Seasonal Variations and Frequency Distributions of Ice Nuclei Concentrations at Abidjan, West Africa

Abstract

Atmospheric ice nuclei concentrations were measured at Abidjan for 27 months, with a mixing chamber operated at −20C. Seasonal variations appear to be linked to the position of the Intertropical Front. Air masses arriving from continental Africa correspond to high ice nuclei concentrations. The washing out of the atmosphere due to rain gives rise to low concentrations. The distribution of daily concentration averages may be represented by a log-normal distribution with high probability of convergence.