Reaction Kinetics of CaOH with H and O₂ and O₂CaOH with O: Implications for the Atmospheric Chemistry of Meteoric Calcium.

ABSTRACT: The ablation of cosmic dust particles entering the Earth's upper atmosphere produces a layer of Ca atoms around 90 km. Here, we present a set of kinetic experiments designed to understand the nature of the Ca molecular reservoirs on the underside of the layer. CaOH was produced by laser ablation of a Ca target in the fast flow tube and detected by non-resonant laser-induced fluorescence, probing the D(²Σ⁺) ← X(²Σ¹) transition at 346.9 nm. The following rate constants were measured (at 298 K): k(CaOH + H → Ca + H₂O) = (1.04 ± 0.24) × 10^-10 cm³ molecule^-1 s^-1, k(CaOH + O → CaO + OH) < 1 × 10^-11 cm³ molecule^-1 s^-1, and k(CaOH + O

SUBMITTER: Gomez Martin JC 

PROVIDER: S-EPMC5611678 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature