Winter
Encyclopedia
Winter is the coldest season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

 of the year in temperate climates, between autumn
Autumn
Autumn is one of the four temperate seasons. Autumn marks the transition from summer into winter usually in September or March when the arrival of night becomes noticeably earlier....

 and spring
Spring (season)
Spring is one of the four temperate seasons, the transition period between winter and summer. Spring and "springtime" refer to the season, and broadly to ideas of rebirth, renewal and regrowth. The specific definition of the exact timing of "spring" varies according to local climate, cultures and...

. At the winter solstice
Winter solstice
Winter solstice may refer to:* Winter solstice, astronomical event* Winter Solstice , former band* Winter Solstice: North , seasonal songs* Winter Solstice , 2005 American film...

, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.

Meteorology

Some authorities attempt to define an astronomical winter, often offset, which is based solely on the position of the Earth in its orbit around the sun. The start of an astronomical winter remains constant in each hemisphere regardless weather conditions, but varies with culture.

Meteorological winter is the method of measuring the winter season used by meteorologists based on "sensible weather patterns" for record keeping purposes, so the start of meteorological winter can change depending on how far north one lives. Winter is often defined by meteorologists to be the three calendar months with the lowest average temperatures. This corresponds to the months of December, January and February in the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

, and June, July and August in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

. The coldest average temperatures of the season are typically experienced in January in the Northern hemisphere and in June or July in the Southern hemisphere. Nighttime predominates the winter season, and in some regions it has the highest rate of precipitation
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...

 as well as prolonged dampness because of permanent snow cover or high precipitation rates coupled with low temperatures, precluding evaporation. Blizzard
Blizzard
A blizzard is a severe snowstorm characterized by strong winds. By definition, the difference between blizzard and a snowstorm is the strength of the wind. To be a blizzard, a snow storm must have winds in excess of with blowing or drifting snow which reduces visibility to 400 meters or ¼ mile or...

s often develop and cause many transportation delays. A rare meteorological phenomenon encountered during winter is ice fog
Ice fog
Ice fog is a type of fog consisting of fine ice crystals suspended in the air. It can happen only in cold areas of the world since water can remain liquid down to -40 °C...

, which comprises ice crystals suspended in the air; it occurs only at very low temperatures, below –30°C (–22°F).

Accumulations of snow and ice are commonly 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°S makes the winters milder; thus, snow and ice are less common in inhabited regions of the Southern Hemisphere. In this region, 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
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...

 region of South America. Snow occurs year-round in Antarctica.

Period

Astronomically, the winter solstice
Winter solstice
Winter solstice may refer to:* Winter solstice, astronomical event* Winter Solstice , former band* Winter Solstice: North , seasonal songs* Winter Solstice , 2005 American film...

, being the day of the year which has fewest hours of daylight, ought to be the middle of the season, but seasonal lag
Seasonal lag
Seasonal lag is the phenomenon whereby the date of maximum average air temperature at a geographical location on a planet is delayed until some time after the date of maximum insolation...

 means that the coldest period normally follows the solstice by a few weeks. In the USA (and sometimes in Britain) the season is regarded as beginning at the solstice and ending on the following equinox
Equinox
An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator...

 — in the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

, depending on the year, this corresponds to the period between 21 or 22 December and 20 or 21 March. In the UK, meteorologists consider winter to be the three coldest months of December, January and February. In Scandinavia, winter traditionally begins on 14 October and ends on the last day of February. In many countries in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

, including Australia, New Zealand and South Africa, winter begins on 1 June and ends on 31 August. In Celtic nations
Celtic nations
The Celtic nations are territories in North-West Europe in which that area's own Celtic languages and some cultural traits have survived.The term "nation" is used in its original sense to mean a people who share a common traditional identity and culture and are identified with a traditional...

 such as Ireland (using the Irish calendar
Irish calendar
The Irish calendar is a pre-Christian Celtic system of timekeeping used during Ireland's Gaelic era and still in popular use today to define the beginning and length of the day, the week, the month, the seasons, quarter days, and festivals...

) and in Scandinavia, the winter solstice is traditionally considered as midwinter, with the winter season beginning 1 November, on All Hallows
Halloween
Hallowe'en , also known as Halloween or All Hallows' Eve, is a yearly holiday observed around the world on October 31, the night before All Saints' Day...

, or Samhain
Samhain
Samhain is a Gaelic harvest festival held on October 31–November 1. It was linked to festivals held around the same time in other Celtic cultures, and was popularised as the "Celtic New Year" from the late 19th century, following Sir John Rhys and Sir James Frazer...

. Winter ends and spring begins on Imbolc
Imbolc
Imbolc , or St Brigid’s Day , is an Irish festival marking the beginning of spring. Most commonly it is celebrated on 1 or 2 February in the northern hemisphere and 1 August in the southern hemisphere...

, or Candlemas, which is 1 or 2 February . 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 through July in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

.)

Also, many mainland European countries tend to recognize Martinmas or St. Martin's Day
St. Martin's Day
St. Martin's Day, also known as the Feast of St. Martin, Martinstag or Martinmas, the Feast of St Martin of Tours or Martin le Miséricordieux, is a time for feasting celebrations. This is the time when autumn wheat seeding is completed. Historically, hiring fairs were held where farm laborers...

