[P-EM12] Coupling Processes in the Atmosphere-Ionosphere System

[PEM12-P04] Laser-based Laboratory Studies Relevant to Mesospheric Nightglow Emissions

*Konstantinos S. Kalogerakis¹ (1.Center for Geospace Studies, SRI International, Menlo Park, California, USA)

Keywords:Airglow, Nightglow, Mesosphere, OH Meinel Band Emission

The OH Meinel band emission dominates the visible and near-infrared portion of the nightglow spectrum. A detailed knowledge of the rate constants and relevant pathways for OH(high v) vibrational relaxation by atomic and molecular oxygen is essential for understanding mesospheric OH emissions and extracting reliable chemical heating rates from atmospheric observations. We have developed laser-based experimental methodologies to study the complex collisional energy transfer processes involving the OH radical and other relevant atmospheric species. Our previous studies have indicated that the total removal rate constant for OH(v = 9) by atomic oxygen at room temperature is more than one order of magnitude larger than that for removal by molecular oxygen. Thus, O atoms are expected to significantly influence the intensity and vibrational distribution of vibrationally excited OH(v). We report on our experimental studies investigating OH(v > 5) + O vibrational relaxation and discuss the implications for the mesospheric OH Meinel band and other mesospheric nightglow emissions.

This research was supported by the NASA Heliophysics (80NSSC23K0694) and NSF Aeronomy Programs (AGS-2113888, AGS-2009960).