It has long been recognized that during solar eclipses, the ionosphere-thermosphere system changes greatly within the eclipse shadow, due to the rapid reduction of solar irradiation. However, the concept that a solar eclipse impacts polar ionosphere behavior and dynamics as well as magnetosphere-ionosphere coupling has not been appreciated.
In this study, we investigate the potential impact of the 21 August 2017 solar eclipse on the polar tongue of ionization (TOI) using a high-resolution, coupled ionosphere-thermosphere-electrodynamics model (TIEGCM). The reduction of electron densities by the eclipse in the middle latitude TOI source region leads to a suppressed TOI in the polar region. The TOI suppression occurred when the solar eclipse moved into the afternoon sector. The GPS total electron content observations show similar tendency of polar-region TEC suppression. This study reveals that, a solar eclipse occurring at middle latitudes may have significant influences on the polar ionosphere and magnetosphere-ionosphere coupling.
Publication Name: Geophysical Research Letters
First HAO Author's Name: Wenbin Wang