Evolution of the quasi separatrix layers and flux ropes through the corona, where their radial height is shown as a function of the day of simulations taken in a cut through the center of the bipoles. The solid lines represent the flux ropes and the dashed lines, the quasi separatrix layers or quasi separators. The labeling is as follows: "T" marks the trailing bipole, "L" marks the lead bipole, "E" marks the external PIL, and "C" marks the initial coronal quasi separator.