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Cirrocumulus lacunosus

From Wikipedia, the free encyclopedia
Cirrocumulus lacunosus
Cirrocumulus lacunosus cloud 07/2023
(crop of full image)
AbbreviationCc la
Symbol
GenusCirro- (curl)
-cumulus (heaped)
Varietylacunosus (full of gaps)
AltitudeAbove 6,000 m
(Above 20,000 ft)
AppearancePerforated with round, frayed holes[1][2][3]
PrecipitationVirga only
Cirrocumulus lacunosus

Description

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Cirrocumulus lacunosus, also known as Cirrocumulus lacunar or Cirrocumulus lacunaris,[4] is a variety[1] of cirrocumulus cloud. The term lacunosus is from Latin, meaning "full of hollows".[5]

Cirrocumulus lacunosus is a relatively rare, fleeting[6] cloud form that occurs as a cloud layer with circular gaps or holes in it.[1][7] These gaps normally have frayed edges, and are often arranged in a manner that resembles a net or a honeycomb.[1][7][8]

Formation of this short-lived[6] phenomenon is commonly attributed to an overlying, cool layer of air mixing with an warmer atmospheric layer beneath. Each downflow of cool air creates an individual hole, and, as the warmer air rises, replacing the cooler air, water vapour condenses and forms ruffles around the gaps.[6][7][9][10]

The term lacunosus is usually used to further define the species stratiformis, castellanus, or floccus.[11]
This results in the following combinations of species and variety denominations for Cirrocumulus lacunosus:

  • Cirrocumulus stratiformis lacunosus
  • Cirrocumulus castellanus lacunosus
  • Cirrocumulus floccus lacunosus

Similar cloud forms

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Lacunosus must not be confused with the superficially similar cloud form cavum, a supplementary cloud feature also known as a fallstreak hole or as a hole punch. A fallstreak hole usually consists of one very large hole in a cloud layer combined with visible downdraft filaments in the centre, as opposed to 'lacunosus', which consists of a compact lattice or honeycomb of small to tiny holes.[7]

See also

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References

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  1. ^ a b c d "Lacunosus (Section 2.2.2.3.5)". World Metereological Organization. wmo.int. Retrieved 1 April 2023. chapter "Definitions of clouds > Varieties > Lacunosus"
  2. ^ "lacunosus". AMS Glossary of Meteorology. American Meteorological Society (AMS). 29 March 2024. Retrieved 11 July 2024.
  3. ^ "Cloud Classification: Genera and Species". skybrary.aero. SKYbrary Aviation Safety. Retrieved 8 November 2024.
  4. ^ "Appendix 3 - History of cloud nomenclature (Section A.3)". cloudatlas.wmo.int.
  5. ^ Numen - The Latin Lexicon. "Definition of stratus". latinlexicon.org. Retrieved 21 July 2011.
  6. ^ a b c "About Lacunosus". cloudappreciationsociety.org. Retrieved 8 November 2024.
  7. ^ a b c d "Lacunosus Cloud Variety: Perforated, Frayed Holes". whatsthiscloud.com. Retrieved 2024-07-02.
  8. ^ Callanan, Martin. "Cirrocumulus lacunosus". International Cloud Atlas. nephology.eu. Archived from the original on 13 November 2022. Retrieved 21 July 2011.[dead link][dead link]
  9. ^ "Cirrocumulus Lacunosus Cloud - EPOD - a service of USRA". epod.usra.edu.
  10. ^ Dunlop, Storm (2003). The weather identification handbook (1st Lyons Press ed.). Guilford, Conn.: Lyons Press. p. 67. ISBN 1-58574-857-9.
  11. ^ Aerographer/Meteorology (2012). "Cloud Variety". meteorologytraining.tpub.com. Archived from the original on 21 December 2012. Retrieved 2 July 2012.
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