Monitoring Temporal-Spatial Changes of Atmospheric Suspended Dust in Selected Provinces of the Western Half of Iran Using MODIS and Sentinel-5 Images

Dust is a significant global challenge. This study aimed to monitor the temporal and spatial changes of suspended atmospheric dust in the western half of Iran, specifically in the provinces of Ilam, Khuzestan, Kermanshah, Kurdistan, and Lorestan. We utilized MODIS sensor products from 2012 to 2021 and Sentinel-5 imagery from 2018 to 2021 within the Google Earth Engine framework. These sensor products are invaluable for managing and addressing dust-related issues. Using Aerosol Optical Depth (AOD) and Absorbing Aerosol Index (AAI) data, we tracked the trends in aerosol concentration over time and across the selected regions. Additionally, we calculated the Enhanced Vegetation Index (EVI) and Bare Soil Index (BSI) from MOD13Q1 images for the same period to assess their average changes. The analysis revealed a downward trend in AOD during January and an upward trend in July. The AAI indicated that January 2021 recorded the lowest aerosol levels, while July and September 2021 experienced the highest concentrations. Classifying aerosol concentrations into three categories highlighted that regions with high aerosol levels, as indicated by MODIS data, were consistently found in Khuzestan and Ilam provinces, while Sentinel data showed sporadic occurrences. Furthermore, the correlation between dust concentration from MODIS imagery and EVI and BSI indices revealed that the highest aerosol concentrations were located in areas with little vegetation and bare soils.