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[[File:Saint-Amant 16 Gelée blanche 2008.jpg|thumb|A patch of grass showing crystalline frost in the below-freezing shade (blue, lower right); frost in the warming but still below freezing strip most recently exposed to sunlight (white, center); and a frost-free region: here, the previous frost has melted from a more prolonged exposure to sunlight (green, upper left.)]]
'''Frost''' is a thin layer of [[ice]] on a [[solid]] surface, which forms from [[water vapor]] in an above [[freezing]] [[atmosphere]] coming in contact with a solid surface whose temperature is below freezing,<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/frost|title=Frost – Definition of frost by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150511025533/http://www.merriam-webster.com/dictionary/frost|archivedate=2015-05-11}}</ref><ref>{{cite web |url=http://www.weatherquestions.com/What_causes_frost.htm |title=What causes frost? |accessdate=2007-12-05 |url-status=live |archiveurl=https://web.archive.org/web/20071210230539/http://www.weatherquestions.com/What_causes_frost.htm |archivedate=2007-12-10 }}</ref> and resulting in a [[phase transition|phase change]] from water vapor (a [[gas]]) to [[ice]] (a solid) as the water vapor reaches the [[freezing point]]. In [[temperate climate]]s, it most commonly appears on surfaces near the ground as fragile white [[crystals]]; in cold climates, it occurs in a greater variety of forms.<ref name="Oliver2005">{{cite book|author=John E. Oliver|title=The Encyclopedia of World Climatology|url=https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|date=1 January 2005|publisher=[[Springer Science & Business Media]]|isbn=978-1-4020-3264-6|pages=382–|url-status=live|archiveurl=https://web.archive.org/web/20160508153444/https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|archivedate=8 May 2016}}</ref> The propagation of crystal formation occurs by the process of [[nucleation]].
The [[ice crystals]] of frost form as the result of [[fractal]] process development. The depth of frost crystals varies depending on the amount of time they have been accumulating, and the concentration of the water vapor ([[humidity]]). Frost crystals may be invisible (black), clear ([[translucent]]), or white; if a mass of frost crystals scatters light in all directions, the coating of frost appears white.
Types of frost include crystalline frost ([[#Hoar frost|hoar frost]] or radiation frost) from [[deposition (phase transition)|deposition]] of [[water vapor]] from air of low humidity, [[#White frost|white frost]] in humid conditions, [[#Window frost|window frost]] on glass surfaces, [[#Advection frost|advection frost]] from cold wind over cold surfaces, [[#Black frost|black frost]] without visible ice at low temperatures and very low humidity, and [[#Rime|rime]] under [[Supercooling|supercooled]] wet conditions.<ref name="Oliver2005"/>
Plants that have evolved in warmer climates suffer damage when the temperature falls low enough to freeze the water in the [[cell (biology)|cells]] that make up the plant [[tissue (biology)|tissue]]. The tissue damage resulting from this process is known as "frost damage". [[Farmer]]s in those regions where frost damage is known to affect their crops often invest in substantial means to protect their crops from such damage.
==Formation==
[[File:Nevada-Apartadero-Merida-Venezuela.jpg|thumb|Frost in the [[list of highest towns by country|highest town in Venezuela]], [[Apartaderos]]. Because of its location in an [[alpine tundra]] [[ecosystem]] called [[páramo]], there exists a daily freeze-and-thaw cycle, sometimes described as "summer every day and winter every night."]]
If a solid surface is chilled below the [[dew point]] of the surrounding humid air and the surface itself is colder than freezing, ice will form on it. If the water deposits as a liquid that then freezes, it forms a coating that may look glassy, opaque, or crystalline, depending on its [[#Types|type]]. Depending on context, that process also may be called [[atmospheric icing]]. The ice it produces differs in some ways from crystalline frost, which consists of spicules of [[ice]] that typically project from the solid surface on which they grow.
The main difference between the ice coatings and frost spicules arises from the fact that the crystalline spicules grow directly from [[deposition (phase transition)|desublimation]] of water vapour from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed the surface must be below the [[dew point#Frost point|frost point]] of the air, meaning that it is sufficiently cold for ice to form without passing through the [[liquid|liquid phase]]. The air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the [[crystal]]s depends largely on the temperature, the amount of [[water vapor]] available, and how long they have been growing undisturbed.
As a rule, except in conditions where supercooled droplets are present in the air, frost will form only if the deposition surface is colder than the surrounding air. For instance frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the warmer ground beneath. Other objects on which frost commonly forms are those with low [[specific heat]] or high [[thermal emissivity]], such as blackened metals; hence the accumulation of frost on the heads of rusty nails.
The apparently erratic occurrence of frost in adjacent localities is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, the [[molar absorptivity|absorptivity]] and specific heat of the ground strongly influence the temperature that the trapped air attains.
==Types==
===Hoar frost===
[[File:Frostweb.jpg|thumb|upright|A [[spider web]] covered in air hoar frost]]
[[File:HoarFrost.jpg|thumb|Hoar frost on the snow]]
[[File:LightLTSEM.jpg|thumb|Depth hoar, [[micrograph|imaged]] with [[optical microscope|optical]] (left) and [[scanning electron microscope|scanning electron]] (right) [[microscopy]]]]
'''Hoar frost''', also '''hoarfrost''', '''radiation frost''', or '''pruina''', refers to white [[ice crystals]] deposited on the ground or loosely attached to exposed objects, such as wires or leaves.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/hoar%20frost|title=Hoarfrost – Definition of hoarfrost by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150219065328/http://www.merriam-webster.com/dictionary/hoar%20frost|archivedate=2015-02-19}}</ref> They form on cold, clear nights when conditions are such that [[radiative cooling#Nocturnal surface cooling|heat radiates]] out to the open air faster than it can be replaced from nearby sources, such as wind or warm objects. Under suitable circumstances, objects cool to below the [[dew point#Frost point|frost point]]<ref name="RohliRohli2013">{{cite book|author1=Louisiana State University Baton Rouge Robert V Rohli|author2=Robert V. Rohli|author3=Anthony J. Vega|title=Climatology|url=https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381|date=13 December 2013|publisher=[[Jones & Bartlett Publishers]]|isbn=978-1-284-05427-9|pages=381–|url-status=live|archiveurl=https://web.archive.org/web/20160519122238/https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381|archivedate=19 May 2016}}</ref> of the surrounding air, well below the freezing point of water. Such freezing may be promoted by effects such as '''flood frost''' or '''frost pocket'''.<ref>{{cite web|url=http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm|title=Weather Facts: Frost hollow – Weather UK – weatheronline.co.uk|work=weatheronline.co.uk|url-status=live|archiveurl=https://web.archive.org/web/20130212022607/http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm|archivedate=2013-02-12}}</ref> These occur when ground-level radiation losses{{huh|date=September 2019}} cool air until it flows downhill and accumulates in pockets of very cold air in valleys and hollows. Hoar frost may freeze in such low-lying cold air even when the air temperature a few feet above ground is well above freezing.
The word ''hoar'' comes from an [[Old English]] adjective that means "showing signs of old age". In this context, it refers to the frost that makes trees and bushes look like white hair. <!-- Please leave out the following bit of folk etymology: "may also have association with hawthorn when covered in ... white spring blossom". The speculation is wrong. See OED! -->
Hoar frost may have different names depending on where it forms:
*'''Air hoar''' is a deposit of hoar frost on objects above the surface, such as tree branches, plant stems, and wires.
*'''Surface hoar''' refers to fern-like ice crystals directly deposited on snow, ice or already frozen surfaces.
*'''Crevasse hoar''' consists of crystals that form in glacial crevasses where water vapour can accumulate under calm weather conditions.
*'''[[Depth hoar]]''' refers to faceted crystals that have slowly grown large within cavities beneath the surface of banks of dry snow. Depth hoar crystals grow continuously at the expense of neighbouring smaller crystals, so typically are visibly stepped and have faceted hollows.
When surface hoar covers sloping snowbanks, the layer of frost crystals may create an [[avalanche]] risk; when heavy layers of new snow cover the frosty surface, furry crystals standing out from the old snow hold off the falling flakes, forming a layer of voids that prevent the new snow layers from bonding strongly to the old snow beneath. Ideal conditions for hoarfrost to form on snow are cold clear nights, with very light, cold air currents conveying humidity at the right rate for growth of frost crystals. Wind that is too strong or warm destroys the furry crystals, and thereby may permit a stronger bond between the old and new snow layers. However, if the winds are strong enough and cold enough to lay the crystals flat and dry, carpeting the snow with cold, loose crystals without removing or destroying them or letting them warm up and become sticky, then the frost interface between the snow layers may still present an avalanche danger, because the texture of the frost crystals differs from the snow texture and the dry crystals will not stick to fresh snow. Such conditions still prevent a strong bond between the snow layers.<ref name="McClungSchaerer2006">{{cite book|author1=David McClung|author2=Peter A. Schaerer|title=The Avalanche Handbook|url=https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72|year=2006|publisher=[[The Mountaineers Books]]|isbn=978-0-89886-809-8|pages=72–|url-status=live|archiveurl=https://web.archive.org/web/20160506012123/https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72|archivedate=2016-05-06}}</ref>
In very low temperatures where fluffy surface hoar crystals form without subsequently being covered with snow, strong winds may break them off, forming a dust of ice particles and blowing them over the surface. The ice dust then may form [[yukimarimo]], as has been observed in parts of Antarctica, in a process similar to the formation of [[dust bunny|dust bunnies]] and similar structures.
[[File:Frosted Flower.jpg|alt=A photo of a flower with advection frost on the tips of its petals.|thumb|A flower with advection frost on the edges of its petals]]
Hoar frost and [[#White frost|white frost]] also occurs in man-made environments such as in freezers or industrial [[refrigeration|cold storage]] facilities. If such cold spaces or the pipes serving them are not well insulated and are exposed to ambient [[humidity]], the moisture will freeze instantly depending on the [[freezer]] [[temperature]]. The frost may coat pipes thickly, partly insulating them, but such inefficient insulation still is a source of heat loss.
===Advection frost===
'''Advection frost''' (also called '''wind frost''') refers to tiny ice spikes that form when very cold [[wind]] is blowing over tree branches, poles, and other surfaces. It looks like rimming on the edges of flowers and leaves and usually forms against the [[windward and leeward|direction of the wind]]. It can occur at any hour, day or night.
===Window frost===
'''Window frost''' (also called '''fern frost''' or '''ice flowers''') forms when a glass pane is exposed to very cold air on the outside and warmer, moderately moist air on the inside. If the pane is not a good [[thermal insulation|insulator]] (for example, if it is a single pane window), water vapour condenses on the glass forming frost patterns. With very low temperatures outside, frost can appear on the bottom of the window even with double pane energy efficient windows because the air convection between two panes of glass ensures that the bottom part of the glazing unit is colder than the top part. On unheated motor vehicles the frost will usually form on the outside surface of the glass first. The glass surface influences the shape of crystals, so imperfections, scratches, or dust can modify the way ice [[nucleation|nucleates]]. The patterns in window frost form a [[fractal]] with a [[fractal dimension]] greater than one but less than two. This is a consequence of the nucleation process being constrained to unfold in two dimensions, unlike a snowflake which is shaped by a similar process but forms in three dimensions and has a fractal dimension greater than two.<ref>{{cite book|last=West|first=Bruce|author2=Mauro Bologna|others=Paolo Grigolini|title=Physics of Fractal Operators|publisher=Springer|date=2003|page=46|isbn=978-0-387-95554-4|url=https://books.google.com/books?id=EgyTpQZOga0C&pg=PA46}}</ref>
If the indoor air is very [[relative humidity|humid]], rather than moderately so, water will first [[condensation|condense]] in small droplets and then freeze into [[clear ice]].
Similar patterns of freezing may occur on other smooth vertical surfaces, but they seldom are as obvious or spectacular as on clear glass.
<gallery>
File:Frost patterns 1.jpg
File:Frost patterns 2.jpg
File:Frost patterns 3.jpg
File:Frost patterns 4.jpg
File:Frost patterns 5.jpg
File:Frost patterns 25.jpg
</gallery>
===White frost===
'''White frost''' is a solid [[deposition (phase transition)|deposition]] of ice that forms directly from [[water vapor|water vapour]] contained in [[air]].
White frost forms when there is a [[relative humidity]] above 90% and a temperature below −8 °C (18 °F) and it grows against the [[wind]] direction, since air arriving from [[windward and leeward|windward]] has a higher humidity than leeward air, but the wind must not be strong or it damages the delicate icy structures as they begin to form. White frost resembles a heavy coating of hoar frost with big, interlocking crystals, usually needle-shaped.
===Rime===
{{Main|Rime ice}}
'''Rime''' is a type of ice [[deposition (phase transition)|deposition]] that occurs quickly, often under heavily humid and windy conditions.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/rime|title=Rime – Definition of rime by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150501193835/http://www.merriam-webster.com/dictionary/rime|archivedate=2015-05-01}}</ref> Technically speaking, it is not a type of frost, since usually [[supercooling|supercooled]] water drops are involved, in contrast to the formation of hoar frost, in which water vapour desublimates slowly and directly. Ships travelling through Arctic seas may accumulate large quantities of rime on the rigging. Unlike hoar frost, which has a feathery appearance, rime generally has an icy, solid appearance.
===Black frost===
'''Black frost''' (or "killing frost") is not strictly speaking frost at all, because it is the condition seen in crops when the humidity is too low for frost to form, but the temperature falls so low that plant tissues freeze and die, becoming blackened, hence the term "black frost". Black frost often is called "killing frost" because white frost tends to be less cold, partly because the [[latent heat]] of freezing of the water reduces the temperature drop.
==Effect on plants==
===Damage===
[[File:Feuilles-avec-glace-leaves-with-ice-1.jpg|right|thumb|Frost on the grass of a public park in November.]]
Many plants can be damaged or killed by freezing temperatures or frost. This varies with the type of plant, the tissue exposed, and how low temperatures get: a "light frost" of {{convert|-2|to|0|C|F}} will damage fewer types of plants than a "hard frost" below {{convert|-2|C|F}}.<ref name="BI_Frost">{{cite web |url=http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables |title=Frost Tolerance of Vegetables |publisher=Botanical Interests |accessdate=Nov 12, 2013 |url-status=live |archiveurl=https://web.archive.org/web/20131113010216/http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables |archivedate=2013-11-13 }}</ref>
Plants likely to be damaged even by a light frost include vines—such as beans, grapes, squashes, melons—along with [[nightshade]]s such as tomatoes, eggplants and peppers. Plants that may tolerate (or even benefit) from frosts include:<ref>{{cite web |url=http://www.grow-it-organically.com/fall-vegetables.html |title=Fall vegetables vs. Summer vegetables |url-status=live |archiveurl=https://web.archive.org/web/20131113011159/http://www.grow-it-organically.com/fall-vegetables.html |archivedate=2013-11-13 }}</ref>
*root vegetables (e.g. beets, carrots, parsnips, onions)
*leafy greens (e.g. lettuces, spinach, chard, cucumber<ref name="JHR_2-2013">{{Citation|url=http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT|last=Klosinska|first=Urszula|date=27 February 2014|publisher=de Gruyter|accessdate=2014-02-28|title=Low temperature seed germination of cucumber: genetic basis of the tolerance trait|journal=Journal of Horticultural Research|volume=21|issue=2|pages=125–130|display-authors=etal|url-status=live|archiveurl=https://web.archive.org/web/20140611011158/http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT|archivedate=11 June 2014|doi=10.2478/johr-2013-0031}}</ref>)
*[[cruciferous vegetables]] (e.g. cabbages, cauliflower, bok choy, broccoli, Brussels sprouts, radishes, kale, collard, mustard, turnips, rutabagas)
Even those plants that tolerate frost may be damaged once temperatures drop even lower (below {{convert|-4|C|F|disp=or}}).<ref name="BI_Frost"/> Hardy perennials, such as ''[[Hosta]]'', become dormant after the first frosts and regrow when spring arrives. The entire visible plant may turn completely brown until the spring warmth, or may drop all of its leaves and flowers, leaving the stem and stalk only. Evergreen plants, such as pine trees, withstand frost although all or most growth stops. [[Frost crack]] is a bark defect caused by a combination of low temperatures and heat from the winter sun.
