Abstract
The Second International Workshop on Condensation and Ice Nuclei, held at Ft. Collins, Colo., in 1970, provided approximately 10,000 measurements by ice nucleus counters of natural and artificial aerosols, with the counters operating under well-defined conditions. Relevant data on nucleus aerosol size and concentration, and the properties of related condensation nuclei were provided. A first review of the data showed a number of serious discrepancies between the various instruments. This paper gives a detailed analysis of data from ten instruments and makes clear the origin of the discrepancies, which are related to the degree of supersaturation and its relationship to the concentration of condensation nuclei during cloud formation. Different instruments respond differently to these variables but the present results make it evident that meaningful results can be obtained with the counters now available.