 (11 November), as the first calendar day of winter. The day falls at midpoint between the old Julian equinox
Equinox
An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator...

 and 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...

 dates. Also, Valentine's Day
Valentine's Day
Saint Valentine's Day, commonly shortened to Valentine's Day, is an annual commemoration held on February 14 celebrating love and affection between intimate companions. The day is named after one or more early Christian martyrs named Saint Valentine, and was established by Pope Gelasius I in 496...

 (14 February) is recognized by some countries as heralding the first rites of spring, such as flowers blooming.

In Chinese astronomy
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...

 and other East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...

n calendars
Chinese calendar
The Chinese calendar is a lunisolar calendar, incorporating elements of a lunar calendar with those of a solar calendar. It is not exclusive to China, but followed by many other Asian cultures as well...

, winter is taken to commence on or around 7 November, 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 late February or early March. This "thermological winter" is earlier than the solstice delimited definition, but later than the daylight (Celtic) definition. Depending on seasonal lag
Seasonal lag
Seasonal lag is the phenomenon whereby the date of maximum average air temperature at a geographical location on a planet is delayed until some time after the date of maximum insolation...

, this period will vary between climatic regions.

Cultural influences such as Christmas creep
Christmas creep
Christmas creep is a merchandising phenomenon in which merchants and retailers exploit the commercialized status of Christmas by moving up the start of the holiday shopping season. The term was first used in the mid 1980s...

 may have led to the winter season being perceived as beginning earlier in recent years, although high latitude countries like Canada and Russia are usually well into their real winters before the December solstice.

Sporting influences can be seen in the UK and Europe, also helping to perceive winter even earlier. In England, the Barclays Premier League switches out the typical White Nike Strike ball for the Nike Seitiro Hi-Vis ball when conditions and visibility begin to deteriorate. In the 2011/12 season, the Premier League began using the 'Hi-Vis ball' on the 5th November. "The Nike Seitiro Hi-Vis ball is engineered to stand out on pitch when conditions are not ideal."
The Spanish La Liga and Italian Serie A also saw a change for the new Hi-Vis ball the weekend before England.

Causes

The tilt of the Earth's axis relative to its orbital plane plays a big role in 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. Compared with these effects, the changes in the distance of the earth from the sun are negligible.

Exceptionally cold winters

  • 1683–84, "The Great Frost", when the Thames, hosting one of many River Thames frost fairs
    River Thames frost fairs
    River Thames frost fairs were held on the Tideway of the River Thames at London between the 15th and 19th centuries when the river froze over. During that time the British winter was more severe than now, and the river was wider and slower....

    , was frozen all the way up to the London Bridge and remained frozen for about two months. Ice was about 27 cm (10.6 in) thick in London and about 120 cm (47.2 in) thick in Somerset. The sea froze up to 2 miles (3.2 km) out around the coast of the southern North Sea, causing severe problems for shipping and preventing use of many harbors.
  • 1739–40, one of the most severe winters in the UK on record. The Thames remained frozen-over for about 8 weeks. The Irish famine of 1740–1741 claimed the lives of at least 300,000 people.
  • 1816 was the Year Without a Summer
    Year Without a Summer
    The Year Without a Summer was 1816, in which severe summer climate abnormalities caused average global temperatures to decrease by about 0.4–0.7 °C , resulting in major food shortages across the Northern Hemisphere...

     in the Northern Hemisphere. The unusual coolness of the winter of 1815–16 and of the following summer was primarily due to the eruption of Mount Tambora
    Mount Tambora
    Mount Tambora is an active stratovolcano, also known as a composite volcano, on the island of Sumbawa, Indonesia. Sumbawa is flanked both to the north and south by oceanic crust, and Tambora was formed by the active subduction zone beneath it. This raised Mount Tambora as high as , making it...

     in Indonesia, in April 1815. There were secondary effects from an unknown eruption or eruptions around 1810, and several smaller eruptions around the world between 1812 and 1814. The cumulative effects were worldwide, but were especially strong in the Eastern USA, Atlantic Canada, and Northern Europe. Frost formed in May in New England, killing many newly-planted crops, and the summer never recovered. Snow fell in New York and Maine in June, and ice formed in lakes and rivers in July and August. In the UK, snow drifts remained on hills until late July, and the Thames froze in September. Agricultural crops failed and livestock died in much of the Northern Hemisphere, resulting in food shortages and the worst famine of the 19th century.
  • 1887–88, there were record cold temperatures in the Upper Midwest, heavy snowfalls worldwide, and amazing storms, including the Schoolhouse Blizzard
    Schoolhouse Blizzard
    The Schoolhouse Blizzard, also known as the Schoolchildren's Blizzard or the Children's Blizzard, hit the U.S. plains states on January 12, 1888...

     of 1888 (in the Midwest in January), and the Great Blizzard of 1888
    Great Blizzard of 1888
    The Great Blizzard of 1888 or Great Blizzard of '88 was one of the most severe blizzards in United States' recorded history. Snowfalls of 40-50 inches fell in parts of New Jersey, New York, Massachusetts and Connecticut, and sustained winds of over produced snowdrifts in excess of...

