What is cloud?

  • (noun): A group of many insects.
    Example: "A cloud of butterflies"
    Synonyms: swarm
    See also — Additional definitions below


In meteorology, a cloud is a visible mass of liquid droplets or frozen crystals made of water or various chemicals suspended in the atmosphere above the surface of a planetary body. These suspended particles are also known as aerosols. Clouds in earth's atmosphere are studied in the cloud physics branch of meteorology. Two processes, possibly acting together, can lead to air becoming saturated; cooling the air or adding water vapor to the air. In general, precipitation will fall to the surface; an exception is virga, which evaporates before reaching the surface.

Read more about Cloud.

Some articles on cloud:

Jeans Instability - Jeans Length
... Jeans' length is the critical radius of a cloud (typically a cloud of interstellar dust) where thermal energy, which causes the cloud to expand, is counteracted by ... Length is where is Boltzmann's constant, is the temperature of the cloud, is the radius of the cloud, is the mass per particle in the cloud, is the Gravitational Constant ... the cloud's mass divided by the cloud's volume) ...
Entrainment (meteorology)
... Entrainment is the mixing of environmental air into a preexisting air current or cloud so that the environmental air becomes part of the current or cloud ... The entrainment coefficient in clouds is one of the most sensitive variables causing uncertainty in climate models ... mixing is a model that assumes that the timescale for the mixing within a cloud was large compared to the condensation timescale ...
Cloud - Extraterrestrial
... Within our Solar System, any planet or moon with an atmosphere also has clouds ... Venus's thick clouds are composed of sulfur dioxide ... Mars has high, thin clouds of water ice ...
Preston Cloud - Professional Career
... Cloud's professional career alternated between the United States Geological Survey (where he was chief paleontologist from 1949-1959) and academia (Misso ... While at UCSB he founded that institution's Preston Cloud Research Laboratory, originally dedicated to paleomicrobiology and to studies of the first lunar geological samples from the Apollo 11 ... Cloud was a member of the National Academy of Sciences for thirty years, he was chairman of the Geology Section and occupied positions in its Council and Executive Committee ...
Cloud Nine
... Cloud nine or on cloud nine is an idiom referring to a state of elation or happiness ... It may also refer to ...

More definitions of "cloud":

  • (noun): Any collection of particles (e.g., smoke or dust) or gases that is visible.
  • (noun): A cause of worry or gloom or trouble.
    Example: "The only cloud on the horizon was the possibility of dissent by the French"
  • (noun): Suspicion affecting your reputation.
    Example: "After that mistake he was under a cloud"
  • (noun): A visible mass of water or ice particles suspended at a considerable altitude.
  • (verb): Billow up in the form of a cloud.
    Example: "The smoke clouded above the houses"
  • (verb): Colour with streaks or blotches of different shades.
    Synonyms: mottle, dapple
  • (verb): Make gloomy or depressed.
    Example: "Their faces were clouded with sadness"
  • (verb): Make overcast or cloudy.
    Synonyms: overcast
  • (verb): Make milky or dull.
    Example: "The chemical clouded the liquid to which it was added"
  • (noun): Out of touch with reality.
    Example: "His head was in the clouds"

Famous quotes containing the word cloud:

    If you wish --
    ... I’ll be irreproachably tender;
    not a man, but—a cloud in trousers!
    Vladimir Mayakovsky (1893–1930)

    Humorists are always pessimists. They’re reactionaries: because they see that every golden cloud has a black lining.
    Christina Stead (1902–1983)

    Not for no cold did freeze,
    Nor any cloud beguile
    Th’eternal flowering spring,
    Torquato Tasso (1544–1595)