Trends and Variability of Aerosol Vertical Distribution and Properties Using Micro-LIDAR and Sun-photometer Measurements

The Sahara desert is the most important global source of mineral dust. Vertical distribution of dust particles and their variability can be studied/monitored from ground-based remote sensing system such as LIDAR. However, regular LIDAR measurements reported in literature are mostly focusing on aged aerosol having been transported over long or medium distances and therefore more addressing to mixing of dust with other aerosols types. Since 2006, routine automatic LIDAR measurements are performed 24 hours per day, 7 days per week, at Dakar, Senegal, simultaneously to AERONET sun-photometer. Joint LIDAR-sun-photometer inversion has been applied to 6 years of measurements to derive aerosol extinction profile, sigma(ext)(z), as well as an effective aerosol extinction-to-backscatter ratio (LIDAR ratio, S-a). Assessment of data quality, monitoring of instrument performances, improvements and validation of automatic inversion method have been performed. A first analysis of time series of these aerosols parameters is presented.