Cumulus humilis clouds in summer over trees, forming in clear polar air. Cumulus clouds typically occur under 2000 metres altitude. They form from water vapour in rising columns of air which condenses as it cools. Cumulus clouds often form at cold fronts where the advancing, cool air forces warm air upwards. The humilis variety occurs either as the first stage of the formation of other cumulus types, or when heat transfer (convection) in the atmosphere is weak. Due to its shallow depth, cumulus humilis does not produce any significant weather. Photographed in the late morning in summer, from near Trelissick, Cornwall, UK. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / STEPHEN BURT |
Taille de l’image : | 5616 px × 3744 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |