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Polar circle

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43-614: A polar circle is a geographic term for a conditional circular line (arc) referring either to the Arctic Circle or the Antarctic Circle . These are two of the keynote circles of latitude (parallels). On Earth , the Arctic Circle is currently drifting northwards at a speed of about 14.5 m per year and is now at a mean latitude (i.e. without taking into account the astronomical nutation ) of 66°33′50.2″ N;

86-659: A New Year cleaning tradition), and "reversal" (as in Saturnalia 's slave and master reversals). Some important Neolithic and early Bronze Age archaeological sites in Europe are associated with the winter solstice, such as Stonehenge in England and Newgrange in Ireland. The primary axes of both of these monuments seem to have been carefully aligned on a sight-line pointing to the winter solstice sunrise (Newgrange) and

129-495: A day a year when the center of the Sun is continuously above the horizon and at least a day a year when it is always below the horizon – a polar day and a polar night as is the case for longer, within the circles. Up to and including the associated poles ( North and South ), known geographically as the frigid zones , such duration extends up to half of the year, namely, close to the poles. Instead, atmospheric refraction and

172-420: Is Earth's nutation , which is a very small change in tilt. Observers higher above sea level can see a tiny amount of the Sun's disc (see horizon ) where at lower places it would not rise. For the Arctic Circle , being 80–100 km north of the circle in winter, and 80–100 km south of the circle in summer; the inverse directions apply to the other circle. Arctic Circle The Arctic Circle

215-467: Is atmospheric refraction , in which the Earth's atmosphere bends light rays near the horizon. The second effect is caused by the angular diameter of the Sun as seen from the Earth's orbital distance (which varies very slightly during each orbit). These factors mean the ground-observed boundaries are 80 to 100 kilometres (50 to 62 mi) away from the circle. A further global factor for this numerical range

258-461: Is visible at local midnight , and at least once the centre is not visible at local noon . Directly on the Arctic Circle these events occur, in principle, exactly once per year: at the June and December solstices , respectively. However, because of atmospheric refraction and mirages , and also because the sun appears as a disk and not a point, part of the midnight sun is visible, on the night of

301-634: Is one of the two polar circles , and the most northerly of the five major circles of latitude as shown on maps of Earth at about 66° 34' N. Its southern equivalent is the Antarctic Circle . The Arctic Circle marks the southernmost latitude at which, on the winter solstice (which is the shortest day of the year) in the Northern Hemisphere , the Sun will not rise all day, and on the Northern Hemisphere's summer solstice (which

344-413: Is put to burn in the fire ( zjarri ) of the hearth ( vatër ) on the night of a winter celebration that falls after the return of the Sun for summer (after the winter solstice), sometimes on the night of Kërshëndella on December 24 ( Christmas Eve ), sometimes on the night of kolendra , or sometimes on New Year's Day or on any other occasion aound the same period, a tradition that is originally related to

387-558: Is the December solstice (December 21, December 22, or December 23) and in the Southern Hemisphere, this is the June solstice (June 20, June 21, or June 22). Although the winter solstice itself lasts only a moment, the term also refers to the day on which it occurs. The term midwinter is also used synonymously with the winter solstice, although it carries other meanings as well. Traditionally, in many temperate regions,

430-461: Is the longest day of the year), the Sun will not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more pronounced these effects become. For example, in the Russian port city of Murmansk , three degrees above the Arctic Circle, the Sun does not rise above the horizon for 40 successive days in midwinter. The position of

473-608: The Arctic Ocean , the Scandinavian Peninsula , North Asia , Northern America , and Greenland. The land within the Arctic Circle is divided among eight countries: Norway, Sweden, Finland, Russia, the United States ( Alaska ), Canada ( Yukon , Northwest Territories , and Nunavut ), Denmark (Greenland), and Iceland (where it passes through the small offshore island of Grímsey ). The climate north of

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516-506: The Greek word ἀρκτικός ( arktikos : "near the Bear , northern") and that from the word ἄρκτος ( arktos : " bear "). The Arctic Circle is the southernmost latitude in the Northern Hemisphere at which the centre of the Sun can remain continuously above or below the horizon for twenty-four hours; as a result, at least once each year at any location within the Arctic Circle the centre of the Sun

