Interhemispheric field-aligned currents: Simulation results

We present simulation results of the 3-D magnetosphere-ionosphere current system including the Region 1 and Region 2 field-aligned currents, ionospheric currents, and interhemispheric field-aligned currents flowing between the northern and southern conjugate ionospheres in the case of asymmetry in ionospheric conductivities in two hemispheres. The model shows that the interhemispheric currents can be an important part of the global 3-D current system in high-latitude ionosphere, especially during summer-winter months, when in winter ionosphere they can be comparable and even exceed both Region 1 and Region 2 currents. An important feature of these interhemispheric currents is that they link together processes in two hemispheres, so that the currents observed in one hemisphere can provide us with information about the currents in the opposite hemisphere. Although the interhemispheric currents might play a notable role in the total 3-D current system, they have not been sufficiently studied yet. The study of the contribution from the interhemispheric currents into the total 3-D current system allows us to improve understanding and forecasting of geomagnetic, auroral, and ionospheric disturbances in two hemispheres.