The atmosphere of the central Arctic is polluted with fine dust from Siberia and North America. This was the result of a preliminary evaluation of the first lidar measurements carried out by the Leibniz Institute for Tropospheric Research (TROPOS) during the one-year MOSAiC expedition on board the RV Polarstern. For the first time, a multi-wavelength lidar was used during polar night in the central Arctic, which can measure dust particles at altitudes of up to 14 kilometres with laser pulses from the ground.