Mass density distribution in the Harris current sheet, where the black contours represent the structure of magnetic field. On the right-hand side of the figure both a) vertical (for x = 0 Mm) and b) horizontal (for y = 37.65 Mm, which is magnetic scale height) slices in mass density are shown, as well as the details of the part of the simulation region illustrating the computational grid, with adaptive mesh refinement (AMR). At the altitude y = 5 Mm the perturbation point, L_P, is marked by full black circle.