F-region electron heating by X-mode radiowaves in underdense conditions
- 1Uppsala University, Uppsala, Sweden
- 2Space and Plasma Physics, School of Electrical Engineering, KTH, Stockholm, Sweden
- 3Univ Tromsø, Dept Phys & Technol, 9037 Tromsø, Norway
- 4Swedish Institute of Space Physics, Uppsala, Sweden
- 5EISCAT, 9027 Ramfjordbotn, Norway
Abstract. Observations of modifications of the electron temperature in the F-region produced by powerful high frequency radiowaves at 4.04 MHz transmitted in X-mode are presented. The experiments were performed during quiet nighttime conditions with low ionospheric densities so no reflections occurred. Electron temperature enhancements of the order of 300–400 K were obtained. Numerical simulation of ohmic heating by the pump wave reproduces both altitude profiles and temporal dependence of the temperature modifications in the experiments.