Mist is a phenomenon caused by small droplets of

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

suspended in the cold

air The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

, usually by condensation. Physically, it is an example of a

dispersion Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns * Price dispersion, a variation in prices across sellers of the same item *Wage dispersion, the amount of variat ...

. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such as in exhaled air in the winter, or when throwing water onto the hot stove of a

sauna A sauna (, ), or sudatory, is a small room or building designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these facilities. The steam and high heat make the bathers perspire. A thermometer in a ...

. It can be created artificially with aerosol canisters if the

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

and

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

conditions are right. It can also occur as part of natural

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

, when humid air cools rapidly, notably when the air comes into contact with surfaces that are much cooler than the air (e.g. mountains). The formation of mist, as of other

suspensions In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye, usually must be larger than one micrometer, and will eventually ...

, is greatly aided by the presence of

nucleation site In thermodynamics, nucleation is the first step in the formation of either a new Phase (matter), thermodynamic phase or Crystal structure, structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically def ...

s on which the suspended water phase can congeal. Thus even such unusual sources of nucleation as small particulates from

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often ...

s, releases of strongly polar gases, and even the

magnetospheric In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynamo. ...

ions associated with polar lights can in right conditions trigger condensation and the formation of mist. Mist is commonly confused with

fog Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...

, which resembles a stratus cloud lying at ground level. These two phenomena differ, but share some commonalities; similar processes form both fog and mist. Fog is denser, more opaque, and generally lasts a longer time, while mist is thinner and more transparent.

Description

Cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud co ...

is often referred to as "mist" when encountered on surfaces of mountains, whereas moisture suspended above a

body of water A body of water or waterbody (often spelled water body) is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as p ...

, cleared or

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

area is usually called "fog". One main difference between mist and

visibility The visibility is the measure of the distance at which an object or light can be clearly discerned. In meteorology it depends on the transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time o ...

. The phenomenon is called fog if the visibility is or less. In the United Kingdom, the definition of fog is visibility less than on the surface for driving purposes, UK Highway Code rule 226, while for pilots the distance is 1 km at cruising height. Otherwise, it is known as mist. Mist makes a

light beam A light beam or beam of light is a directional projection of light energy radiating from a light source. Sunlight forms a light beam (a sunbeam) when filtered through media such as clouds, foliage, or windows. To artificially produce a light ...

visible from the side via

refraction In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomeno ...

and scattering on the suspended water droplets, and

rainbows A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows ca ...

can be possibly created. "Scotch mist" is a light steady drizzle that appears like mist. Mist usually occurs near the shores and is often associated with fog. Mist can be as high as mountain tops when extreme temperatures are low and strong condensation occurs. Freezing mist is similar to

freezing fog Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...

, only the density is less and the visibility greater. When fog falls below 0°C, it is known as freezing fog, however it still stays suspended).

Gallery

File:Mist - Ensay region3.jpg, Mist lying in the folds of hills, Australia File:Fog in Albuquerque - AAfog3.jpg, Sunlight through mist on a crisp winter morning in

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

File:Misty morning02.jpg, Misty morning at Swifts Creek File:Herbert Lake beim Icefields Parkway.jpg, Mist on a lake in

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

, Canada File:NeblinaJBCuritiba2.JPG,

Curitiba Curitiba () is the capital and largest city in the state of Paraná (state), Paraná in Brazil. The city's population was 1,948,626 , making it the List of cities in Brazil by population, eighth most populous city in Brazil and the largest in ...

, Brazil File:Labugama26.jpg,

Labugama Labugama ( si, ලබුගම, ta, லாபுகம) is a village in Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly k ...

, Sri Lanka File:River Exe in mist - geograph.org.uk - 266487.jpg, River Exe in mist

References

{{reflist Air pollution Fog Psychrometrics

Description

Gallery

See also

References