     (in the Eastern US and Canada in March).
  • In Europe, the winters of early 1947, February 1956, 1962–63, 1981–82 and 2009–10
    Winter of 2009–2010 in Europe
    The winter of 2009–2010 in Europe was unusually cold. Globally, atypical weather patterns brought cold, moist air from the north. Weather systems were undergoing cyclogenesis from North American storms moving across the Atlantic Ocean to the west, and saw many parts of Europe experiencing heavy...

     were abnormally cold. The UK winter of 1946–47 started out relatively normal, but became one of the snowiest UK winters to date, with nearly continuous snowfall from late January until March.

Other historically-significant winters

  • 1310–1330, many severe winters and cold, wet summers in Europe – the first clear manifestation of the unpredictable weather of the Little Ice Age
    Little Ice Age
    The Little Ice Age was a period of cooling that occurred after the Medieval Warm Period . While not a true ice age, the term was introduced into the scientific literature by François E. Matthes in 1939...

     that lasted for several centuries (from about 1300 to 1900). The persistently cold, wet weather caused great hardship, was primarily responsible for the Great Famine of 1315–1317
    Great Famine of 1315–1317
    The Great Famine of 1315–1317 was the first of a series of large scale crises that struck Northern Europe early in the fourteenth century...

    , and strongly contributed to the weakened immunity and malnutrition leading up to the Black Death
    Black Death
    The Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. Of several competing theories, the dominant explanation for the Black Death is the plague theory, which attributes the outbreak to the bacterium Yersinia pestis. Thought to have...

     (1348–1350).
  • 1600–1602, extremely cold winters in Switzerland and Baltic region after eruption of Huaynaputina
    Huaynaputina
    Huaynaputina is a stratovolcano located in a volcanic upland in southern Peru. The volcano does not have an identifiable mountain profile, but instead has the form of a large volcanic crater. It has produced high-potassium andesite and dacite...

     in Peru in 1600.
  • 1607–08, in North America, ice persisted on Lake Superior until June. Londoners held their first frost fair on the frozen-over River Thames.
  • 1622, in Turkey, the Golden Horn
    Golden Horn
    The Golden Horn is a historic inlet of the Bosphorus dividing the city of Istanbul and forming the natural harbor that has sheltered Greek, Roman, Byzantine, Ottoman and other ships for thousands of...

     and southern section of Bosphorus froze over.
  • 1690s, extremely cold, snowy, severe winters. Ice surrounded Iceland for miles in every direction.
  • 1779–80, Scotland's coldest winter on record, and ice surrounded Iceland in every direction (like in the 1690s). In the USA, a record five-week cold spell bottomed out at -20 F at Hartford, Connecticut, and 16 °F (-8.9 °C) in New York City. Hudson River and New York's harbor froze over.
  • 1783–86, the Thames partially froze, and snow remained on the ground for months. In February 1784, the North Carolina was frozen stuck in the Chesapeake Bay.
  • 1794–95, severe winter, with the coldest January in the UK and lowest temperature ever recorded in London (-21 C on January 25). The cold began on Christmas Eve
    Christmas Eve
    Christmas Eve refers to the evening or entire day preceding Christmas Day, a widely celebrated festival commemorating the birth of Jesus of Nazareth that takes place on December 25...

     and lasted until late March, with a few temporary warm-ups. The Severn and Thames froze, and frost fairs started up again. The French fleet was able to invade the Netherlands over its frozen rivers, while the Dutch fleet was stuck in its harbor. The winter had Easterlies (from Siberia) as its dominant feature.
  • 1813–14, severe cold, last freeze-over of Thames, and last frost fair. (Removal of old London Bridge and changes to river's banks made freeze-overs less likely.)
  • 1883–1888, colder temperatures worldwide, including an unbroken string of abnormally cold and brutal winters in the Upper Midwest, related to the explosion of Krakatoa
    Krakatoa
    Krakatoa is a volcanic island made of a'a lava in the Sunda Strait between the islands of Java and Sumatra in Indonesia. The name is used for the island group, the main island , and the volcano as a whole. The island exploded in 1883, killing approximately 40,000 people, although some estimates...

     in August 1883. There was snow recorded in the UK as early as October and as late as July during this time period.
  • 1976–77, one of the coldest winters in the US in decades.
  • 1985, Arctic outbreak in US resulting from shift in polar vortex, with many cold temperature records broken.
  • 2010–11, persistent bitter cold in the entire eastern half of the USA from December onward, with few or no mid-winter warm-ups, and with cool conditions continuing into spring. La Niña
    La Niña
    La Niña is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño-Southern Oscillation climate pattern. During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3–5 °C...

     and negative Arctic oscillation
    Arctic oscillation
    The Arctic oscillation or Northern Annular Mode/Northern Hemisphere Annular Mode is an index of the dominant pattern of non-seasonal sea-level pressure variations north of 20N latitude, and it is characterized by pressure anomalies of one sign in the Arctic with the opposite anomalies centered...

     were strong factors.

Ecology

To survive the harshness of winter, many animals have developed different behavioral and morphological adaptations for overwintering:
  • Migration
    Bird migration
    Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...

     is a common effect of winter upon animals, notably bird
    Bird
    Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

    s. However, the majority of birds do not migrate—the cardinal
    Cardinal (bird)
    The Cardinals or Cardinalidae are a family of passerine birds found in North and South America. The South American cardinals in the genus Paroaria are placed in another family, the Thraupidae ....

     and European Robin
    European Robin
    The European Robin , most commonly known in Anglophone Europe simply as the Robin, is a small insectivorous passerine bird that was formerly classed as a member of the thrush family , but is now considered to be an Old World flycatcher...

