JapaneseGEMSIS-Sun
Fine Structure of the Polar Coronal Magnetic Field
The solar wind acceleration mechanisms and coronal heating processes are two of the biggest puzzles in solar physics. The polar coronal region could be the source of the fast solar wind. Recently, a high-resolution vectormagnetogram obtained with SOT aboard the Hinode satellite revealed the existence of patchy strong magnetic concentrations (kG patches) in polar coronal holes. In this study, we calculated the three-dimensional coronal magnetic field in the polar region, adopting the SOT observation as the boundary condition. The results indicated that most open magnetic flux was rooted to the kG patches observed with SOT, forming canopy structures in which magnetic flux showed rapid lateral expansions near the solar surface.
The polar magnetic field declines as the solar activity increases. Its magnetic polarity is reversed at around the solar maximum. Then, its strength increase as the solar activity declines. We study how the fine structure of the polar coronal magentci field changes associated with the solar acivity variation.
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