559-513: The Hindu calendar , in reference to deity Surya (sun). It is observed each year in January. It marks the first day of Sun's transit into Makara (Capricorn) , marking the end of the month with the winter solstice and the start of longer days. Iranian people celebrate the night of the Northern Hemisphere's winter solstice as, " Yalda night ", which is known to be the "longest and darkest night of

602-632: The talmudic hypothesis that Adam first established the tradition of fasting before the winter solstice , and rejoicing afterward, which festival later developed into the Roman Saturnalia and Kalendae . When the First Man saw that the day was continuously shortening, he said, "Woe is me! Because I have sinned, the world darkens around me, and returns to formlessless and void. This is the death to which Heaven has sentenced me!" He decided to spend eight days in fasting and prayer. When he saw

645-562: The Antarctic Circle is currently drifting southwards at a speed of about 14.5 m per year and is now at a mean latitude of 66°33′50.2″ S. Polar circles are often equated with polar regions of Earth . Due to their inherent climate environment , the bulk of the Arctic Circle, much of which is sea, is sparsely settled whereas this applies to all of Antarctica which is mainly land and sheltered ice shelves. If Earth had no atmosphere, then both polar circles (arcs) would see at least

688-526: The Arctic Circle is generally cold, but the coastal areas of Norway have a generally mild climate as a result of the Gulf Stream , which makes the ports of northern Norway and northwest Russia ice-free all year long. In the interior, summers can be quite warm, while winters are extremely cold. For example, summer temperatures in Norilsk , Russia will sometimes reach as high as 30 °C (86 °F), while

731-537: The Arctic Circle is not fixed and currently runs 66°33′50.2″ north of the Equator . Its latitude depends on the Earth's axial tilt , which fluctuates within a margin of more than 2° over a 41,000-year period, owing to tidal forces resulting from the orbit of the Moon . Consequently, the Arctic Circle is currently drifting northwards at a speed of about 14.5 m (48 ft) per year. The word arctic comes from

774-604: The Arctic Circle with about 5,000 inhabitants. The largest such community in Canada is Inuvik in the Northwest Territories , with 3,137 inhabitants. Download coordinates as: The Arctic Circle is roughly 16,000 km (9,900 mi) in circumference. The area north of the Circle is about 20,000,000 km (7,700,000 sq mi) and covers roughly 4% of Earth's surface. The Arctic Circle passes through

817-466: The Arctic Circle, lying 6 km (4 mi) south of the line. Salekhard (51,186) in Russia is the only city in the world located directly on the Arctic Circle. In contrast, the largest North American community north of the Arctic Circle, Sisimiut ( Greenland ), has approximately 5,600 inhabitants. In the United States, Utqiagvik, Alaska (formerly known as Barrow) is the largest settlement north of

860-672: The Christian Haakon had moved Yule from "midwinter" and aligned it with the Christian Christmas celebration. Historically, this has made some scholars believe that Yule originally was a sun festival on the winter solstice. Modern scholars generally do not believe this, as midwinter in medieval Iceland was a date about four weeks after the solstice. During the Christianisation of the Germanic peoples , Yule

903-495: The North and South Pole, respectively) minus the axial tilt (that is, of the Earth's axis of daily rotation relative to the ecliptic , the plane of the Earth's orbit). This predominant, average tilt of the Earth varies slightly, a phenomenon described as nutation. Therefore, the latitudes noted above are calculated by averaging values of tilt observed over many years. The axial tilt also exhibits long-term variations as described in

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946-473: The Roman winter solstice festival marking the sun god's birthday ( Dies Natalis Solis Invicti ). According to C. Philipp E. Nothaft, a professor at Trinity College Dublin , though this theory "is nowadays used as the default explanation for the choice of 25 December as Christ's birthday, few advocates of this theory seem to be aware of how paltry the available evidence actually is." In Anglo-Saxon England

