Some factors controlling the concentration of small ions near the ground

Summary During continuous measurements of the concentration of small ions near the ground made over the period of many months, several causes of variation were identified. During rain in large electric fields, ions of sign opposite to that of the potential gradient were produced in sufficiently large numbers to give rise to very high concentrations over short periods. Sometimes, after rain, a considerable increase in the density of small ions was found, suggesting a reduction in the numbers of nuclei and large ions. In moderate electric fields, a reduction was observed in the concentration of ions of sign opposite to that of the potential gradient in a way corresponding to the electrode effect. A simplified theory of the effect predicts results similar to those found in practice.The paper will appear elsewhere.