Comparison of Hα and UV Mg II and Si IV IRIS intensity and Doppler velocity. From left to right: Hα intensity; Mg II k₃ and Doppler velocity; Si IV peak intensity and Si IV Doppler-velocity maps for three RoIs (see the red boxes in the k₃ intensity middle panels of Fig. 6). The Mg II k₃ and Si IV Doppler-velocity maps are shown in the range from [−10, 10] to [−30,30] km s⁻¹ as the original maps of Fig 10. In the Mg II k₃ and Si IV intensity and Doppler-velocity maps, the red and blue contours represent upflows (−1 and −3 km s⁻¹) and downflows (1 and 3 km s⁻¹), respectively, corresponding to the Doppler velocities of Mg II k₃ and Si IV.