    , for example. Some butterflies
    Butterfly
    A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

     also migrate seasonally.
  • Hibernation
    Hibernation
    Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

     is a state of reduced metabolic activity
    Metabolism
    Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

     during the winter. Some animals "sleep" during winter and only come out when the warm weather returns; e.g., gopher
    Gopher (animal)
    The term gopher as it is commonly used does not relate to any one species, but is a generic term used to describe any of several small burrowing rodents endemic to North America, including the pocket gopher , also called true gophers, and the ground squirrel , including Richardson's ground squirrel...

    s, frogs, snakes, and bats.
  • Some animals store food for the winter and live on it instead of hibernating completely. This is the case for squirrel
    Squirrel
    Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots , flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa and have been introduced to Australia...

    s, beaver
    Beaver
    The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...

    s, skunk
    Skunk
    Skunks are mammals best known for their ability to secrete a liquid with a strong, foul odor. General appearance varies from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora...

    s, badger
    Badger
    Badgers are short-legged omnivores in the weasel family, Mustelidae. There are nine species of badger, in three subfamilies : Melinae , Mellivorinae , and Taxideinae...

    s, and raccoon
    Raccoon
    Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...

    s.
  • Resistance is observed when an animal endures winter but changes in ways such as color and musculature. The color of the fur or plumage changes to white (in order to be confused with snow) and thus retains its cryptic coloration year-round. Examples are the Rock Ptarmigan, arctic fox
    Arctic fox
    The arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...

    , weasel
    Weasel
    Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....

    , white-tailed jackrabbit
    Hare
    Hares and jackrabbits are leporids belonging to the genus Lepus. Hares less than one year old are called leverets. Four species commonly known as types of hare are classified outside of Lepus: the hispid hare , and three species known as red rock hares .Hares are very fast-moving...

    , and mountain hare
    Mountain Hare
    The Mountain Hare , also known as Blue Hare, Tundra Hare, Variable Hare, White Hare, Alpine Hare and Irish Hare, is a hare, which is largely adapted to polar and mountainous habitats. It is distributed from Fennoscandia to eastern Siberia; in addition there are isolated populations in the Alps,...

    .
  • Some fur-coated mammals grow a heavier coat during the winter; this improves the heat-retention qualities of the fur. The coat is then shed following the winter season to allow better cooling. The heavier coat in winter made it a favorite season for trappers, who sought more profitable skins.
  • Snow also affects the ways animals behave; many take advantage of the insulating properties of snow by burrowing in it. Mice and vole
    Vole
    A vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...

    s typically live under the snow layer.


Some annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

s never survive the winter. Other annual plants require winter cold to complete their life cycle, this is known as vernalization
Vernalization
Vernalization is the acquisition of a plant's ability to flower or germinate in the spring by exposure to the prolonged cold of winter...

. As for perennial
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

s, many small ones profit from the insulating effects of snow by being buried in it. Larger plants, particularly deciduous trees
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

, usually let their upper part go dormant, but their roots are still protected by the snow layer. Few plants bloom in the winter, one exception being the flowering plum, which flowers in time for Chinese New Year
Chinese New Year
Chinese New Year – often called Chinese Lunar New Year although it actually is lunisolar – is the most important of the traditional Chinese holidays. It is an all East and South-East-Asia celebration...

. The process by which plants become acclimated to cold weather is called hardening
Hardening (botany)
Hardening in botany is the process by which an individual plant becomes tolerant to the effects of freezing during a period of weeks to months. It is a three stage process. During the first stage, carbohydrates are translocated to the roots of the plant and cell membrane permeability increases...

.

Mankind and winter

Humans evolved in tropical climates, and met cold weather as they migrated into Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

, although earlier populations certainly encountered Southern Hemisphere winters in Southern Africa
Cradle of Humankind
The Cradle of Humankind is a World Heritage Site first named by UNESCO in 1999, about 50 kilometres northwest of Johannesburg, South Africa in the Gauteng province. This site currently occupies ; it contains a complex of limestone caves, including the Sterkfontein Caves, where the 2.3-million...

. Micro-evolution in Caucasian, Asiatic and Inuit people show some adaptation to the climate.

Winter and human health

Humans are sensitive to cold, see hypothermia
Hypothermia
Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...

. Snowblindness, norovirus, seasonal depression, slipping on black ice and falling icicle
Icicle
An icicle is a spike of ice formed when water dripping or falling from an object freezes. Typically, icicles will form when ice or snow is melted by either sunlight or some other heat source , and the resulting melted water runs off into an area where the ambient temperature is below the freezing...

s are other health concerns associated with cold and snowy weather.

Winter and transportation

Snow can block railway lines, close airports (airplanes are often unable to move in dense fog) and block roads. Black ice
Black ice
Black ice, sometimes called glare ice or clear ice, refers to a thin coating of glazed ice on a surface.While not truly black, it is virtually transparent, allowing black asphalt/macadam roadways to be seen through it, hence the term "black ice"...

 is also a major threat on the roads at this time. Snow ploughs, road salt, grit, sand, hand tools (like shovels, brooms, etc.) and rock salt to help combat it.

