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Natural ice‐particle nuclei
Author(s) -
Palmer H. P.
Publication year - 1949
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49707532303
Subject(s) - ice nucleus , thunderstorm , cloud chamber , atmospheric sciences , atmosphere (unit) , particle (ecology) , environmental science , cloud condensation nuclei , meteorology , physics , geology , aerosol , nuclear physics , thermodynamics , nucleation , oceanography
Determinations of the temperature for the first formation of ice in a small cloud chamber at different levels in the free atmosphere are described. The construction in the laboratory of a cloud chamber in which five litres of air can be examined for ice‐forming nuclei is reported. An estimate is made of the concentration of nuclei required, if each raindrop observed at the surface originates as an ice‐particle, to form the rainfall from depressions and from thunderstorms, and it is suggested that the nuclei active in natural cloud are those present in concentrations of 20/litre or less, which can only be detected in a large cloud chamber. Finally estimates are made of the threshold temperatures for the concentrations of these nuclei in surface air, required to form these two types of rain.