Updated SABER Night Atomic Oxygen and Implications for SABER Ozone and Atomic Hydrogen

Updated night atomic oxygen concentration (O) profiles from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the National Aeronautics and Space Administration TIMED satellite are presented. These are derived from measurements of the OH(upsilon=9+8) volume emission rates and photochemical balance relationships. The new night O concentrations are smaller than those originally derived in 2013 and yield physically realistic global annual mean energy budgets in the upper mesosphere and lower thermosphere. The update to the night O atom profiles is motivated by recent discovery and verification of large rates of collisional quenching of OH(upsilon) by atomic oxygen. The kinetic model relating the SABER-observed OH emission rates to atomic oxygen is now consistent with these larger quenching rates and other literature values. The new, smaller SABER night O also confirms that SABER daytime ozone is too large. The new night O and OH(upsilon) model impacts the inference of day and night atomic hydrogen. Plain Language Summary An updated data set of night atomic oxygen in the terrestrial mesosphere is presented. The atomic oxygen is derived from measurements made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the National Aeronautics and Space Administration TIMED satellite. Atomic oxygen is a critical component of the chemistry and energy budget of the mesosphere and lower thermosphere. The data set is a 16-year record intended to replace a prior data set published in 2013. The new atomic oxygen data set covers the mesopause region, approximately 80 to 100km in altitude. The major change is that the new atomic oxygen concentrations are significantly smaller than the original data set. The new data yield a physically realistic global annual mean energy budget, in contrast to the original data set. A significant consequence of the new night data set is that the SABER daytime ozone concentrations (derived from measurements of 9.6m emission) are too large, confirming previous suggestions published in the literature. The results also impact the atomic hydrogen derived from SABER, both day and night.