Retrieval of Nighttime Distributions of Mesosphere–Lower Thermosphere Characteristics from Satellite Data

The database of SABER/TIMED satellite campaign includes the distributions of nighttime O, H and some other characteristics of mesosphere – lower thermosphere region which are retrieved from the measurements of OH* volume emission rate (near 2 μm), temperature and ozone. In the core of the retrieval procedure lies the assumption about photochemical equilibrium of nighttime ozone and airglow model that considers two excited states of OH (levels ν = 9, 8). In this work, a modified OH* model (with the rate constants updated according to contemporary publications) is used to retrieve O, H, OH, HO2 and the chemical heating rate at 80–100 km altitudes from to SABER/TIMED measurements in 2002–2021. It was found that the use of new parameters in the retrieval procedure leads to significant (up to 2 times or more) changes in the resulting spatial distributions of O, H and chemical heating rate, while the corresponding changes in OH and HO2 distributions are minor.