A brief report on statistical study of net electric current in solar active regions with longitudinal fields of opposite polarity

TL;DR

This study statistically analyzes the net electric current in solar active regions, revealing a hemispheric pattern and its reversal during solar minimum, contributing to understanding solar magnetic dynamics.

Contribution

It provides new statistical evidence of hemispheric electric current patterns and their reversal during solar minimum, enhancing knowledge of solar magnetic field behavior.

Findings

Net electric current is weak and varies with hemisphere.

Systematic current flows from negative to positive polarity in the north.

Reversal of current tendency occurs during solar minimum.

Abstract

Dynamic processes occurring in solar active regions are dominated by the solar magnetic field. As of now, observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field. The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current. We found that the electric current in areas with positive (negative) polarity due to the longitudinal magnetic field have both positive and negative signs in an active region, however, the net current is found to be an order-of-magnitude less than the mean absolute magnitude and has a preferred sign. In particular, we have statistically found that there is a systematic net electric current from areas with negative (positive) polarity to areas with positive (negative) polarity in solar active regions in the northern (southern) hemisphere, but during the solar minimum this tendency is reversed over time at some latitudes. The result indicates that there is weak net electric current in areas of solar active regions with opposite polarity, thus providing further details about the hemispheric helicity rule found in a series of previous studies.