Mist is a phenomenon caused by small droplets of water 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 vapor to ...

. 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 conditions are right. It can also occur as part of natural weather, 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 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 Stratus clouds are low-level clouds characterized by horizontal layering with a uniform base, as opposed to convective or cumuliform clouds that are formed by rising thermals. More specifically, the term ''stratus'' is used to describe flat, haz ...

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, cleared or marsh 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 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 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 influe ...

, 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 File:Misty morning02.jpg, Misty morning at Swifts Creek File:Herbert Lake beim Icefields Parkway.jpg, Mist on a lake in Alberta, Canada File:NeblinaJBCuritiba2.JPG, Curitiba, 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