SOLAR CONTROL OF THE IONOSPHERE AT HEIGHTS BETWEEN 100 AND 200 KM - A COMPARISON OF THEORY AND EXPERIMENTAL-DATA

Theoretical results on the vertical distribution of ionospheric plasma in the E and F1 layers are reviewed, and compared with experimental data. Treated generally are ion production and recombination, particularly the role of vibrationally excited nitric oxide ions. Emphasis is placed on the conditions responsible for the `valley' between the E and F1 regions. Finally, certain invariants, that is functional relationships between particular parameters of the distribution of ionospheric plasma, are created and their uses evaluated.