Characteristics of aerosol types and identifying the external dust sources (the case of Mashhad city, Iran)

Aerosols, consisting of solid, liquid, and gaseous particles, emerge from both natural and humaninduced origins, impacting air quality over substantial distances. This investigation focuses on discerning dust origins in the polluted city of Mashhad, Iran. Crucial parameters, such as aerosol optical thickness (AOT) and Ångström exponent (AE), play a vital role in understanding aerosols and atmospheric pollutants. Ground-based sun photometers (Calitoo) were employed for calculating AOT and AE at different wavelengths to determine the aerosol characteristics and to reveal the prevalence of urban-industrial pollution. The research detect dust and identifies dust sources from both domestic and neighboring deserts, noting seasonal variations. The results highlight the importance of comprehensive monitoring and understanding of aerosol dynamics for effective air quality management.