Ionospheric Investigations Conducted by Chinese Mainland Scientists in 2020-2021

In this report,we outline works done by scientists from the Mainland of China on various ionospheric topics after the release of the National Report of China in 2020 on ionospheric researchto the Committee on Space Research(COSPAR).More than 170 papers were published in 2020-2021.The current report covers the following topics:ionospheric space weather,ionospheric structures and climatology,ionospheric dynamics and couplings,ionospheric irregularity and scintillation,modeling and data assimilation,and ionosphere and sounding techniques.Planetary ionospheres are included for the first time.