PostDoctoral Research Fellowship

Lyatskaya Inna V, Greenbelt MD

Investigators

Abstract

This award is to (1) develop a numerical model of Interhemispherical Field-Aligned Currents (IHCs) flowing between polar ionospheres in two hemispheres, (2) examine expected effects of these currents on geomagnetic activity, ionosphere, and upper atmosphere in the polar regions in both hemispheres, and (3) compare the modeling results with experimental data. The IHCs flow between the Northern and Southern high-latitude ionospheres exists predominantly due to differences in the ionospheric conductivity of the respective polar regions. Due to the Earth's orientation, the northern summer (southern winter) these interhemispherical currents can be very strong and comparable in magnitude with the total field-aligned currents (FACs) flowing in and out of the respective hemispheres at the specific Universal Time (UT) intervals. While crossing an equatorial plane, the IHCs do not change their direction; and as a result, they may increase the total FACs strength in one hemisphere, but decrease it in the opposite hemisphere. This can lead to the strong asymmetry in the total FACs system, as well as to specific geomagnetic and ionospheric disturbances in the two polar regions. The research will bring better understanding of interhemispherical asymmetry in the FACs system, northern and southern auroras, and ionospheric disturbances and UT variations in geomagnetic activity. The proposed model of interhemispherical currents would also be an important component of the set of Space Weather models, improving space weather forecasts of geomagnetic and ionospheric disturbances over two hemispheres and their potential effects on the low-orbiting spacecraft.