SIMULATION STUDIES OF IONOSPHERIC ELECTRIC-FIELDS AND CURRENTS IN RELATION TO FIELD-ALIGNED CURRENTS .2. SUBSTORMS

The computer simulation scheme for calculating the electric fields and currents in the global ionosphere in relation to field-aligned currents for quiet periods that the authors previously developed is extended to disturbed conditions. Current knowledge of characteristics of auroral enhancement in the ionospheric electric conductivities as well as changes in the intensity and location of field-aligned currents are taken into account in a series of simulations representing various substorms. The possible effects of these variable parameters in producing the observed complexity of the electric field and current patterns are studied. The results are discussed.