Abstract
Abstract The orientation, chirality, and dynamics of solar eruptive filaments are key to our understanding of the magnetic field of coronal mass ejections (CMEs), and therefore to predicting the geoeffectiveness of CMEs arriving at Earth. However, confusion and contention remain over the relationship between the filament chirality, magnetic helicity, and the sense of rotation during eruption. To resolve the ambiguity in observations, in this paper we used stereoscopic observations to determine the rotation direction of filament apex and the method proposed by Chen et al. to determine the filament chirality. Our sample of 12 eruptive active-region filaments establishes a strong one-to-one relationship, i.e., during the eruption, sinistral/dextral filaments (located in the southern/northern hemisphere) rotate clockwise/counterclockwise when viewed from above, and corroborates a weak hemispheric preference, i.e., a filament and related sigmoid both exhibit a forward (reverse) S shape in the southern (northern) hemisphere, which suggests that the sigmoidal filament is associated with a low-lying magnetic flux rope with its axis dipped in the middle. As a result of rotation, the projected S shape of a filament is anticipated to be reversed during eruption.
Highlights
Solar filament eruptions, flares, and coronal mass ejections (CMEs) are closely associated with each other, usually originating from the same polarity inversion line (PIL) of an active region (Green et al 2018)
The orientation, chirality, and dynamics of solar eruptive filaments is a key to understanding the magnetic field of coronal mass ejections (CMEs) and to predicting the geoeffectiveness of CMEs arriving at Earth
The Solar Terrestrial Relations Observatory (STEREO; Kaiser et al 2008), aided by ground-based telescopes and space-born instruments operating at the Earth orbit such as the Solar Dynamics Observatory (SDO; Pesnell et al 2012) and Hinode (Kosugi et al 2007), has made it possible to observe the Sun with high-resolution high-cadence images taken from as many as three viewing angles
Summary
Flares, and coronal mass ejections (CMEs) are closely associated with each other, usually originating from the same polarity inversion line (PIL) of an active region (Green et al 2018). It is noticed that an erupting filament which is S-shaped before the eruption could reverse the sense of its S shape through rotation during eruption (Rust & LaBonte 2005; Romano et al 2005; Green et al 2007) This is interpreted as a signature of the conservation of helicity when a writhed flux rope transforms from having a dipped central section to a humped one while maintaining the sign of writhe (Torok et al 2010). The Solar Terrestrial Relations Observatory (STEREO; Kaiser et al 2008), aided by ground-based telescopes and space-born instruments operating at the Earth orbit such as the Solar Dynamics Observatory (SDO; Pesnell et al 2012) and Hinode (Kosugi et al 2007), has made it possible to observe the Sun with high-resolution high-cadence images taken from as many as three viewing angles This gives us an unprecedented advantage to resolve the above-mentioned ambiguity as compared with previous studies.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
