Disk-integrated spectrum of the HDO transition at 1344.90 cm^-1 recorded by TEXES on January 14, 2016 (20:33 UT). The date and duration of the corresponding observation are indicated in Table 2. The January 2016 run corresponds to the strongest SO₂ content measured at the cloudtop between 2012 and 2016. Thick black line: the TEXES data; thin lines: models. Green: H₂O = 0.5 ppmv; red (best fit): H₂O = 1.0 ppmv; blue: H₂O = 1.5 ppmv. For the conversion between the HDO and H2O abundances on Venus, we assume a D/H ratio of 200 times the VSMOW (Fedorova et al. 2008).