Authors: Zihao Yang (Peking University; NCAR/HAO), Christian Bethge (USRA), Hui Tian (Peking University), Steven Tomcyzk (NCAR/HAO), Richard Morton (Northumbria University), Giulio Del Zanna (University of Cambridge), Scott Mcintosh (NCAR), Bidya Binay Karak (Indian Institute of Technology), Sarah Gibson (NCAR/HAO), Tanmoy Samanta (India Institute of Astrophysics), Jansen He (Peking University), Yajie Chen (Peking University), Linghua Wang (Peking University)

Being the primary source of energy in the solar corona, the magnetic field plays a dominant role in driving solar eruptions and heating the coronal plasma. However, direct measurement of coronal magnetic field suffers from several limitations, and is extremely difficult to obtain. Using observations from the Coronal Multi-channel Polarimeter, we derived the spatial distribution of plasma density and phase speed of the prevalent transverse magnetohydrodynamic wave in the corona, which allows us to map the coronal magnetic field strength. Such measurements of the global coronal magnetic field provide critical information to disentangle different initiation mechanisms of solar eruptions and unveil the physical processes of coronal heating.