Examples of normalized H_α spectral profiles in the jet and its footpoint (right panels). The top right panel corresponds to the profiles of the jet footpoint at 18:15:26 UT. The normalized H_α spectral profile (yellow line) at the footpoint of the jet and reference profile (green line) are shown in the right panel. The footpoint (yellow dot) and the quiet region (green box) are marked in the image of the H_α +0.8 Å in panel a. In panels b and c, the upflow (blue dot) and downflow (red dot) of intermittent jets are marked in the images of H_α +0.8 Å at 18:05 UT and at 18:06 UT, respectively. The normalized H_α spectral profile of the upflow (blue line), downflow (red line), and the reference profile (green line) are shown in the corresponding right panels.