Spectral line observed with ALMA at the eastern limb and at 35°N, in the beacon. Because the line is asymmetrical in its broad wings (see explanation in the text), the line is fitted with the wind retrieval algorithm (and its symmetrical analytical function parametrized following Benmahi et al. 2022) only within ±1.5 MHz of the line center, to avoid an erroneous wind speed retrieval. The line is shown in black and the fit in red, with the fitted interval highlighted with the light yellow box.