Quality assessment of aerosol lidars at 1064 nm in the framework of the MEMO campaign

Abstract. Aerosol lidar network can play an important role on revealing structural characteristics of atmospheric boundary layer, urban heat island effect, spatial distribution of aerosols, especially monitoring atmospheric pollution in a megacity. To fulfill the need of monitoring and numerical forecast of atmospheric pollution, an aerosol lidar network is proposed by China Meteorological Administration, which serves as an important part of "MegaCity Experiment on Integrated Meteorological Observation in China" (MEMO). To ensure high standard of data quality and traceability of measurement error, an inter-comparison campaign, dedicated for quality assessment of lidar systems from different institutes and manufacturers, was designed and performed at Beijing Southern Suburb Observatory in September 2021. Six Mie-Rayleigh lidar systems at 1064 nm were involved in this campaign. The strategies for lidar self-evaluations and inter-comparisons were predefined. A lidar system at 1064 nm, which was developed by Atmospheric Remote Sensing group at Wuhan University, was selected as the reference lidar system after passing all self-evaluations quality checks in a strict way. The reference lidar system serves as the corner stone for evaluating the performance of other lidar systems. After using the self-test of Rayleigh fit and signalto- noise evaluation for each individual lidar system to fast check the data quality, the range-corrected signal and backscatter coefficient obtained from all the lidar systems were inter-compared with a reference lidar system. In the end, the lidar systems were quality assured, of which the standard deviation of range-corrected signal can be controlled within 5 % at 500–2000 m while 10 % at 2000–5000 m. For the derived aerosol backscatter coefficients, standard deviations can be controlled within 10 % at 500–2000 m and 2000–5000 m. The quality assurance strategy lays down a solid basis for atmospheric lidar at near-infrared wavelength and will be applied in Chinese lidar network development.