Seasonal and Diurnal Variations of Temperature near the Mesopause from Fabry-Perot Interferometer Observations of OH Meinel Emissions

The seasonal and diurnal variations of temperature, intensity and winds within the mesopause region have been obtained, over a 22 month period, by analysing ground-based Fabry-Perot observations of the hydroxyl (OH) (6,2) Meinel band emission at 843.0 nm. Tidal variations are revealed clearly in the monthly-averaged hourly-mean temperature data. The dirrnal variations of hydroxyl temperature and intensity are usually out-of-phase, while for other emissions, e.g. O2, the temperature and intensity variations are normally in-phase. The amplitudes of the tidal variations in temperature and intensity are generally larger in winter than in summer. Throughout most seasons, the zonal and meridional winds also show pronounced tidal variations, although the largest tidal amplitudes of the winds occur in late summer and autumn