Atmospheric atomic sulfur ion reactions

The apparent observation of atomic sulfur ions below 86 km in the ionosphere stimulates an interest in their possible production and loss processes. Toward this end we have measured the following reactions at 300°K: S+ + NO → NO+ + S, for k = 4.2 × 10−10 cm³ sec−1, and S+ + O2 → SO+ + O, for k = 1.6 × 10−11 cm³ sec−1. The very fast loss rates for S+ in the D region implied by these reactions, especially by the second reaction, put a very severe burden on any possible S+ production source. As yet, no reasonable S+ source has been proposed.