Three decades of Dust Storm Dynamics in Thar Desert region of India: Evolving Aerosol Properties and Impacts on Urban Air Quality.

In the Anthropocene, interactions between natural mineral dust and anthropogenic emissions have become a major driver of deteriorating air quality across the Indian subcontinent. While the Indo-Gangetic Plain (IGP) remains a persistent hotspot for fine-mode urban pollution, increasingly frequent and intense pre-monsoon dust storms now act as powerful amplifiers of existing aerosol burdens. This study presents a three-decade (1995–2025) spatiotemporal assessment of dust-storm dynamics using the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis product, multi-sensor satellite observations including the Moderate Resolution Imaging Spectroradiometer (MODIS), Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), and ground-level Particulate Matter (PM) monitoring.

Across these three decades, all datasets show a systematic intensification of pre-monsoon dust activity, with percentage changes derived from contrasts between monthly means of the early decade (1995–2005) and the most recent decade (2015–2025). In May, Aerosol Optical Depth (AOD) increases by 26%, Dust Column Mass Density (DCMD) by 15%, and Ångström Exponent (AE) by 31%, indicating stronger dust uplift accompanied by enhanced mixing with fine anthropogenic particles. In comparison, June shows a modest rise in AOD (9%) and DCMD (~2%) with a smaller AE increase (14%), suggesting a gradual end of the peak dust-activity season in the IGP.

Using a three decades long dataset rather than a shorter record is crucial: two-decade comparisons masked the gradual shift in dust-storm timing and the emergence of mixed dust–pollution regimes, whereas the full 1995–2025 time frame reveals coherent, climatologically robust transitions. The results show that strengthening dust intrusions now interact with rapidly evolving urban emissions, modifying aerosol properties and elevating exposure risks. Accounting for these dust–pollution couplings is essential for realistic air-quality assessment and climate–health planning.