•Studied aerosol optical depth at urban and rural locations (2005–2018) in Indo-Gangetic Plains
•Observed positive trend of aerosol optical depth over both urban and rural areas
•Aerosol optical depth over a rural area is increasing at 0.50–0.67% per year.
•Crop residue burning increases aerosol optical depth during post-monsoon season.
•Established empirical relation between aerosol optical depth and PM10 for the region
DOI: https://doi.org/10.1016/j.scitotenv.2020.140963
(Tanbir Singh, Khaiwal Ravindra, Pawan Gupta, Harjinder Sembhi, Sachchida Nand Tripathi, and Suman Mor are other authors of this paper.)