The Electric Field Distribution in High-latitude Ionosphere Based on the Field-aligned Currents

This paper is based on the TRIADobserved statistical diurnal Variation of the field-aligned currents. The analytical solution of the electric potential in high-latitude both under homogeneous and inhomogeneous conductivities are deduced respectively by using the simple model method and the Fourier series expansion of the observed diurnal distribution of the fieldjaligned currents. The pattern of the electric potential based on TEIADobservations and the effects of the conductivities under such conditions are discussed through the model calculation. The results show that the'shielding'of the E-fie-Ids are caused by the region 2 field-aligned currents in our case, and under the distribution of the field-aligned currents used here the enhancement of Hall conductivities in the auroral zone may even weaken the'shielding'. During |AL|≥100r, the combined efect of the two rigions of field-aligned currents may produce a 8?rotation of the convection cells, however, the further rotation of the whole pattern is the results of the enhancement of Hall conductivities in auroral zone, and the enhancement of Pederson conductivities has no effect on this rotation. It is also .shown, even without the day-night gradient of the conductivities the two eovection cells can be unsymmetrical, this unsymmetry is caused by the complicated diurnal variation of the two regions of the field-aligned currents.The structure of the oacuilated E-field based on TEIADmeasurments is in agreement reasonably with the observed E-field pattern such as by STAREand by many other experiments. The effect of the three sheet pattern of field-aligned currents pre-midnight and of the cusp current around noon are not taken into account in this work.