Panel a: normalised shallowest (blue solid line) and deepest (magenta dash-dot-dot-dot line) profiles described in Figs. 6a and 12 of Fontenla et al. (1988), respectively, overlapped with a normalised Gaussian coronal profile (black dotted line) computed by setting the coronal H I temperature at 1.5 × 10⁶ K, considering θ = 0°. Panel b: Doppler factor as a function of v_w calculated considering each chromospheric profile. Triangles, squares, and asterisks: see Fig. 3. Panels c and d: same as in panels a and b, but concerning the bluest asymmetric profile (I peak − blue/I peak − red = 1.16) observed on October 28, 1996 (green dash-dotted line; Lemaire et al. 2015) and the reddest asymmetric profile (I peak − blue/I peak − red = 0.86; red solid line), respectively.