Temporal evolution of the absorption spectra of one ion for each gas phase, generated with a light ray passing through the centre of the cloud. The absorption lines are generated at t = 0.2, 1.2, 2.2, 3.2 Myr (or t/t_cc = 0.2, 0.9, 1.7, 2.5) respectively. We display C II as representative ion for the cold phase (top), C IV for the intermediate temperature one (middle), and O VI for the warm gas (bottom). As in Section 3.4, on the left side we show the simulation R32-AL, with an aligned magnetic field and on the right R32-TR, with a transverse magnetic field. We see that in R32-TR the gas reaches overall higher velocities than R32-AL at all times, particularly for the intermediate ions, which show velocities of 100 − 200 km s⁻¹ at t/t_cc = 1.7. We also stress that the intermediate gas phase is the one that shows broader and deeper lines at all times when the magnetic field is transverse.