Internal gravity and tidal waves in the mesopause region in Yakutia

The temperature of the mesopause region (87 km) is monitored at the Maimaga station (63.04 ° N, 129.51 ° E) using the Shamrock (Andor) spectrograph recording the hydroxyl (OH) band (3, 1). The temperature data obtained for the seasons from 2013 to 2017 are investigated. The standard deviations corresponding to the internal gravity σ_gw and tidal waves σ_td were obtained. The seasonal course of the tidal component σ_td varies from 2 to 5 K throughout all observation seasons. The seasonal variation of the gravitational component σ_gw observed at Maimaga station almost coincides for three observation seasons except for the 2014-2015 season. In this observation season, σ_gw has lower values in winter than in other seasons. Moreover, in this season average monthly temperatures exceed similar values in other seasons.