Numerical studies of Type 2 equatorial electrojet irregularity development

A computer simulation based on fluid equations of motion seems to account for basic observational features of short wavelength type 2 (subsonically propagating) ionization irregularities in the equatorial electrojet. The short wavelengths (less than 28 m for parameters taken here) are excited only after long wavelength, horizontally propagating waves grow to an amplitude sufficient to trigger the nonlinear growth of secondary vertically propagating modes. The result is a complicated two-dimensional turbulent flow, with convective elements moving with comparable vertical and horizontal velocities. The density fluctuation power spectrum obeys approximately a power law k-3.5. These results agree with theory and observation. (auth)