Ground-based mesospheric temperatures at mid-latitude derived from O2 and OH airglow SATI data: Comparison with SABER measurements

Rotational temperatures obtained from the O2 Atmospheric (0–1) nightglow band and from the OH (6–2) band, with a Spectral Airglow Temperature Imager (SATI) instrument at Sierra Nevada Observatory (37.06∘N37.06∘N, 3.38∘W3.38∘W) are presented. A revision of the temperatures obtained from the Q branch of the (6–2) Meinel band has been undertaken. First, new experimental Einstein coefficients for these lines have been introduced and the temperatures derived from the Q lines (1, 2 and 3) of the (6–2) OH Meinel band have been compared to those deduced from the P lines (2 and 4) of the same band of spectra taken by a spectrograph at Boston University. The new set of SATI data has been used to analyse the seasonal behaviour of the mesospheric and lower thermospheric temperatures. Atmospheric temperatures deduced from SATI and from satellite observations with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the TIMED satellite, have also been compared. SABER temperatures at 95 km are slightly warmer (about 2.5 K) than SATI temperatures while at 87 km they are slightly colder (about 5.7 K). Also, similar patterns of seasonal and day to day variations are found in the temperatures retrieved from both instruments at the latitude of 37∘N37∘N.