TERMIUM Plus®

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UNSTABLE ATMOSPHERE [9 records]

Record 1 2023-02-23

English

Subject field(s)
  • Atmospheric Physics
  • Environmental Studies and Analyses
CONT

Vertical atmospheric motion. Most brief but violent disturbances in Earth's wind systems involve large areas of ascending and descending air.... a thunderstorm is said to develop when the atmosphere becomes "unstable to vertical motion[. "] Such an instability can arise whenever relatively warm, light air is overlain by cooler, heavier air. Under such conditions[, ] the cooler air tends to sink, displacing the warmer air upward.

French

Domaine(s)
  • Physique de l'atmosphère
  • Études et analyses environnementales
OBS

mouvement atmosphérique vertical; mouvement vertical atmosphérique : désignations habituellement utilisées au pluriel.

Key term(s)
  • mouvements atmosphériques verticaux
  • mouvements verticaux atmosphériques

Spanish

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Record 2 2012-11-21

English

Subject field(s)
  • Atmospheric Physics
CONT

stable : A non-convective state in the atmosphere, opposite of unstable.

French

Domaine(s)
  • Physique de l'atmosphère
CONT

stable : État non convectif de l'atmosphère, opposé à «instable».

Spanish

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Record 3 2009-11-09

English

Subject field(s)
  • Atomic Physics
DEF

The splitting of atoms in the upper atmosphere through the bombardment of cosmic rays.

OBS

This results in the formation of new, often unstable, isotopes. Spallation reactions occur in the upper atmosphere when cosmic rays hit gas molecules and also at the surface of the earth by direct cosmic ray irradiation of atoms in solid geological materials.

French

Domaine(s)
  • Physique atomique
DEF

Réaction nucléaire où les noyaux sont éclatés en particules.

Spanish

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Record 4 2005-04-25

English

Subject field(s)
  • Atmospheric Physics
DEF

The layering of different temperatures of ... air caused by different densities, less dense floating on more dense layers.

CONT

Thermal stratification of the atmosphere is characteristic of the Nocturnal Boundary Layer (NBL), particularly in basin topography where surface cooling combines with drainage flows from competing sources to create a complex thermal structure that can play an important role in transport and diffusion of pollution.

CONT

Atmospheric stability describes the thermal stratification or vertical temperature structure of the atmosphere. Generally, six or seven different classes of atmospheric stability are used to describe the atmosphere. These classes range from extremely unstable(when atmospheric turbulence is greatest) to extremely stable(when atmospheric mixing is at a minimum and wind speeds are low). When the atmosphere is unstable, pollutants can rapidly diffuse through a large volume of the atmosphere. When the atmosphere is stable, pollutants will diffuse much more slowly in a vertical direction

PHR

Mean, stable, vertical thermal stratification of the atmosphere,

PHR

Lower, stable, unstable, weak, atmospheric thermal stratification.

French

Domaine(s)
  • Physique de l'atmosphère
CONT

L'inversion de température [...] affecte les 50 premiers mètres de la troposphère. Avec la nuit, surtout en hiver, le sol se refroidit plus rapidement que les couches d'air. Au cours de la nuit les premières couches d'air vont peu à peu devenir plus froide que celle située au dessus, la stratification thermique (plus on monte, plus il fait froid) est donc inversée.

CONT

La stratification thermique de l'air est importante pour la compréhension de la dispersion des polluants. Si la température diminue de façon constante avec l'altitude, l'atmosphère est alors dite instable, le polluant se disperse davantage en hauteur. S'il se met en place une couche d'inversion, c'est à dire que la température augmente de nouveau en altitude, l'atmosphère est dite stable. Si le polluant est émis en dessous de cette limite d'inversion, dans la couche limite atmosphérique, le polluant sera bloqué dans sa progression verticale, tandis que s'il est émis au dessus, sa dispersion vers le sol sera bloquée.

CONT

Les échanges verticaux entre les différentes couches de l'atmosphère sont limités par la stratification thermique de l'atmosphère et par les différents régimes de vents.

PHR

Stratification thermique horizontale, instable, inverse, verticale.

Spanish

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Record 5 2004-10-29

English

Subject field(s)
  • Atmospheric Physics
DEF

Air mass having static instability in its lower layers ...

