NUMERICAL SIMULATIONS OF ELF/VLF WAVE GENERATED BY MODULATED BEAT-WAVE IONOSPHERIC HEATING IN HIGH LATITUDE REGIONS

Based on the theory of ionospheric heating, with the self-consistent model in the low ionosphere, the Extremely-Low-Frequency (ELF) and Very-Low-Frequency (VLF) waves generated by modulated beat-wave ionospheric heating are analyzed theoretically. In the consideration of the stratified ionosphere, the magnetic fields generated by the equivalent ELF/VLF dipole source above the sea surface are studied by using the quasi-longitudinal approximation method. Taking the high latitude regions as an example, the variations of the electron temperature, the increments of Pedersen and Hall conductivities and the changing of the oscillating current density with the modulation frequency in beatwave heating are numerically discussed. The distribution of the magnetic fields is presented. It turns out that in high latitude regions, the efficiency of rectangular wave modulated heating in generating ELF/VLF wave is higher than that of modulated beat-wave heating, and the order of magnitude of the magnetic fields received above the sea surface is 10−7 A/m in beat-wave modulation.