total cloud amount

fractional cloud cover

quotient of the sum of the solid angles subtended by clouds and the solid angle 2π sr of the whole sky

Note 1 to entry: Observation of total cloud amount is usually recorded in tenths or oktas, where one okta indicates an extent of cloud cover equal to one eighth of the sky.

Note 2 to entry: The total cloud amount has unit one.

Note 3 to entry: This entry was numbered 845-09-92 in IEC 60050-845:1987.

Note 4 to entry: This entry was numbered 17-1321 in CIE S 017:2011.

Publication date: 2020-12
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