Latitudinal distribution of HDO abundance above Venus' clouds by ground-based 2.3 μm spectroscopy

► We measured HDO mixing ratios above the Venus dayside clouds. ► The hemispherical average found is 0.22 ± 0.03 ppm at 62-67 km. ► No clearly defined structure is found in the observed latitudinal distribution. ► The present data support the increasing HDO/H2O ratio with altitude.