Laboratory Studies of OH(v) Production from the H + O3 Reaction

The hydroxyl radical is a key player in the chemistry and energy balance of the middle terrestrial atmosphere and numerous studies have investigated the relevant photochemical processes. Nevertheless, several gaps exist in the understanding of its photochemistry, including the details of its production by the H + O₃ reaction. A detailed understanding of the sources for mesospheric OH is necessary for the interpretation of the prominent OH Meinel band emissions. This knowledge is also a prerequisite for estimates of the heating efficiency of the highly exothermic H + O₃ reaction, a key factor included in photochemical models of the upper atmosphere.

We will report on our laboratory measurements to investigate the production pathways and yields of highly vibrationally excited hydroxyl radical, OH(v), produced from H + O₃. This knowledge is critical for a reliable analysis and interpretation of data from ground- and space-based observations of the nightglow OH Meinel band emission.

Research supported by NASA Heliophysics (LNAPP) under Grant 80NSSC23K0694.