Spatial Structures of the North–South Asymmetry in the Green Coronal Line and Magnetic Fields

Abstract

The spatial distribution of the north–south (N–S) asymmetry over 1977–2001 is studied. A comparison of the distributions and time variations of the asymmetry index $$A$$ in the green coronal Fe XIV 530.3 nm line, in the total coronal magnetic field, and in small- and large-scale fields has shown that at low latitudes the distribution of $$A$$ for small-scale fields bears the greatest similarity to its distribution in the green line brightness. An anticorrelation between the behaviors of $$A$$ in the green line and large-scale magnetic fields is observed at latitudes above $$40^{\circ}$$ . Previously, it has been shown that the latitude–longitude regions with a predominance of the green line brightness in one of the hemispheres are replaced by regions similar in shape with its predominance in the other hemisphere after 14–18 rotations, i.e., the map, as it were, changes to a ‘‘negative’’ one. In the current paper this conclusion is confirmed by a consideration of the behavior of the N–S asymmetry in the magnetic field strength. The change of the map to a negative one is most pronounced for large-scale fields. The N–S asymmetry is evidence and a measure of the fact that there exist differences (desynchronization) in the operation of the two solar hemispheres. This fact should be taken into account in the construction of up-to-date dynamo theories.