Examination of possible synergy between lidar and ceilometer for the monitoring of atmospheric aerosols

In this paper the possible synergy between advanced lidars and ceilometers for the monitoring of atmospheric aerosols is evaluated. The advanced measurement capabilities of the multi-wavelength Raman lidar are used to investigate the capability of ceilometers to provide reliable information about the atmospheric aerosol content. At the CNR-IMAA Atmospheric Observatory (CIAO), a ceilometer is operational since September 2009 providing vertical profiles of atmospheric backscatter at 1064nm up to 15km; at the same location, the Potenza EArlinet Raman Lidar (PEARL), a quality-assured, multi-wavelength Raman lidar operates in the framework of EARLINET and performs regular measurements plus measurements of special events (Sahara dust outbreaks, volcanic eruptions etc.). Using the PEARL data products as a reference, the capability of ceilometers to detect aerosol layers and provide quantitative information about the atmospheric aerosol load is investigated. The variation of ceilometers' performance in different atmospheric conditions is analysed. A procedure for obtaining backscatter coefficient profiles from ceilometer signals is proposed and its limitations are discussed.