This week appears to have been overtaken by clouds, as a central theme. Yesterday’s Tuesday Photo Challenge is about clouds, Monday’s response to dreams included a cloud as a central character, and now today.
As I am in Israel this week and lucky enough to be staying at a hotel right at the beach, I have been able to observe some interesting cloud formations develop during the evening. While I am certainly not an expert on clouds, the particular cloud in the image that I captured the other event made me curious enough to look for more detail.
The cloud in the image is recognized by most of us as a cumulonimbus cloud, or a rain cloud, as we have seen enough of them. What made me curious is the updrafts that were forming to create the top of this cloud, which led me to find out that there are several distinct types of cumulonimbus clouds.
Cumulonimbus calvus is a moderately tall cumulonimbus cloud which is capable of precipitation, but has not yet reached the tropopause, which is the height of stratospheric stability where it forms into a cumulonimbus capillatus (fibrous-top) or cumulonimbus incus (anvil-top). Cumulonimbus calvus clouds develop from cumulus congestus, and its further development under auspicious conditions will result in cumulonimbus incus.
This cloud consists mainly of water droplets. By definition of cumulonimbus cloud, at its top water droplets are transformed into ice crystals, but for cumulonimbus calvus content of ice crystals is small and freezing is in early stage, so cloud top still looks round and puffy.
Cumulonimbus calvus is characterized by distinctive (between other types of cumulonimbus cloud) rounded shape and relatively sharp edges of its top area, unlike cumulonimbus incus or cumulonimbus capillatus, which have cirriform tops. Developing cumulonimbus calvus loses sharp outlines of the top as more water droplets transform into ice crystals. Strong updrafts may form pileus or thin vertical stripes protruding upwards out of the cloud. When upper part of the cloud freezes to greater extent and clearly visible cirriforms appears, cumulonimbus calvus turns into another species of cumulonimbus.
Hope this was interesting to you!
Technical Details
This image was captured at the beach in Herzliya, Israel, using an iPhone 6S with the standard Camera app.
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