Midnight sun
Encyclopedia
The midnight sun is a natural phenomenon
Natural phenomenon
A natural phenomenon is a non-artificial event in the physical sense, and therefore not produced by humans, although it may affect humans . Common examples of natural phenomena include volcanic eruptions, weather, decay, gravity and erosion...
occurring in summer months at latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s north and nearby to the south of the Arctic Circle
Arctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
, and south and nearby to the north of the Antarctic Circle
Antarctic Circle
The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. For 2011, it is the parallel of latitude that runs south of the Equator.-Description:...
where the sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
remains visible at the local midnight. Given fair weather, the sun is visible for a continuous 24 hours, mostly north of the Arctic Circle and south of the Antarctic Circle. The number of days per year with potential midnight sun increases the farther poleward one goes from the equator. Although approximately defined by the polar circles, in practice midnight sun can be seen as much as 90 km beyond the polar circle, because the sun is a disk and not a point, and the exact latitudes of the farthest reaches of midnight sun depend on topography and vary slightly year-to-year.
There are no permanent human settlements south of the Antarctic Circle, so the countries and territories whose populations experience it are limited to the ones crossed by the Arctic Circle, e.g. Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
(Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
, Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, and Nunavut
Nunavut
Nunavut is the largest and newest federal territory of Canada; it was separated officially from the Northwest Territories on April 1, 1999, via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the actual boundaries had been established in 1993...
), Denmark
Kingdom of Denmark
The Kingdom of Denmark or the Danish Realm , is a constitutional monarchy and sovereign state consisting of Denmark proper in northern Europe and two autonomous constituent countries, the Faroe Islands in the North Atlantic and Greenland in North America. Denmark is the hegemonial part, where the...
(Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
), Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
, Lapland, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
, the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
(Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
), and extremities of Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
. A quarter of Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
's territory lies north of the Arctic Circle
Arctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
and at the country's northernmost point the sun does not set at all for 60 days during summer. In Svalbard
Svalbard
Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...
, Norway, the northernmost inhabited region of Europe, there is no sunset from approximately 19 April to 23 August. The extreme sites are the poles where the sun can be continuously visible for a half year.
The opposite phenomenon, polar night
Polar night
The polar night occurs when the night lasts for more than 24 hours. This occurs only inside the polar circles. The opposite phenomenon, the polar day, or midnight sun, occurs when the sun stays above the horizon for more than 24 hours.-Description:...
, occurs in winter when the sun stays below the horizon
Horizon
The horizon is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting...
throughout the day.
Since the Earth's axis is tilted with respect to the ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
by approximately 23 degrees 27 minutes, the sun does not set at high latitudes in (local) summer. The duration of the midnight sun increases from one day during the summer solstice
Solstice
A solstice is an astronomical event that happens twice each year when the Sun's apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes...
at the polar circle
Polar circle
A polar circle is either the Arctic Circle or the Antarctic Circle. On Earth, the Arctic Circle is located at a latitude of N, and the Antarctic Circle is located at a latitude of S....
to approximately six months at the poles. At extreme latitudes, it is usually referred to as polar day. The length of the time the sun is above the horizon varies from couple of days at the Arctic Circle and Antarctic Circle to 186 days at the poles
Geographical pole
A geographical pole is either of the two points—the north pole and the south pole—on the surface of a rotating planet where the axis of rotation meets the surface of the body...
.
At the poles themselves, the sun only rises once and sets once each year. During the six months when the sun is above the horizon at the poles, the sun spends the days constantly moving around the horizon, reaching its highest circuit of the sky at the summer solstice.
Due to refraction, the midnight sun may be experienced at latitudes slightly below the polar circle, though not exceeding one degree (depending on local conditions). For example, it is possible to experience the midnight sun in Iceland, even though most of it (Grímsey
Grímsey
Grímsey is a small island in the country of Iceland, off the north coast of the main island of Iceland and straddling the Arctic Circle. In January 2011 it had 86 inhabitants....
being a notable exception) is slightly south of the Arctic Circle. Even the northern extremities of Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
(and those places on similar latitudes) experience a permanent "dusk" or glare in the northern skies at these times.
Time zones and daylight saving time
For purposes of this article, the term "midnight sun" refers to the phenomena of 24 consecutive hours of sunlight north of the Arctic Circle or south of the Antarctic Circle. There are, however, some instances which are sometimes referred to as "midnight sun", even though they are in reality due to meandering time zones and the observance of daylight saving timeDaylight saving time
Daylight saving time —also summer time in several countries including in British English and European official terminology —is the practice of temporarily advancing clocks during the summertime so that afternoons have more daylight and mornings have less...
