Relationship between the degree of development of the F1-layer and the vertical distribution of gas density during the breakdown of diffusional equilibrium

The paper presents results of an analysis of modeled height-frequency characteristics corresponding to the breakdown of the diffusional equilibrium of gas-density distribution. It is shown that the pattern of vertical-structure changes in the thermosphere is reflected most distinctly in the development of the F1-layer. Variations of the gas-density profile equal to + or -10 percent can lead to electron-density-profile deviations up to 6 percent at the F1-layer maximum level.