Longitudinal peculiarities of meridional circulation in lower thermosphere and mesosphere

Average monthly longitudinal profiles of geostrophic wind in winter are presented. Positive values correspond to meridional movements from north to south. It is concluded that the normal longitudinal meridional circulation is characterized by the presence of sectors where meridional flows do not change their direction in the course of time comparable with synoptic periods. The longitudinal distribution of meridional wind in middle latitudes taken from the analysis results of radiometeor and ionospheric stations observational data obtained in 1976 to 1980 are presented. Meridional winds have a longitudinal variability that is equivalent to both the warm and cold half years.