Variations of a charged particle concentration in the high-latitude ionosphere during magnetospheric ionospheric disturbances in September 1977 according to data of the ''Kosmos-900'' satellite

On the basis of ''Kosmos-900'' satellite data on variation of concentration of positive ions obtained in September 1977 in various phases of geomagnetic disturbances development the analysis of influence of ionospheric magnetospheric interaction on high latitude ionosphere is performed. In particular, the magnetospheric electric field strengthening during geomagnetic storm leads to the shift of midlatitude ionospheric dip to low latitudes, being maximum during the main phase of storm. Increase of quantity and intensity of nonuniformities and rise of small scale non-uniformities against a background of more large scale ones during the main phase of magnetic storm are caused by low-frequency radiation generation at the ring current interaction with plasmapause. Rise of additional dips in charged particles concentration in the period of ring current decay testifies to the influence of precipitating at that time particles on ionospheric plasma. The midlatitude ionization dip form depends on geomagnetic storm phase