• Photos/Telescopes

Calculs cloud



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m
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Décimales

Cloud base height

The cloud base (or the base of the cloud) is the lowest altitude of the visible portion of the cloud. The height of the cloud base can be measured using a ceilometer. This device reflects a beam of light off the cloud base and then calculates its distance using either triangulation or travel time. Alternatively, the cloud base can be estimated from surface measurements of air temperature and humidity. In well-defined air masses, many (or even most) clouds may have a similar cloud base because this variable is largely controlled by the thermodynamic properties of that air mass, which are relatively homogeneous on a large spatial scale. This is not the case for the cloud tops, which can vary widely from cloud to cloud, as the depth of the cloud is determined by the strength of local convection. Cloud base is an important meteorological variable for aviation safety, as it determines whether pilots may use Visual Flight Rules (VFR) or must follow Instrument Flight Rules for take-off or landing.


Style

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Unités

Langue



Icônes


Température

Humidité

Pression

Vitesse du vent

Rafale de vent

Précipitations

Rayonnement solaire

Neige

Température ressentie

Point de rosée

INDICE UV

Visibilité

Base des nuages

Evapotraspiration

Température intérieure

Humidité intérieure


Lever du soleil

Coucher du soleil

Lever de lune

Coucher de lune

Time

Menu

De

à

Plein écran

Exporter comme image

Réglages

Page d\'accueil

Caméra Web

Table

Graphique

Carte

Stable

En hausse

En baisse

Vigilance

Latitude

Longitude

Historique

éclipse solaire

éclipse de lune

GPS

Élévation

Jour

Mois

Année

Haut température

Basse température

Jour

Nuit

Printemps

Été

Automne

Hiver