Aerosol classification in Europe, Middle East, North Africa and Arabian Peninsula based on AERONET Version 3

The aerosol optical properties from Version 3 (V3) of AERONET are used to classify the aerosol types in Europe, Middle East/North Africa (MENA) and Arabian Peninsula, during 2008-2017. Quality-assured data of Single Scattering Albedo (SSA), Fine Mode Fraction (FMF) and Angstrom Exponent (AE) from 39 stations are used to classify the aerosol types, based on threshold limits of these optical properties. The aerosol type depends on the location and the sources of each region of study; for example, in Atlantic, Arabian Peninsula and MENA, the dominant aerosol type is coarse absorbing due to dust from Sahara and Arabian deserts. However, in Arabian Peninsula, fine particles are also observed in autumn and winter. In addition, the lower percentages of coarse absorbing particles across MENA are observed in the East because of increased fine particle emissions from human activities. In the stations of the Group A of South Europe, a bimodal size distribution is revealed and the dominant aerosol types are the fine-slightly absorbing and non-absorbing, followed by coarse absorbing due to Sahara dust outbreaks. In the stations of the Group B of South Europe, fine slightly absorbing and non-absorbing particles are primarily observed since the stations are located in urban/industrial regions. In Central and East Europe, the prevailing aerosol type is fine-non absorbing which is followed by the fine slightly absorbing aerosols from urban/industrial sites. The results of the aerosol type characterization are presumed to give a better assessment of regional climate and local air pollution. The proposed method could be used to compare aerosol classification results from satellite and chemical transport models, as well as for the validation of satellite data and the improved performance of models and remote sensing algorithms in the future.