CONT

If the airmass is unstable, air which is pushed upward by some force will continue upward. An unstable airmass usually contains relatively warm(usually moist) air near the earth's surface and relatively cold(usually dry) air in the mid and upper levels of the atmosphere.

OBS

unstable air mass: ... convective clouds and precipitation occur if its moisture content is sufficiently high.

Key term(s)
  • unstable air-mass

French

Domaine(s)
  • Physique de l'atmosphère
DEF

Masse d'air présentant de l'instabilité hydrostatique dans ses couches inférieures [...]

OBS

masse d'air instable : [...] des nuages convectifs et des précipitations se produisent si sa teneur en humidité est suffisamment élevée

Spanish

Campo(s) temático(s)
  • Física de la atmósfera
DEF

Masa de aire que presenta inestabilidad hidrostática en las capas inferiores [...]

OBS

masa de aire inestable: [...] se producen nubes convectivas y precipitaciones si el contenido de humedad es suficientemente alto.

Save record 5

Record 6 2002-11-04

English

Subject field(s)
  • Chemical Elements and Compounds
  • Pollutants
  • Climate Change
CONT

The chemical agents implicated in the ozone depletion phenomena are the halogenated compounds known as "halocarbons. "Though stable in the lower atmosphere, scientists believe they become unstable in sunlight in the atmosphere, and react with ozone, forming new compounds, thereby depleting the ozone available for screening.

CONT

Measurements of concentration trends and sensitivity studies by means of radiation models have resolved that the strongest climatic change signals are to be expected from CFCl3 (F 11), FC2Cl[subscript 2 (F 12), CH4, N2O and O3. A number of other halogenated compounds and hydrocarbons altogether probably are less important than any one of the above mentioned constituents and will not be considered specifically in the present context.

French

Domaine(s)
  • Éléments et composés chimiques
  • Agents de pollution
  • Changements climatiques
DEF

[Composé] chimique qui renferme au moins un halogène.

OBS

Les halogènes sont le fluor, le chlore, le brome, l'iode et l'astate; seuls les quatre premiers sont vraiment considérés dans le processus d'halogénation. Le chlore, parmi tous les halogènes, représente le produit le plus menaçant pour la couche d'ozone stratosphérique.

Spanish

Campo(s) temático(s)
  • Elementos y compuestos químicos
  • Agentes contaminantes
  • Cambio climático
Save record 6

Record 7 1992-12-31

English

Subject field(s)
  • Air Pollution
DEF

A pollution plume with a flat base but appreciable vertical spread indicative of an atmosphere which is statically stable up to the base of the plume and unstable above.

French

Domaine(s)
  • Pollution de l'air
DEF

Panache de pollution à base plate mais d'extension verticale importante, qui indique une atmosphère statiquement stable jusqu'à la base du panache et instable au-dessus.

Spanish

Campo(s) temático(s)
  • Contaminación del aire
DEF

Penacho de contaminación de base plana, pero de apreciable extensión vertical, que indica una atmósfera estáticamente estable hasta la base e inestable por encima.

Save record 7

Record 8 1992-12-31

English

Subject field(s)
  • Air Pollution
  • Atmospheric Physics
  • Chimneys (Building Elements)
DEF

Formation of a pollution plume which is distorted by large vertical eddies in an unstable atmosphere.

French

Domaine(s)
  • Pollution de l'air
  • Physique de l'atmosphère
  • Cheminées (Éléments du bâtiment)
DEF

Panache de pollution distordu par de grands tourbillons verticaux dans une atmosphère instable.

Spanish

Campo(s) temático(s)
  • Contaminación del aire
  • Física de la atmósfera
  • Chimeneas (Elementos de edificios)
DEF

Formación de un penacho de contaminación causado por turbulencias verticales en una atmósfera inestable.

Save record 8

Record 9 1988-04-14

English

Subject field(s)
  • Air Pollution
  • Environmental Studies and Analyses
  • Meteorology
CONT

Between the source and sink of a pollutant in the atmosphere dispersion and transport occur simultaneously. Dispersion is caused by turbulent eddies which develop in air that is thermally unstable or that is subjected to a strong wind shear. Transport is controlled by air circulations whose driving force may be local, regional or global in extent.

French

Domaine(s)
  • Pollution de l'air
  • Études et analyses environnementales
  • Météorologie

Spanish

Save record 9

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