An alternative method for generation of ULF waves by ionospheric heating

Abstract

We present results from a numerical study of the generation of ULF waves by the ionospheric feedback instability (IFI) initiated by heating the ionosphere with a powerful HF transmitter. Previous investigations in this area suggested that even a relatively weak modification of the ionospheric conductivity by the heater can initiate IFI and enhance its development, if the heating wave is modulated with a frequency of the most feedback‐unstable ULF mode. In this paper, we show that the development of the instability and, as a result, the generation of ULF waves, can be significantly enhanced if the heating spot is moved in the direction of the background electric field with the velocity defined from a simulation of the coupled magnetosphere‐ionosphere model.