<title>Aerosol measurements by lidar in the nocturnal boundary layer</title>

Abstract

A lidar system capable to perform simultaneous measurements of atmospheric water vapor and aerosols have been developed in Tito Scalo, in the context of a cooperation between Universita della Baslicata and Istituo di Metodolgoie Avanzate di Analisis Ambientale. Aerosol observations by lidar in the nocturnal boundary laser (NBL) have been performed in the period 20 January- 20 February 1997, Radiosondes were launched during the measurement campaign simultaneously to lidar operation. Lidar observations have been sued to retrieve aerosol properties and dimensional characteristics. Aerosol sizes are determined by comparison measured and theoretical values of (beta) <SUB>A,723</SUB>(z)/(beta) <SUB>A,355</SUB>(z), with (beta) <SUB>A,723</SUB>(z) and (beta) <SUB>A,355</SUB>(z) being the aerosol backscattering coefficient at 723.37 and 355 nm, respectively. Furthermore, lidar and radiosonde data have been compared in order to study the NBL vertical structure and evolution. Lidar measurements of (beta) <SUB>A,723</SUB>(z) are compared with simultaneous radiosonde data expressed in terms of potential temperature and relative humidity, with particular emphasis on the estimate of the residual layer height from both lidar and radiosonde data. Results from the present measurements campaign will be reported and discussed in this presentation.