Vegetation is not necessarily damaged when leaf temperatures drop below the freezing point of their cell contents. In the absence of a site [[nucleation|nucleating]] the formation of ice crystals, the leaves remain in a [[supercooled]] liquid state, safely reaching temperatures of {{convert|-4|to|-12|C|F}}. However, once frost forms, the leaf [[cell (biology)|cells]] may be damaged by sharp ice crystals. [[Hardening (botany)|Hardening]] is the process by which a plant becomes tolerant to low temperatures. See also [[Cryobiology]].
Certain [[bacterium|bacteria]], notably ''[[Pseudomonas syringae]]'', are particularly effective at triggering frost formation, raising the nucleation temperature to about {{convert|-2|C|F}}.<ref>{{cite journal |vauthors=Maki LR, Galyan EL, Chang-Chien MM, Caldwell DR |title=Ice Nucleation Induced by Pseudomonas syringae |journal=Applied Microbiology |volume=28 |issue=3 |year=1974 |pages=456–459 |pmid=4371331 |pmc=186742}}</ref> Bacteria lacking ice [[nucleation]]-active proteins ([[ice-minus bacteria]]) result in greatly reduced frost damage.<ref>{{cite journal
|last= Lindow |first= Stephen E. |authorlink= Steven E. Lindow |author2=Deane C. Arny |author3=Christen D. Upper |title= Bacterial Ice Nucleation: A Factor in Frost Injury to Plants
|journal= Plant Physiology
|volume= 70
|issue= 4
|pages= 1084–1089
|date= October 1982
|pmid= 16662618
|doi= 10.1104/pp.70.4.1084
|pmc= 1065830}}</ref>
===Protection methods===
[[File:Winterschutz.jpg|thumb|right|250px|[[Roses]] with protection against frost - [[Volksgarten, Vienna]]]]
[[File:CuritibaFrostGeada.jpg|thumb|right|250px|[[Curitiba]] ([[Southern Brazil]]) is the coldest of [[Brazil]]'s [[state capital]]s; the [[greenhouse]] of the [[Botanical Garden of Curitiba]] protects sensitive plants.]]
Typical measures to prevent frost or reduce its severity include one or more of:
*deploying powerful blowers to simulate wind, thereby preventing the formation of accumulations of cold air. There are variations on this theme. One of them is the [[selective inverted sink]]<ref>[http://www.rolexawards.com/laureates/laureate-20-guarga.html Selective Inverted Sink] {{webarchive|url=https://web.archive.org/web/20060318212517/http://www.rolexawards.com/laureates/laureate-20-guarga.html |date=2006-03-18}} Rolex Awards site (won award in ''Technology and Innovation'' category) 1998.</ref>, a device which prevents frost by drawing cold air from the ground and blowing it up through a chimney. It was originally developed to prevent frost damage to [[citrus]] fruits in [[Uruguay]]. In New Zealand, [[helicopter]]s are used in similar fashion, especially in the [[vineyard]] regions like [[Marlborough Region|Marlborough]]. By dragging down warmer air from the [[Inversion (meteorology)|inversion layers]], and preventing the ponding of colder air on the ground, the low-flying helicopters prevent damage to the fruit buds. As the operations are conducted at night, and have in the past involved up to 130 aircraft per night in one region, safety rules are strict.<ref>''Helicopters Fight Frost'' – ''Vector'', [[Civil Aviation Authority of New Zealand]], September/ October 2008, Page 8-9</ref> Although not a dedicated method, [[wind turbine]]s have similar (small) effect of vertically mixing air layers of different temperature.<ref name="Nature-2010.12.23">[http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html Turbines and turbulence] {{webarchive|url=https://web.archive.org/web/20111201212633/http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html |date=2011-12-01}}, ''[[Nature (journal)]]'', 468, 1001, 23 December 2010, DOI:10.1038/4681001a, published online 22 December 2010.</ref><ref name="Roy+Traiteur">Somnath Baidya Roy and Justin J. Traiteur. [http://www.pnas.org/content/early/2010/10/12/1000493107.abstract Impacts of wind farms on surface air temperatures], Proceedings of the National Academy of Sciences, Vol. 107, No. 42, October 19, 2010, p. 17,899.</ref><ref name="ScienceDaily-2005">[https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm Wind farms impacting weather] {{webarchive|url=https://web.archive.org/web/20100906101845/https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm |date=2010-09-06}}, Science Daily.</ref>
*for high-value crops, farmers may wrap trees and cover crops.
*heating to slow the drop in temperature. This is not practical except for high value crops grown over small areas.
*production of smoke to reduce cooling by radiation
*spraying crops with a layer of water that releases latent heat, preventing harmful freezing of the tissues of the plants that it coats.
Such measures need to be applied with discretion, because they may do more harm than good; for example, spraying crops with water can cause damage if the plants become overburdened with ice. An effective '''low cost''' method for small crop farms and plant nurseries, exploits the [[enthalpy of fusion|latent heat of freezing]]. A pulsed irrigation timer<ref name=Nurseries/> delivers water through existing overhead sprinklers at a low volumes to combat frosts down to {{convert|-5|C|F}}.<ref name=Nurseries>{{cite web|title=A practical method of frost protection|url=http://plantsale.com.au/Articles/FrostProtection|accessdate=31 October 2011|url-status=live|archiveurl=https://web.archive.org/web/20120320075831/http://www.plantsale.com.au/Articles/FrostProtection/|archivedate=20 March 2012}}</ref><ref name=SmallCrops>{{cite web|last=Selders|first=Arthur W.|title=Frost protection with sprinkler irrigation|url=http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf|publisher=West Virginia university|accessdate=31 October 2011|url-status=dead|archiveurl=https://web.archive.org/web/20111114032130/http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf|archivedate=14 November 2011}}</ref> If the water freezes it giving off its latent heat, preventing the temperature of the foliage from falling much below zero.<ref name=SmallCrops/>
==Frost-free areas==
Frost-free areas are found mainly in the tropics, where they cover almost all land except at [[altitude]]s above about {{convert|3000|m|ft|-2|disp=or}} near the equator and around {{convert|2000|m|ft|-2|disp=or}} in the semi-arid middle tropics, but also in areas with [[subtropical climate]]s that have winters tempered by strong oceanic influences. The most poleward frost-free areas are the lower altitudes of the [[Azores]], [[Île Amsterdam]], [[Île Saint-Paul]], and [[Tristan da Cunha]].
The only reliably frost-free areas in the contiguous [[United States]] are the [[Florida Keys]] and the coastal areas of the [[Channel Islands (California)|Channel Islands of California]]. The [[hardiness zone]]s there are 11a and 11b.
==Personifications==
{{Further|Ded Moroz|Father Frost (fairy tale)}}
Frost is personified in Russian culture as [[Ded Moroz]]. [[Indigenous peoples of Russia]] such as the [[Mordvins]] have their own traditions of frost deities.
English folklore tradition holds that [[Jack Frost]], an elfish creature, is responsible for feathery patterns of frost found on windows on cold mornings.
==Gallery==
<gallery caption="Frost" widths="150px" heights="120px" perrow="5">
File:Frost on a nettle, Netherlands.jpg|Frost on a nettle
File:Saskatoon-Frost.jpg|Large feathery crystals
File:Fern Frost.JPG|Fern frost on a window
File:Window-Frost.jpg|Window frost
File:Frost on leaves.jpg|Frost on plant leaves in the [[Himalayas]]
File:Hoar Frost.JPG|Surface hoar in [[Alaska]]
File:Frost on Birch Tree in Stockholm 20180110.jpg|Frost on Birch Tree in [[Stockholm]]
File:Frost on birch tree.jpg|Frost on birch stem in [[Norway]]
File:Sydneyfrost.jpg|Frost on grass in [[Sydney]]
File:Leaf with frost.jpg|An oak leaf with frost in [[Sweden]]
</gallery>
==See also==
*[[Black ice]]
*[[Frost (temperature)]]
*[[Frost heaving]]
*[[Frost line]]
*[[Frostbite]]
*[[Ground frost]]
*[[Icing (nautical)]]
*[[Needle ice]]
==References==
{{Reflist|30em}}
==External links==
{{Commons category|Frost}}
{{Wiktionary}}
*[http://www.its.caltech.edu/~atomic/snowcrystals/frost/frost.htm Guide to Frost]
*[https://www.bbc.com/weather/features/41763562 How much do you know about frost?] – ''BBC''
*[http://glossary.ametsoc.org/wiki/Frost American Meteorological Society, ''Glossary of Meteorology'' – Hoarfrost]
*[http://www.islandnet.com/~see/weather/whys/frost.htm The Weather Doctor – Weather Whys – Frost]
*{{cite NIE|wstitle=Frost|short=x|year=1906}}
{{Ice}}
{{Authority control}}
[[Category:Precipitation]]
[[Category:Psychrometrics]]
[[Category:Water ice]]' |
New page wikitext, after the edit (new_wikitext) | '{{Other uses}}
[[File:Saint-Amant 16 FROG POOPche 2008.jpg|thumb|A patch of grass showing crystalline frost in the below-freezing shade (blue, lower right); frost in the warming but still below freezing strip most recently exposed to sunlight (white, center); and a frost-free region: here, the previous frost has melted from a more prolonged exposure to sunlight (green, upper left.)]]
'''Frost''' is a thin layer of [[ice]] on a [[solid]] surface, which forms from [[water vapor]] in an above [[freezing]] [[atmosphere]] coming in contact with a solid surface whose temperature is below freezing,<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/frost|title=Frost – Definition of frost by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150511025533/http://www.merriam-webster.com/dictionary/frost|archivedate=2015-05-11}}</ref><ref>{{cite web |url=http://www.weatherquestions.com/What_causes_frost.htm |title=What causes frost? |accessdate=2007-12-05 |url-status=live |archiveurl=https://web.archive.org/web/20071210230539/http://www.weatherquestions.com/What_causes_frost.htm |archivedate=2007-12-10 }}</ref> and resulting in a [[phase transition|phase change]] from water vapor (a [[gas]]) to [[ice]] (a solid) as the water vapor reaches the [[freezing point]]. In [[temperate climate]]s, it most commonly appears on surfaces near the ground as fragile white [[crystals]]; in cold climates, it occurs in a greater variety of forms.<ref name="Oliver2005">{{cite book|author=John E. Oliver|title=The Encyclopedia of World Climatology|url=https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|date=1 January 2005|publisher=[[Springer Science & Business Media]]|isbn=978-1-4020-3264-6|pages=382–|url-status=live|archiveurl=https://web.archive.org/web/20160508153444/https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|archivedate=8 May 2016}}</ref> The propagation of crystal formation occurs by the process of [[nucleation]].
The [[ice crystals]] of frost form as the result of [[fractal]] process development. The depth of frost crystals varies depending on the amount of time they have been accumulating, and the concentration of the water vapor ([[humidity]]). Frost crystals may be invisible (black), clear ([[translucent]]), or white; if a mass of frost crystals scatters light in all directions, the coating of frost appears white.
Types of frost include crystalline frost ([[#Hoar frost|hoar frost]] or radiation frost) from [[deposition (phase transition)|deposition]] of [[water vapor]] from air of low humidity, [[#White frost|white frost]] in humid conditions, [[#Window frost|window frost]] on glass surfaces, [[#Advection frost|advection frost]] from cold wind over cold surfaces, [[#Black frost|black frost]] without visible ice at low temperatures and very low humidity, and [[#Rime|rime]] under [[Supercooling|supercooled]] wet conditions.<ref name="Oliver2005"/>
Plants that have evolved in warmer climates suffer damage when the temperature falls low enough to freeze the water in the [[cell (biology)|cells]] that make up the plant [[tissue (biology)|tissue]]. The tissue damage resulting from this process is known as "frost damage". [[Farmer]]s in those regions where frost damage is known to affect their crops often invest in substantial means to protect their crops from such damage.
==Formation==
[[File:Nevada-Apartadero-Merida-Venezuela.jpg|thumb|Frost in the [[list of highest towns by country|highest town in Venezuela]], [[Apartaderos]]. Because of its location in an [[alpine tundra]] [[ecosystem]] called [[páramo]], there exists a daily freeze-and-thaw cycle, sometimes described as "summer every day and winter every night."]]
If a solid surface is chilled below the [[dew point]] of the surrounding humid air and the surface itself is colder than freezing, ice will form on it. If the water deposits as a liquid that then freezes, it forms a coating that may look glassy, opaque, or crystalline, depending on its [[#Types|type]]. Depending on context, that process also may be called [[atmospheric icing]]. The ice it produces differs in some ways from crystalline frost, which consists of spicules of [[ice]] that typically project from the solid surface on which they grow.
The main difference between the ice coatings and frost spicules arises from the fact that the crystalline spicules grow directly from [[deposition (phase transition)|desublimation]] of water vapour from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed the surface must be below the [[dew point#Frost point|frost point]] of the air, meaning that it is sufficiently cold for ice to form without passing through the [[liquid|liquid phase]]. The air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the [[crystal]]s depends largely on the temperature, the amount of [[water vapor]] available, and how long they have been growing undisturbed.
As a rule, except in conditions where supercooled droplets are present in the air, frost will form only if the deposition surface is colder than the surrounding air. For instance frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the warmer ground beneath. Other objects on which frost commonly forms are those with low [[specific heat]] or high [[thermal emissivity]], such as blackened metals; hence the accumulation of frost on the heads of rusty nails.
The apparently erratic occurrence of frost in adjacent localities is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, the [[molar absorptivity|absorptivity]] and specific heat of the ground strongly influence the temperature that the trapped air attains.
==Types==
===Hoar frost===
[[File:Frostweb.jpg|thumb|upright|A [[spider web]] covered in air hoar frost]]
[[File:HoarFrost.jpg|thumb|Hoar frost on the snow]]
[[File:LightLTSEM.jpg|thumb|Depth hoar, [[micrograph|imaged]] with [[optical microscope|optical]] (left) and [[scanning electron microscope|scanning electron]] (right) [[microscopy]]]]
'''Hoar frost''', also '''hoarfrost''', '''radiation frost''', or '''pruina''', refers to white [[ice crystals]] deposited on the ground or loosely attached to exposed objects, such as wires or leaves.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/hoar%20frost|title=Hoarfrost – Definition of hoarfrost by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150219065328/http://www.merriam-webster.com/dictionary/hoar%20frost|archivedate=2015-02-19}}</ref> They form on cold, clear nights when conditions are such that [[radiative cooling#Nocturnal surface cooling|heat radiates]] out to the open air faster than it can be replaced from nearby sources, such as wind or warm objects. Under suitable circumstances, objects cool to below the [[dew point#Frost point|frost point]]<ref name="RohliRohli2013">{{cite book|author1=Louisiana State University Baton Rouge Robert V Rohli|author2=Robert V. Rohli|author3=Anthony J. Vega|title=Climatology|url=https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381|date=13 December 2013|publisher=[[Jones & Bartlett Publishers]]|isbn=978-1-284-05427-9|pages=381–|url-status=live|archiveurl=https://web.archive.org/web/20160519122238/https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381|archivedate=19 May 2016}}</ref> of the surrounding air, well below the freezing point of water. Such freezing may be promoted by effects such as '''flood frost''' or '''frost pocket'''.<ref>{{cite web|url=http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm|title=Weather Facts: Frost hollow – Weather UK – weatheronline.co.uk|work=weatheronline.co.uk|url-status=live|archiveurl=https://web.archive.org/web/20130212022607/http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm|archivedate=2013-02-12}}</ref> These occur when ground-level radiation losses{{huh|date=September 2019}} cool air until it flows downhill and accumulates in pockets of very cold air in valleys and hollows. Hoar frost may freeze in such low-lying cold air even when the air temperature a few feet above ground is well above freezing.
The word ''hoar'' comes from an [[Old English]] adjective that means "showing signs of old age". In this context, it refers to the frost that makes trees and bushes look like white hair. <!-- Please leave out the following bit of folk etymology: "may also have association with hawthorn when covered in ... white spring blossom". The speculation is wrong. See OED! -->
Hoar frost may have different names depending on where it forms:
*'''Air hoar''' is a deposit of hoar frost on objects above the surface, such as tree branches, plant stems, and wires.
