Characterization of dust aerosol over United Arab Emirates

One-year of ground-based Raman lidar observations have been conducted in order to characterize the aerosol properties over United Arab Emirates (UAE). In total, over 1000 aerosol layers were detected during the one-year campaign period which was carried between March 2018 and February 2019. We found that the measurement site is a receptor of frequent dust events but predominantly the dust is mixed with anthropogenic and/or aerosol of marine origin. With our multiwavelength PollyXT Raman lidar we are able to retrieve the backscatter coefficients (at 355, 532 and 1064 nm), extinction coefficients (at 387 and 607nm), particle depolarization ratios (at 355 and 532 nm), water vapour concentration (at 407 nm), and further on lidar ratios and Ångström exponents to characterize the aerosols properties in detail. In general, the average lidar ratios and linear particle depolarization ratios already showed strong presence of dust aerosols. Since the region is both a source and a receptor of mineral dust, we have also explored the pure mineral dust properties in the region. The findings suggest that the mineral dust properties over the Middle East and western Asia, including the observation site, are comparable to those of the African mineral dust regarding the particle depolarization ratios but not the lidar ratios. The lower lidar ratio values are attributed to different geochemical characteristics of the under-study region compared to soil originating from Northern Africa.