Cirrocumulus (Cc) - the name is a composite of the Latin cirrus = wisp or curl and cumulus = small heap. Cirrocumulus is a member of the ten fundamental cloud types (or cloud genera). Cirrocumuli are high-level clouds appearing as a formation of small masses of white or pale blue, fleecy clouds in a globular, wavelike, rippled pattern, usually in regularly arranged groupings. However, unlike cirrus or cirrostratus they are always broken up into tiny elements and ripples. They form at altitudes between about 5 and 10km (about 16,600 and 30,000ft).
Cirrocumuli are often inconspicuous and overlooked, both because it is thin, and also because the individual cloud elements are small. More over they are more distant than the similar lower clouds, altocumulus and stratocumulus. In fact, there is a relationship among these three cloud genera: the thicker the cloud elements and cloud layer, the higher the cloud. Sheets of cirrocumuli are often very thin, always transparent and extremely low in contrast and difficult to see against the sky. Sun or moon are always visible and objects on the ground still cast shadows. Cirrocumulus elements normally show no shading, in contrast do the darker shading thicker, lower altocumulus.
Cirrocumulus are composed of highly
supercooled water droplets (which tend to be converted into ice crystals very rapidly), ice crystals, or a mixture of both. The even-sized cloud particles may produce
coronae and iridescence around the Sun or Moon.
Common types and varieties of cirrocumulus:
What do cirrocumuli tell about the weather?