*'''Surface hoar''' refers to fern-like ice crystals directly deposited on snow, ice or already frozen surfaces.
*'''Crevasse hoar''' consists of crystals that form in glacial crevasses where water vapour can accumulate under calm weather conditions.
*'''[[Depth hoar]]''' refers to faceted crystals that have slowly grown large within cavities beneath the surface of banks of dry snow. Depth hoar crystals grow continuously at the expense of neighbouring smaller crystals, so typically are visibly stepped and have faceted hollows.
When surface hoar covers sloping snowbanks, the layer of frost crystals may create an [[avalanche]] risk; when heavy layers of new snow cover the frosty surface, furry crystals standing out from the old snow hold off the falling flakes, forming a layer of voids that prevent the new snow layers from bonding strongly to the old snow beneath. Ideal conditions for hoarfrost to form on snow are cold clear nights, with very light, cold air currents conveying humidity at the right rate for growth of frost crystals. Wind that is too strong or warm destroys the furry crystals, and thereby may permit a stronger bond between the old and new snow layers. However, if the winds are strong enough and cold enough to lay the crystals flat and dry, carpeting the snow with cold, loose crystals without removing or destroying them or letting them warm up and become sticky, then the frost interface between the snow layers may still present an avalanche danger, because the texture of the frost crystals differs from the snow texture and the dry crystals will not stick to fresh snow. Such conditions still prevent a strong bond between the snow layers.<ref name="McClungSchaerer2006">{{cite book|author1=David McClung|author2=Peter A. Schaerer|title=The Avalanche Handbook|url=https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72|year=2006|publisher=[[The Mountaineers Books]]|isbn=978-0-89886-809-8|pages=72–|url-status=live|archiveurl=https://web.archive.org/web/20160506012123/https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72|archivedate=2016-05-06}}</ref>
In very low temperatures where fluffy surface hoar crystals form without subsequently being covered with snow, strong winds may break them off, forming a dust of ice particles and blowing them over the surface. The ice dust then may form [[yukimarimo]], as has been observed in parts of Antarctica, in a process similar to the formation of [[dust bunny|dust bunnies]] and similar structures.
[[File:Frosted Flower.jpg|alt=A photo of a flower with advection frost on the tips of its petals.|thumb|A flower with advection frost on the edges of its petals]]
Hoar frost and [[#White frost|white frost]] also occurs in man-made environments such as in freezers or industrial [[refrigeration|cold storage]] facilities. If such cold spaces or the pipes serving them are not well insulated and are exposed to ambient [[humidity]], the moisture will freeze instantly depending on the [[freezer]] [[temperature]]. The frost may coat pipes thickly, partly insulating them, but such inefficient insulation still is a source of heat loss.
===Advection frost===
'''Advection frost''' (also called '''wind frost''') refers to tiny ice spikes that form when very cold [[wind]] is blowing over tree branches, poles, and other surfaces. It looks like rimming on the edges of flowers and leaves and usually forms against the [[windward and leeward|direction of the wind]]. It can occur at any hour, day or night.
===Window frost===
'''Window frost''' (also called '''fern frost''' or '''ice flowers''') forms when a glass pane is exposed to very cold air on the outside and warmer, moderately moist air on the inside. If the pane is not a good [[thermal insulation|insulator]] (for example, if it is a single pane window), water vapour condenses on the glass forming frost patterns. With very low temperatures outside, frost can appear on the bottom of the window even with double pane energy efficient windows because the air convection between two panes of glass ensures that the bottom part of the glazing unit is colder than the top part. On unheated motor vehicles the frost will usually form on the outside surface of the glass first. The glass surface influences the shape of crystals, so imperfections, scratches, or dust can modify the way ice [[nucleation|nucleates]]. The patterns in window frost form a [[fractal]] with a [[fractal dimension]] greater than one but less than two. This is a consequence of the nucleation process being constrained to unfold in two dimensions, unlike a snowflake which is shaped by a similar process but forms in three dimensions and has a fractal dimension greater than two.<ref>{{cite book|last=West|first=Bruce|author2=Mauro Bologna|others=Paolo Grigolini|title=Physics of Fractal Operators|publisher=Springer|date=2003|page=46|isbn=978-0-387-95554-4|url=https://books.google.com/books?id=EgyTpQZOga0C&pg=PA46}}</ref>
If the indoor air is very [[relative humidity|humid]], rather than moderately so, water will first [[condensation|condense]] in small droplets and then freeze into [[clear ice]].
Similar patterns of freezing may occur on other smooth vertical surfaces, but they seldom are as obvious or spectacular as on clear glass.
<gallery>
File:Frost patterns 1.jpg
File:Frost patterns 2.jpg
File:Frost patterns 3.jpg
File:Frost patterns 4.jpg
File:Frost patterns 5.jpg
File:Frost patterns 25.jpg
</gallery>
===White frost===
'''White frost''' is a solid [[deposition (phase transition)|deposition]] of ice that forms directly from [[water vapor|water vapour]] contained in [[air]].
White frost forms when there is a [[relative humidity]] above 90% and a temperature below −8 °C (18 °F) and it grows against the [[wind]] direction, since air arriving from [[windward and leeward|windward]] has a higher humidity than leeward air, but the wind must not be strong or it damages the delicate icy structures as they begin to form. White frost resembles a heavy coating of hoar frost with big, interlocking crystals, usually needle-shaped.
===Rime===
{{Main|Rime ice}}
'''Rime''' is a type of ice [[deposition (phase transition)|deposition]] that occurs quickly, often under heavily humid and windy conditions.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/rime|title=Rime – Definition of rime by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150501193835/http://www.merriam-webster.com/dictionary/rime|archivedate=2015-05-01}}</ref> Technically speaking, it is not a type of frost, since usually [[supercooling|supercooled]] water drops are involved, in contrast to the formation of hoar frost, in which water vapour desublimates slowly and directly. Ships travelling through Arctic seas may accumulate large quantities of rime on the rigging. Unlike hoar frost, which has a feathery appearance, rime generally has an icy, solid appearance.
===Black frost===
'''Black frost''' (or "killing frost") is not strictly speaking frost at all, because it is the condition seen in crops when the humidity is too low for frost to form, but the temperature falls so low that plant tissues freeze and die, becoming blackened, hence the term "black frost". Black frost often is called "killing frost" because white frost tends to be less cold, partly because the [[latent heat]] of freezing of the water reduces the temperature drop.
==Effect on plants==
===Damage===
[[File:Feuilles-avec-glace-leaves-with-ice-1.jpg|right|thumb|Frost on the grass of a public park in November.]]
Many plants can be damaged or killed by freezing temperatures or frost. This varies with the type of plant, the tissue exposed, and how low temperatures get: a "light frost" of {{convert|-2|to|0|C|F}} will damage fewer types of plants than a "hard frost" below {{convert|-2|C|F}}.<ref name="BI_Frost">{{cite web |url=http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables |title=Frost Tolerance of Vegetables |publisher=Botanical Interests |accessdate=Nov 12, 2013 |url-status=live |archiveurl=https://web.archive.org/web/20131113010216/http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables |archivedate=2013-11-13 }}</ref>
Plants likely to be damaged even by a light frost include vines—such as beans, grapes, squashes, melons—along with [[nightshade]]s such as tomatoes, eggplants and peppers. Plants that may tolerate (or even benefit) from frosts include:<ref>{{cite web |url=http://www.grow-it-organically.com/fall-vegetables.html |title=Fall vegetables vs. Summer vegetables |url-status=live |archiveurl=https://web.archive.org/web/20131113011159/http://www.grow-it-organically.com/fall-vegetables.html |archivedate=2013-11-13 }}</ref>
*root vegetables (e.g. beets, carrots, parsnips, onions)
*leafy greens (e.g. lettuces, spinach, chard, cucumber<ref name="JHR_2-2013">{{Citation|url=http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT|last=Klosinska|first=Urszula|date=27 February 2014|publisher=de Gruyter|accessdate=2014-02-28|title=Low temperature seed germination of cucumber: genetic basis of the tolerance trait|journal=Journal of Horticultural Research|volume=21|issue=2|pages=125–130|display-authors=etal|url-status=live|archiveurl=https://web.archive.org/web/20140611011158/http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT|archivedate=11 June 2014|doi=10.2478/johr-2013-0031}}</ref>)
*[[cruciferous vegetables]] (e.g. cabbages, cauliflower, bok choy, broccoli, Brussels sprouts, radishes, kale, collard, mustard, turnips, rutabagas)
Even those plants that tolerate frost may be damaged once temperatures drop even lower (below {{convert|-4|C|F|disp=or}}).<ref name="BI_Frost"/> Hardy perennials, such as ''[[Hosta]]'', become dormant after the first frosts and regrow when spring arrives. The entire visible plant may turn completely brown until the spring warmth, or may drop all of its leaves and flowers, leaving the stem and stalk only. Evergreen plants, such as pine trees, withstand frost although all or most growth stops. [[Frost crack]] is a bark defect caused by a combination of low temperatures and heat from the winter sun.
Vegetation is not necessarily damaged when leaf temperatures drop below the freezing point of their cell contents. In the absence of a site [[nucleation|nucleating]] the formation of ice crystals, the leaves remain in a [[supercooled]] liquid state, safely reaching temperatures of {{convert|-4|to|-12|C|F}}. However, once frost forms, the leaf [[cell (biology)|cells]] may be damaged by sharp ice crystals. [[Hardening (botany)|Hardening]] is the process by which a plant becomes tolerant to low temperatures. See also [[Cryobiology]].
Certain [[bacterium|bacteria]], notably ''[[Pseudomonas syringae]]'', are particularly effective at triggering frost formation, raising the nucleation temperature to about {{convert|-2|C|F}}.<ref>{{cite journal |vauthors=Maki LR, Galyan EL, Chang-Chien MM, Caldwell DR |title=Ice Nucleation Induced by Pseudomonas syringae |journal=Applied Microbiology |volume=28 |issue=3 |year=1974 |pages=456–459 |pmid=4371331 |pmc=186742}}</ref> Bacteria lacking ice [[nucleation]]-active proteins ([[ice-minus bacteria]]) result in greatly reduced frost damage.<ref>{{cite journal
|last= Lindow |first= Stephen E. |authorlink= Steven E. Lindow |author2=Deane C. Arny |author3=Christen D. Upper |title= Bacterial Ice Nucleation: A Factor in Frost Injury to Plants
|journal= Plant Physiology
|volume= 70
|issue= 4
|pages= 1084–1089
|date= October 1982
|pmid= 16662618
|doi= 10.1104/pp.70.4.1084
|pmc= 1065830}}</ref>
===Protection methods===
[[File:Winterschutz.jpg|thumb|right|250px|[[Roses]] with protection against frost - [[Volksgarten, Vienna]]]]
[[File:CuritibaFrostGeada.jpg|thumb|right|250px|[[Curitiba]] ([[Southern Brazil]]) is the coldest of [[Brazil]]'s [[state capital]]s; the [[greenhouse]] of the [[Botanical Garden of Curitiba]] protects sensitive plants.]]
Typical measures to prevent frost or reduce its severity include one or more of:
*deploying powerful blowers to simulate wind, thereby preventing the formation of accumulations of cold air. There are variations on this theme. One of them is the [[selective inverted sink]]<ref>[http://www.rolexawards.com/laureates/laureate-20-guarga.html Selective Inverted Sink] {{webarchive|url=https://web.archive.org/web/20060318212517/http://www.rolexawards.com/laureates/laureate-20-guarga.html |date=2006-03-18}} Rolex Awards site (won award in ''Technology and Innovation'' category) 1998.</ref>, a device which prevents frost by drawing cold air from the ground and blowing it up through a chimney. It was originally developed to prevent frost damage to [[citrus]] fruits in [[Uruguay]]. In New Zealand, [[helicopter]]s are used in similar fashion, especially in the [[vineyard]] regions like [[Marlborough Region|Marlborough]]. By dragging down warmer air from the [[Inversion (meteorology)|inversion layers]], and preventing the ponding of colder air on the ground, the low-flying helicopters prevent damage to the fruit buds. As the operations are conducted at night, and have in the past involved up to 130 aircraft per night in one region, safety rules are strict.<ref>''Helicopters Fight Frost'' – ''Vector'', [[Civil Aviation Authority of New Zealand]], September/ October 2008, Page 8-9</ref> Although not a dedicated method, [[wind turbine]]s have similar (small) effect of vertically mixing air layers of different temperature.<ref name="Nature-2010.12.23">[http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html Turbines and turbulence] {{webarchive|url=https://web.archive.org/web/20111201212633/http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html |date=2011-12-01}}, ''[[Nature (journal)]]'', 468, 1001, 23 December 2010, DOI:10.1038/4681001a, published online 22 December 2010.</ref><ref name="Roy+Traiteur">Somnath Baidya Roy and Justin J. Traiteur. [http://www.pnas.org/content/early/2010/10/12/1000493107.abstract Impacts of wind farms on surface air temperatures], Proceedings of the National Academy of Sciences, Vol. 107, No. 42, October 19, 2010, p. 17,899.</ref><ref name="ScienceDaily-2005">[https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm Wind farms impacting weather] {{webarchive|url=https://web.archive.org/web/20100906101845/https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm |date=2010-09-06}}, Science Daily.</ref>
*for high-value crops, farmers may wrap trees and cover crops.
*heating to slow the drop in temperature. This is not practical except for high value crops grown over small areas.
*production of smoke to reduce cooling by radiation
*spraying crops with a layer of water that releases latent heat, preventing harmful freezing of the tissues of the plants that it coats.
Such measures need to be applied with discretion, because they may do more harm than good; for example, spraying crops with water can cause damage if the plants become overburdened with ice. An effective '''low cost''' method for small crop farms and plant nurseries, exploits the [[enthalpy of fusion|latent heat of freezing]]. A pulsed irrigation timer<ref name=Nurseries/> delivers water through existing overhead sprinklers at a low volumes to combat frosts down to {{convert|-5|C|F}}.<ref name=Nurseries>{{cite web|title=A practical method of frost protection|url=http://plantsale.com.au/Articles/FrostProtection|accessdate=31 October 2011|url-status=live|archiveurl=https://web.archive.org/web/20120320075831/http://www.plantsale.com.au/Articles/FrostProtection/|archivedate=20 March 2012}}</ref><ref name=SmallCrops>{{cite web|last=Selders|first=Arthur W.|title=Frost protection with sprinkler irrigation|url=http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf|publisher=West Virginia university|accessdate=31 October 2011|url-status=dead|archiveurl=https://web.archive.org/web/20111114032130/http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf|archivedate=14 November 2011}}</ref> If the water freezes it giving off its latent heat, preventing the temperature of the foliage from falling much below zero.<ref name=SmallCrops/>
==Frost-free areas==
Frost-free areas are found mainly in the tropics, where they cover almost all land except at [[altitude]]s above about {{convert|3000|m|ft|-2|disp=or}} near the equator and around {{convert|2000|m|ft|-2|disp=or}} in the semi-arid middle tropics, but also in areas with [[subtropical climate]]s that have winters tempered by strong oceanic influences. The most poleward frost-free areas are the lower altitudes of the [[Azores]], [[Île Amsterdam]], [[Île Saint-Paul]], and [[Tristan da Cunha]].
The only reliably frost-free areas in the contiguous [[United States]] are the [[Florida Keys]] and the coastal areas of the [[Channel Islands (California)|Channel Islands of California]]. The [[hardiness zone]]s there are 11a and 11b.
==Personifications==
{{Further|Ded Moroz|Father Frost (fairy tale)}}
Frost is personified in Russian culture as [[Ded Moroz]]. [[Indigenous peoples of Russia]] such as the [[Mordvins]] have their own traditions of frost deities.
English folklore tradition holds that [[Jack Frost]], an elfish creature, is responsible for feathery patterns of frost found on windows on cold mornings.
