Initial magnetic field configuration in the PLUTO code taken from Domínguez-Fernández et al. (2020). The streamlines are colored according to the magnitude of the magnetic field: green, light colors denote higher values, while dark blue color indicates lower values. Here, I denotes the post-shock region, II the uniform pre-shock region, and III the turbulent pre-shock region (see Sect. 2.1). The left side is a uniform medium with a B_x component matching the mean value of the B_x of the turbulent medium. We have one Lagrangian particle per cell placed in the whole regions II and III.