Vertical profiles, in a log(τ)-scale, of the MHD physical parameters leading to the emergent synthetic Stokes profiles shown in Fig. 10, at the location of a supersonic downflow in the tail of a CEF-carrying filament: panel a: magnetic field strength, panel b: vertical flow velocity (negative values indicate downflows), panel c: temperature, panel d: field inclination, panel e: gas density, and panel f: geometrical height at the location of the grid-cell containing the supersonic downflows from the MURaM simulation. Vertical dashed lines delimit the approximate τ−range where the lines show a significant response, i.e., between log(τ) = − 2 and 0.