“…The Paul Melchior Medalists 2021 are David Crossley, Gerhard Jentzsch, and Walter Zu ¨rn. The laudatios for the 2021 three awardees are found in the appendix of the Editorial of the special volume in Geodesy and Geodynamics (Sun et al 2022a) and the 89 Symposium abstracts are found in the appendix of the Review of the Symposium (Sun et al 2022b).…”