A lidar method is presented that permits the estimation of heightprofiles of ice nuclei concentrations (INC) in desert dust layers. Thepolarization lidar technique is applied to separate dust and non-dustbackscatter and extinction coefficients. The desert dust extinctioncoefficients σ are then converted to aerosol particle numberconcentrations APC which consider particles with radius> 280 nm only. By using profiles of APC and ambienttemperature along the laser beam, the profile of INC can be estimatedwithin a factor of 3 by means of APC--INC parameterizations from theliterature. The observed close relationship between σ at 500 nmand APC is of key importance for a successful INC retrieval. Westudied this link by means of AERONET (Aerosol Robotic Network) sun/skyphotometer observations at Morocco, Cabo Verde, Barbados, and Cyprus duringdesert dust outbreaks. The new INC retrieval method is applied to lidarobservations of dust layers with the spaceborne lidar CALIOP (Cloud AerosolLidar with Orthogonal Polarization) during two overpasses over the EARLINET(European Aerosol Research Lidar Network) lidar site of the Cyprus Universityof Technology (CUT), Limassol (34.7° N, 33° E), Cyprus. Thegood agreement between the CALIOP and CUT lidar retrievals of σ, APC, and INC profiles corroborates the potential of CALIOP toprovide 3-D global desert dust APC and INC data sets.
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