Middle atmospheric thermal structure obtained from Rayleigh lidar and TIMED/SABER observations: A comparative study

Abstract

A novel measurement of seasonal variability of the middle atmospheric thermal structure has been carried out by comparing ground-based lidar and space-based TIMED/ SABER observations from a low-latitude station, Gadanki (13.5° N, 79.2°E), India. Lidar temperature has been cross-verified by retrieving from Cooperative Institute for Research in the Atmosphere’s (CIRA) CIRA-86 model and SABER observation density and pressure values independently. Observed results are also compared with CIRA-86 model data. Model data show significant difference with observed ones. Observed results match nicely among themselves throughout the year, which further validates the SABER data at low latitude with an average deviation of ~2 K in 35–75 km altitude range with respect to the Rayleigh lidar. Seasonal pattern of adiabatic lapse rate all over the altitude range reveals a statically stable atmosphere during the observation period. Stratopause temperature shows semiannual oscillation (SAO) in seasonal pattern of variation, which matches with previous observations from low-latitude stations.