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. Physically, it is an example of a dispersion. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such as in

exhale Exhalation (or expiration) is the flow of the breath out of an organism. In animals, it is the movement of air from the lungs out of the airways, to the external environment during breathing. This happens due to elastic properties of the lungs, ...

d 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 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 on ...

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 eventua ...

, 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, 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 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 ...

, cleared or marsh area is usually called "fog". One main difference between mist and fog 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 and scattering 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 Ter ...

, 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 c ...

, 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