==Gallery==
<gallery caption="Frost" widths="150px" heights="120px" perrow="5">
File:Frost on a nettle, Netherlands.jpg|Frost on a nettle
File:Saskatoon-Frost.jpg|Large feathery crystals
File:Fern Frost.JPG|Fern frost on a window
File:Window-Frost.jpg|Window frost
File:Frost on leaves.jpg|Frost on plant leaves in the [[Himalayas]]
File:Hoar Frost.JPG|Surface hoar in [[Alaska]]
File:Frost on Birch Tree in Stockholm 20180110.jpg|Frost on Birch Tree in [[Stockholm]]
File:Frost on birch tree.jpg|Frost on birch stem in [[Norway]]
File:Sydneyfrost.jpg|Frost on grass in [[Sydney]]
File:Leaf with frost.jpg|An oak leaf with frost in [[Sweden]]
</gallery>
==See also==
*[[Black ice]]
*[[Frost (temperature)]]
*[[Frost heaving]]
*[[Frost line]]
*[[Frostbite]]
*[[Ground frost]]
*[[Icing (nautical)]]
*[[Needle ice]]
==References==
{{Reflist|30em}}
==External links==
{{Commons category|Frost}}
{{Wiktionary}}
*[http://www.its.caltech.edu/~atomic/snowcrystals/frost/frost.htm Guide to Frost]
*[https://www.bbc.com/weather/features/41763562 How much do you know about frost?] – ''BBC''
*[http://glossary.ametsoc.org/wiki/Frost American Meteorological Society, ''Glossary of Meteorology'' – Hoarfrost]
*[http://www.islandnet.com/~see/weather/whys/frost.htm The Weather Doctor – Weather Whys – Frost]
*{{cite NIE|wstitle=Frost|short=x|year=1906}}
{{Ice}}
{{Authority control}}
[[Category:Precipitation]]
[[Category:Psychrometrics]]
[[Category:Water ice]]' |
Unified diff of changes made by edit (edit_diff) | '@@ -1,4 +1,4 @@
{{Other uses}}
-[[File:Saint-Amant 16 Gelée blanche 2008.jpg|thumb|A patch of grass showing crystalline frost in the below-freezing shade (blue, lower right); frost in the warming but still below freezing strip most recently exposed to sunlight (white, center); and a frost-free region: here, the previous frost has melted from a more prolonged exposure to sunlight (green, upper left.)]]
+[[File:Saint-Amant 16 FROG POOPche 2008.jpg|thumb|A patch of grass showing crystalline frost in the below-freezing shade (blue, lower right); frost in the warming but still below freezing strip most recently exposed to sunlight (white, center); and a frost-free region: here, the previous frost has melted from a more prolonged exposure to sunlight (green, upper left.)]]
'''Frost''' is a thin layer of [[ice]] on a [[solid]] surface, which forms from [[water vapor]] in an above [[freezing]] [[atmosphere]] coming in contact with a solid surface whose temperature is below freezing,<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/frost|title=Frost – Definition of frost by Merriam-Webster|work=merriam-webster.com|url-status=live|archiveurl=https://web.archive.org/web/20150511025533/http://www.merriam-webster.com/dictionary/frost|archivedate=2015-05-11}}</ref><ref>{{cite web |url=http://www.weatherquestions.com/What_causes_frost.htm |title=What causes frost? |accessdate=2007-12-05 |url-status=live |archiveurl=https://web.archive.org/web/20071210230539/http://www.weatherquestions.com/What_causes_frost.htm |archivedate=2007-12-10 }}</ref> and resulting in a [[phase transition|phase change]] from water vapor (a [[gas]]) to [[ice]] (a solid) as the water vapor reaches the [[freezing point]]. In [[temperate climate]]s, it most commonly appears on surfaces near the ground as fragile white [[crystals]]; in cold climates, it occurs in a greater variety of forms.<ref name="Oliver2005">{{cite book|author=John E. Oliver|title=The Encyclopedia of World Climatology|url=https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|date=1 January 2005|publisher=[[Springer Science & Business Media]]|isbn=978-1-4020-3264-6|pages=382–|url-status=live|archiveurl=https://web.archive.org/web/20160508153444/https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382|archivedate=8 May 2016}}</ref> The propagation of crystal formation occurs by the process of [[nucleation]].
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Parsed HTML source of the new revision (new_html) | '<div class="mw-parser-output"><div role="note" class="hatnote navigation-not-searchable">For other uses, see <a href="/enwiki/wiki/Frost_(disambiguation)" class="mw-disambig" title="Frost (disambiguation)">Frost (disambiguation)</a>.</div>
<div class="thumb tright"><div class="thumbinner" style="width:182px;"><a href="/enwiki//en.wikipedia.org/wiki/Special:Upload?wpDestFile=Saint-Amant_16_FROG_POOPche_2008.jpg" class="new" title="File:Saint-Amant 16 FROG POOPche 2008.jpg">File:Saint-Amant 16 FROG POOPche 2008.jpg</a> <div class="thumbcaption">A patch of grass showing crystalline frost in the below-freezing shade (blue, lower right); frost in the warming but still below freezing strip most recently exposed to sunlight (white, center); and a frost-free region: here, the previous frost has melted from a more prolonged exposure to sunlight (green, upper left.)</div></div></div>
<p><b>Frost</b> is a thin layer of <a href="/enwiki/wiki/Ice" title="Ice">ice</a> on a <a href="/enwiki/wiki/Solid" title="Solid">solid</a> surface, which forms from <a href="/enwiki/wiki/Water_vapor" title="Water vapor">water vapor</a> in an above <a href="/enwiki/wiki/Freezing" title="Freezing">freezing</a> <a href="/enwiki/wiki/Atmosphere" title="Atmosphere">atmosphere</a> coming in contact with a solid surface whose temperature is below freezing,<sup id="cite_ref-1" class="reference"><a href="#cite_note-1">[1]</a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2">[2]</a></sup> and resulting in a <a href="/enwiki/wiki/Phase_transition" title="Phase transition">phase change</a> from water vapor (a <a href="/enwiki/wiki/Gas" title="Gas">gas</a>) to <a href="/enwiki/wiki/Ice" title="Ice">ice</a> (a solid) as the water vapor reaches the <a href="/enwiki/wiki/Freezing_point" class="mw-redirect" title="Freezing point">freezing point</a>. In <a href="/enwiki/wiki/Temperate_climate" title="Temperate climate">temperate climates</a>, it most commonly appears on surfaces near the ground as fragile white <a href="/enwiki/wiki/Crystals" class="mw-redirect" title="Crystals">crystals</a>; in cold climates, it occurs in a greater variety of forms.<sup id="cite_ref-Oliver2005_3-0" class="reference"><a href="#cite_note-Oliver2005-3">[3]</a></sup> The propagation of crystal formation occurs by the process of <a href="/enwiki/wiki/Nucleation" title="Nucleation">nucleation</a>.
</p><p>The <a href="/enwiki/wiki/Ice_crystals" title="Ice crystals">ice crystals</a> of frost form as the result of <a href="/enwiki/wiki/Fractal" title="Fractal">fractal</a> process development. The depth of frost crystals varies depending on the amount of time they have been accumulating, and the concentration of the water vapor (<a href="/enwiki/wiki/Humidity" title="Humidity">humidity</a>). Frost crystals may be invisible (black), clear (<a href="/enwiki/wiki/Translucent" class="mw-redirect" title="Translucent">translucent</a>), or white; if a mass of frost crystals scatters light in all directions, the coating of frost appears white.
</p><p>Types of frost include crystalline frost (<a href="#Hoar_frost">hoar frost</a> or radiation frost) from <a href="/enwiki/wiki/Deposition_(phase_transition)" title="Deposition (phase transition)">deposition</a> of <a href="/enwiki/wiki/Water_vapor" title="Water vapor">water vapor</a> from air of low humidity, <a href="#White_frost">white frost</a> in humid conditions, <a href="#Window_frost">window frost</a> on glass surfaces, <a href="#Advection_frost">advection frost</a> from cold wind over cold surfaces, <a href="#Black_frost">black frost</a> without visible ice at low temperatures and very low humidity, and <a href="#Rime">rime</a> under <a href="/enwiki/wiki/Supercooling" title="Supercooling">supercooled</a> wet conditions.<sup id="cite_ref-Oliver2005_3-1" class="reference"><a href="#cite_note-Oliver2005-3">[3]</a></sup>
</p><p>Plants that have evolved in warmer climates suffer damage when the temperature falls low enough to freeze the water in the <a href="/enwiki/wiki/Cell_(biology)" title="Cell (biology)">cells</a> that make up the plant <a href="/enwiki/wiki/Tissue_(biology)" title="Tissue (biology)">tissue</a>. The tissue damage resulting from this process is known as "frost damage". <a href="/enwiki/wiki/Farmer" title="Farmer">Farmers</a> in those regions where frost damage is known to affect their crops often invest in substantial means to protect their crops from such damage.
</p>
<div id="toc" class="toc"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none" /><div class="toctitle" lang="en" dir="ltr"><h2>Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"></label></span></div>
<ul>
<li class="toclevel-1 tocsection-1"><a href="#Formation"><span class="tocnumber">1</span> <span class="toctext">Formation</span></a></li>
<li class="toclevel-1 tocsection-2"><a href="#Types"><span class="tocnumber">2</span> <span class="toctext">Types</span></a>
<ul>
<li class="toclevel-2 tocsection-3"><a href="#Hoar_frost"><span class="tocnumber">2.1</span> <span class="toctext">Hoar frost</span></a></li>
<li class="toclevel-2 tocsection-4"><a href="#Advection_frost"><span class="tocnumber">2.2</span> <span class="toctext">Advection frost</span></a></li>
<li class="toclevel-2 tocsection-5"><a href="#Window_frost"><span class="tocnumber">2.3</span> <span class="toctext">Window frost</span></a></li>
<li class="toclevel-2 tocsection-6"><a href="#White_frost"><span class="tocnumber">2.4</span> <span class="toctext">White frost</span></a></li>
<li class="toclevel-2 tocsection-7"><a href="#Rime"><span class="tocnumber">2.5</span> <span class="toctext">Rime</span></a></li>
<li class="toclevel-2 tocsection-8"><a href="#Black_frost"><span class="tocnumber">2.6</span> <span class="toctext">Black frost</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-9"><a href="#Effect_on_plants"><span class="tocnumber">3</span> <span class="toctext">Effect on plants</span></a>
<ul>
<li class="toclevel-2 tocsection-10"><a href="#Damage"><span class="tocnumber">3.1</span> <span class="toctext">Damage</span></a></li>
<li class="toclevel-2 tocsection-11"><a href="#Protection_methods"><span class="tocnumber">3.2</span> <span class="toctext">Protection methods</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-12"><a href="#Frost-free_areas"><span class="tocnumber">4</span> <span class="toctext">Frost-free areas</span></a></li>
<li class="toclevel-1 tocsection-13"><a href="#Personifications"><span class="tocnumber">5</span> <span class="toctext">Personifications</span></a></li>
<li class="toclevel-1 tocsection-14"><a href="#Gallery"><span class="tocnumber">6</span> <span class="toctext">Gallery</span></a></li>
<li class="toclevel-1 tocsection-15"><a href="#See_also"><span class="tocnumber">7</span> <span class="toctext">See also</span></a></li>
<li class="toclevel-1 tocsection-16"><a href="#References"><span class="tocnumber">8</span> <span class="toctext">References</span></a></li>
<li class="toclevel-1 tocsection-17"><a href="#External_links"><span class="tocnumber">9</span> <span class="toctext">External links</span></a></li>
</ul>
</div>
<h2><span class="mw-headline" id="Formation">Formation</span></h2>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/enwiki/wiki/File:Nevada-Apartadero-Merida-Venezuela.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/e/ea/Nevada-Apartadero-Merida-Venezuela.jpg/220px-Nevada-Apartadero-Merida-Venezuela.jpg" decoding="async" width="220" height="165" class="thumbimage" data-file-width="2560" data-file-height="1920" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:Nevada-Apartadero-Merida-Venezuela.jpg" class="internal" title="Enlarge"></a></div>Frost in the <a href="/enwiki/wiki/List_of_highest_towns_by_country" title="List of highest towns by country">highest town in Venezuela</a>, <a href="/enwiki/wiki/Apartaderos" title="Apartaderos">Apartaderos</a>. Because of its location in an <a href="/enwiki/wiki/Alpine_tundra" title="Alpine tundra">alpine tundra</a> <a href="/enwiki/wiki/Ecosystem" title="Ecosystem">ecosystem</a> called <a href="/enwiki/wiki/P%C3%A1ramo" title="Páramo">páramo</a>, there exists a daily freeze-and-thaw cycle, sometimes described as "summer every day and winter every night."</div></div></div>
<p>If a solid surface is chilled below the <a href="/enwiki/wiki/Dew_point" title="Dew point">dew point</a> of the surrounding humid air and the surface itself is colder than freezing, ice will form on it. If the water deposits as a liquid that then freezes, it forms a coating that may look glassy, opaque, or crystalline, depending on its <a href="#Types">type</a>. Depending on context, that process also may be called <a href="/enwiki/wiki/Atmospheric_icing" title="Atmospheric icing">atmospheric icing</a>. The ice it produces differs in some ways from crystalline frost, which consists of spicules of <a href="/enwiki/wiki/Ice" title="Ice">ice</a> that typically project from the solid surface on which they grow.
</p><p>The main difference between the ice coatings and frost spicules arises from the fact that the crystalline spicules grow directly from <a href="/enwiki/wiki/Deposition_(phase_transition)" title="Deposition (phase transition)">desublimation</a> of water vapour from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed the surface must be below the <a href="/enwiki/wiki/Dew_point#Frost_point" title="Dew point">frost point</a> of the air, meaning that it is sufficiently cold for ice to form without passing through the <a href="/enwiki/wiki/Liquid" title="Liquid">liquid phase</a>. The air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the <a href="/enwiki/wiki/Crystal" title="Crystal">crystals</a> depends largely on the temperature, the amount of <a href="/enwiki/wiki/Water_vapor" title="Water vapor">water vapor</a> available, and how long they have been growing undisturbed.
</p><p>As a rule, except in conditions where supercooled droplets are present in the air, frost will form only if the deposition surface is colder than the surrounding air. For instance frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the warmer ground beneath. Other objects on which frost commonly forms are those with low <a href="/enwiki/wiki/Specific_heat" class="mw-redirect" title="Specific heat">specific heat</a> or high <a href="/enwiki/wiki/Thermal_emissivity" class="mw-redirect" title="Thermal emissivity">thermal emissivity</a>, such as blackened metals; hence the accumulation of frost on the heads of rusty nails.
</p><p>The apparently erratic occurrence of frost in adjacent localities is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, the <a href="/enwiki/wiki/Molar_absorptivity" class="mw-redirect" title="Molar absorptivity">absorptivity</a> and specific heat of the ground strongly influence the temperature that the trapped air attains.
</p>
<h2><span class="mw-headline" id="Types">Types</span></h2>
<h3><span class="mw-headline" id="Hoar_frost">Hoar frost</span></h3>
<div class="thumb tright"><div class="thumbinner" style="width:172px;"><a href="/enwiki/wiki/File:Frostweb.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/5/5f/Frostweb.jpg/170px-Frostweb.jpg" decoding="async" width="170" height="227" class="thumbimage" data-file-width="1536" data-file-height="2048" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:Frostweb.jpg" class="internal" title="Enlarge"></a></div>A <a href="/enwiki/wiki/Spider_web" title="Spider web">spider web</a> covered in air hoar frost</div></div></div>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/enwiki/wiki/File:HoarFrost.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/3/37/HoarFrost.jpg/220px-HoarFrost.jpg" decoding="async" width="220" height="165" class="thumbimage" data-file-width="4032" data-file-height="3024" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:HoarFrost.jpg" class="internal" title="Enlarge"></a></div>Hoar frost on the snow</div></div></div>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/enwiki/wiki/File:LightLTSEM.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/c/c9/LightLTSEM.jpg/220px-LightLTSEM.jpg" decoding="async" width="220" height="143" class="thumbimage" data-file-width="1603" data-file-height="1042" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:LightLTSEM.jpg" class="internal" title="Enlarge"></a></div>Depth hoar, <a href="/enwiki/wiki/Micrograph" title="Micrograph">imaged</a> with <a href="/enwiki/wiki/Optical_microscope" title="Optical microscope">optical</a> (left) and <a href="/enwiki/wiki/Scanning_electron_microscope" title="Scanning electron microscope">scanning electron</a> (right) <a href="/enwiki/wiki/Microscopy" title="Microscopy">microscopy</a></div></div></div>
<p><b>Hoar frost</b>, also <b>hoarfrost</b>, <b>radiation frost</b>, or <b>pruina</b>, refers to white <a href="/enwiki/wiki/Ice_crystals" title="Ice crystals">ice crystals</a> deposited on the ground or loosely attached to exposed objects, such as wires or leaves.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4">[4]</a></sup> They form on cold, clear nights when conditions are such that <a href="/enwiki/wiki/Radiative_cooling#Nocturnal_surface_cooling" title="Radiative cooling">heat radiates</a> out to the open air faster than it can be replaced from nearby sources, such as wind or warm objects. Under suitable circumstances, objects cool to below the <a href="/enwiki/wiki/Dew_point#Frost_point" title="Dew point">frost point</a><sup id="cite_ref-RohliRohli2013_5-0" class="reference"><a href="#cite_note-RohliRohli2013-5">[5]</a></sup> of the surrounding air, well below the freezing point of water. Such freezing may be promoted by effects such as <b>flood frost</b> or <b>frost pocket</b>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6">[6]</a></sup> These occur when ground-level radiation losses<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/enwiki/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (September 2019)">clarification needed</span></a></i>]</sup> cool air until it flows downhill and accumulates in pockets of very cold air in valleys and hollows. Hoar frost may freeze in such low-lying cold air even when the air temperature a few feet above ground is well above freezing.