989-434: The Sun's light reaching the planet as an extended object rather than a point source means that just within each circle the Earth's surface does not experience any proper polar night, 24 hours where the sun does not rise. By these same two factors, just outward of each circle still experiences a polar day (a day in which the sun does not fully set). The latitude of the polar circles is + or −90 degrees (which refers to

1032-537: The Sun; the gradual waning of daylight hours is reversed and begins to grow again. Some ancient monuments such as Newgrange , Stonehenge , Cahokia Woodhenge , and Ahu Tongariki are aligned with the sunrise or sunset on the winter solstice. There is evidence that the winter solstice was deemed an important moment of the annual cycle for some cultures as far back as the Neolithic (New Stone Age). Astronomical events were often used to guide farming activities, such as

1075-404: The angular diameter of the Sun. Observing that it occurred within a two-day period is easier, requiring an observation precision of only about 1/16 of the angular diameter of the Sun. Thus, many observations are of the day of the solstice rather than the instant. This is often done by observing sunrise and sunset or using an astronomically aligned instrument that allows a ray of light to be cast on

1118-586: The birthday of Sol Invictus or the 'Invincible Sun'. Gary Forsythe, Professor of Ancient History, says "This celebration would have formed a welcome addition to the seven-day period of the Saturnalia (December 17–23), Rome's most joyous holiday season since Republican times, characterized by parties, banquets, and exchanges of gifts". A widely-held theory is that the Church chose December 25 as Christ's birthday ( Dies Natalis Christi ) to appropriate

1161-541: The cult of the Sun. In East Asia , the winter solstice has been celebrated as one of the Twenty-four Solar Terms , called Dongzhi (冬至) in Chinese . In Japan , in order not to catch cold in the winter, there is a custom to soak oneself in a yuzu hot bath ( Japanese : 柚子湯 = Yuzuyu). Makara Sankranti, also known as Makara Sankrānti ( Sanskrit : मकर संक्रांति) or Maghi, is a festival day in

1204-422: The fire, lighting pine trees at night, luck divination tests with crackling in the fire or with coins in ritual bread, making and consuming ritual foods, performing various magical ritualistic actions in livestock, fields, vineyards and orchards, and so on. Nata e Buzmit, " Yule log 's night", is celebrated between December 22 and January 6. Buzmi is a ritualistic piece of wood (or several pieces of wood) that

1247-424: The mating of animals, the sowing of crops and the monitoring of winter reserves of food. The winter solstice was important because the people were economically dependent on monitoring the progress of the seasons. Starvation was common during the first months of the winter, January to April (northern hemisphere) or July to October (southern hemisphere). Livestock were slaughtered so they would not have to be fed during

1290-411: The northern summer solstice , at a latitude of about 50 minutes of arc (′) (90 km (56 mi)) south of the Arctic Circle. Similarly, on the day of the northern winter solstice , part of the Sun may be seen up to about 50′ north of the Arctic Circle. That is true at sea level ; those limits increase with elevation above sea level , although in mountainous regions there is often no direct view of

1333-489: The pagan rites that were practiced by Albanians to celebrate this festivity, but without success. The old rites of this festivity were accompanied by collective fires ( zjarre ) based on the house, kinship or neighborhood, a practice performed in order to give strength to the Sun according to the old beliefs. The rites related to the cult of vegetation, which expressed the desire for increased production in agriculture and animal husbandry, were accompanied by animal sacrifices to

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1376-461: The precise timing of its occurrence is now public knowledge. The precise instant of the solstice cannot be directly detected (by definition, people cannot observe that an object has stopped moving until it is later observed that it has not moved further from the preceding spot, or that it has moved in the opposite direction). To be precise to a single day, observers must be able to view a change in azimuth or elevation less than or equal to about 1/60 of

1419-460: The reference article (a difference of 1 second of arc (″) in the tilt is equivalent to a change of about 31 metres north or south in the positions of the polar circles on the Earth's surface). The polar circles would almost precisely match the boundaries for the zones where the polar night and the polar day would occur throughout the winter solstice and summer solstice day respectively. They do so loosely due to two effects. The first one

