|
|||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Winter |
| Part of the Nature series on Weather |
| Seasons |
|---|
| Storms |
|
Thunderstorm · Tornado |
| Precipitation |
|
Fog · Drizzle · Rain |
| Topics |
| Weather Portal |
 |
This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (February 2008) |
Winter is one of the four seasons of temperate zones. Calculated astronomically, it begins on the solstice and ends on the equinox. It is the season with the shortest days and the lowest average temperatures. It has colder weather and, especially in the higher latitudes or altitudes, snow and ice. The coldest average temperatures of the season are typically experienced in January in the Northern Hemisphere and in July in the Southern Hemisphere.
Contents |
Meteorological winter is the season having the shortest days and the lowest temperatures. Night-time predominates the winter season, and in some regions it has the highest rate of precipitation as well as prolonged dampness because of permanent snow cover or high precipitation rates coupled with low temperatures, precluding evaporation. Blizzards often develop and cause many transportation delays. A rare meteorological phenomenon encountered during winter is ice fog, which is composed of ice crystals suspended in the air and happening only at very low temperatures, below about −30 °C [1].
Accumulations of snow and ice are mostly associated with winter in the Northern Hemisphere, due to the large land masses there. In the Southern Hemisphere, the more maritime climate and the relative lack of land south of 40 degrees South makes the winters more mild, and thus snow and ice are less common in inhabited regions of the Southern Hemisphere. In the Southern Hemisphere, snow occurs every year in elevated regions such as the Andes, the Great Dividing Range in Australia, and the mountains of New Zealand, and also occurs in the southerly Patagonia region of South America. Snow occurs year-round in Antarctica.
Astronomically, winter starts with the winter solstice and ends with the vernal equinox. Others consider the seasons to be defined by weather, winter being approximately the whole months of June, July, and August in the Southern Hemisphere and December, January, and February in the Northern Hemisphere. By still another definition, the seasons are spoken of, not as quarters of the year, but elastic periods in a particular place determined by the weather, winter in that reckoning being when the weather turns decidedly cold.
In Celtic nations such as Ireland using the Irish calendar, the winter solstice is traditionally considered as midwinter, with the winter season beginning November 1 on All Hallows or Samhain. Winter ends and spring begins on Imbolc or Candlemas, which is February 1 or February 2. This system of seasons is based on the length of days exclusively. The three-month period of the shortest days and weakest solar radiation occurs during November, December and January in the Northern Hemisphere and May-July in the Southern Hemisphere.
Also many mainland European countries tend to recognize Martinmas, St. Martin's day (November 11) as the first calendar day of winter. The day falls at midpoint between the old Julian equinox and solstice dates. Also, Valentines Day (February 14) is recognized by some countries as heralding the first rites of Spring (season), such as flower blooming.
In Chinese astronomy (and other East Asian calendars), winter is taken to commence on or around November 7, with the Jiéqì known as (立冬 lì dōng, literally "establishment of winter".)
The three-month period associated with the coldest average temperatures typically begins somewhere in late November or early December in the Northern Hemisphere and lasts through early March. If "winter" is defined as the statistically coldest quarter of the year, then the astronomical definition is too late by almost all local climate standards, and the traditional English/Irish definition of November 1 (May 1 in the Southern Hemisphere) is usually too early to fit this standard. (In other words, there are very few temperate climates in which the vernal equinox is on average colder than the winter solstice, and very few temperate climates in which Samhain is on average colder than Imbolc). No matter the reckoning, winter is the only season that spans two calendar years in the northern hemisphere.
The tilt of the Earth's axis relative to its orbital plane has a dramatic effect on the weather. The Earth is tilted at an angle of 23.44° to the plane of its orbit, and this causes different latitudes on the Earth to directly face the Sun as the Earth moves through its orbit. It is this variation that primarily brings about the seasons. When it is winter in the Northern Hemisphere, the Southern Hemisphere faces the Sun more directly and thus experiences warmer temperatures than the Northern Hemisphere. Conversely, winter in the Southern Hemisphere occurs when the Northern hemisphere is tilted more toward the Sun. From the perspective of an observer on the Earth, the winter Sun has a lower maximum altitude in the sky than the summer Sun.
