Definition of the asf sign and the in- and outbound regions of the MC in X and R spacial coordinates. From top to bottom, the first two rows show the magnetic field magnitude B and the B_y component in function of time. The B_y profile is dominating in χ_R (Eq. (8)) to determine the sign of the asf. The third and fourth rows show the in- and outbound regions of the MC in X and R spacial coordinates, respectively. Column a corresponds to an MC observed on 22 August 1995 as an example of an asf >  0 with R_in >  R₀ >  R_out as the schema shown in Fig. 3a. Furthermore, in this case R_inf = R_out and R_sup = R_in. Column b corresponds to an MC observed on 24 July 2004 as an example of an asf <  0 with R_in <  R₀ <  R_out as the schema shown in Fig. 3b. In this case, R_inf = R_in and R_sup = R_out.