Abstract
By means of comparison of the positions of 665 observed coronal holes (CHs) and the structures of the magnetic field at different heights, it was shown that 43% of the observed CHs are not associated with unipolar regions of the background field at the photosphere. With height increasing from 1 to 2.5 solar radii, the structure of the magnetic field varies in 57% of all CHs. In 16% of the cases, variations of the structure can be observed at heights as small as 2500–10 000 km. Comparison of the positions of CHs with the longitudinal distribution of long-lived +/− and −/+ boundaries of the large-scale structure of the magnetic field at all the heights was carried out. It was shown that CHs adjoin or intersect with the Hale boundaries half as often as with those having the opposite distribution of the fields at both sides of the boundary. These results attest to a closer connection between the CHs and the photospheric and subphotospheric fields than with coronal fields. The magnetic fields of coronal structures can shield the coronal holes, thus creating “closed” CHs with a limited output of high-speed solar wind streams.
Published Version
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