Chinese New Year

The Chinese Spring Festival is the most important of the traditional Chinese holidays
Traditional Chinese holidays
The traditional Chinese holidays are an essential part of Chinese culture. Many holidays are associated with Chinese mythology and folklore tales, but more realistically, they probably originated from ancient farmer rituals for celebrating harvests or prayer offerings...

. It is often called the Lunar New Year
Chinese New Year
Chinese New Year – often called Chinese Lunar New Year although it actually is lunisolar – is the most important of the traditional Chinese holidays. It is an all East and South-East-Asia celebration...

, especially by people in mainland China, Taiwan, Singapore and Malaysia. The festival traditionally begins on the first day of the first month in the Chinese calendar
Chinese calendar
The Chinese calendar is a lunisolar calendar, incorporating elements of a lunar calendar with those of a solar calendar. It is not exclusive to China, but followed by many other Asian cultures as well...

 and ends on the 15th; this day is called Lantern Festival
Lantern Festival
The Lantern Festival ; is a festival celebrated on the fifteenth day of the first month in the lunisolar year in the Chinese calendar, the last day...

. Chinese New Year's Eve is known as Chúxī. It literally means "Year-pass Eve". The usual starting date is the second new moon after the winter solstice, i.e. between mid-January and mid-February in the Gregorian calendar.

Poush Mela

Poush is the first winter month in the Bengali calendar. Poush Mela
Poush Mela
Poush Mela is an annual fair and festival that takes place in Santiniketan, in Birbhum District in the Indian state of West Bengal, marking the harvest season. Commencing on the 7th day of the month of Poush, the fair officially lasts for three days, although vendors may stay up until the month-end...

 (meaning the fair of Poush) is a fair that takes place in different places of Bengal.

Snow activities

Many winter activities involve the use of snow in some form (which sometimes is man-made, using snow cannons):
  • Bobsledding — a winter sport
    Winter sport
    A winter sport is a sport which is played on snow or ice. Most such sports are variations of skiing, ice skating and sledding. Traditionally such sports were only played in cold areas during winter, but artificial snow and ice allow more flexibility...

     in which teams make timed runs down narrow, twisting, banked, purpose-built ice-covered tracks in a steerable sled
    Sled
    A sled, sledge, or sleigh is a land vehicle with a smooth underside or possessing a separate body supported by two or more smooth, relatively narrow, longitudinal runners that travels by sliding across a surface. Most sleds are used on surfaces with low friction, such as snow or ice. In some cases,...

    .
  • Skiing
    Skiing
    Skiing is a recreational activity using skis as equipment for traveling over snow. Skis are used in conjunction with boots that connect to the ski with use of a binding....

     — the activity of gliding over snow using fiberglass planks called skis that are strapped to the skiers' feet with ski bindings.
  • Sledding
    Sledding
    Sledding , sledging , sleding or tobogganing is a common activity in wintry areas, similar to sliding, but in a prone or seated position requiring a device or vehicle generically known in the US as a sled or in other countries as a sledge or toboggan...

     — a gravity-powered activity using a sled to glide downhill.
  • Snow castle
    Snow fort
    A snow fort or snow castle is a usually open-topped temporary structure made of snow walls that is used for recreational purposes. Snow forts are generally built by children as a playground game or winter pastime and are used as defensive structures in snowball fights...

     building — for example, constructions such as the SnowCastle of Kemi, the largest in the world.
  • Snowball fight
    Snowball fight
    A snowball fight is a physical game in which balls of snow are thrown with the intention of hitting somebody else. The game is similar to dodgeball in its major factors, though typically less organized. This activity is primarily played during months when there is sufficient snowfall.Today, the...

     — a physical game
    Game
    A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...

     in which snowballs are thrown with the intention of hitting someone else.
  • Snowboarding
    Snowboarding
    Snowboarding is a sport that involves descending a slope that is covered with snow on a snowboard attached to a rider's feet using a special boot set onto mounted binding. The development of snowboarding was inspired by skateboarding, sledding, surfing and skiing. It was developed in the U.S.A...

     — an increasingly common sport in which participants strap a composite board to their feet and slide down a snow-covered mountain.
  • Snowman
    Snowman
    A snowman is an anthropomorphic snow sculpture. They are customarily built by children as part of a family project in celebration of winter. In some cases, participants in winter festivals will build large numbers of snowmen...

     building — creating a manlike model out of snow.
  • Snowmobiling — driving snowmobiles in snow, across frozen lakes, on public trails, or around mountains.
  • Snowshoeing — a means of travel on top of the snow by increasing the surface area
    Surface area
    Surface area is the measure of how much exposed area a solid object has, expressed in square units. Mathematical description of the surface area is considerably more involved than the definition of arc length of a curve. For polyhedra the surface area is the sum of the areas of its faces...

     of the feet by wearing snowshoes.
  • Winter camping - cooking, eating and sleeping outside in the snow during the winter. Those who winter camp build a shelter from evergreen tree boughs, dig a snow cave
    Snow cave
    A snow cave is a shelter constructed in snow by certain animals in the wild, human mountain climbers, winter recreational enthusiasts, and winter survivalists. It has thermal properties similar to an Igloo and is particularly effective at providing protection from wind as well as low temperatures...

