Comparison of the Coronal Green-line Intensities with the EUV Measurements from SDO/AIA

Abstract

The intensity of the green line (Fe XIV 5303 \AA) is the strongest in the visible spectrum of the solar corona,}} and this line has been used as long-term powerful diagnostic tools for studying the coronal configurations and hot plasma dynamics. However, it is an open question if there exists close relationship between the green line intensities and the coronal EUV line emissions for various coronal structures. In this paper, we use the green-line data by the Lijiang YOGIS Lyot coronagraph and the EUV data from the SDO/AIA instruments to make the direct comparisons and studies, based on two algorithms developed to extract particular features in low corona. It is found that, among the correlation coefficients obtained between the intensities of 5303 \AA\ and the EUV lines, the coefficients between the green line and the 211 \AA\ wavelength for different coronal structures and different limb locations always keep the highest values (ranging from 0.89 to 0.99), which has not been reported before. This result can help to connect the physical processes observed in different heights in the corona by precisely tracking the bright loops or other features observed in 5303 \AA\ above the limb down to the correct surface locations revealed by the 211 \AA\ data. \textbf{\textcolor[rgb]{0.00,0.00,1.00}{Furthermore, the ground-based observations of the coronal green line and the space-based EUV observations at 211 \AA\ can complement each other when there is a need.

Experimental study of the scattering background produced by dust on the objective lens of the Lijiang 10-cm Coronagraph

“…Using this instrument, Zhang et al (2022a) found that the coefficients between the green line coronal data and the 211 Å data of SDO/AIA (Lemen et al, 2012) always keep the high values. Zhang et al (2022b) also suggested that the correlation between the coronal green line and the magnetic field is strong.…”