Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
Abstract Coronal loops in active regions are often characterized by quasi-circular and helically twisted (sigmoidal) geometries, which are consistent with dipolar potential field (PF) models in the former case, and with nonlinear force-free field models with vertical currents in the latter case. Alternatively, Parker-type nanoflare models of the solar corona …