Appearance of the Doppler excursions at 2.5 Mm in intensity and velocity. Top: velocity proxies. Red: difference of H_2V and H_2R. Black: position of the line core. The blue and red dashed vertical lines denote the locations of blue/red shifts. Bottom: intensity of H_2V (blue), H_2R (red), and the H-index (black). The vertical black dashed lines indicate local maxima of the H-index. The abscissa is in Mm.