Change of the Chlorine : Sodium Ratio in the Atmosphere with Altitude and Distance from the Source of Sodium Chloride, and the Distribution of Atmospheric Nitrate over the United States

Abstract

THE change of the chlorine : sodium ratio in rain-water with inland distance from seas is a well-known phenomenon. The experimental evidence available has lately been discussed by Eriksson¹, while further data on an almost continental scale have been supplied by Junge and Werby². The latter measurements were recently used by Papée and Smith for an evaluation of trends between components of rain-water and physical variables³. From those computations, an indication of a decrease in the ratio between chlorine and sodium with the altitude of the sampling stations became available, and it was pointed out recently to one of us that a semi-empirical evaluation of the phenomenon might be of interest to workers in mountainous countries. In view of the importance of the process in atmospheric chemistry in general, and especially because of the possible role of activated sodium chloride as nuclei of atmospheric precipitation^4,5, a further study of Junge's data with particular emphasis on this problem was made. Prior to a broader evaluation of the problem and to a laboratory study of the phenomena involved, some results obtained are reported in this communication.