Twist and writhe of δ-island active regions
نویسندگان
چکیده
منابع مشابه
Twist and writhe of 8 active region magnetic fields
Twist is a parameter to measure turning of the field lines around axis of the flux tube. Observations show that each active region (AR) has a pronounced overall twist, following hemispheric helicity rule (Pevtsov et al. 1995; Bao & Zhang 1998). etbest, best-fit single value for a whole AR, is used to characterize the overall twist. Writhe is a measure of the spatial turning of the axis of the f...
متن کاملViscous Nonlinear Dynamics of Twist and Writhe
Exploiting the “natural” frame of space curves, we formulate an intrinsic dynamics of a twisted elastic filament in a viscous fluid. Coupled nonlinear equations describing the temporal evolution of the filament’s complex curvature and twist density capture the dynamic interplay of twist and writhe. These equations are used to illustrate a remarkable nonlinear phenomenon: geometric untwisting of...
متن کاملThe Viscous Nonlinear Dynamics of Twist and Writhe
Exploiting the “natural” frame of space curves, we formulate an intrinsic dynamics of twisted elastic filaments in viscous fluids. A pair of coupled nonlinear equations describing the temporal evolution of the filament’s complex curvature and twist density embodies the dynamic interplay of twist and writhe. These are used to illustrate a novel nonlinear phenomenon: geometric untwisting of open ...
متن کاملThe Origin and Role of Twist in Active Regions
The implications of twist in active region magnetic elds is considered in this paper. The latitudinal distribution of twist that has been derived from recent vector magnetogram observations may be explained by the eeects of convective turbulence with a non-zero kinetic helicity acting on active region scale magnetic ux tubes as they rise through the convection zone. Highly twisted, kink unstabl...
متن کاملTwist-writhe partitioning in a coarse-grained DNA minicircle model.
Here we present a systematic study of supercoil formation in DNA minicircles under varying linking number by using molecular-dynamics simulations of a two-bead coarse-grained model. Our model is designed with the purpose of simulating long chains without sacrificing the characteristic structural properties of the DNA molecule, such as its helicity, backbone directionality, and the presence of m...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2010
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s174392131101516x