</p><p>The word <i>hoar</i> comes from an <a href="/enwiki/wiki/Old_English" title="Old English">Old English</a> adjective that means "showing signs of old age". In this context, it refers to the frost that makes trees and bushes look like white hair.
</p><p>Hoar frost may have different names depending on where it forms:
</p>
<ul><li><b>Air hoar</b> is a deposit of hoar frost on objects above the surface, such as tree branches, plant stems, and wires.</li>
<li><b>Surface hoar</b> refers to fern-like ice crystals directly deposited on snow, ice or already frozen surfaces.</li>
<li><b>Crevasse hoar</b> consists of crystals that form in glacial crevasses where water vapour can accumulate under calm weather conditions.</li>
<li><b><a href="/enwiki/wiki/Depth_hoar" title="Depth hoar">Depth hoar</a></b> refers to faceted crystals that have slowly grown large within cavities beneath the surface of banks of dry snow. Depth hoar crystals grow continuously at the expense of neighbouring smaller crystals, so typically are visibly stepped and have faceted hollows.</li></ul>
<p>When surface hoar covers sloping snowbanks, the layer of frost crystals may create an <a href="/enwiki/wiki/Avalanche" title="Avalanche">avalanche</a> risk; when heavy layers of new snow cover the frosty surface, furry crystals standing out from the old snow hold off the falling flakes, forming a layer of voids that prevent the new snow layers from bonding strongly to the old snow beneath. Ideal conditions for hoarfrost to form on snow are cold clear nights, with very light, cold air currents conveying humidity at the right rate for growth of frost crystals. Wind that is too strong or warm destroys the furry crystals, and thereby may permit a stronger bond between the old and new snow layers. However, if the winds are strong enough and cold enough to lay the crystals flat and dry, carpeting the snow with cold, loose crystals without removing or destroying them or letting them warm up and become sticky, then the frost interface between the snow layers may still present an avalanche danger, because the texture of the frost crystals differs from the snow texture and the dry crystals will not stick to fresh snow. Such conditions still prevent a strong bond between the snow layers.<sup id="cite_ref-McClungSchaerer2006_7-0" class="reference"><a href="#cite_note-McClungSchaerer2006-7">[7]</a></sup>
</p><p>In very low temperatures where fluffy surface hoar crystals form without subsequently being covered with snow, strong winds may break them off, forming a dust of ice particles and blowing them over the surface. The ice dust then may form <a href="/enwiki/wiki/Yukimarimo" title="Yukimarimo">yukimarimo</a>, as has been observed in parts of Antarctica, in a process similar to the formation of <a href="/enwiki/wiki/Dust_bunny" title="Dust bunny">dust bunnies</a> and similar structures.
</p>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/enwiki/wiki/File:Frosted_Flower.jpg" class="image"><img alt="A photo of a flower with advection frost on the tips of its petals." src="/upwiki/wikipedia/commons/thumb/b/b2/Frosted_Flower.jpg/220px-Frosted_Flower.jpg" decoding="async" width="220" height="176" class="thumbimage" data-file-width="1200" data-file-height="962" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:Frosted_Flower.jpg" class="internal" title="Enlarge"></a></div>A flower with advection frost on the edges of its petals</div></div></div>
<p>Hoar frost and <a href="#White_frost">white frost</a> also occurs in man-made environments such as in freezers or industrial <a href="/enwiki/wiki/Refrigeration" title="Refrigeration">cold storage</a> facilities. If such cold spaces or the pipes serving them are not well insulated and are exposed to ambient <a href="/enwiki/wiki/Humidity" title="Humidity">humidity</a>, the moisture will freeze instantly depending on the <a href="/enwiki/wiki/Freezer" class="mw-redirect" title="Freezer">freezer</a> <a href="/enwiki/wiki/Temperature" title="Temperature">temperature</a>. The frost may coat pipes thickly, partly insulating them, but such inefficient insulation still is a source of heat loss.
</p>
<h3><span class="mw-headline" id="Advection_frost">Advection frost</span></h3>
<p><b>Advection frost</b> (also called <b>wind frost</b>) refers to tiny ice spikes that form when very cold <a href="/enwiki/wiki/Wind" title="Wind">wind</a> is blowing over tree branches, poles, and other surfaces. It looks like rimming on the edges of flowers and leaves and usually forms against the <a href="/enwiki/wiki/Windward_and_leeward" title="Windward and leeward">direction of the wind</a>. It can occur at any hour, day or night.
</p>
<h3><span class="mw-headline" id="Window_frost">Window frost</span></h3>
<p><b>Window frost</b> (also called <b>fern frost</b> or <b>ice flowers</b>) forms when a glass pane is exposed to very cold air on the outside and warmer, moderately moist air on the inside. If the pane is not a good <a href="/enwiki/wiki/Thermal_insulation" title="Thermal insulation">insulator</a> (for example, if it is a single pane window), water vapour condenses on the glass forming frost patterns. With very low temperatures outside, frost can appear on the bottom of the window even with double pane energy efficient windows because the air convection between two panes of glass ensures that the bottom part of the glazing unit is colder than the top part. On unheated motor vehicles the frost will usually form on the outside surface of the glass first. The glass surface influences the shape of crystals, so imperfections, scratches, or dust can modify the way ice <a href="/enwiki/wiki/Nucleation" title="Nucleation">nucleates</a>. The patterns in window frost form a <a href="/enwiki/wiki/Fractal" title="Fractal">fractal</a> with a <a href="/enwiki/wiki/Fractal_dimension" title="Fractal dimension">fractal dimension</a> greater than one but less than two. This is a consequence of the nucleation process being constrained to unfold in two dimensions, unlike a snowflake which is shaped by a similar process but forms in three dimensions and has a fractal dimension greater than two.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8">[8]</a></sup>
</p><p>If the indoor air is very <a href="/enwiki/wiki/Relative_humidity" title="Relative humidity">humid</a>, rather than moderately so, water will first <a href="/enwiki/wiki/Condensation" title="Condensation">condense</a> in small droplets and then freeze into <a href="/enwiki/wiki/Clear_ice" title="Clear ice">clear ice</a>.
</p><p>Similar patterns of freezing may occur on other smooth vertical surfaces, but they seldom are as obvious or spectacular as on clear glass.
</p>
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<div class="thumb" style="width: 150px;"><div style="margin:35px auto;"><a href="/enwiki/wiki/File:Frost_patterns_4.jpg" class="image"><img alt="Frost patterns 4.jpg" src="/upwiki/wikipedia/commons/thumb/5/51/Frost_patterns_4.jpg/120px-Frost_patterns_4.jpg" decoding="async" width="120" height="80" data-file-width="3960" data-file-height="2640" /></a></div></div>
<div class="gallerytext">
</div>
</div></li>
<li class="gallerybox" style="width: 155px"><div style="width: 155px">
<div class="thumb" style="width: 150px;"><div style="margin:35px auto;"><a href="/enwiki/wiki/File:Frost_patterns_5.jpg" class="image"><img alt="Frost patterns 5.jpg" src="/upwiki/wikipedia/commons/thumb/6/69/Frost_patterns_5.jpg/120px-Frost_patterns_5.jpg" decoding="async" width="120" height="80" data-file-width="4288" data-file-height="2848" /></a></div></div>
<div class="gallerytext">
</div>
</div></li>
<li class="gallerybox" style="width: 155px"><div style="width: 155px">
<div class="thumb" style="width: 150px;"><div style="margin:33px auto;"><a href="/enwiki/wiki/File:Frost_patterns_25.jpg" class="image"><img alt="Frost patterns 25.jpg" src="/upwiki/wikipedia/commons/thumb/4/42/Frost_patterns_25.jpg/120px-Frost_patterns_25.jpg" decoding="async" width="120" height="84" data-file-width="1195" data-file-height="832" /></a></div></div>
<div class="gallerytext">
</div>
</div></li>
</ul>
<h3><span class="mw-headline" id="White_frost">White frost</span></h3>
<p><b>White frost</b> is a solid <a href="/enwiki/wiki/Deposition_(phase_transition)" title="Deposition (phase transition)">deposition</a> of ice that forms directly from <a href="/enwiki/wiki/Water_vapor" title="Water vapor">water vapour</a> contained in <a href="/enwiki/wiki/Air" class="mw-redirect" title="Air">air</a>.
</p><p>White frost forms when there is a <a href="/enwiki/wiki/Relative_humidity" title="Relative humidity">relative humidity</a> above 90% and a temperature below −8 °C (18 °F) and it grows against the <a href="/enwiki/wiki/Wind" title="Wind">wind</a> direction, since air arriving from <a href="/enwiki/wiki/Windward_and_leeward" title="Windward and leeward">windward</a> has a higher humidity than leeward air, but the wind must not be strong or it damages the delicate icy structures as they begin to form. White frost resembles a heavy coating of hoar frost with big, interlocking crystals, usually needle-shaped.
</p>
<h3><span class="mw-headline" id="Rime">Rime</span></h3>
<div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/enwiki/wiki/Rime_ice" title="Rime ice">Rime ice</a></div>
<p><b>Rime</b> is a type of ice <a href="/enwiki/wiki/Deposition_(phase_transition)" title="Deposition (phase transition)">deposition</a> that occurs quickly, often under heavily humid and windy conditions.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9">[9]</a></sup> Technically speaking, it is not a type of frost, since usually <a href="/enwiki/wiki/Supercooling" title="Supercooling">supercooled</a> water drops are involved, in contrast to the formation of hoar frost, in which water vapour desublimates slowly and directly. Ships travelling through Arctic seas may accumulate large quantities of rime on the rigging. Unlike hoar frost, which has a feathery appearance, rime generally has an icy, solid appearance.
</p>
<h3><span class="mw-headline" id="Black_frost">Black frost</span></h3>
<p><b>Black frost</b> (or "killing frost") is not strictly speaking frost at all, because it is the condition seen in crops when the humidity is too low for frost to form, but the temperature falls so low that plant tissues freeze and die, becoming blackened, hence the term "black frost". Black frost often is called "killing frost" because white frost tends to be less cold, partly because the <a href="/enwiki/wiki/Latent_heat" title="Latent heat">latent heat</a> of freezing of the water reduces the temperature drop.
</p>
<h2><span class="mw-headline" id="Effect_on_plants">Effect on plants</span></h2>
<h3><span class="mw-headline" id="Damage">Damage</span></h3>
<div class="thumb tright"><div class="thumbinner" style="width:222px;"><a href="/enwiki/wiki/File:Feuilles-avec-glace-leaves-with-ice-1.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/2/2c/Feuilles-avec-glace-leaves-with-ice-1.jpg/220px-Feuilles-avec-glace-leaves-with-ice-1.jpg" decoding="async" width="220" height="165" class="thumbimage" data-file-width="1600" data-file-height="1200" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:Feuilles-avec-glace-leaves-with-ice-1.jpg" class="internal" title="Enlarge"></a></div>Frost on the grass of a public park in November.</div></div></div>
<p>Many plants can be damaged or killed by freezing temperatures or frost. This varies with the type of plant, the tissue exposed, and how low temperatures get: a "light frost" of −2 to 0 °C (28 to 32 °F) will damage fewer types of plants than a "hard frost" below −2 °C (28 °F).<sup id="cite_ref-BI_Frost_10-0" class="reference"><a href="#cite_note-BI_Frost-10">[10]</a></sup>
</p><p>Plants likely to be damaged even by a light frost include vines—such as beans, grapes, squashes, melons—along with <a href="/enwiki/wiki/Nightshade" class="mw-redirect" title="Nightshade">nightshades</a> such as tomatoes, eggplants and peppers. Plants that may tolerate (or even benefit) from frosts include:<sup id="cite_ref-11" class="reference"><a href="#cite_note-11">[11]</a></sup>
</p>
<ul><li>root vegetables (e.g. beets, carrots, parsnips, onions)</li>
<li>leafy greens (e.g. lettuces, spinach, chard, cucumber<sup id="cite_ref-JHR_2-2013_12-0" class="reference"><a href="#cite_note-JHR_2-2013-12">[12]</a></sup>)</li>
<li><a href="/enwiki/wiki/Cruciferous_vegetables" title="Cruciferous vegetables">cruciferous vegetables</a> (e.g. cabbages, cauliflower, bok choy, broccoli, Brussels sprouts, radishes, kale, collard, mustard, turnips, rutabagas)</li></ul>
<p>Even those plants that tolerate frost may be damaged once temperatures drop even lower (below −4 °C or 25 °F).<sup id="cite_ref-BI_Frost_10-1" class="reference"><a href="#cite_note-BI_Frost-10">[10]</a></sup> Hardy perennials, such as <i><a href="/enwiki/wiki/Hosta" title="Hosta">Hosta</a></i>, become dormant after the first frosts and regrow when spring arrives. The entire visible plant may turn completely brown until the spring warmth, or may drop all of its leaves and flowers, leaving the stem and stalk only. Evergreen plants, such as pine trees, withstand frost although all or most growth stops. <a href="/enwiki/wiki/Frost_crack" title="Frost crack">Frost crack</a> is a bark defect caused by a combination of low temperatures and heat from the winter sun.
</p><p>Vegetation is not necessarily damaged when leaf temperatures drop below the freezing point of their cell contents. In the absence of a site <a href="/enwiki/wiki/Nucleation" title="Nucleation">nucleating</a> the formation of ice crystals, the leaves remain in a <a href="/enwiki/wiki/Supercooled" class="mw-redirect" title="Supercooled">supercooled</a> liquid state, safely reaching temperatures of −4 to −12 °C (25 to 10 °F). However, once frost forms, the leaf <a href="/enwiki/wiki/Cell_(biology)" title="Cell (biology)">cells</a> may be damaged by sharp ice crystals. <a href="/enwiki/wiki/Hardening_(botany)" class="mw-redirect" title="Hardening (botany)">Hardening</a> is the process by which a plant becomes tolerant to low temperatures. See also <a href="/enwiki/wiki/Cryobiology" title="Cryobiology">Cryobiology</a>.
