Global Ionospheric Current Systems During Magnetosphere-Ionosphere Coupling

Prompt penetration electric fields (PPEF), initiated by sudden southward turnings in the Interplanetary Magnetic Field (IMF), impact global ionospheric electrodynamics and structures. The southward IMF first generally induces an increased polar convection electric field. However, as this electric field strengthens, the Earth’s magnetosphere responds by establishing a shielding effect. This shielding effect essentially works to counterbalance or mitigate the influence of the external electric field, thereby competing with it. The differences in temporal and spatial evolution between these two processes are not well understood. Before shielding has been established, the resultant electric field promptly penetrates to equatorial and low-latitudes, changing the ionospheric electrodynamics there. Depending on the upstream solar wind conditions, such as IMF, solar wind dynamic pressure, etc., the relative strength of convection and shielding electric fields changes which leads to variable prompt penetration electric fields.
Utilizing a Magnetohydrodynamic (MHD) simulation of the magnetosphere, we analyze a solar rotation with two active periods occurring in May-June 2013. This simulation informs the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and its extended 3D dynamo model, enabling a comprehensive investigation of ionospheric dynamics and electrodynamics. Our study examines ionospheric plasma density distribution, equivalent current patterns, and associated magnetic fields during this solar rotation, encompassing quiet periods and two distinct geomagnetic storm times. This study will improve our understanding of the spatiotemporal evolution of ionospheric currents and magnetic perturbations during prompt penetration events. Understanding these phenomena is crucial for advancing our comprehension of space weather dynamics and improving predictive capabilities.