Drift spread and stratification of irregularities in ionosphere in the presence of electric field

Numerical solution of nonlinear equations describing evolution of concentrationsheterogeneities of charged particles under the effect of diffusion and drift in ionospherical plasma is obtained and analyzed. Ionosphere model close to reality and heterogeneous by height is used. It is determined, that under certain conditions excluding heterogeneity splitting into two under the effect of spreading dispersion mechanism the splitting of heterogeneity into separate strata down along magnetic field with 50-500 m transverse size occurs, that is possibly resulted from drift instability. Dependence of stratification time on value of external transverse electric field, initial disturbance of concentration in heterogeneity and its transverse size is investigated