</p><p>Certain <a href="/enwiki/wiki/Bacterium" class="mw-redirect" title="Bacterium">bacteria</a>, notably <i><a href="/enwiki/wiki/Pseudomonas_syringae" title="Pseudomonas syringae">Pseudomonas syringae</a></i>, are particularly effective at triggering frost formation, raising the nucleation temperature to about −2 °C (28 °F).<sup id="cite_ref-13" class="reference"><a href="#cite_note-13">[13]</a></sup> Bacteria lacking ice <a href="/enwiki/wiki/Nucleation" title="Nucleation">nucleation</a>-active proteins (<a href="/enwiki/wiki/Ice-minus_bacteria" title="Ice-minus bacteria">ice-minus bacteria</a>) result in greatly reduced frost damage.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14">[14]</a></sup>
</p>
<h3><span class="mw-headline" id="Protection_methods">Protection methods</span></h3>
<div class="thumb tright"><div class="thumbinner" style="width:252px;"><a href="/enwiki/wiki/File:Winterschutz.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/1/1a/Winterschutz.jpg/250px-Winterschutz.jpg" decoding="async" width="250" height="167" class="thumbimage" data-file-width="4563" data-file-height="3042" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:Winterschutz.jpg" class="internal" title="Enlarge"></a></div><a href="/enwiki/wiki/Roses" class="mw-redirect" title="Roses">Roses</a> with protection against frost - <a href="/enwiki/wiki/Volksgarten,_Vienna" title="Volksgarten, Vienna">Volksgarten, Vienna</a></div></div></div>
<div class="thumb tright"><div class="thumbinner" style="width:252px;"><a href="/enwiki/wiki/File:CuritibaFrostGeada.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/6/6c/CuritibaFrostGeada.jpg/250px-CuritibaFrostGeada.jpg" decoding="async" width="250" height="188" class="thumbimage" data-file-width="3456" data-file-height="2592" /></a> <div class="thumbcaption"><div class="magnify"><a href="/enwiki/wiki/File:CuritibaFrostGeada.jpg" class="internal" title="Enlarge"></a></div><a href="/enwiki/wiki/Curitiba" title="Curitiba">Curitiba</a> (<a href="/enwiki/wiki/Southern_Brazil" class="mw-redirect" title="Southern Brazil">Southern Brazil</a>) is the coldest of <a href="/enwiki/wiki/Brazil" title="Brazil">Brazil</a>'s <a href="/enwiki/wiki/State_capital" class="mw-redirect" title="State capital">state capitals</a>; the <a href="/enwiki/wiki/Greenhouse" title="Greenhouse">greenhouse</a> of the <a href="/enwiki/wiki/Botanical_Garden_of_Curitiba" title="Botanical Garden of Curitiba">Botanical Garden of Curitiba</a> protects sensitive plants.</div></div></div>
<p>Typical measures to prevent frost or reduce its severity include one or more of:
</p>
<ul><li>deploying powerful blowers to simulate wind, thereby preventing the formation of accumulations of cold air. There are variations on this theme. One of them is the <a href="/enwiki/wiki/Selective_inverted_sink" title="Selective inverted sink">selective inverted sink</a><sup id="cite_ref-15" class="reference"><a href="#cite_note-15">[15]</a></sup>, a device which prevents frost by drawing cold air from the ground and blowing it up through a chimney. It was originally developed to prevent frost damage to <a href="/enwiki/wiki/Citrus" title="Citrus">citrus</a> fruits in <a href="/enwiki/wiki/Uruguay" title="Uruguay">Uruguay</a>. In New Zealand, <a href="/enwiki/wiki/Helicopter" title="Helicopter">helicopters</a> are used in similar fashion, especially in the <a href="/enwiki/wiki/Vineyard" title="Vineyard">vineyard</a> regions like <a href="/enwiki/wiki/Marlborough_Region" title="Marlborough Region">Marlborough</a>. By dragging down warmer air from the <a href="/enwiki/wiki/Inversion_(meteorology)" title="Inversion (meteorology)">inversion layers</a>, and preventing the ponding of colder air on the ground, the low-flying helicopters prevent damage to the fruit buds. As the operations are conducted at night, and have in the past involved up to 130 aircraft per night in one region, safety rules are strict.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16">[16]</a></sup> Although not a dedicated method, <a href="/enwiki/wiki/Wind_turbine" title="Wind turbine">wind turbines</a> have similar (small) effect of vertically mixing air layers of different temperature.<sup id="cite_ref-Nature-2010.12.23_17-0" class="reference"><a href="#cite_note-Nature-2010.12.23-17">[17]</a></sup><sup id="cite_ref-Roy+Traiteur_18-0" class="reference"><a href="#cite_note-Roy+Traiteur-18">[18]</a></sup><sup id="cite_ref-ScienceDaily-2005_19-0" class="reference"><a href="#cite_note-ScienceDaily-2005-19">[19]</a></sup></li>
<li>for high-value crops, farmers may wrap trees and cover crops.</li>
<li>heating to slow the drop in temperature. This is not practical except for high value crops grown over small areas.</li>
<li>production of smoke to reduce cooling by radiation</li>
<li>spraying crops with a layer of water that releases latent heat, preventing harmful freezing of the tissues of the plants that it coats.</li></ul>
<p>Such measures need to be applied with discretion, because they may do more harm than good; for example, spraying crops with water can cause damage if the plants become overburdened with ice. An effective <b>low cost</b> method for small crop farms and plant nurseries, exploits the <a href="/enwiki/wiki/Enthalpy_of_fusion" title="Enthalpy of fusion">latent heat of freezing</a>. A pulsed irrigation timer<sup id="cite_ref-Nurseries_20-0" class="reference"><a href="#cite_note-Nurseries-20">[20]</a></sup> delivers water through existing overhead sprinklers at a low volumes to combat frosts down to −5 °C (23 °F).<sup id="cite_ref-Nurseries_20-1" class="reference"><a href="#cite_note-Nurseries-20">[20]</a></sup><sup id="cite_ref-SmallCrops_21-0" class="reference"><a href="#cite_note-SmallCrops-21">[21]</a></sup> If the water freezes it giving off its latent heat, preventing the temperature of the foliage from falling much below zero.<sup id="cite_ref-SmallCrops_21-1" class="reference"><a href="#cite_note-SmallCrops-21">[21]</a></sup>
</p>
<h2><span class="mw-headline" id="Frost-free_areas">Frost-free areas</span></h2>
<p>Frost-free areas are found mainly in the tropics, where they cover almost all land except at <a href="/enwiki/wiki/Altitude" title="Altitude">altitudes</a> above about 3,000 metres or 9,800 feet near the equator and around 2,000 metres or 6,600 feet in the semi-arid middle tropics, but also in areas with <a href="/enwiki/wiki/Subtropical_climate" class="mw-redirect" title="Subtropical climate">subtropical climates</a> that have winters tempered by strong oceanic influences. The most poleward frost-free areas are the lower altitudes of the <a href="/enwiki/wiki/Azores" title="Azores">Azores</a>, <a href="/enwiki/wiki/%C3%8Ele_Amsterdam" title="Île Amsterdam">Île Amsterdam</a>, <a href="/enwiki/wiki/%C3%8Ele_Saint-Paul" title="Île Saint-Paul">Île Saint-Paul</a>, and <a href="/enwiki/wiki/Tristan_da_Cunha" title="Tristan da Cunha">Tristan da Cunha</a>.
</p><p>The only reliably frost-free areas in the contiguous <a href="/enwiki/wiki/United_States" title="United States">United States</a> are the <a href="/enwiki/wiki/Florida_Keys" title="Florida Keys">Florida Keys</a> and the coastal areas of the <a href="/enwiki/wiki/Channel_Islands_(California)" title="Channel Islands (California)">Channel Islands of California</a>. The <a href="/enwiki/wiki/Hardiness_zone" title="Hardiness zone">hardiness zones</a> there are 11a and 11b.
</p>
<h2><span class="mw-headline" id="Personifications">Personifications</span></h2>
<div role="note" class="hatnote navigation-not-searchable">Further information: <a href="/enwiki/wiki/Ded_Moroz" title="Ded Moroz">Ded Moroz</a> and <a href="/enwiki/wiki/Father_Frost_(fairy_tale)" title="Father Frost (fairy tale)">Father Frost (fairy tale)</a></div>
<p>Frost is personified in Russian culture as <a href="/enwiki/wiki/Ded_Moroz" title="Ded Moroz">Ded Moroz</a>. <a href="/enwiki/wiki/Indigenous_peoples_of_Russia" class="mw-redirect" title="Indigenous peoples of Russia">Indigenous peoples of Russia</a> such as the <a href="/enwiki/wiki/Mordvins" title="Mordvins">Mordvins</a> have their own traditions of frost deities.
</p><p>English folklore tradition holds that <a href="/enwiki/wiki/Jack_Frost" title="Jack Frost">Jack Frost</a>, an elfish creature, is responsible for feathery patterns of frost found on windows on cold mornings.
</p>
<h2><span class="mw-headline" id="Gallery">Gallery</span></h2>
<ul class="gallery mw-gallery-traditional" style="max-width: 965px;_width: 965px;">
<li class="gallerycaption">Frost</li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:15px auto;"><a href="/enwiki/wiki/File:Frost_on_a_nettle,_Netherlands.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/3/38/Frost_on_a_nettle%2C_Netherlands.jpg/90px-Frost_on_a_nettle%2C_Netherlands.jpg" decoding="async" width="90" height="120" data-file-width="2136" data-file-height="2848" /></a></div></div>
<div class="gallerytext">
<p>Frost on a nettle
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:15px auto;"><a href="/enwiki/wiki/File:Saskatoon-Frost.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/4/4e/Saskatoon-Frost.jpg/90px-Saskatoon-Frost.jpg" decoding="async" width="90" height="120" data-file-width="2748" data-file-height="3664" /></a></div></div>
<div class="gallerytext">
<p>Large feathery crystals
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:25px auto;"><a href="/enwiki/wiki/File:Fern_Frost.JPG" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/a/a3/Fern_Frost.JPG/150px-Fern_Frost.JPG" decoding="async" width="150" height="100" data-file-width="4288" data-file-height="2848" /></a></div></div>
<div class="gallerytext">
<p>Fern frost on a window
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:18.5px auto;"><a href="/enwiki/wiki/File:Window-Frost.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/9/9c/Window-Frost.jpg/150px-Window-Frost.jpg" decoding="async" width="150" height="113" data-file-width="1920" data-file-height="1440" /></a></div></div>
<div class="gallerytext">
<p>Window frost
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:25px auto;"><a href="/enwiki/wiki/File:Frost_on_leaves.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/a/af/Frost_on_leaves.jpg/150px-Frost_on_leaves.jpg" decoding="async" width="150" height="100" data-file-width="5202" data-file-height="3465" /></a></div></div>
<div class="gallerytext">
<p>Frost on plant leaves in the <a href="/enwiki/wiki/Himalayas" title="Himalayas">Himalayas</a>
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:25px auto;"><a href="/enwiki/wiki/File:Hoar_Frost.JPG" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/8/8f/Hoar_Frost.JPG/150px-Hoar_Frost.JPG" decoding="async" width="150" height="100" data-file-width="4288" data-file-height="2848" /></a></div></div>
<div class="gallerytext">
<p>Surface hoar in <a href="/enwiki/wiki/Alaska" title="Alaska">Alaska</a>
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:15px auto;"><a href="/enwiki/wiki/File:Frost_on_Birch_Tree_in_Stockholm_20180110.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/4/4b/Frost_on_Birch_Tree_in_Stockholm_20180110.jpg/90px-Frost_on_Birch_Tree_in_Stockholm_20180110.jpg" decoding="async" width="90" height="120" data-file-width="3000" data-file-height="4000" /></a></div></div>
<div class="gallerytext">
<p>Frost on Birch Tree in <a href="/enwiki/wiki/Stockholm" title="Stockholm">Stockholm</a>
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:15px auto;"><a href="/enwiki/wiki/File:Frost_on_birch_tree.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/5/5b/Frost_on_birch_tree.jpg/80px-Frost_on_birch_tree.jpg" decoding="async" width="80" height="120" data-file-width="3312" data-file-height="4968" /></a></div></div>
<div class="gallerytext">
<p>Frost on birch stem in <a href="/enwiki/wiki/Norway" title="Norway">Norway</a>
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:18.5px auto;"><a href="/enwiki/wiki/File:Sydneyfrost.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/e/ea/Sydneyfrost.jpg/150px-Sydneyfrost.jpg" decoding="async" width="150" height="113" data-file-width="3264" data-file-height="2448" /></a></div></div>
<div class="gallerytext">
<p>Frost on grass in <a href="/enwiki/wiki/Sydney" title="Sydney">Sydney</a>
</p>
</div>
</div></li>
<li class="gallerybox" style="width: 185px"><div style="width: 185px">
<div class="thumb" style="width: 180px;"><div style="margin:25px auto;"><a href="/enwiki/wiki/File:Leaf_with_frost.jpg" class="image"><img alt="" src="/upwiki/wikipedia/commons/thumb/5/5d/Leaf_with_frost.jpg/150px-Leaf_with_frost.jpg" decoding="async" width="150" height="100" data-file-width="1881" data-file-height="1254" /></a></div></div>
<div class="gallerytext">
<p>An oak leaf with frost in <a href="/enwiki/wiki/Sweden" title="Sweden">Sweden</a>
</p>
</div>
</div></li>
</ul>
<h2><span class="mw-headline" id="See_also">See also</span></h2>
<ul><li><a href="/enwiki/wiki/Black_ice" title="Black ice">Black ice</a></li>
<li><a href="/enwiki/wiki/Frost_(temperature)" title="Frost (temperature)">Frost (temperature)</a></li>
<li><a href="/enwiki/wiki/Frost_heaving" title="Frost heaving">Frost heaving</a></li>
<li><a href="/enwiki/wiki/Frost_line" title="Frost line">Frost line</a></li>
<li><a href="/enwiki/wiki/Frostbite" title="Frostbite">Frostbite</a></li>
<li><a href="/enwiki/wiki/Ground_frost" title="Ground frost">Ground frost</a></li>
<li><a href="/enwiki/wiki/Icing_(nautical)" title="Icing (nautical)">Icing (nautical)</a></li>
<li><a href="/enwiki/wiki/Needle_ice" title="Needle ice">Needle ice</a></li></ul>
<h2><span class="mw-headline" id="References">References</span></h2>
<div class="reflist columns references-column-width" style="-moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;">
<ol class="references">
<li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.merriam-webster.com/dictionary/frost">"Frost – Definition of frost by Merriam-Webster"</a>. <i>merriam-webster.com</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150511025533/http://www.merriam-webster.com/dictionary/frost">Archived</a> from the original on 2015-05-11.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=merriam-webster.com&rft.atitle=Frost+%E2%80%93+Definition+of+frost+by+Merriam-Webster&rft_id=http%3A%2F%2Fwww.merriam-webster.com%2Fdictionary%2Ffrost&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><style data-mw-deduplicate="TemplateStyles:r935243608">.mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .id-lock-free a,.mw-parser-output .citation .cs1-lock-free a{background:url("/upwiki/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .id-lock-limited a,.mw-parser-output .id-lock-registration a,.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("/upwiki/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .id-lock-subscription a,.mw-parser-output .citation .cs1-lock-subscription a{background:url("/upwiki/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("/upwiki/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}</style></span>
</li>
<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.weatherquestions.com/What_causes_frost.htm">"What causes frost?"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20071210230539/http://www.weatherquestions.com/What_causes_frost.htm">Archived</a> from the original on 2007-12-10<span class="reference-accessdate">. Retrieved <span class="nowrap">2007-12-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=What+causes+frost%3F&rft_id=http%3A%2F%2Fwww.weatherquestions.com%2FWhat_causes_frost.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-Oliver2005-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-Oliver2005_3-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Oliver2005_3-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation book">John E. Oliver (1 January 2005). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382"><i>The Encyclopedia of World Climatology</i></a>. <a href="/enwiki/wiki/Springer_Science_%26_Business_Media" class="mw-redirect" title="Springer Science & Business Media">Springer Science & Business Media</a>. pp. 382–. <a href="/enwiki/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/enwiki/wiki/Special:BookSources/978-1-4020-3264-6" title="Special:BookSources/978-1-4020-3264-6"><bdi>978-1-4020-3264-6</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160508153444/https://books.google.com/books?id=-mwbAsxpRr0C&pg=PA382">Archived</a> from the original on 8 May 2016.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Encyclopedia+of+World+Climatology&rft.pages=382-&rft.pub=Springer+Science+%26+Business+Media&rft.date=2005-01-01&rft.isbn=978-1-4020-3264-6&rft.au=John+E.+Oliver&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3D-mwbAsxpRr0C%26pg%3DPA382&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
