Magnetic field models with low and high twists. Panels a, b represent the low-twist () and high-twist flux rope (), respectively. Yellow lines denote the core flux-rope field, and cyan lines denote the background potential field. The twist error is the standard deviation of all sample field lines. Panel c: side view along the y-axis showing two flux ropes in the same coordinate system, where the green and blue lines represent the low-twist and high-twist flux ropes, respectively.