The dataset consists of water vapor profiles including the errors of the Raman lidar measurements performed by the PollyXT_Lidar “Arielle” in the Oceanet container at the bow area of Research Vessel Polarstern from 28 September 2019 till 29 February 2020. The profiles are averaged over 30 s and additionally smoothed with a sliding average over 10 min with the smooth2-function. The vertical averaging is 5 bins (bin-width is 7.5 m; the lidar is pointing with a Zenit angle of 5°). Additionally, signal-to-noise (SNR) ratios of the two signals (H2O and N2) and a quality mask (QM) are provided. The quality mask QM is equal to 1 if the SNR_N2<1 or the SNR_H2O<SNR-threshold (set to 5). The difference of AOD (Aerosol Optical Depth) between 387 nm and 407 nm is not taken into account. For more information about the water vapor calibration (determination of the calibration constant), please go to Dai, G., et al. (2018) and Seidel, C. (2022).