Some aspects of the metal ion chemistry of the Earth's atmosphere

Abstract

Measurements of some metal ion reactions with ozone have been made in a flowing afterglow reaction system. The ions Fe+, Mg+, and Ca+ react rapidly to form the metal oxide ion; Na+ and K+ do not. Three-body reactions of the same metals with O2 and a third body argon to form the metal dioxide ions have also been measured. Again Fe+, Mg+, and Ca+ have large rate constants, but Na+ and K+ do not. The rapid Mg+ + O3 → MgO+ + O2 reaction is not effective in deionizing sporadic E layers of the ionosphere because it is followed by a rapid reaction MgO+ + O → Mg+ + O2, which has also been measured and which keeps the Mg+/MgO+ ratio large in the E region. A similar situation will probably occur for the other metal ions. Even efficient three-body association reactions are too slow for effective ion loss at E-region altitudes. It thus appears likely that ion chemistry does not play a significant role in the deionization of sporadic E layers in the ionosphere. The three-body ion association reactions may play an important role in meteor trail deionization at lower D-region altitudes.