Remote sensing of aerosols by sunphotometer and lidar techniques

Abstract

Active and passive remote sensing devices such as lidars and sunphotometers, respectively, are peculiar tools to follow the spatial and temporal evolution of aerosol loads and get complementary data to properly characterize aerosol optical and microphysical properties. A XeF-based Raman lidar is routinely used at the physics department of Lecce's University (40°20 ′N, 18°6 ′E), to monitor aerosol vertical distributions and characterize aerosol optical properties by the vertical profiles of the backscatter and extinction coefficient, lidar ratio, and depolarization ratio. In addition, a sun/sky radiometer operating within AERONET is used to supplement lidar measurements and better infer aerosol types and properties by columnar values of the particle size distribution, the real and imaginary refractive index, the single scattering albedo and the Angstrom exponent (Å). The main objective of this paper is to provide some results on the spatial and temporal evolution of the aerosol properties over south-east Italy, in the central-east Mediterranean basin, by using lidar and sunphotometer measurements. Specifi cally, results on the characterization of the aerosol load from July 18 to July 21, 2005 are reported and particular attention is devoted to the Sahara dust outbreak that has occurred over south-east Italy on July 18 and 19, 2005. Keywords: Aerosols, lidar, remote sensing, sunphotometer © 2008 Springer Science+Business Media B.V.