Cirrocumulus cloud

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Cirrocumulus cloud
Cirrocumulus at the top of the image
Abbreviation	CC
Genus	Cirro- (curl of hair) -cumulus (heaped)
Altitude	Above 6000 m (20,000 ft)
Classification	Family A (High-level)
Appearance	Small, high, patched clouds, in rows
Precipitation cloud?	Sometimes; occasional virga
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Cirrocumulus clouds are high-altitude clouds that usually occur at an altitude of 5 km to 12 km. Like other cumulus clouds, cirrocumulus clouds signify convection. Unlike other cirrus clouds, cirrocumulus include a small amount of liquid water droplets, although these are in a supercooled state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled water drops in the cloud to rapidly freeze, transforming the cirrocumulus into cirrostratus. This process can also produce precipitation in the form of a virga consisting of ice or snow. Thus cirrocumulus clouds are usually short-lived.^[1]

Properly, the term cirrocumulus refers to each cloud, but is typically also used to refer to an entire patch of cirrocumulus. When used in this way, each cirrocumulus element is referred to as a "cloudlet".^{[citation needed]}

Appearance

A cirrocumulus is typically a large, white patch or tuft without a gray shadow. Each cloudlet is no larger than a finger held at arms length.^[1] It occurs in patches or sheets along with other cirrocumulus. These often are organized in rows like other cumulus, but since they are so small, cirrocumulus patches take on a finer appearance, sometimes referred to colloquially as "herringbone" or "mackerel".

The cirrocumulus is distinguished from the somewhat similar altocumulus in several ways, although the two cloud types can occasionally occur together with no clear demarcation between them. Cirrocumulus generally occur at higher altitudes than altocumulus, and thus the "cloudlets" appear smaller as they are more distant from observation at ground level. They are also colder. Cirrocumulus clouds never cast self-shadows and are translucent to certain degree. They are also typically found amongst other cirrus clouds in the sky, and are usually themselves seen to be transforming into these other types of cirrus.^[1]

References

1. ^ ^{a b c} The cloud collectors handbook Gavin Pretor-Pinney, ISBN 978 0 340 91943 9 page 21

External links

International Cloud Atlas - Cirrocumulus