Evolutionary Changes in the Configuration of the Magnetic Field of the Solar Corona in the Epoch of the Minimum

Abstract

The evolution of the magnetic configuration in the solar corona is studied. The curvature of the K-corona helmets obtained from an analytical approximation of the geometry of the helmet axis was used as an indicator of the configuration change. The period of minimum solar activity was analyzed with solar eclipse materials. As a result of the analysis, the dependence of the curvature value on the latitude of the position of the helmet base and the phase of the solar cycle has been obtained. It has been established that this dependence is different for the period of solar-activity growth (the beginning of the cycle) and its decline. It was found that there is a sharp decrease in the curvature to almost zero at the beginning of the solar cycle. During the decline of the 23rd cycle and at the beginning of the 24th cycle, the change of the curvature of the helmets differs from the trend of the previous solar cycles. The apparent reason for this is a change in the conditions of the generation of the solar magnetic field. The found latitudinal–phase dependences of the curvature of the coronal helmets indicate a difference in the coronal magnetic configuration during periods of decline and increase in solar activity, as well as a sharp reorganization of the configuration at the beginning of the new solar cycle.