Global Cowling Effects in the Sq‐EEJ Current System Under Electrostatic Approximation: Theoretical Simulation

Abstract

Abstract The solar quiet (Sq) current and equatorial electrojet are widely known as one of the fundamental currents in ionosphere. Although the Sq‐EEJ current system has been extensively investigated, the manner in which Hall and Pedersen current components collectively organize the system has not been clearly described. To examine this, we perform a quasi‐three‐dimensional numerical simulation using the electrodynamics component of the GAIA model with a simplified neutral wind and a tilted dipole magnetic field. By applying a Hall polarization field separation method, we show that the Cowling effect operates globally through complementary roles of Pedersen and Hall currents: the primary field Pedersen and secondary field Hall currents enhance the Sq‐EEJ system, while the primary Hall and secondary Pedersen currents provide compensating closure. This component‐resolved description clarifies the physical basis of the Sq‐EEJ current system and advances understanding of ionospheric electrodynamics.