Study of Electromagnetic Waves by Using the onboard Electric Field Detector on the ZH-1 Satellite for Earthquake Precursors

Abstract

The China Seismo-Electromagnetic Satellite (CSES) mission provides valuable observations of the ionospheric electric field for studying space weather and seismo-electromagnetic phenomena. In this work, ELF (Extremely Low Frequency) electric field data recorded during orbit #032021 on 31 August 2018 were analyzed. The three components of the electric field (Ex, Ey, Ez) were examined along the satellite track. Results indicate strong fluctuations in Ex and Ez near southern mid-latitudes (~–60°), suggesting localized ionospheric disturbances. The Ey component remained relatively stable, with only minor variations. A broad systematic trend was observed in Ez across latitudes, with enhanced deviations compared to the horizontal components. These findings highlight the spatial variability of ionospheric electric fields and demonstrate the capability of CSES to detect both localized perturbations and large-scale latitudinal structures, which may be linked to natural ionospheric processes, space weather activity, or lithosphere–atmosphere–ionosphere coupling.