During winter in either hemisphere, the lower altitude of the Sun in winter causes the sunlight to hit that hemisphere at an oblique angle. In regions experiencing winter, the same amount of solar radiation is spread out over a larger area. This effect is compounded by the larger distance that the light must travel through the atmosphere, allowing the atmosphere to dissipate more heat.
To survive the harshness of winter, many animals have developed different behavioral and morphological adaptations for Overwintering:
Annual plants never survive the winter. As for perennial plants, many small ones profit from the insulating effects of snow by being buried in it. Larger plants, particularly deciduous trees, usually let their upper part go dormant, but their roots are still protected by the snow layer. Few plants bloom in the winter, with exceptions including the flowering plum (which flowers in time for Chinese New Year).
Many winter activities involve the use of snow in some form (which sometimes may still be manmade, via snow cannons):
Many other winter activities and sports focus on ice, which may be contained in an ice rink.
Passing seasons change the habits and moods of people. During the winter months in the northern hemisphere, a gloominess nicknamed "winter blues", "February blahs", "Holiday depression", or doldrums, is informally noted amongst people. The severest cases of this type of depression is diagnosed as seasonal affective disorder (SAD). Symptoms include sleeping more, tiredness, depression, and physical aches. Although causes include genetic disposition and stress, the prevailing environmental influence is decreased exposure to light because of the angle of the sun and cloudcover and the increased amount of clothing that must be worn to keep warm.
Some use winter to suggest death, as in Robert Frost's "Stopping by Woods on a Snowy Evening". Some use it to suggest the absence of hope, as in C. S. Lewis's The Lion, the Witch and the Wardrobe, where it was always winter but never Christmas. Winter is one concerto in Antonio Vivaldi's "The Four Seasons"; and there are many examples of four paintings, all showing the same scene in different seasons. Ursula K. LeGuin's novel The Left Hand of Darkness is set on a planet named Winter. In Alex Raymond's comic strip, Flash Gordon, there is a land called Frigia, where it is always winter. The land of Frigia is also featured in the serial Flash Gordon Conquers the Universe. Other uses of winter in the graphic arts occur in Winsor McCay's Little Nemo in Slumberland. There are many films in which a winter setting plays an important role, Fargo being an example. Novels such as Ethan Frome also use a winter setting to mirror the bleak, frozen feelings that the characters harbor. The film Requiem for a Dream concludes with "Act III: Winter", in which the movie reaches its hellish and chilling climax.
In Greek mythology, Hades kidnapped Persephone to be his wife. Zeus ordered Hades to return her to Demeter, the goddess of the earth and her mother. However, Hades tricked Persephone into eating the food of the dead so Zeus decreed Persephone would spend six months with Demeter and six months with Hades. During the time when her daughter is with Hades, Demeter becomes depressed and causes winter. In Welsh Mythology, Gwyn ap Nudd abducted a maiden named Creiddylad. On May Day her lover Gwythr ap Greidawl fought Gwyn to win her back. The battle between them represented the contest between summer and winter.
 An allegory of Winter, by Ambrogio Lorenzetti |
 Winter, by Giuseppe Arcimboldo |
 19th century etching of Jack Frost as a United States major-general during the American Civil War |
|
 A depiction of Snegurochka by Victor Vasnetsov |
 'Winter Windows' (1966-1967) by Jane Frank, jagged holes reveal a bleak and wintery second canvas |
 The Triumph of Winter, by Antoine Caron |
|
Human-related: |
Weather-related: |
|
||||||||||
 |
 |
 |
 |
 |
 |
 |
 |
