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Special clouds with pouch-shaped protuberances could be admired on Monday evening. These are so-called mamma clouds, which usually form behind retreating and dissipating thunderstorms.
The formation of the Mamma clouds has been researched for more than 100 years. To date, however, there are various theories for the origin of the breast.
evaporation and sublimation
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Evaporation and sublimation lead to Mamma clouds.
FELIX DIETZSCH
One of the most common theories is that ice or snow crystals and water droplets fall from the cloud into the dry air layer below and evaporate or sublimate there (direct transition from solid to gaseous). This results in a subsidence of the whole cloud, which leads to Mamma clouds.
melting processes
As with evaporation and sublimation, heat is extracted from the air below the cloud during formation by melting processes. The air becomes more unstable and the protuberances visible in the photos are formed.
Mammatus: Hanging protuberances, like pouches, on the undersurface of a cloud.
radiation effects
Mamma clouds could also be caused by long-wave radiation from the top of the cloud. This would result in a so-called downward convection, which could also result in the typical “sacks”.
None of the theories has been proven and there are various observations that make the individual theories impossible as the sole cause.
Different types of clouds
Mamma clouds usually form on the underside of a thundercloud, i.e. a cumulonimbus cloud. However, they have also been observed in the cloud genera Cirrus, Cirrocumulus, Altocumulus, Altostratus and Stratocumulus.