. For instance, in Fairbanks, Alaska
Fairbanks, Alaska
Fairbanks is a home rule city in and the borough seat of the Fairbanks North Star Borough in the U.S. state of Alaska.Fairbanks is the largest city in the Interior region of Alaska, and second largest in the state behind Anchorage...
, which is located south of the Arctic Circle, the sun sets at 12:47 a.m. on the Summer Solstice
Summer solstice
The summer solstice occurs exactly when the axial tilt of a planet's semi-axis in a given hemisphere is most inclined towards the star that it orbits. Earth's maximum axial tilt to our star, the Sun, during a solstice is 23° 26'. Though the summer solstice is an instant in time, the term is also...
. This is because Fairbanks is one hour ahead of its idealized time zone
Time zone
A time zone is a region on Earth that has a uniform standard time for legal, commercial, and social purposes. In order for the same clock time to always correspond to the same portion of the day as the Earth rotates , different places on the Earth need to have different clock times...
(due to meandering for the purpose of keeping most of the state on one time zone) and because the state of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
observes daylight saving time. This means that solar culmination occurs at roughly 2 p.m. instead of at 12 noon, as in most places. Conversely, astronomical midnight occurs at 2 a.m. In Bethel
Bethel, Alaska
Bethel is a city located near the west coast of the U.S. state of Alaska, west of Anchorage. Accessible only by air and river, Bethel is the main port on the Kuskokwim River and is an administrative and transportation hub for the 56 villages in the Yukon-Kuskokwim Delta.Bethel is the largest...
, which is further south than Anchorage
Anchorage, Alaska
Anchorage is a unified home rule municipality in the southcentral part of the U.S. state of Alaska. It is the northernmost major city in the United States...
, the sun sets on the Summer Solstice at 12:24 a.m. for the same reasons. These examples are not true midnight sun phenomena, however, since the sun is below the horizon on every day of the year at the local astronomical midnight.
White Nights
Locations above 60 degrees latitude that are south of the Arctic Circle or north of the Antarctic Circle experience midnight twilightTwilight
Twilight is the time between dawn and sunrise or between sunset and dusk, during which sunlight scattering in the upper atmosphere illuminates the lower atmosphere, and the surface of the earth is neither completely lit nor completely dark. The sun itself is not directly visible because it is below...
instead. The sun is at the horizon to 6 degrees below the horizon, so that daytime activities, such as reading, are still possible without artificial light, if it is not cloudy.
White Nights have become a common symbol of Saint Petersburg
Saint Petersburg
Saint Petersburg is a city and a federal subject of Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, where they occur from about 11 June to 2 July, and the last 10 days of June are celebrated with cultural events.
When to see the midnight sun
According to Visit Norway the midnight sun is visible at the Arctic CircleArctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
from June 12 until July 1. The further north one goes the longer this period extends.
At North Cape
North Cape, Norway
North Cape is a cape on the island of Magerøya in Northern Norway, in the municipality of Nordkapp. Its 307 m high, steep cliff is often referred to as the northernmost point of Europe, located at , 2102.3 km from the North Pole. However, the neighbouring point Knivskjellodden is actually...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, known as the northernmost point of Continental Europe
Continental Europe
Continental Europe, also referred to as mainland Europe or simply the Continent, is the continent of Europe, explicitly excluding European islands....
this period extends approximately from May 14 to July 29. On the Svalbard
Svalbard
Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...
archipelago further north this period extends from April 20 to August 22.
Effect on people
Many find it difficult to fall asleep during the night when the sun is shining. In general, visitors and newcomers are most affected. Some natives are also affected, but in general to a lesser degree. The effect of the midnight sun, that is, not experiencing night for long durations of time, is said to cause hypomaniaHypomania
Hypomania is a mood state characterized by persistent and pervasive elevated or irritable mood, as well as thoughts and behaviors that are consistent with such a mood state...
, which is characterized by persistent and pervasive elevated or irritable mood.
ADHD symptoms could be caused by this, changing attention spans for people that have to rush through the little daylight at night and the irritability and hyperactivity of continuous sunlight.
The midnight sun also poses special challenges to religious people such as Jewish people who have religious rites based around the 24 hour day/night cycle. In the Jewish community this has given rise to a body of Jewish law in the polar regions
Jewish law in the polar regions
The observance of Jewish law in the polar regions of Earth presents unique problems. Many mitzvot, such as Jewish prayer and the Jewish sabbath, rely on the consistent cycle of day and night in 24-hour periods that is commonplace in most of the world...
, which attempts to deal with the special challenges of adhering to the Mitzvah
Mitzvah
The primary meaning of the Hebrew word refers to precepts and commandments as commanded by God...
in such conditions. Another related religion that suffers from this is Islam, where fasting during daylight hours in ramadan
Ramadan
Ramadan is the ninth month of the Islamic calendar, which lasts 29 or 30 days. It is the Islamic month of fasting, in which participating Muslims refrain from eating, drinking, smoking and sex during daylight hours and is intended to teach Muslims about patience, spirituality, humility and...
would imply total abstinence.
In fiction
- In the film InsomniaInsomnia (1997 film)Insomnia is a 1997 Norwegian thriller film about a police detective investigating a murder in a town located above the Arctic Circle. The investigation goes horribly wrong when he mistakenly shoots his partner and subsequently attempts to cover up his bungle...
and its American remakeInsomnia (2002 film)Insomnia is an American psychological thriller film directed by Christopher Nolan and starring Al Pacino, Robin Williams, and Hilary Swank. The film, released on 24 May 2002, is a remake of the 1997 Norwegian film of the same name.-Plot:...
, the protagonistProtagonistA protagonist is the main character of a literary, theatrical, cinematic, or musical narrative, around whom the events of the narrative's plot revolve and with whom the audience is intended to most identify...
suffers from insomnia partially brought on by the midnight sun while investigating a murder north of the Arctic Circle (Norway in the original, and Alaska in the remake). - In The Midnight SunThe Midnight Sun"The Midnight Sun" is an episode of the American television anthology series The Twilight Zone.-Synopsis:The Earth has begun moving away from its usual orbit and is gradually falling in its rotation towards the sun. A prolific artist, Norma, and her landlady, Mrs. Bronson, are the last people in...
, an episode of The Twilight ZoneThe Twilight ZoneThe Twilight Zone is an American television anthology series created by Rod Serling. Each episode is a mixture of self-contained drama, psychological thriller, fantasy, science fiction, suspense, or horror, often concluding with a macabre or unexpected twist...
, the Earth is on a collision course with the sun, causing a midnight sun effect. - The episode of Northern ExposureNorthern ExposureNorthern Exposure is an American television series that ran on CBS from 1990 to 1995, with a total of 110 episodes.-Overview:The series was given a pair of consecutive Peabody Awards: in 1991–92 for the show's "depict[ion] in a comedic and often poetic way, [of] the cultural clash between a...
entitled Midnight Sun explores the effects of the phenomenon on the small Alaskan town's residents. - In the Stephen SondheimStephen SondheimStephen Joshua Sondheim is an American composer and lyricist for stage and film. He is the winner of an Academy Award, multiple Tony Awards including the Special Tony Award for Lifetime Achievement in the Theatre, multiple Grammy Awards, a Pulitzer Prize and the Laurence Olivier Award...
musical 'A Little Night MusicA Little Night MusicA Little Night Music is a musical with music and lyrics by Stephen Sondheim and book by Hugh Wheeler. Inspired by the Ingmar Bergman film Smiles of a Summer Night, it involves the romantic lives of several couples. Its title is a literal English translation of the German name for Mozart's Serenade...
', the two Night Waltzes deal specifically with the phenomenon of Midnight Sun.
See also
- Eagle SummitEagle Summit (Alaska)Eagle Summit is a -tall gap through the White Mountains of central Alaska. The gap was named after the nearby Eagle River by prospectors from nearby Circle, Alaska....
, which experiences midnight sun despite being south of the Arctic Circle because of altitude - Land of the Midnight SunLand of the Midnight SunThe Land of the Midnight Sun may refer to any of the world's northern regions above the Arctic Circle including:* Canada, including the Yukon, Northwest Territories, and Nunavut* Denmark * Finland* Iceland* Lapland* Norway* Russia* Sweden...
- Polar nightPolar nightThe polar night occurs when the night lasts for more than 24 hours. This occurs only inside the polar circles. The opposite phenomenon, the polar day, or midnight sun, occurs when the sun stays above the horizon for more than 24 hours.-Description:...
- The opposite phenomenon experienced in winter: a day without sunrise.