Effects of the 21 June 2020 Solar Eclipse on Conjugate Hemispheres: A Modeling Study

An annual solar eclipse occurred on 21 June 2020. The maximum eclipse path of this solar eclipse covers the geomagnetic latitude 10-20 degrees N in East Asia. The geomagnetic conjugate region of the eclipse region covers most of the land in Australia. It provides a valuable opportunity to study the ionospheric responses not only in the solar eclipse region but also in the conjugate region. Utilizing a coupled ionosphere and thermosphere model, we modeled global ionospheric responses and identified significant variations in electron density and electron temperature in both the eclipse region and its conjugate region. The simulated results show a significant enhancement in electron density and large decrease in electron temperature at high altitudes in the conjugate region. Two control simulations were carried out to study the main reason for the ionospheric disturbances in the conjugate hemisphere by cutting off transhemisphere photoelectron transport and thermal conduction process along field lines. The simulated results suggest that the ionospheric disturbances in the conjugate hemisphere are caused by the combined effects of transhemisphere photoelectron transport, thermal conduction, and thermospheric wind changes. Furthermore, the thermal conduction process along filed lines should be the main reason.