Seasonal variation of upper-atmospheric emission in the atomic oxygen 558 nm line over east Siberia

Upper-atmospheric airglow observations were used to investigate the seasonal variation of upper-atmospheric emission in the atomic oxygen 558 nm [OI] line over the region of East Siberia (52° N, 103° E). There is qualitative agreement with the seasonal variations of 558 nm emission obtained in preceding decades at other mid-latitude stations, as well as with model approximations. Quantitative differences of the seasonal variation of 558 nm emission for the region of East Siberia are considered, which imply a more pronounced autumn maximum and larger values of monthly mean 558 nm emission intensities in the winter months (December–January). An analysis of the factors and phenomena that are responsible for the seasonal variation of 558 nm emission, and a comparison with the wind regime dynamics of the upper mesosphere - lower thermosphere as well as with stratospheric warmings in the region of East Siberia suggests the existence of regional (longitudinal) features in the seasonal variation of 558 nm emission.