Retrieving spatial variation of aerosol level over urban mixed land surfaces using Landsat imageries: Degree of air pollution in Dhaka Metropolitan Area

Aerosols, or suspended particles in the atmosphere, are critical in the production of cloud nuclei, climate change, poor air quality and reduced ambient visibility, as well as public health and disease. Since there are limited ground monitoring stations in the Dhaka Metropolitan Area (DMA), calculating the degree of Aerosol Optical Depth (AOD) and PM2.5 is thus a challenge. The research aimed to retrieve the AOD at 30 m spatial resolution using the Simplified Aerosol Retrieval Algorithm (SARA) based on Landsat imageries. Landsat 4–5 and 8 cloud-free images at 30 m spatial resolution were obtained from 1999 to 2019 at 5 years interval to retrieve AOD and estimate Particulate Matter 2.5 (PM2.5) concentrations. The results showed significant increase in PM2.5 concentrations…