Temporal and spatial power spectrum studies of numerical simulations of Type II gradient drift irregularities in the equatorial electrojet

Temporal and spatial power spectra from computer simulations of the equations modeling type II irregularities in the equatorial electrojet are presented. The power spectra are computed using the code of Ferch and Sudan (1977), averaging over times as long as 20 s. The dependence of the average frequencies and line widths on wavelength and angle from the electrojet drift is studied. The mean frequencies obtained agree well with linear theory except at short wavelengths, while the line widths are greater than those predicted by the linear damping rates. The spatial power spectra were also computed and found to be approximately isotropic. Favorable comparisons are made with radar observations and the theory of Sudan and Keskinen (1977).