This research will address several key theoretical issues related to ~5kHz to ~5MHz frequency-range radio waves observed on the ground in the auroral zone. First, the PI will incorporate proper models of the ionospheric plasma and low-density cavity into the study to understand how electromagnetic wave propagate in realistic models of cavity and ionospheric plasma. Then, he will conduct a detailed parametric study of various physical attributes associated with energetic electrons, establishing a firm understanding of the general characteristics of direct emission theory. Next, he will investigate the "indirect emission theory," based on the notion of electrostatic waves interacting among themselves inside the radiation source, thus converting to free space electromagnetic waves. Finally, he will calculate various physical quantities associated with radio waves, including the wave intensity and spectral pattern that can be directly compared with experimentally observed quantities. All of these tasks will enhance basic understanding of wave and particle processes in the auroral zones.
