Investigating the spatial and temporal variation of aerosols and cloud parameters over South Asia using remote sensing

The most important component in determining the spatiotemporal distribution of aerosol at local and regional levels is aerosol optical depth (AOD). In this study, data has been obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to examine spatiotemporal variations in AOD and their effects on the Angstrom Exponent (AE), and clouds parameters, namely cloud fraction, cloud optical thickness, cloud top pressure, cloud top temperature, ice cloud water path, liquid cloud water path, ice cloud effective radius, and liquid cloud effective radius over South Asia from July 2002 to July 2021. The highest values of AOD (0.53–0.7) were observed in the Indo-Gangetic basin (IGB) region over South Asia. The value of AOD of 0.7 is observed in the IGB region during summer. The 0.2 AOD value is observed in winter. The highest mean AOD (0.63 ± 0.09) observed in Bangladesh is due to the noteworthy increase in agricultural activities. The negative correlation between AOD and AE was noticed in Karachi (−0.24), Lahore (−0.04), Rawalpindi (−0.08), Mumbai (−0.03), Kathmandu (−0.49), Colombo (−0.19), and in Kabul (−0.51). A positive correlation is observed in Delhi (0.21), Bangalore (0.09), and Dhaka (0.17).