Abstract
The present study aims to investigate the spatiotemporal variability and long-term seasonal trends of aerosol optical depth and cloud properties across the Indian subcontinent. Monthly cloud properties data obtained from CLARA-A3 and monthly AOD data from Copernicus Atmosphere Monitoring Service (CAMS) has been used for the study during 18 years period from 2003 to 2020. Statistically robust non-parametric Mann-Kendall test has been used to investigate the statistically significant trend at 95% confidence interval. From results it is observed that the region exhibits a strong heterogeneity in aerosol loading and cloud parameters, with mean aerosol loading (AOD > 0.5) higher over the Indo-Gangetic Plains (IGP) and lower over Central India (CI). Cloud microphysical parameters are higher across all India except North-West and Southern India. From the Seasonal variation of cloud microphysics properties, it is observed that cloud microphysics properties higher during the monsoon (JJAS) season and lower during winter (JF) season. An increasing trend in both AOD and cloud properties is found across the Indian subcontinent, except for cloud-top temperature and cloud-top pressure. The cloud effective radius exhibits a positive correlation with AOD (r > 0.35) over central India, while a negative correlation is observed over the Indo-Gangetic Plains (r < -0.3), both of which are statistically significant at the 5% significance level. Seasonal correlation between AOD and cloud macro-physical properties reveal a statistically significant positive association during the winter and post-monsoon seasons, whereas negative association during the monsoon season.