A Study of the Distribution of Electric Currents and Current Helicity in the Photosphere at the Growth Stage of a Bipolar Active Region

摘要

The process of active region formation was researched by analyzing the densities of electric current and electric current helicity in the photosphere. The observational data were obtained with the vector magnetograph of the Sayan observatory. The appearance (as the sunspot developed) of the part of current helicity which is determined by the vertical components of the magnetic field and electric current density was studied. It is concluded that the loop-like magnetic flux tube which is responsible for the active region emergence contains thinner tubes with the same structure. The electric current system in a sunspot is simplified as the sunspot forms perhaps because the thinner flux tubes are merged together.