Green coronal intensity enhancements and their relation to the underlying photospheric/chromospheric activity

Abstract

Analysis of the photospheric and chromospheric activity at the sites of enhanced 5303 Å coronal intensity revealed some important aspects of their association. We have examined the daily maps of 5303 Å coronal line intensity of Lomnický Štít for the low sunspot activity years 1985 and 1986 in association with the cotemporal daily maps of sunspots, plages and Stanford magnetograms and identified strong field gradients at the sites of enhanced intensity regions. We found that the peak intensity does not depend on the strength of the underlying magnetic field though the coronal intensity-enhanced feature is almost sure to occur at the locations of sunspots with strong magnetic fields and at the locations of plages having larger areas.