[PEM15-P10] D- and E-region ion temperature measured with EISCAT radar facility
Keywords:upper atmosphere, temperature , Incoherent scatter radar
We have investigated ion temperature variations in the D- and E-region using the EISCAT UHF radars located in Tromsoe, Norway. Our results show that a lower limit of reliable ion temperature derivation was about 87 km altitude at noon in winter. Time variations of the daytime ion temperature at altitudes between 88 and 95 km derived from EISCAT were very close to those of ambipolar diffusion coefficients at the same altitudes from the Tromsoe meteor radar data even when geomagnetic activity was high. This indicates that ion temperature at 88-95 km altitudes seems to be equal to neutral temperature at the same altitudes. We discuss what decides lower limits of the reliable ion temperature derivation, based on EISCAT data analysis under several geomagnetic/geophysical conditions.