Variation of the 557.7 nm airglow intensity (emitting layer height is 85–115 km) in the 23-rd solar cycle are analyzed. The experimental data of the 557.7 nm atomic oxygen emission obtained at ISTP Geophysical observatory near Irkutsk (52 N, 103 E) are used. The feature of observed 557.7 nm intensity variations is an infringement of direct correlation dependence between the emission intensity and solar activity level ((F10,7) in individual years. Also, the results received in the 18th–22d solar cycles at the other mid-latitude stations are analyzed. It is revealed, that the features of the long-term variations of 557.7 nm intensity in the 23rd and 20th solar cycles are the most similar. There are some solar cycles, in which the phase synchronism of 557.7 nm emission variations with 11-years cycle of solar activity is broken. In these cycles the periods about 4–6 years in 557.7 nm emission variations are dominant. The possible reasons of interannual variations of 557.7 nm atmospheric emission are associated with the influence of lower atmosphere.
solar cycles; upper atmosphere; atmospheric emission of 557.7 nm