Investigating the spatial and temporal variation of Aerosols and Cloud Parameters over South Asia, using remote sensing.

Abstract

Abstract Aerosol optical depth (AOD) is the most crucial factor in determining how aerosol at local, and regional levels are spatiotemporally distributed. In this study, data has been obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to examine spatiotemporal variations in aerosol optical depth (AOD) and their effects on the Angstrom Exponent (AE), and clouds parameters, namely cloud fraction (CF), cloud optical thickness (COT), cloud top pressure (CTP), cloud top temperature (CTT), ice cloud water path (ICWP), liquid cloud water path (LCWP), ice cloud effective radius (ICER), and liquid cloud effective radius (LCER) 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 highest values of AE (1.36 to 1.7) were observed in south-eastern India, Nepal, north-western Bangladesh, and Bhutan. The highest value of AOD is observed to be 0.7 in the IGB region during summer. The lowest value of AOD (0.2) was observed in winter. The highest mean value of 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).