, there are still two or three hours of light a day as the sun
skirts just below the horizon, never fully rising. During the longer “days” of
the Polar Night, in November and January, the skies can be filled with up to
six hours of sunrise and sunset-like colors.
Thanks to
the warm current of the Gulf Stream, Tromsø is considered “sub-arctic” despite
its northern location, but Svalbard is the real thing. With a population of
only 2,000, Svalbard’s residents are required to carry guns with them if they
leave the island’s main town, to protect themselves from hungry polar bears.
Both in terms of light and temperature, Svalbard feels much more extreme than
Tromsø; its average January temperatures range from -4 to 8 degrees Fahrenheit,
compared to 20 – 28 degrees Fahrenheit in Tromsø. The Polar Night of Svalbard
is significantly darker: absent even indirect sunlight, with no change in light
to mark the passage of a 24-hour time span.
The Arctic Circle is the parallel of latitude that runs 66° 33'
39," or roughly 66.5°, north of the Equator.
Approximately 15,000 kilometers (9,300 miles) to the south is the Antarctic
Circle, of equal diameter to and parallel to the Arctic Circle as well as
equally distant from the Equator. Together with the Equator and the tropics of
Cancer and Capricorn, these five unseen circular lines comprise the major
circles of latitude that mark maps of the Earth. All five are determined by the Earth's rotation on its
axis and the Earth's tilt toward and away from the Sun in its orbit. The
circle, though invisible and, in fact, moving, is a product of the same
phenomenon that provides the world with four seasons and this largely austere
part of the globe with an odd formula of light and darkness shared only by its
polar opposite.
In the Arctic, during the winter months of November through February, the
sun remains very low in the sky or does not rise at all. Where it does rise,
the days are short, and the sun's low position in the sky means that, even at
noon, not much energy is reaching the surface. Furthermore, most of the small
amount of solar radiation that reaches the surface is reflected away by the
bright snow cover. Cold snow reflects between 70% and 90% of the solar
radiation that reaches it (Serreze and Barry, 2005), and most of the Arctic,
with the exception of the ice-free parts of the sea, have snow covering the
land or ice surface in winter. These factors result in a negligible input of
solar energy to the Arctic in winter; the only things keeping the Arctic from
continuously cooling all winter are the transport of warmer air and ocean water
into the Arctic from the south and the transfer of heat from the subsurface
land and ocean (both of which gain heat in summer and release it in winter) to
the surface and atmosphere.
Almost all of the energy available to the Earth's surface and atmosphere
comes from the sun in the form of solar radiation (light from the sun, including invisible ultraviolet and infrared light).
Variations in the amount of solar radiation reaching different parts of the
Earth are a principal driver of global and regional climate. Averaged over a
year, latitude is the most important factor determining the amount of solar radiation
reaching the top of the atmosphere; the incident solar radiation decreases
smoothly from the Equator to the poles.
Polar night
refers to the longer-than-24-hour nights that occur seasonally on the Earth's polar regions. Because the Earth's axis is tipped 26
degrees with respect to the plane of the elliptic, there are parts of the poles
whose rotation path never gets exposed to light. The North and South Poles are
the darkest areas of all, which each receive six months of continuous night and six months of continuous day. The depth of
the polar night in
the polar regions is when the lowest temperatures
on Earth have ever been recorded, 89 degrees Celsius below zero, or negative
128 degrees Fahrenheit, measured at Vostok Station, Antarctica. Without heavy
furs, this can lead to death in under two minutes.
The formal definition of the
Arctic and Antarctic Circle has to do with polar night. Within the circle, there is at least one 24-hour
period of complete darkness in the year, while outside it, darkness lasts less
than 24 hours. Some far north and far south settlements experience very long
nights, with only a few hours of sunshine throughout the day during winter.
Examples include Hammerfest, Norway and research stations throughout most of
Antarctica. Being deprived of light to this degree can be a risk factor for
depression.
Source:
http://www.theatlantic.com/health/archive/2015/07/t-norwegian-town-where-the-sun-doesnt-rise/396746/
http://www.newworldencyclopedia.org/entry/Artic_Circle
http://www.wisegeek.com/what-is-a-polar-night.htm
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