1462-516: The true horizon. The largest communities north of the Arctic Circle are situated in Russia, Norway, and Sweden: Murmansk (population 295,374) and Norilsk (178,018) in Russia; Tromsø (75,638) in Norway, Vorkuta (58,133) in Russia, Bodø (52,357) and Harstad (24,703) in Norway; and Kiruna , Sweden (22,841). Rovaniemi (62,667) in Finland is the largest settlement in the immediate vicinity of

1505-412: The winter solstice is the day with the shortest period of daylight and longest night of the year, and when the Sun is at its lowest daily maximum elevation in the sky. Each polar region experiences continuous darkness or twilight around its winter solstice. The opposite event is the summer solstice . The winter solstice occurs during the hemisphere's winter . In the Northern Hemisphere, this

1548-402: The winter solstice is seen as the middle of winter; although today in some countries and calendars it is seen as the beginning of winter. Other names are the "extreme of winter" ( Dongzhi ), or the "shortest day". Since prehistory, the winter solstice has been a significant time of year in many cultures and has been marked by festivals and rites . It marked the symbolic death and rebirth of

1591-470: The winter solstice sunset (Stonehenge). It is significant that at Stonehenge the Great Trilithon was oriented outwards from the middle of the monument, i.e. its smooth flat face was turned towards the midwinter Sun. In the ancient Roman calendar, December 25 was the date of the winter solstice. In AD 274, the emperor Aurelian made this the date of the festival Dies Natalis Solis Invicti ,

1634-663: The winter solstice was generally deemed to be December 25, and in Old English , midwinter could mean both the winter solstice and Christmas . The North Germanic peoples celebrated a winter holiday called Yule . The Heimskringla , written in the 13th century by the Icelander Snorri Sturluson , describes a Yule feast hosted by the Norwegian king Haakon the Good (c. 920–961). According to Snorri,

1677-589: The winter solstice, and he saw that the day was continuously lengthening, he said, "It is the order of the world!" He went and feasted for eight days. The following year, he feasted for both. He established them in Heaven's name, but they established them in the name of idolatry Although the instant of the solstice can be calculated, direct observation of the moment by visual perception is elusive. The Sun moves too slowly or appears to stand still (the meaning of "solstice"). However, by use of astronomical data tracking ,

1720-440: The winter temperatures frequently fall below −50 °C (−58 °F). Starting at the prime meridian and heading eastwards, the Arctic Circle passes through: Winter solstice The winter solstice , also called the hibernal solstice , occurs when either of Earth 's poles reaches its maximum tilt away from the Sun . This happens twice yearly, once in each hemisphere ( Northern and Southern ). For that hemisphere,

1763-493: The winter, so it was almost the only time of year when a plentiful supply of fresh meat was available. Because the winter solstice is the reversal of the Sun's apparent ebbing in the sky, in ancient times it was seen as the symbolic death and rebirth of the Sun or of a Sun god . In cultures which used cyclic calendars based on the winter solstice, the "year as reborn" was celebrated with reference to life-death-rebirth deities or "new beginnings" (such as Hogmanay 's redding ,

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1806-551: The year". Yalda night celebration, or as some call it "Shabe Chelleh" ("the 40th night"), is one of the oldest Iranian traditions that has been present in Persian culture from ancient times. In this night all the family gather together, usually at the house of the eldest, and celebrate it by eating, drinking and reciting poetry (esp. Hafez). Nuts, pomegranates and watermelons are particularly served during this festival. An Aggadic legend found in tractate Avodah Zarah 8a puts forth

1849-621: Was incorporated into the Christmas celebrations and the term and its cognates remain used to refer to Christmas in modern Northern European languages such as English and Swedish. Albanian traditional festivities around the winter solstice celebrate the return of the Sun ( Dielli ) for summer and the lengthening of the days. The Albanian traditional rites during the winter solstice period are pagan, and very ancient. Albanologist Johann Georg von Hahn (1811 – 1869) reported that Christian clergy, during his time and before, have vigorously fought

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