Global Distribution of Ion and Electron Temperatures in the Outer Ionosphere During Maximum of the Solar Cycle 22

Ion temperature (Ti) and related electron temperature (Te) distributions have been studied on the base of data measured by Radiofrequency Probe and Retarding Potential Analyzer onboard the Intercosmos 24 (perigee 500 km, apogee 2500 km, inclination 83 deg). Results from the period 1989-1991 have been analyzed. Seasonal variation of the recently evaluated ion temperature (from a large number of volt-ampere characteristics) in individual altitude levels in the range of 500 - 1500 km and the related Te is shown. Also comparison of measured Ti with those modeled by IRI2001 (International Reference Ionosphere) is done. We also discuss reliability of the modeling approach for ion temperature used in IRI model based on energy exchange between ions, electrons and neutrals.