Methodology and sample results of retrieving aerosol parameters by combined multi-wavelength lidar and Sun-sky scanning measurements

摘要

Scientific groups engaged within the frame of the observation networks AERONET and EARLINET perform this work. The methodology of coordinated multi-frequency lidar and radiometric investigations of atmospheric aerosols is being developed for using in network observations. The method to process data of a comprehensive experiment utilizes the approach designed to process CIMEL data. The retrieval of altitude profiles of aerosol parameters is based on solving a common equation set including lidar equations, equations for the whole atmospheric depth, and constraints on the smoothness of the solutions. The results of numerical experiments are given in the paper to estimate errors while retrieving aerosol parameters. The measurement procedure and algorithms for data processing were refined during the summer-autumn, 2002 at the stations of the Institute of Physics (Minsk, Belarus) and Institute of Geophysics (Belsk, Poland). The stations were equipped by devices CIMEL and three-frequency lidars (532, 694, and 1064 nm). The CIMELs operated according to the routine AERONET program during the measurements. To provide gathering the data on the whole aerosol layer, a series of lidar observations was made at different elevation angles. A procedure to successively approach to an optimal estimation of aerosol parameters is proposed in this work to enable data processing with real measurement errors. The results of retrieving vertical profiles of aerosol fraction concentrations are presented for different quality of measurement information.