[P-EM14] Frontiers in solar physics

[PEM14-01] Coronal magnetic field measurements with UCoMP through 2D coronal seismology

★Invited Papers

*Zihao Yang^1,2, Hui Tian¹, Steven Tomczyk², Richard Morton³, Sarah Gibson², Xianyu Liu¹ (1.Peking University, 2.High Altitude Observatory, National Center for Atmospheric Research, 3.Northumbria University)

Keywords:solar corona, coronal magnetic field, MHD waves

Coronal seismology, a technique of magnetic field diagnostics based on observations of MHD waves, has been widely used to estimate the field strengths of oscillating structures in the corona. However, previously coronal seismology was mostly applied to occasionally occurring oscillation events, providing an estimate of only the average field strength or one-dimensional distribution of field strength along an oscillating structure. This restriction could be eliminated if we apply coronal seismology to the pervasive propagating transverse MHD waves discovered with the Upgraded Coronal Multi-channel Polarimeter (UCoMP). Using several UCoMP observations of the Fe XIII 1074.7 nm and 1079.8 nm spectral lines, we obtained maps of the plasma density and wave phase speed in the corona, which allow us to map both the strength and direction of the coronal magnetic field in the plane of sky routinely. We also compared the results with PSIMAS models, and confirmed the measured results are emissivity-weighted magnetic field averaged along the line-of-sight. Such measurements could provide critical information to advance our understanding of the Sun's magnetism and the magnetic coupling of the whole solar atmosphere.