ABSTRACT
I. Ambient Environments 14
I. AMBIENT ENVIRONMENTS
Naturally occurring small ion levels near ground level vary over a wide range. Fair weather values over land are typically in the range of 500 to 1000 but can easily vary from 200 to 3000 ions/cm3 of both polarities. Because of this variability, it is difficult to give a mean value. Results of several measurements of ambient ion concentrations during fair weather conditions are given in Table 1. The ratio of positive to negative ion density near ground level is usually in the range of 1.1 to 1.3.