    , create a quinzhee
    Quinzhee
    A quinzhee or quinzee is a shelter made by hollowing out a pile of settled snow. This is in contrast to an igloo, which is made from blocks of hard snow...

     or sleep in a tent for shelter overnight.

Ice activities

Many other winter activities and sports focus on ice, which may be contained in an ice rink
Ice rink
An ice rink is a frozen body of water and/or hardened chemicals where people can skate or play winter sports. Besides recreational ice skating, some of its uses include ice hockey, figure skating and curling as well as exhibitions, contests and ice shows...

.
  • Curling
    Curling
    Curling is a sport in which players slide stones across a sheet of ice towards a target area. It is related to bowls, boule and shuffleboard. Two teams, each of four players, take turns sliding heavy, polished granite stones, also called "rocks", across the ice curling sheet towards the house, a...

     — a team sport using brooms and stones. The object of the game is to slide your stones in a bullseye and get your opponent's stones out of it.
  • Ice biking — the continuation of regular cycling
    Cycling
    Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists or bicyclists...

     activities in the winter and cold weather.
  • Ice boat
    Ice boat
    An ice boat is a boat or purpose-built framework similar in functional design to a sail boat but fitted with skis or runners and designed to run over ice instead of through water. Ice yachting is the sport of sailing and racing iceboats. Sailable ice is known in the sport as "hard water" versus...

    ing — a means of travel in a specialized boat similar in appearance to a sailboat but fitted with skis or runners (skates) and designed to run over ice instead of (liquid) water.
  • Ice climbing
    Ice climbing
    Ice climbing, as the term indicates, is the activity of ascending inclined ice formations. Usually, ice climbing refers to roped and protected climbing of features such as icefalls, frozen waterfalls, and cliffs and rock slabs covered with ice refrozen from flows of water. For the purposes of...

     — the recreational activity of climbing ice formations such as icefalls and frozen waterfalls.
  • Ice diving
    Ice diving
    Ice diving is a type of penetration diving where the dive takes place under ice. Because diving under ice places the diver in an overhead environment typically with only a single entry/exit point, it is considered an advanced type of diving requiring special training...

     — a type of penetration diving
    Penetration diving
    Penetration diving or no clear surface diving is a type of diving where the scuba diver enters a space from which there is no direct, purely vertical ascent to the safety of breathable air of the atmosphere at the surface...

     where the dive takes place under ice.
  • Ice fishing
    Ice fishing
    Ice fishing is the practice of catching fish with lines and fish hooks or spears through an opening in the ice on a frozen body of water. Ice anglers may sit on the stool in the open on a frozen lake, or in a heated cabin on the ice, some with bunks and amenities.-Locations:It is a popular pastime...

     — the sport of catching fish
    Fishing
    Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....

     with lines and hooks through an opening in the ice on a frozen body of water.
  • Ice hockey
    Ice hockey
    Ice hockey, often referred to as hockey, is a team sport played on ice, in which skaters use wooden or composite sticks to shoot a hard rubber puck into their opponent's net. The game is played between two teams of six players each. Five members of each team skate up and down the ice trying to take...

     — a team sport played on the ice with skates, sticks, and a puck. The goal is to send the puck into the opposing team's net.
  • Ice racing
    Ice racing
    Ice racing is a form of racing that uses cars, motorcycles, snowmobiles, All-terrain vehicles, or other motorized vehicles. Ice racing takes place on frozen lakes or rivers, or on carefully groomed frozen lots...

     — automobile racing on ice surfaces.
  • Ice sculpture
    Ice sculpture
    Ice sculpture is a form of sculpture that uses ice as the raw material. Sculptures from ice can be abstract or realistic and can be functional or purely decorative...

     — elaborate sculptures are carved out of blocks of ice.
  • Ice skating
    Ice skating
    Ice skating is moving on ice by using ice skates. It can be done for a variety of reasons, including leisure, traveling, and various sports. Ice skating occurs both on specially prepared indoor and outdoor tracks, as well as on naturally occurring bodies of frozen water, such as lakes and...

     — a means of travelling on ice with skates, narrow (and sometimes parabolic) bladelike devices molded into special boot
    Boot
    A boot is a type of footwear but they are not shoes. Most boots mainly cover the foot and the ankle and extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearly distinguishable from the rest of the sole, even if the two are made of one piece....

    s.

Use in art

Many artists like the Dutch artist Hendrick Avercamp
Hendrick Avercamp
Hendrick Avercamp was a Dutch painter.Avercamp was born in Amsterdam, where he studied with the Danish-born portrait painter Pieter Isaacks , and perhaps also with David Vinckboons. In 1608 he moved from Amsterdam to Kampen in the province of Overijssel...

 painted pictures of winter life over the centuries. See:

Symbolism

Some use winter to suggest death, as in Robert Frost
Robert Frost
Robert Lee Frost was an American poet. He is highly regarded for his realistic depictions of rural life and his command of American colloquial speech. His work frequently employed settings from rural life in New England in the early twentieth century, using them to examine complex social and...

's "Stopping by Woods on a Snowy Evening
Stopping by Woods on a Snowy Evening
"Stopping by Woods on a Snowy Evening" is a poem written in 1922 by Robert Frost, and published in 1923 in his New Hampshire volume. Imagery and personification are prominent in the work...

