Aerosolizirani črni ogljik in puščavski pesek v ozračju nad Arabskim zalivom

We investigate the optical properties of aerosols in the Arabian Gulf region, focusing on the size-separated absorption characteristics of mineral dust (MD) and black carbon (BC). The analysis is based on one year of measurements performed at two locations in the Qatar peninsula. We aim to provide a comprehensive understanding of atmospheric composition and processes in both urban background (QU) and regional background (RM) sites by analyzing aerosol properties during dust storm (DS) and non-dust storm (nDS) periods. Presence of BC particles in the coarse aerosol fraction challenges the prevailing assumption that this fraction consists mainly of MD. Separating contributions of dust and BC to absorption within the coarse fraction to identify distinct spectral dependencies for dust is crucial for understanding the regional atmospheric dynamics. During the nDS periods, the QU site exhibits a weak correlation between elemental carbon and organic carbon, indicating mixed anthropogenic and biogenic carbonaceous sources. Chemical analysis consistently reveals higher carbonaceous species’ concentrations at QU, reflecting urban emissions' influence. We identify MD as the dominant component throughout all periods, with the surprising result being that there is more MD in QU than RM which we interpret as urban resuspension. Determined specific Absorption Angström Exponent (AAE) values for desert dust and BC in the coarse fraction offer insights into aerosol mixing states. The Mass Absorption Cross-section derived for different aerosol components reveals slight differences between the two sites. Urban emissions increase fine and coarse particle concentrations. Source regions are investigated using Potential Source Contribution Function (PSCF) and Concentration Weighted Trajectory (CWT) based models, highlighting seasonal dependencies. We find that the dynamics of aerosol dispersion require comprehensive monitoring to capture complex interactions of various sources contributions. The discrepancy between the PSCF- and CWT-based results underscores the necessity of utilizing multiple models to achieve accurate understanding pollutant behavior.