Wind-induced aerosol transport and associated precipitation enhancement over South - East Asia

As the most populous and rapidly developing region, Asia has garnered significant attention regarding the anthropogenic influence on the atmospheric composition, climate, and hydrological cycle. Air pollution due to industrialization and urbanization is a local issue; however, its influence may go beyond regional scales due to large-scale atmospheric circulations along with the transport and evolution of particles. In this study, we investigated the impact of atmospheric circulation on regional air quality and its associated influence on regional precipitation. The datasets used for the analysis are the Cloud and the Earth’s Radiant Energy System (CERES – MODIS) and MERRA-2 Aerosol Optical Depth (AOD), Tropical Rainfall Measuring Mission (TRMM) rainfall and ERA-5 wind components for the years 2000 - 2019. The eastward drift of aerosol, along with the wind patterns, is observed. Also, the impacts of the long-range transport of natural and anthropogenic aerosols, as well as dust particles originating from the surrounding land masses, on the deepening of marine clouds and precipitation are evident over Southeast Asia. Moreover, the frequency and intensity of rain events exhibit modulation in response to the aerosol type and through their transport and interaction with clouds, and their vertical profile mainly by its impact on atmospheric heating. The Indian Ocean and Maritime Continent experience significant variability in both precipitation and AOD, reflecting the strong influence of the Madden-Julian Oscillation (MJO) in these regions. This highlights the importance of MJO in modulating aerosol distribution, which can further influence radiative forcing and local weather patterns. Understanding this coupling is critical for assessing regional air quality, hydrological cycles, and climate variability in tropical regions affected by the MJO.