Comparison of Electron Temperature with Thermosphere Probe Data

Abstract

DURING the past few years evidence has been obtained for the existence of thermal non-equilibrium in the F-region of the ionosphere. A number of heat sources have been proposed to account for the observed selective heating of electrons in the ionosphere. The solar ultraviolet radiation from the Sun was shown to be the main heat source for the daytime heating of the lower- and mid-latitude ionosphere1–3. A comparison between measurements of electron temperature Te, obtained from the Dumbbell rocket probe4,5 and the atmospheric model values of neutral gas temperature Tg, has provided the first evidence for thermal non-equilibrium of the ionosphere. The simultaneous measurements of Te and Tg with the modified “thermosphere probe” have now confirmed that the electron temperature in the ionosphere is considerably larger than the gas temperature. With the help of recent measurements of solar ultra-violet flux and absorption cross-section, we have calculated the heat input and electron temperature in the F-region of the ionosphere and have compared it with the thermosphere probe data6.