". In some cases it is also used to symbolise trash Jake Woodworth's poem collection. Some use it to suggest the absence of hope, as in C.S. Lewis' The Lion, the Witch and the Wardrobe
The Lion, the Witch and the Wardrobe
The Lion, the Witch and the Wardrobe is a fantasy novel for children by C. S. Lewis. Published in 1950 and set circa 1940, it is the first-published book of The Chronicles of Narnia and is the best known book of the series. Although it was written and published first, it is second in the series'...

,
where it was always winter but never Christmas. Winter is one concerto in Antonio Vivaldi
Antonio Vivaldi
Antonio Lucio Vivaldi , nicknamed because of his red hair, was an Italian Baroque composer, priest, and virtuoso violinist, born in Venice. Vivaldi is recognized as one of the greatest Baroque composers, and his influence during his lifetime was widespread over Europe...

'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
The Left Hand of Darkness
The Left Hand of Darkness is a 1969 science fiction novel by Ursula K. Le Guin. It is part of the Hainish Cycle, a series of books by Le Guin all set in the fictional Hainish universe....

is set on a planet named Winter. In Alex Raymond
Alex Raymond
Alexander Gillespie "Alex" Raymond was an American cartoonist, best known for creating Flash Gordon for King Features in 1934...

's comic strip Flash Gordon
Flash Gordon
Flash Gordon is the hero of a science fiction adventure comic strip originally drawn by Alex Raymond. First published January 7, 1934, the strip was inspired by and created to compete with the already established Buck Rogers adventure strip. Also inspired by these series were comics such as Dash...

, 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
Flash Gordon Conquers the Universe
Flash Gordon Conquers the Universe is a 1940 twelve episode serial film about Flash Gordon. It was the last of three Flash Gordon serials made from 1936 to 1940. The serial was produced and copyrighted by Universal Pictures....

. Other uses of winter in the graphic arts occur in Winsor McCay
Winsor McCay
Winsor McCay was an American cartoonist and animator.A prolific artist, McCay's pioneering early animated films far outshone the work of his contemporaries, and set a standard followed by Walt Disney and others in later decades...

's Little Nemo in Slumberland. There are many films in which a winter setting plays an important role, Fargo
Fargo (film)
Fargo is a 1996 American dark comedy-crime film produced, directed and written by brothers Joel and Ethan Coen. It stars Frances McDormand as a pregnant police chief who investigates a series of homicides, William H...

being an example. Novels such as Ethan Frome
Ethan Frome
Ethan Frome is a novel published in 1911 by the Pulitzer Prize-winning American author Edith Wharton. It is set in the fictitious town of Starkfield, Massachusetts, New England, United States...

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 chilling climax. The final vignette in James Joyce
James Joyce
James Augustine Aloysius Joyce was an Irish novelist and poet, considered to be one of the most influential writers in the modernist avant-garde of the early 20th century...

's Dubliners
Dubliners
Dubliners is a collection of 15 short stories by James Joyce, first published in 1914. They were meant to be a naturalistic depiction of Irish middle class life in and around Dublin in the early years of the 20th century....

, 'The Dead', employs a winter motif in conjunction with themes of regret and isolation.

In various cultures

In Persian culture the night starting winter is called Yalda
Yalda
Yalda , Yalda Night / Shab-e Yaldâ , or Shab-e Chelleh is the Persian Winter Solstice Celebration which has been popular since ancient times. Yalda is celebrated on the Northern Hemisphere's longest night of the year, that is, on the eve of the Winter Solstice...

 (meaning: birth) and it has been celebrated for thousands of years. It is referred to as the eve of the birth of Mithra, the Sun God, who symbolised light, goodness and strength on earth. By the whiteness of Winter, the Sun (the white) rises again to fade away the darkness of the long night (Yalda). It is also believed that the last day of Winter (the white), which is the first day of Spring (also known as Nowrouz), is the day that all the "Good"s will over come all the "Bad"s for ever.

In Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

, Hades
Hades
Hades , Hadēs, originally , Haidēs or , Aidēs , meaning "the unseen") was the ancient Greek god of the underworld. The genitive , Haidou, was an elision to denote locality: "[the house/dominion] of Hades". Eventually, the nominative came to designate the abode of the dead.In Greek mythology, Hades...

 kidnapped Persephone
Persephone
In Greek mythology, Persephone , also called Kore , is the daughter of Zeus and the harvest-goddess Demeter, and queen of the underworld; she was abducted by Hades, the god-king of the underworld....

 to be his wife. Zeus
Zeus
In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus...

 ordered Hades to return her to Demeter
Demeter
In Greek mythology, Demeter is the goddess of the harvest, who presided over grains, the fertility of the earth, and the seasons . Her common surnames are Sito as the giver of food or corn/grain and Thesmophoros as a mark of the civilized existence of agricultural society...

, the goddess of the Earth and her mother. However, Hades tricked Persephone into eating the food of the dead, so Zeus decreed that Persephone would spend six months with Demeter and six months with Hades. During the time her daughter is with Hades, Demeter became depressed and caused winter. In Welsh mythology
Welsh mythology
Welsh mythology, the remnants of the mythology of the pre-Christian Britons, has come down to us in much altered form in medieval Welsh manuscripts such as the Red Book of Hergest, the White Book of Rhydderch, the Book of Aneirin and the Book of Taliesin....

