Cyclic variations in distribution of the coronal green line brightness and solar magnetic field

Abstract

Cyclic variations of the coronal green line brightness (CGLB) are investigated analysing a series of synoptic charts and a special movie assembled of them, covering 1943-2001. Regular changes of the large-scale CGLB distribution in dependence on the phase in the solar cycle are presented. A quantitative relation between the coronal green line intensity I and the total mag- netic field strength B is derived for the period 1977-2001; the B was calculated under potential approximation. A simple exponential relation of type IB q was found to exist between the above two quantities. It is shown that the q exponent may have opposite sign in the equatorial and polar zones. During phases of the solar cycle maxima the I versus B relation is much more complicated and cannot be expressed by such a simple formula.