Recent investigation on the coupling between the ionosphere and upper atmosphere

Scientific attention has recently been focused on the coupling of the earth\textquoterights upper atmosphere and ionosphere. In the present work, we review the advances in this field, emphasizing the studies and contributions of Chinese scholars. This work first introduces new developments in the observation instruments of the upper atmosphere. Two kinds of instruments are involved: optical instruments (lidars, FP interferometers and all-sky airglow imagers) and radio instruments (MST radars and all-sky meteor radars). Based on the data from these instruments and satellites, the researches on climatology and wave disturbances in the upper atmosphere are then introduced. The studies on both the sporadic sodium layer and sporadic E-layer are presented as the main works concerning the coupling of the upper atmosphere and the low ionosphere. We then review the investigations on the ionospheric longitudinal structure and the causative atmospheric non-migrating tide as the main progress of the coupling between the atmosphere and the ionospheric F2-region. Regarding the ionosphere-thermosphere coupling, we introduce studies on the equatorial thermospheric anomaly, as well as the influence of the thermospheric winds and gravity waves to the ionospheric F2-region. Chinese scholars have made much advancement on the coupling of the ionosphere and upper atmosphere, including the observation instruments, data precession, and modeling, as well as the mechanism analysis.