Inter-comparison of lidar and ceilometer retrievals for aerosol and Planetary Boundary Layer profiling over Athens, Greece

摘要

This study presents an inter-comparison of two active remote sensors (lidarand ceilometer) to determine the mixing layer height and structure of thePlanetary Boundary Layer (PBL) and to retrieve tropospheric aerosol verticalprofiles over Athens, Greece. This inter-comparison was performed undervarious strongly different aerosol loads/types (urban air pollution, biomassburning and Saharan dust event), implementing two different lidar systems(one portable Raymetrics S.A. lidar system running at 355 nm and onemulti-wavelength Raman lidar system running at 355 nm, 532 nm and 1064 nm)and one CL31 Vaisala S.A. ceilometer (running at 910 nm). Spectralconversions of the ceilometer's data were performed using the?ngstr?m exponent estimated by ultraviolet multi-filter radiometer(UV-MFR) measurements. The inter-comparison was based on two parameters: themixing layer height determined by the presence of the suspended aerosols andthe attenuated backscatter coefficient. Additionally, radiosonde data wereused to derive the PBL height. In general, a good agreement was foundbetween the ceilometer and the lidar techniques in both inter-comparedparameters in the height range from 500 m to 5000 m, while the limitationsof each instrument are also examined.