Multi-spectral Lidar characterization of the vertical structure of Saharan dust aerosol over southern Spain

Abstract

Measurements during Saharan dust transport events have been performed at the Andalusian Centre for Environmental Studies (CEAMA) (37.16°N, 3.58°W, 680 m a.s.l.), located in the city of Granada (south-eastern Iberian Peninsula). During 2005, as many as 22 dust outbreaks took place over the study area in south-eastern Spain. The arrival of Saharan air masses induced sharp changes in the background aerosol optical depth (AOD) and the Angström exponent during the analysed events. This fact, in addition to a back-trajectory analysis, identified the Saharan dust events. In order to improve knowledge of Saharan dust over the southern Iberian Peninsula, vertical characterization of temporal evolutions has been performed in terms of the backscatter coefficient, aerosol depolarization ratio and colour ratio. Two severe events in July 2005 have been selected for detailed analysis. Both events lasted several days, allowing the characterization of the evolution of the dust layers over our station. The impact of Saharan dust outbreaks has been followed with the Lidar, and their effects at the surface have been determined in the air quality network of the regional government.