Clouds 101: Cirrocumulus

Cirrocumulus (Cc) is a thin, white patch/sheet or layer of cloud without shading. Composed of very small elements in the form of grains, ripples etc. – merged or separate and more or less regularly arranged. Cirrocumulus is composed, almost exclusively, of ice crystals; strongly supercooled water droplets may be present but are usually rapidly replaced by ice crystals. Cirrocumulus generally occurs in more or less extensive sheets, consisting of very small elements in the form of grains, ripples etc. These sheets often show one or two systems of undulations. They may have fibrous margins. On rare occasions a Cirrocumulus sheet may show small, more or less regularly distributed round holes, many of them with fringed edges, which often give the cloud the appearance of a net or honeycomb. Cirrocumulus also occurs in patches in the shape of lenses or almonds, often very elongated and usually with well-defined outlines. More rarely, the elements of Cirrocumulus may consist of very small tufts with ragged lower parts or they may be in the form of very small turret-like protuberances which rise from a common horizontal base. Cirrocumulus clouds are always transparent enough to reveal the position of the sun or the moon. A corona or irisation is sometimes observed in clouds of this genus. Cirrocumulus may for in clear air. They may also result from the transformation of Cirrus or Cirrostratus or from a decrease in size of the elements of a patch, sheet or layer of Altocumulus. Cirrocumulus in the shape of almonds or lenses is usually produced by local orographic lifting of a layer of moist air.

Cirokumulusni oblaci (Cc) su tanka, bijela plahta, odnosno sloj visokih oblaka kod kojih nije prisutno znatno sjencenje, niti tamniji obrisi. Sastoje se od jako malih elemenata u obliku zrna, talasa vode i sl. Ti elementi mogu biti samostalni ili spojeni te manje-vise pravilno rasporedjeni na nebu. Cirokumulusni oblaci se, skoro iskljucivo, sastoje od ledenih kristala. I snazno prehladjene/pothladjene kapljice vode mogu biti prisutne no njih obicno u kratkom roku zamjenjuju ledeni kristali. Cirokumulusi se obicno pojavljuju u relativno prostranim plahtama koje su opet sastavljene iz ranije sopmenutih elemenata (oblik zrna, talasa itd.). Te oblacne plahte cesto kreiraju jedan ili dva sistema talasa (undulacija). Ivice im mogu biti vlaknaste (fibrozne). U rijetkim prilikama ce u oblacnom sloju Cirokumulusa biti vidljive male, relativno pravilno rasporedjene rupice od kojih ce mnogima ivice biti obrubljene resicama. Zbog toga ovi oblaci izgledaju i asociraju na mrezu ili pcelinju kosnicu. Cirokumulusi se takodjer prikazuju u krpicama oblika lece ili badema koje su cesto izduzene i lijepo definisanih obrisa. Jos rijedji prizor su Cirokumulusi koji su sastavljeni od malih cuperaka/pramenova te dosta poderanih, pocjepanih podnozja ili cak mogu biti u obliku manjih izbocina u obliku tornjeva koji se uzdizu iz dosta ravne, zajednicke baze. Osvijetljeni vijenac ili irizacija takodjer mogu biti osmotreni medju ovim oblacima. Cirokumulusi se mogu formirati u cistom zraku a mogu nastati kao posljedica transformacije Cirusa ili Cirostratusa kao i uslijed smanjivanja dimenzija elemenata dijela ili cijelog oblacnog sloja Altokumulusa. Cirokumulusi u obliku badema ili lece se obicno formiraju uslijed lokalno orografski uslovljenog uzdizanja sloja vlaznog zraka.