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<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.merriam-webster.com/dictionary/hoar%20frost">"Hoarfrost – Definition of hoarfrost by Merriam-Webster"</a>. <i>merriam-webster.com</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150219065328/http://www.merriam-webster.com/dictionary/hoar%20frost">Archived</a> from the original on 2015-02-19.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=merriam-webster.com&rft.atitle=Hoarfrost+%E2%80%93+Definition+of+hoarfrost+by+Merriam-Webster&rft_id=http%3A%2F%2Fwww.merriam-webster.com%2Fdictionary%2Fhoar%2520frost&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
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<li id="cite_note-RohliRohli2013-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-RohliRohli2013_5-0">^</a></b></span> <span class="reference-text"><cite class="citation book">Louisiana State University Baton Rouge Robert V Rohli; Robert V. Rohli; Anthony J. Vega (13 December 2013). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381"><i>Climatology</i></a>. <a href="/enwiki/wiki/Jones_%26_Bartlett_Publishers" class="mw-redirect" title="Jones & Bartlett Publishers">Jones & Bartlett Publishers</a>. pp. 381–. <a href="/enwiki/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/enwiki/wiki/Special:BookSources/978-1-284-05427-9" title="Special:BookSources/978-1-284-05427-9"><bdi>978-1-284-05427-9</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160519122238/https://books.google.com/books?id=AxWEAgAAQBAJ&pg=PA381">Archived</a> from the original on 19 May 2016.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Climatology&rft.pages=381-&rft.pub=Jones+%26+Bartlett+Publishers&rft.date=2013-12-13&rft.isbn=978-1-284-05427-9&rft.au=Louisiana+State+University+Baton+Rouge+Robert+V+Rohli&rft.au=Robert+V.+Rohli&rft.au=Anthony+J.+Vega&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DAxWEAgAAQBAJ%26pg%3DPA381&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm">"Weather Facts: Frost hollow – Weather UK – weatheronline.co.uk"</a>. <i>weatheronline.co.uk</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20130212022607/http://www.weatheronline.co.uk/reports/wxfacts/Frost-hollow.htm">Archived</a> from the original on 2013-02-12.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=weatheronline.co.uk&rft.atitle=Weather+Facts%3A+Frost+hollow+%E2%80%93+Weather+UK+%E2%80%93+weatheronline.co.uk&rft_id=http%3A%2F%2Fwww.weatheronline.co.uk%2Freports%2Fwxfacts%2FFrost-hollow.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-McClungSchaerer2006-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-McClungSchaerer2006_7-0">^</a></b></span> <span class="reference-text"><cite class="citation book">David McClung; Peter A. Schaerer (2006). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72"><i>The Avalanche Handbook</i></a>. <a href="/enwiki/wiki/The_Mountaineers_Books" class="mw-redirect" title="The Mountaineers Books">The Mountaineers Books</a>. pp. 72–. <a href="/enwiki/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/enwiki/wiki/Special:BookSources/978-0-89886-809-8" title="Special:BookSources/978-0-89886-809-8"><bdi>978-0-89886-809-8</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160506012123/https://books.google.com/books?id=0Bpscs7Gqb8C&pg=PA72">Archived</a> from the original on 2016-05-06.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Avalanche+Handbook&rft.pages=72-&rft.pub=The+Mountaineers+Books&rft.date=2006&rft.isbn=978-0-89886-809-8&rft.au=David+McClung&rft.au=Peter+A.+Schaerer&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3D0Bpscs7Gqb8C%26pg%3DPA72&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><cite class="citation book">West, Bruce; Mauro Bologna (2003). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=EgyTpQZOga0C&pg=PA46"><i>Physics of Fractal Operators</i></a>. Paolo Grigolini. Springer. p. 46. <a href="/enwiki/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/enwiki/wiki/Special:BookSources/978-0-387-95554-4" title="Special:BookSources/978-0-387-95554-4"><bdi>978-0-387-95554-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Physics+of+Fractal+Operators&rft.pages=46&rft.pub=Springer&rft.date=2003&rft.isbn=978-0-387-95554-4&rft.aulast=West&rft.aufirst=Bruce&rft.au=Mauro+Bologna&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DEgyTpQZOga0C%26pg%3DPA46&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.merriam-webster.com/dictionary/rime">"Rime – Definition of rime by Merriam-Webster"</a>. <i>merriam-webster.com</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150501193835/http://www.merriam-webster.com/dictionary/rime">Archived</a> from the original on 2015-05-01.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=merriam-webster.com&rft.atitle=Rime+%E2%80%93+Definition+of+rime+by+Merriam-Webster&rft_id=http%3A%2F%2Fwww.merriam-webster.com%2Fdictionary%2Frime&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-BI_Frost-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-BI_Frost_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-BI_Frost_10-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables">"Frost Tolerance of Vegetables"</a>. Botanical Interests. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20131113010216/http://www.botanicalinterests.com/articles/view/26/Frost-Tolerance-of-Vegetables">Archived</a> from the original on 2013-11-13<span class="reference-accessdate">. Retrieved <span class="nowrap">Nov 12,</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Frost+Tolerance+of+Vegetables&rft.pub=Botanical+Interests&rft_id=http%3A%2F%2Fwww.botanicalinterests.com%2Farticles%2Fview%2F26%2FFrost-Tolerance-of-Vegetables&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.grow-it-organically.com/fall-vegetables.html">"Fall vegetables vs. Summer vegetables"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20131113011159/http://www.grow-it-organically.com/fall-vegetables.html">Archived</a> from the original on 2013-11-13.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Fall+vegetables+vs.+Summer+vegetables&rft_id=http%3A%2F%2Fwww.grow-it-organically.com%2Ffall-vegetables.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-JHR_2-2013-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-JHR_2-2013_12-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFKlosinska2014" class="citation">Klosinska, Urszula; et al. (27 February 2014), <a rel="nofollow" class="external text" href="http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT">"Low temperature seed germination of cucumber: genetic basis of the tolerance trait"</a>, <i>Journal of Horticultural Research</i>, de Gruyter, <b>21</b> (2): 125–130, <a href="/enwiki/wiki/Digital_object_identifier" title="Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.2478%2Fjohr-2013-0031">10.2478/johr-2013-0031</a>, <a rel="nofollow" class="external text" href="https://web.archive.org/web/20140611011158/http://www.degruyter.com/view/j/johr.2013.21.issue-2/johr-2013-0031/johr-2013-0031.xml?format=INT">archived</a> from the original on 11 June 2014<span class="reference-accessdate">, retrieved <span class="nowrap">2014-02-28</span></span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Horticultural+Research&rft.atitle=Low+temperature+seed+germination+of+cucumber%3A+genetic+basis+of+the+tolerance+trait&rft.volume=21&rft.issue=2&rft.pages=125-130&rft.date=2014-02-27&rft_id=info%3Adoi%2F10.2478%2Fjohr-2013-0031&rft.aulast=Klosinska&rft.aufirst=Urszula&rft_id=http%3A%2F%2Fwww.degruyter.com%2Fview%2Fj%2Fjohr.2013.21.issue-2%2Fjohr-2013-0031%2Fjohr-2013-0031.xml%3Fformat%3DINT&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><cite class="citation journal">Maki LR, Galyan EL, Chang-Chien MM, Caldwell DR (1974). <a rel="nofollow" class="external text" href="/enwiki//www.ncbi.nlm.nih.gov/pmc/articles/PMC186742">"Ice Nucleation Induced by Pseudomonas syringae"</a>. <i>Applied Microbiology</i>. <b>28</b> (3): 456–459. <a href="/enwiki/wiki/PubMed_Central" title="PubMed Central">PMC</a> <span class="cs1-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="/enwiki//www.ncbi.nlm.nih.gov/pmc/articles/PMC186742">186742</a></span>. <a href="/enwiki/wiki/PubMed_Identifier" class="mw-redirect" title="PubMed Identifier">PMID</a> <a rel="nofollow" class="external text" href="/enwiki//pubmed.ncbi.nlm.nih.gov/4371331">4371331</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+Microbiology&rft.atitle=Ice+Nucleation+Induced+by+Pseudomonas+syringae&rft.volume=28&rft.issue=3&rft.pages=456-459&rft.date=1974&rft_id=%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC186742&rft_id=info%3Apmid%2F4371331&rft.aulast=Maki&rft.aufirst=LR&rft.au=Galyan%2C+EL&rft.au=Chang-Chien%2C+MM&rft.au=Caldwell%2C+DR&rft_id=%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC186742&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><cite class="citation journal"><a href="/enwiki/w/index.php?title=Steven_E._Lindow&action=edit&redlink=1" class="new" title="Steven E. Lindow (page does not exist)">Lindow, Stephen E.</a>; Deane C. Arny; Christen D. Upper (October 1982). <a rel="nofollow" class="external text" href="/enwiki//www.ncbi.nlm.nih.gov/pmc/articles/PMC1065830">"Bacterial Ice Nucleation: A Factor in Frost Injury to Plants"</a>. <i>Plant Physiology</i>. <b>70</b> (4): 1084–1089. <a href="/enwiki/wiki/Digital_object_identifier" title="Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1104%2Fpp.70.4.1084">10.1104/pp.70.4.1084</a>. <a href="/enwiki/wiki/PubMed_Central" title="PubMed Central">PMC</a> <span class="cs1-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="/enwiki//www.ncbi.nlm.nih.gov/pmc/articles/PMC1065830">1065830</a></span>. <a href="/enwiki/wiki/PubMed_Identifier" class="mw-redirect" title="PubMed Identifier">PMID</a> <a rel="nofollow" class="external text" href="/enwiki//pubmed.ncbi.nlm.nih.gov/16662618">16662618</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Plant+Physiology&rft.atitle=Bacterial+Ice+Nucleation%3A+A+Factor+in+Frost+Injury+to+Plants&rft.volume=70&rft.issue=4&rft.pages=1084-1089&rft.date=1982-10&rft_id=%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1065830&rft_id=info%3Apmid%2F16662618&rft_id=info%3Adoi%2F10.1104%2Fpp.70.4.1084&rft.aulast=Lindow&rft.aufirst=Stephen+E.&rft.au=Deane+C.+Arny&rft.au=Christen+D.+Upper&rft_id=%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1065830&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.rolexawards.com/laureates/laureate-20-guarga.html">Selective Inverted Sink</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20060318212517/http://www.rolexawards.com/laureates/laureate-20-guarga.html">Archived</a> 2006-03-18 at the <a href="/enwiki/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a> Rolex Awards site (won award in <i>Technology and Innovation</i> category) 1998.</span>
</li>
<li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><i>Helicopters Fight Frost</i> – <i>Vector</i>, <a href="/enwiki/wiki/Civil_Aviation_Authority_of_New_Zealand" title="Civil Aviation Authority of New Zealand">Civil Aviation Authority of New Zealand</a>, September/ October 2008, Page 8-9</span>
</li>
<li id="cite_note-Nature-2010.12.23-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-Nature-2010.12.23_17-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html">Turbines and turbulence</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20111201212633/http://www.nature.com/nature/journal/v468/n7327/full/4681001a.html">Archived</a> 2011-12-01 at the <a href="/enwiki/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>, <i><a href="/enwiki/wiki/Nature_(journal)" title="Nature (journal)">Nature (journal)</a></i>, 468, 1001, 23 December 2010, DOI:10.1038/4681001a, published online 22 December 2010.</span>
</li>
<li id="cite_note-Roy+Traiteur-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-Roy+Traiteur_18-0">^</a></b></span> <span class="reference-text">Somnath Baidya Roy and Justin J. Traiteur. <a rel="nofollow" class="external text" href="http://www.pnas.org/content/early/2010/10/12/1000493107.abstract">Impacts of wind farms on surface air temperatures</a>, Proceedings of the National Academy of Sciences, Vol. 107, No. 42, October 19, 2010, p. 17,899.</span>
</li>
<li id="cite_note-ScienceDaily-2005-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-ScienceDaily-2005_19-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm">Wind farms impacting weather</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20100906101845/https://www.sciencedaily.com/videos/2005/1012-wind_farms_impacting_weather.htm">Archived</a> 2010-09-06 at the <a href="/enwiki/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>, Science Daily.</span>
</li>
<li id="cite_note-Nurseries-20"><span class="mw-cite-backlink">^ <a href="#cite_ref-Nurseries_20-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Nurseries_20-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://plantsale.com.au/Articles/FrostProtection">"A practical method of frost protection"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20120320075831/http://www.plantsale.com.au/Articles/FrostProtection/">Archived</a> from the original on 20 March 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">31 October</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=A+practical+method+of+frost+protection&rft_id=http%3A%2F%2Fplantsale.com.au%2FArticles%2FFrostProtection&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
<li id="cite_note-SmallCrops-21"><span class="mw-cite-backlink">^ <a href="#cite_ref-SmallCrops_21-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-SmallCrops_21-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation web">Selders, Arthur W. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20111114032130/http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf">"Frost protection with sprinkler irrigation"</a> <span class="cs1-format">(PDF)</span>. West Virginia university. Archived from <a rel="nofollow" class="external text" href="http://www.wvu.edu/~agexten/hortcult/fruits/om101.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 14 November 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">31 October</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Frost+protection+with+sprinkler+irrigation&rft.pub=West+Virginia+university&rft.aulast=Selders&rft.aufirst=Arthur+W.&rft_id=http%3A%2F%2Fwww.wvu.edu%2F~agexten%2Fhortcult%2Ffruits%2Fom101.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></span>
</li>
</ol></div>
<h2><span class="mw-headline" id="External_links">External links</span></h2>
<table role="presentation" class="mbox-small plainlinks sistersitebox" style="background-color:#f9f9f9;border:1px solid #aaa;color:#000">
<tbody><tr>
<td class="mbox-image"><img alt="" src="/upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="noviewer" srcset="/upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, /upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></td>
<td class="mbox-text plainlist">Wikimedia Commons has media related to <i><b><a href="https://commons.wikimedia.org/wiki/Category:Frost" class="extiw" title="commons:Category:Frost"><span style="">Frost</span></a></b></i>.</td></tr>
</tbody></table>
<table role="presentation" class="mbox-small plainlinks sistersitebox" style="background-color:#f9f9f9;border:1px solid #aaa;color:#000">
<tbody><tr>
