Magnetic Twists of Solar Filaments

Stability of spiral wave vortex filaments with phase twists

In this paper we investigate the stability of a straight vortex filament with phase twist described by the three-dimensional complex Ginzburg-Landau equation ~CGLE!. The results of the linear stability analysis show that the straight filament is stable in a limited region of the two parameter space of the CGLE. The stable region is dependent on the phase twist imposed on the filament and shrink...

Latitude migration of solar filaments

ABSTRACT The Carte Synoptique catalogue of solar filaments from March 1919 to December 1989, corresponding to complete cycles 16 to 21 is utilized to show latitudinal migration of filaments at low latitudes ( less than 50), and the latitudinal drift of solar filaments in each hemisphere in each cycle of the time interval is compared with the corresponding drift of sunspot groups. The latitudina...

Reconstruction of Solar Coronal Linear Force-Free Magnetic Field

The Helicial Flux Rope Structure of Solar Filaments

According to J. B. Taylor’s relaxation theory for magnetized plasmas, helical flux ropes should be the fundamental building blocks of magnetism in the solar atmosphere. Although flux ropes are clearly ejected from the Sun, there has been some controversy about whether they exist in the sun’s atmosphere before ejection. The issue is important because of the need to understand how eruptions are i...

Automatic Detection of Solar Filaments Versus Manual Digitization

The technique which is presented here is based on careful attention to image cleaning in order to achieve robust automatic filament detection and avoid confusion between filaments and image defects, due to particular shapes of filaments. The main part of the detection process is based on seed selection and region growing. The procedures developed have been tested on four months of full-disk ima...