Measurements of the mesosphere temperature by two molecular emissions in Yakutsk (62°N, 129,5°E)

The results of the hydroxyl and oxygen molecules rotational temperature measurements during two observational seasons 1999-2001 at Maymaga station (φ=63°N;λ=129.50°E) are presented. The rotational temperatures of OH(6,2) and O2 (0,1) bands have been measured with the infrared spectrograph equipped by the cooled CCD registration system. It is shown that the amplitude of seasonal change of hydroxyl rotational temperature is greater than the molecular oxygen variation. OH temperatures have been systematically higher the O2 ones during winter. An abrupt decrease of the O2 intensity connected with the springtime transition of the atmospheric circulation is found in both time series. For the first time a change of the temperature vertical gradient sign caused by mesopause height displacemet to a higher (winter) level was shown in the data of August-September 2001.