A STUDY OF DAYTIME ELECTRON TEMPERATURE

The electron density and electron and ion temperatures given by the Saint-Santin-Nançay Thomson scatter experiment allow a detailed energy balance study for thermal electrons including their energy loss to ions and neutral particles, the energy received by conduction from the magnetosphere, and the energy they gain from photoelectrons. The collision process recently pointed out by Dalgarno and Degges (1968) (concerning electronatomic oxygen collisions involving the fine structure of O) is taken into account, but it cannot explain the relatively low temperatures observed around 200 km. Nevertheless, by taking the non-local heating into account, the agreement between theory and experiment is significantly improved. The same Thomson scatter observations were used by Vasseur and Waldteufel (1968) to solve approximately the continuity equation for electron density. This solution gives a value for the production of primary photoelectrons which is compared with our independent determination of the same quantity, obtained through the thermal electron energy balance. © 1969.