<td class="mbox-image"><img alt="" src="/upwiki/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/40px-Wiktionary-logo-en-v2.svg.png" decoding="async" width="40" height="40" class="noviewer" srcset="/upwiki/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/60px-Wiktionary-logo-en-v2.svg.png 1.5x, /upwiki/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/80px-Wiktionary-logo-en-v2.svg.png 2x" data-file-width="512" data-file-height="512" /></td>
<td class="mbox-text plainlist">Look up <i><b><a href="https://en.wiktionary.org/wiki/Special:Search/frost" class="extiw" title="wiktionary:Special:Search/frost">frost</a></b></i> in Wiktionary, the free dictionary.</td></tr>
</tbody></table>
<ul><li><a rel="nofollow" class="external text" href="http://www.its.caltech.edu/~atomic/snowcrystals/frost/frost.htm">Guide to Frost</a></li>
<li><a rel="nofollow" class="external text" href="https://www.bbc.com/weather/features/41763562">How much do you know about frost?</a> – <i>BBC</i></li>
<li><a rel="nofollow" class="external text" href="http://glossary.ametsoc.org/wiki/Frost">American Meteorological Society, <i>Glossary of Meteorology</i> – Hoarfrost</a></li>
<li><a rel="nofollow" class="external text" href="http://www.islandnet.com/~see/weather/whys/frost.htm">The Weather Doctor – Weather Whys – Frost</a></li>
<li><cite class="citation encyclopaedia"><span class="cs1-ws-icon" title="s:The New International Encyclopædia/Frost"><a class="external text" href="https://en.wikisource.org/wiki/The_New_International_Encyclop%C3%A6dia/Frost">"Frost" </a></span>. <i><a href="/enwiki/wiki/New_International_Encyclopedia" class="mw-redirect" title="New International Encyclopedia">New International Encyclopedia</a></i>. 1906.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Frost&rft.btitle=New+International+Encyclopedia&rft.date=1906&rfr_id=info%3Asid%2Fen.wikipedia.org%3AFrost" class="Z3988"></span><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r935243608"/></li></ul>
<div role="navigation" class="navbox" aria-labelledby="Ice" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div class="plainlinks hlist navbar mini"><ul><li class="nv-view"><a href="/enwiki/wiki/Template:Ice" title="Template:Ice"><abbr title="View this template" style=";;background:none transparent;border:none;-moz-box-shadow:none;-webkit-box-shadow:none;box-shadow:none; padding:0;">v</abbr></a></li><li class="nv-talk"><a href="/enwiki/wiki/Template_talk:Ice" title="Template talk:Ice"><abbr title="Discuss this template" style=";;background:none transparent;border:none;-moz-box-shadow:none;-webkit-box-shadow:none;box-shadow:none; padding:0;">t</abbr></a></li><li class="nv-edit"><a class="external text" href="https://en.wikipedia.org/enwiki/w/index.php?title=Template:Ice&action=edit"><abbr title="Edit this template" style=";;background:none transparent;border:none;-moz-box-shadow:none;-webkit-box-shadow:none;box-shadow:none; padding:0;">e</abbr></a></li></ul></div><div id="Ice" style="font-size:114%;margin:0 4em"><a href="/enwiki/wiki/Ice" title="Ice">Ice</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div id="the_solid_state_of_water">the <a href="/enwiki/wiki/Solid" title="Solid">solid</a> <a href="/enwiki/wiki/State_of_matter" title="State of matter">state</a> of <a href="/enwiki/wiki/Water" title="Water">water</a></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/enwiki/wiki/Ice#Phases" title="Ice">Crystalline types</a></th><td class="navbox-list navbox-odd" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Ice_Ih" title="Ice Ih">I<span style="position: relative; top: 0.2em;"><span style="font-size:90%;">h</span></span></a></li>
<li><a href="/enwiki/wiki/Ice_Ic" title="Ice Ic">I<span style="position: relative; top: 0.2em;"><span style="font-size:90%;">c</span></span></a></li>
<li><a href="/enwiki/wiki/Ice_II" title="Ice II">II</a></li>
<li><a href="/enwiki/wiki/Ice_III" title="Ice III">III</a></li>
<li><a href="/enwiki/wiki/Ice_IV" class="mw-redirect" title="Ice IV">IV</a></li>
<li><a href="/enwiki/wiki/Ice_V" title="Ice V">V</a></li>
<li><a href="/enwiki/wiki/Ice_VI" title="Ice VI">VI</a></li>
<li><a href="/enwiki/wiki/Ice_VII" title="Ice VII">VII</a></li>
<li><a href="/enwiki/wiki/Ice_VIII" title="Ice VIII">VIII</a></li>
<li><a href="/enwiki/wiki/Ice_IX" title="Ice IX">IX</a></li>
<li><a href="/enwiki/wiki/Ice_X" class="mw-redirect" title="Ice X">X</a></li>
<li><a href="/enwiki/wiki/Ice_XI" title="Ice XI">XI</a></li>
<li><a href="/enwiki/wiki/Ice_XII" title="Ice XII">XII</a></li>
<li><a href="/enwiki/wiki/Ice_XIII" class="mw-redirect" title="Ice XIII">XIII</a></li>
<li><a href="/enwiki/wiki/Ice_XIV" class="mw-redirect" title="Ice XIV">XIV</a></li>
<li><a href="/enwiki/wiki/Ice_XV" title="Ice XV">XV</a></li>
<li><a href="/enwiki/wiki/Ice_XVI" title="Ice XVI">XVI</a></li>
<li><a href="/enwiki/w/index.php?title=Ice_XVII&action=edit&redlink=1" class="new" title="Ice XVII (page does not exist)">XVII</a></li>
<li><a href="/enwiki/wiki/Ice_XVIII" class="mw-redirect" title="Ice XVIII">XVIII</a></li>
<li><a href="/enwiki/wiki/Ice_crystals#Square_crystals" title="Ice crystals">Square crystals</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Formations and<br />phenomena</th><td class="navbox-list navbox-even" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Amorphous_ice" title="Amorphous ice">Amorphous solid</a></li>
<li><a href="/enwiki/wiki/Anchor_ice" title="Anchor ice">Anchor</a></li>
<li><a href="/enwiki/wiki/Black_ice" title="Black ice">Black</a></li>
<li><a href="/enwiki/wiki/Clathrate_hydrate" title="Clathrate hydrate">Clathrate hydrates</a></li>
<li><a href="/enwiki/wiki/Ice_cap" title="Ice cap">Cap</a></li>
<li><a href="/enwiki/wiki/Ice_cave" title="Ice cave">Cave</a></li>
<li><a href="/enwiki/wiki/Ice_circle" title="Ice circle">Circle or disc</a></li>
<li><a href="/enwiki/wiki/Clear_ice" title="Clear ice">Clear</a></li>
<li><a href="/enwiki/wiki/Ice_crystals" title="Ice crystals">Crystals</a></li>
<li><a href="/enwiki/wiki/Ice_dam_(roof)" title="Ice dam (roof)">Dam</a> (roof)</li>
<li><a href="/enwiki/wiki/Diamond_dust" title="Diamond dust">Diamond dust</a></li>
<li><a href="/enwiki/wiki/Drift_ice" title="Drift ice">Drift</a></li>
<li><a href="/enwiki/wiki/Ice_dune" title="Ice dune">Dune</a></li>
<li><a href="/enwiki/wiki/Ice_field" title="Ice field">Field</a></li>
<li><a href="/enwiki/wiki/Firn" title="Firn">Firn</a></li>
<li><a href="/enwiki/wiki/Ice_fog" title="Ice fog">Fog</a></li>
<li><a href="/enwiki/wiki/Frazil_ice" title="Frazil ice">Frazil</a></li>
<li><a class="mw-selflink selflink">Frost</a></li>
<li><a href="/enwiki/wiki/Frost_heaving" title="Frost heaving">Frost heave</a></li>
<li><a href="/enwiki/wiki/Frost_flower" title="Frost flower">Frost flower</a> (<a href="/enwiki/wiki/Frost_flower_(sea_ice)" title="Frost flower (sea ice)">sea ice</a>)</li>
<li><a href="/enwiki/wiki/Glacier" title="Glacier">Glacier</a></li>
<li><a href="/enwiki/wiki/Glaze_(ice)" title="Glaze (ice)">Glaze</a></li>
<li><a href="/enwiki/wiki/Hair_ice" title="Hair ice">Hair ice</a></li>
<li><a href="/enwiki/wiki/Iceberg" title="Iceberg">Iceberg</a> (<a href="/enwiki/wiki/Ice_calving" title="Ice calving">calving</a>)</li>
<li><a href="/enwiki/wiki/Icicle" title="Icicle">Icicle</a></li>
<li><a href="/enwiki/wiki/Ice_jacking" title="Ice jacking">Jacking</a></li>
<li><a href="/enwiki/wiki/Ice_jam" title="Ice jam">Jam</a></li>
<li><a href="/enwiki/wiki/Ice_nucleus" title="Ice nucleus">Nucleus</a></li>
<li><a href="/enwiki/wiki/Ice_sheet" title="Ice sheet">Sheet</a></li>
<li><a href="/enwiki/wiki/Ice_shove" title="Ice shove">Shove</a></li>
<li><a href="/enwiki/wiki/Ice_spike" title="Ice spike">Spike</a></li>
<li><a href="/enwiki/wiki/Stalactite#Ice_stalactites" title="Stalactite">Stalactites</a></li>
<li><a href="/enwiki/wiki/Macroscopic_quantum_phenomena" title="Macroscopic quantum phenomena">Macroscopic quantum phenomena</a></li>
<li><a href="/enwiki/wiki/N%C3%A9v%C3%A9" title="Névé">Névé</a></li>
<li><a href="/enwiki/wiki/Needle_ice" title="Needle ice">Needle</a></li>
<li><a href="/enwiki/wiki/Frost#Rime" title="Frost">Rime</a>
<ul><li><a href="/enwiki/wiki/Hard_rime" class="mw-redirect" title="Hard rime">hard</a></li>
<li><a href="/enwiki/wiki/Soft_rime" class="mw-redirect" title="Soft rime">soft</a></li></ul></li>
<li><a href="/enwiki/wiki/Sea_ice" title="Sea ice">Sea</a></li>
<li><a href="/enwiki/wiki/Slurry_ice" title="Slurry ice">Slurry</a></li>
<li><a href="/enwiki/wiki/Slush" title="Slush">Slush</a></li>
<li><a href="/enwiki/wiki/Snow" title="Snow">Snow</a></li>
<li><a href="/enwiki/wiki/Ice_storm" title="Ice storm">Storm</a></li>
<li><a href="/enwiki/wiki/Superionic_water" title="Superionic water">Superionic</a></li>
<li><a href="/enwiki/wiki/Ice_volcano" title="Ice volcano">Volcano</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Ice-related<br />activities</th><td class="navbox-list navbox-odd" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Ice_bath" title="Ice bath">Bathing</a></li>
<li><a href="/enwiki/wiki/Ice_blasting" title="Ice blasting">Blasting</a></li>
<li><a href="/enwiki/wiki/Ice_blocking" title="Ice blocking">Blocking</a></li>
<li><a href="/enwiki/wiki/Ice_climbing" title="Ice climbing">Climbing</a></li>
<li><a href="/enwiki/wiki/Ice_fishing" title="Ice fishing">Fishing</a></li>
<li><a href="/enwiki/wiki/Ice_rafting" title="Ice rafting">Rafting</a></li>
<li><a href="/enwiki/wiki/Ice_sculpture" title="Ice sculpture">Sculpture</a></li>
<li><a href="/enwiki/wiki/Ice_skating" title="Ice skating">Skating</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight: normal;"><a href="/enwiki/wiki/Winter_sport" class="mw-redirect" title="Winter sport">Sports</a></th><td class="navbox-list navbox-even" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Bandy" title="Bandy">Bandy</a></li>
<li><a href="/enwiki/wiki/Ice_boat" title="Ice boat">Boating</a> / <a href="/enwiki/wiki/Ice_yachting" title="Ice yachting">yachting</a></li>
<li><a href="/enwiki/wiki/Ice_cricket" title="Ice cricket">Cricket</a></li>
<li><a href="/enwiki/wiki/Curling" title="Curling">Curling</a></li>
<li><a href="/enwiki/wiki/Icetrack_cycling" title="Icetrack cycling">Cycling</a></li>
<li><a href="/enwiki/wiki/Figure_skating" title="Figure skating">Figure skating</a></li>
<li><a href="/enwiki/wiki/Ice_hockey" title="Ice hockey">Hockey</a></li>
<li><a href="/enwiki/wiki/Ice_racing" title="Ice racing">Racing</a></li>
<li><a href="/enwiki/wiki/Tour_skating" title="Tour skating">Tour skating</a></li></ul>
</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Constructions</th><td class="navbox-list navbox-odd" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Ice_bar" title="Ice bar">Bar</a></li>
<li><a href="/enwiki/wiki/Ice_bridge" title="Ice bridge">Bridge</a></li>
<li><a href="/enwiki/wiki/Ice_hotel" title="Ice hotel">Hotel</a></li>
<li><a href="/enwiki/wiki/Igloo" title="Igloo">Igloo</a></li>
<li><a href="/enwiki/wiki/Ice_palace" title="Ice palace">Palace</a></li>
<li><a href="/enwiki/wiki/Ice_pier" title="Ice pier">Pier</a></li>
<li><a href="/enwiki/wiki/Pykrete" title="Pykrete">Pykrete</a></li>
<li><a href="/enwiki/wiki/Ice_road" title="Ice road">Road</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Work</th><td class="navbox-list navbox-even" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Ice_cutting" title="Ice cutting">Cutting</a></li>
<li><a href="/enwiki/wiki/Icebox" title="Icebox">Icebox</a></li>
<li><a href="/enwiki/wiki/Ice_house_(building)" title="Ice house (building)">Icehouse</a></li>
<li><a href="/enwiki/wiki/Iceman_(occupation)" title="Iceman (occupation)">Iceman (occupation)</a></li>
<li><a href="/enwiki/wiki/Ice_pick" title="Ice pick">Pick</a></li>
<li><a href="/enwiki/wiki/Ice_trade" title="Ice trade">Trade</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other uses</th><td class="navbox-list navbox-odd" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Ice_chips" title="Ice chips">Chips</a></li>
<li><a href="/enwiki/wiki/Ice_core" title="Ice core">Core</a></li>
<li><a href="/enwiki/wiki/Ice_cream" title="Ice cream">Cream</a></li>
<li><a href="/enwiki/wiki/Ice_cube" title="Ice cube">Cube</a></li>
<li><a href="/enwiki/wiki/Ice_pack" title="Ice pack">Pack</a></li></ul>
</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/enwiki/wiki/Ice_age" title="Ice age">Ice ages</a></th><td class="navbox-list navbox-even" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><a href="/enwiki/wiki/Glaciology" title="Glaciology">Glaciology</a></li>
<li><a href="/enwiki/wiki/Little_Ice_Age" title="Little Ice Age">Little Ice Age</a></li>
<li><a href="/enwiki/wiki/Pleistocene" title="Pleistocene">Pleistocene</a></li></ul>
</div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>
<ul><li> <img alt="Category" src="/upwiki/wikipedia/en/thumb/4/48/Folder_Hexagonal_Icon.svg/16px-Folder_Hexagonal_Icon.svg.png" decoding="async" title="Category" width="16" height="14" srcset="/upwiki/wikipedia/en/thumb/4/48/Folder_Hexagonal_Icon.svg/24px-Folder_Hexagonal_Icon.svg.png 1.5x, /upwiki/wikipedia/en/thumb/4/48/Folder_Hexagonal_Icon.svg/32px-Folder_Hexagonal_Icon.svg.png 2x" data-file-width="36" data-file-height="31" /> <a href="/enwiki/wiki/Category:Water_ice" title="Category:Water ice">Category</a></li>
<li> <img alt="Commons page" src="/upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" title="Commons page" width="12" height="16" srcset="/upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, /upwiki/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /> <a href="https://commons.wikimedia.org/wiki/Category:Ice" class="extiw" title="commons:Category:Ice">Wikimedia Commons</a></li>
<li> <img alt="Wiktionary page" src="/upwiki/wikipedia/commons/thumb/e/ec/Wiktionary-logo.svg/16px-Wiktionary-logo.svg.png" decoding="async" title="Wiktionary page" width="16" height="15" srcset="/upwiki/wikipedia/commons/thumb/e/ec/Wiktionary-logo.svg/24px-Wiktionary-logo.svg.png 1.5x, /upwiki/wikipedia/commons/thumb/e/ec/Wiktionary-logo.svg/32px-Wiktionary-logo.svg.png 2x" data-file-width="370" data-file-height="350" /> <a href="https://en.wiktionary.org/wiki/ice" class="extiw" title="wikt:ice">Wiktionary</a></li></ul>
</div></td></tr></tbody></table></div>
<div role="navigation" class="navbox authority-control" aria-labelledby="Authority_control_frameless_&#124;text-top_&#124;10px_&#124;alt=Edit_this_at_Wikidata_&#124;link=https&#58;//www.wikidata.org/wiki/Q4590598&#124;Edit_this_at_Wikidata" style="padding:3px"><table class="nowraplinks hlist navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th id="Authority_control_frameless_&#124;text-top_&#124;10px_&#124;alt=Edit_this_at_Wikidata_&#124;link=https&#58;//www.wikidata.org/wiki/Q4590598&#124;Edit_this_at_Wikidata" scope="row" class="navbox-group" style="width:1%"><a href="/enwiki/wiki/Help:Authority_control" title="Help:Authority control">Authority control</a> <a href="https://www.wikidata.org/wiki/Q4590598" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="/upwiki/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" style="vertical-align: text-top" srcset="/upwiki/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, /upwiki/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></th><td class="navbox-list navbox-odd" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px"><div style="padding:0em 0.25em">
<ul><li><span class="nowrap"><a href="/enwiki/wiki/Library_of_Congress_Control_Number" title="Library of Congress Control Number">LCCN</a>: <span class="uid"><a rel="nofollow" class="external text" href="https://id.loc.gov/authorities/subjects/sh85052084">sh85052084</a></span></span></li>
<li><span class="nowrap"><a href="/enwiki/wiki/National_Diet_Library" title="National Diet Library">NDL</a>: <span class="uid"><a rel="nofollow" class="external text" href="https://id.ndl.go.jp/auth/ndlna/00570993">00570993</a></span></span></li></ul>
</div></td></tr></tbody></table></div>
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Whether or not the change was made through a Tor exit node (tor_exit_node) | false |
Unix timestamp of change (timestamp) | 1579642221 |
