BEHAVIOR OF THE IONOSPHERIC THERMAL O(++) IONS DURING VARIOUS PHASES OF GEOMAGNETIC STORMS

Thermal ion O++ densities in the outer ionosphere have been studied us ing data from the low altitude Intercosmos 24 and Intercosmos 25 satel lites to analyse their behaviour during various phases of a geomagneti c storm. Characteristic enhancements in the latitudinal O++ density pr ofiles have often been observed at middle latitudes. A statistical sur vey investigating their dependence upon magnetospheric and ring curren t activity is presented. The relationship between their position and t he plasmapause is analysed. Simultaneous measurements of thermal elect ron temperature are discussed.