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Clouds : classification
Genera species Subspecies

Special forms

Cirrocumulus undulatus (Ci un)

Cirrocumuli (v. Lat. Cirrus "lock of hair, a tuft of horse hair, plume" and cumulus "accumulation"; abbr. : Cc ) are thin, white spots, areas or layers of clouds without self-shadowing , consisting of very small, grainy, gerippelt ( small fleecy clouds) or similar-looking, intergrown or isolated cloud particles and are more or less regularly arranged. Most cloud parts have an apparent latitude of less than one degree. This corresponds roughly to the apparent width of the little finger with an outstretched arm.

Cirrocumulus clouds can get so high that they form atypical shadows underneath and can be mistaken for altocumulus . The cirrocumulus can also look similar to the cirrostratus , but is called a cirrocumulus as long as the greater part of its underside is ribbed or divided into small clouds.

Special types of cirrocumulus are stratiformis , lenticularis , castellanus , and floccus as well as the subspecies undulatus and lacunosus . For special forms, accompanying and mother clouds, see the article cloud.

Physical structure and appearance

The cirrocumulus consists almost exclusively of ice crystals. Severely supercooled water droplets may be present, but are usually quickly replaced by ice crystals. Cirrocumuli usually occur in more or less extensive fields, which consist of very small, granular, rippled or similar-looking cloud parts (stratiformis). These fields are often arranged in one or two wave systems (undulatus). They can have ragged edges. In rare cases, a cirrocumulus field can also have more or less regularly distributed, small round gaps with often frayed edges, which often gives the appearance of a net or a honeycomb (lacunosus).

Cirrocumuli also occur in lenticular or almond-shaped banks, which are often very elongated and usually have sharply defined outlines (lenticularis). In rare cases, the individual parts of a cirrocumulus cloud can also consist of very small, torn tufts below (floccus), or they can also have the form of very small, tower-like swellings that grow out of a common horizontal base (castellanus). The clouds are always so translucent that they show the position of the sun and moon. Sometimes iridescence or the formation of a corona is observed in clouds of this genus .


A cirrocumulus can arise in a cloud-free space, but also when cirrus or cirrostratus reshapes, as well as due to the shrinking of the partial clouds of a patch, a field or a layer of altocumulus. A cirrocumulus lenticularis is usually caused by the local orographical uplift of a layer of moist air.


Cirrocumulus is to be distinguished from other similar looking forms.

Cirrus and Cirrostratus

Cirrocumuli in rounded tufts or in the form of small rounded turrets that grow out of a common base can be confused with similar looking cirrus. The distinguishing feature is that the cirrocumulus tufts or turrets, unlike those of the cirrus, have a width of less than 1 degree, provided they are observed at an angle of more than 30 degrees above the horizon. A cirrocumulus field differs from cirrus and cirrostratus in its rippled shape and subdivision into very small clouds. Fibrous, silky or smooth-looking sections (which are characteristic of Cirrus or Cirrostratus) can occur; However, they only make up the smaller part overall.


Cirrocumulus differs from Altocumulus in that most of the cloud parts are very small (by definition they have a latitude of less than 1 degree if they are observed at an angle of more than 30 degrees above the horizon) and do not form any shadows of their own.

Web links

Commons : Cirrocumulus  - album with pictures, videos and audio files