EXCITATION OF GLOBAL ARTIFICIAL Pc1 SIGNALS DURING FENICS-2024 EXPERIMENT: 2. MODELING

During the active experiment FENICS-2024 on the Kola Peninsula using a decommissioned power transmission line as a horizontal radiating antenna, ultra-low-frequency signals of the 1–6 Hz range were recorded at magnetic stations located from ~1600 km to ~2100 km from the transmission line with normalized amplitudes from ~0.3 fT/A to ~0.8 fT/A. Observational results are compared with approximate analytical estimates of the magnetic field excited by the magnetic dipole. The calculations turned out to be in qualitative agreement with the observational results. To assess the possible response in the upper ionosphere, a numerical model of the ULF field in the atmosphere and ionosphere generated by the horizontal surface current was employed. The model is based on solving the system of Maxwell equations in the vertically inhomogeneous atmosphere and ionosphere. The fundamental feature of this model is that it correctly takes into account the contribution of ionospheric waveguide propagation. The observational results supported by numerical simulation have shown the potential of active experiments of the new type for signal generation for large-area magnetotelluric sounding and for modification of near-Earth plasma with artificial signals.