The Thessaloniki lidar system (THELISYS) is operated and maintained by the Laboratory of Atmospheric Physics that is located at the School of Physics of the Aristotle University of Thessaloniki (40.5∘ N, 22.9∘ E; 50 m). The THELISYS instrument was re-designed by Raymetrics in June 2021, in order to perform automated continuous profiling of aerosols and clouds.

The lidar system has been used for the detection of aerosol particles as a part of European Aerosol Research Lidar Network (EARLINET; Pappalardo et al., 2014) since 2000 in the frame of Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS; Systematic measurements are performed following EARLINET’s schedule. Additional measurements are performed during Saharan dust outbreaks, smoke advection from biomass burning and volcano eruptions. The current setup of THELISYS includes three elastic backscatter channels at 355, 532 and 1064 nm, two nitrogen Raman channels at 387 and 607 nm, a depolarization channel at 532nm, a water vapor and fluorescence channels at 408 and 466 nm respectively.

Data from THELISYS are regularly analyzed and quality assured and are publicly available at