Silicon molecular ions in the D‐region

Abstract

During a recent rocket campaign to study the phenomenology of noctilucent clouds (NLC‐93), mass spectrometer measurements showed the presence of ions at m/e=45 and 61. These ions are attributed to SiOH + and SiO 2 H + ; the former is formed by reaction of Si + with H 2 O and the latter is formed by reaction of SiOH + with O 3 . The data provide the first observation of a chemical sequence of reactions beginning with the ablation of meteoric elements and a sequential reaction scheme.