A cloud is composed of water or ice droplets. The air is completely saturated.
Types of cooling #
To saturate air (at almost constant pressure), it must be cooled. There are 4 types of cooling:
Frontal cooling
Two air masses of different properties (warm and cold) meet. They do not mix. The warmer one is forced to rise (it is the lighter one). As it rises, it cools and condenses.
Orographic uplift
An air mass encounters a mountain and is forced to rise. The air cools and condensation can occur.
Convective cooling
The ground heats the air at its contact forcing it to rise. As it rises, it cools and condenses (figure at left).
Base cooling
Warm, moist air flows onto a cooler surface.
Classification of different clouds #
You can recognize a cloud by its shape and altitude (see Recognizing Clouds for pictures).
The different types of clouds
- Etage supérieur (5000 m et plus) : cirro.
- Etage moyen(2000–5000m) : alto.
- Etage bas (2000m et moins) à développement vertical : cumulo.
- En couche : air stable, nuage stratiforme.
- Développement vertical : air instable, nuage cumuliforme.
Comment appelle t’on la couche de l’étage supérieur?
Réponse
La couche cirro.
Complétez la phrase suivante: “Les nuages à développement vertical sont de la famille des ____ et sont de nature ____, les nuages à développement en couche sont de la famille des ____ et sont de nature ____"
Réponse
Vertically developing clouds are of the cumuliform family and are unstable in nature, layer developing clouds are of the stratiform family and are stable in nature.