Overhaul of the stratospheric lidar at Dumont d’Urville, Antarctica: three-wavelength setup, processing and observations

Abstract. The stratospheric cloud and aerosol lidar instrument Liraan (LIdar pour la Recherche Antarctique Aérosol et Nuages) has been operated at the French Antarctic station Dumont d'Urville since 1989. Following a major upgrade conducted between 2022 and 2024, this paper presents the instrument configuration and its scientific capabilities. Liraan now enables the retrieval of backscatter coefficients at 355 nm, 532 nm and 1064 nm and depolarization ratios at 355 nm and 532 nm. The new configuration is described in detail, along with an improved data inversion algorithm, which is further used as input to a dedicated microphysical retrieval methodology. A unified 532 nm lidar time series spanning 1991–2025 at Dumont d'Urville is also presented for the first time. Finally, 2025 multispectral lidar measurements are used in a case study of volcanic aerosol size distribution retrieval.