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 ...

suspended in the cold air, usually by

condensation Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapo ...

. 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 variatio ...

. 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. 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 dep ...

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, is greatly aided by the presence of nucleation sites on which the suspended water phase can congeal. Thus even such unusual sources of nucleation as small particulates from volcanic eruptions, releases of strongly polar gases, and even the magnetospheric ions associated with

polar lights An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of br ...

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 c ...

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

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

is visibility. 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 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 phenomen ...

and

scattering Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including ...

on the suspended water droplets, and rainbows 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, 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, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

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 T ...

, Canada File:NeblinaJBCuritiba2.JPG,

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

, Brazil File:Labugama26.jpg, Labugama, 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