(Ci)
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Height of base: |
above 5000 to
15000 m (16500 - 45000 ft) (high-level clouds) |
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Description: |
Wispy, threadlike
clouds; drawn out by high
winds across the sky often together
with cirrostratus and cirrocumulus highest and
fastest moving clouds (although they may not appear thus) |
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Occurrence: |
World-wide |
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Made of: |
falling ice
crystals |
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Precipitation: |
None |
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Formation: |
Ice
deposition on deposition nuclei, Falling
through layers of different wind speed leads to drawn appearance Evaporation
if reaching layers with higher temperature |
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Species: |
Fibratus,
uncinus, spissatus, castellanus, floccus |
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Varieties: |
Intortus,
radiatus, vertebrates, duplicatus |
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How to
distinguish from … |
Cirrocumulus (Cc) |
Cc has cloudlets,
Ci does not have a dappled or grainy structure |
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Cirrostratus (Cs) |
Cs is thin milky
veil, while Ci has separate streaks and elements |
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Cirrus floccus (Kerkhoven, March 2006) |
Cirrus intortus (Morris, Sep 07) |
Cirrus fibratus radiatus Morris, October 07 |
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Cirrus floccus intortus Morris, Sep 07 |
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Cirrus intortus and altocumulus
castellanus Morris, March 28, 2008 |
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Cirrus radiatus and altocumulus
lenticularis Morris, May 16, 2008 |
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Last
modified: 5/16/2008
Maintained
by Sylke Boyd