, Gwyn ap Nudd
Gwyn ap Nudd
Gwyn ap Nudd is a Welsh mythological figure, the king of the Tylwyth Teg or "fair folk" and ruler of the Welsh Otherworld, Annwn. Described as a great warrior with a "blackened face", Gwyn is intimately associated with the otherworld in medieval Welsh literature, and is associated with the...

 abducted a maiden named Creiddylad
Creiddylad
Creiddylad is a figure from Welsh mythology known from the early medieval Welsh Arthurian tale of Culhwch ac Olwen, one of the tales of the Mabinogion. She is the daughter of Lludd Llaw Eraint...

. On May Day, her lover, Gwythr ap Greidawl
Gwythr ap Greidawl
In Welsh mythology, Gwythyr ap Greidawl was a rival of Gwyn ap Nudd, a deity connected with the otherworld. In the Middle Welsh prose tale Culhwch ac Olwen, he is named as a member of Arthur's retinue and takes part in the quest to win the hand of Olwen for Arthur's cousin, Culhwch. Gwthyr would...

, fought Gwyn to win her back. The battle between them represented the contest between summer and winter.

Personifications

Old Man Winter is also known as Father Winter,
  • Jack Frost
    Jack Frost
    Jack Frost is a sprite-like character with roots in Viking lore. There, he is known as Jokul Frosti . In Britain and United States, Jack is a variant of Old Man Winter and is held responsible for frosty weather, for nipping the nose and toes in such weather, coloring the foliage in autumn, and...

    ,
  • Ded Moroz
    Ded Moroz
    Ded Moroz is a fictional character who in some Slavic cultures plays a role similar to that of Santa Claus. The literal translation of the name would be Grandfather Frost, although the name is often translated as Father Frost....

    ,
  • Snegurochka
    Snegurochka
    Snegurochka , or The Snow Maiden, is a character in Russian fairy tales.In one story, she is the daughter of Spring and Frost, and yearns for the companionship of mortal humans. She grows to like a shepherd named Lel, but her heart is unable to know love...

    ,
  • Vetr
    Sumarr and Vetr
    In Norse mythology, Sumarr and Vetr are personified seasons. Sumarr and Vetr, personified, are attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda, written in the 13th century by Snorri Sturluson...

    ,
  • Sinterklaas
    Sinterklaas
    Sinterklaas is a traditional Winter holiday figure still celebrated today in the Low Countries, including the Netherlands and Belgium, as well as French Flanders and Artois...

     etc.


In Bangla the advent of winter is often expressed by the sentence-"Sheeter buri ashchhe dheye" which means "the winter old woman is coming fast" (Sheeter buri means the old woman winter). This is used especially when it is said to a child. Thus winter is personified in Bangla.

See also


Human-related:
  • Fimbulvetr
  • List of winter festivals
  • Winter City
    Winter City
    Winter City or Winter Cities is a concept for communities in northern latitudes that encourages them to plan their transportation systems, buildings, and recreation project around the idea of using their infrastructure during all four seasons, rather than just two seasons .-Background:The Livable...

  • Arctic warfare
    Arctic warfare
    Arctic warfare or winter warfare is a term used to describe armed conflict that takes place in an exceptionally cold weather, usually in snowy and icy terrain, sometimes on ice-covered bodies of water...

  • Winter Olympic Games
    Winter Olympic Games
    The Winter Olympic Games is a sporting event, which occurs every four years. The first celebration of the Winter Olympics was held in Chamonix, France, in 1924. The original sports were alpine and cross-country skiing, figure skating, ice hockey, Nordic combined, ski jumping and speed skating...

  • Winter War
    Winter War
    The Winter War was a military conflict between the Soviet Union and Finland. It began with a Soviet offensive on 30 November 1939 – three months after the start of World War II and the Soviet invasion of Poland – and ended on 13 March 1940 with the Moscow Peace Treaty...



Weather-related:
  • Cold wave
    Cold wave
    A cold wave is a weather phenomenon that is distinguished by a cooling of the air. Specifically, as used by the U.S. National Weather Service, a cold wave is a rapid fall in temperature within a 24 hour period requiring substantially increased protection to agriculture, industry, commerce, and...

  • Global cooling
    Global cooling
    Global cooling was a conjecture during the 1970s of imminent cooling of the Earth's surface and atmosphere along with a posited commencement of glaciation...

  • Nuclear winter
    Nuclear winter
    Nuclear winter is a predicted climatic effect of nuclear war. It has been theorized that severely cold weather and reduced sunlight for a period of months or even years could be caused by detonating large numbers of nuclear weapons, especially over flammable targets such as cities, where large...

  • Pineapple Express
    Pineapple Express
    Pineapple Express is a non-technical term for a meteorological phenomenon characterized by a strong and persistent flow of atmospheric moisture and associated heavy rainfall from the waters adjacent to the Hawaiian Islands and extending to any location along the Pacific coast of North America...

  • Siberian Express
    Siberian Express
    Siberian Express is a shorthand meteorological term in the United States describing the arrival of an extremely cold air mass of Arctic origins. It does not necessarily refer to an origin in Siberia...

  • Volcanic winter
    Volcanic winter
    A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun and raising Earth's albedo after a large particularly explosive type of volcanic eruption...



Further reading

  • Rosenthal, Norman E. (1998). Winter Blues. New York: The Guilford Press. ISBN 1-57230-395-6

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK