Meaning of roughness length in English:
roughness length
noun
MeteorologyA parameter used in representing the variation of horizontal wind speed with height immediately above the ground (or water surface), and typically corresponding to the unevenness of the surface; also "surface roughness length".
Origin
1930s; earliest use found in Quarterly Journal of the Royal Meteorological Society. Translating German Linearabmessung der Rauhigkeiten (L. Prandtl 1932, in Beiträge zur Physik der Atmosphäre 19 190.
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